drivers/gpu/drm/drm_dp_mst_topology.c

   1 /*
   2  * Copyright © 2014 Red Hat
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that copyright
   7  * notice and this permission notice appear in supporting documentation, and
   8  * that the name of the copyright holders not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  The copyright holders make no representations
  11  * about the suitability of this software for any purpose.  It is provided "as
  12  * is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20  * OF THIS SOFTWARE.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/errno.h>
  27 #include <linux/sched.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/i2c.h>
  30 #include <drm/drm_dp_mst_helper.h>
  31 #include <drm/drmP.h>
  32
  33 #include <drm/drm_fixed.h>
  34
  35 /**
  36  * DOC: dp mst helper
  37  *
  38  * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
  39  * protocol. The helpers contain a topology manager and bandwidth manager.
  40  * The helpers encapsulate the sending and received of sideband msgs.
  41  */
  42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
  43                                   char *buf);
  44 static int test_calc_pbn_mode(void);
  45
  46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
  47
  48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
  49                                      int id,
  50                                      struct drm_dp_payload *payload);
  51
  52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
  53                                   struct drm_dp_mst_port *port,
  54                                   int offset, int size, u8 *bytes);
  55
  56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
  57                                      struct drm_dp_mst_branch *mstb);
  58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
  59                                            struct drm_dp_mst_branch *mstb,
  60                                            struct drm_dp_mst_port *port);
  61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
  62                                  u8 *guid);
  63
  64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
  65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
  66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
  67 /* sideband msg handling */
  68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
  69 {
  70         u8 bitmask = 0x80;
  71         u8 bitshift = 7;
  72         u8 array_index = 0;
  73         int number_of_bits = num_nibbles * 4;
  74         u8 remainder = 0;
  75
  76         while (number_of_bits != 0) {
  77                 number_of_bits--;
  78                 remainder <<= 1;
  79                 remainder |= (data[array_index] & bitmask) >> bitshift;
  80                 bitmask >>= 1;
  81                 bitshift--;
  82                 if (bitmask == 0) {
  83                         bitmask = 0x80;
  84                         bitshift = 7;
  85                         array_index++;
  86                 }
  87                 if ((remainder & 0x10) == 0x10)
  88                         remainder ^= 0x13;
  89         }
  90
  91         number_of_bits = 4;
  92         while (number_of_bits != 0) {
  93                 number_of_bits--;
  94                 remainder <<= 1;
  95                 if ((remainder & 0x10) != 0)
  96                         remainder ^= 0x13;
  97         }
  98
  99         return remainder;
 100 }
 101
 102 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
 103 {
 104         u8 bitmask = 0x80;
 105         u8 bitshift = 7;
 106         u8 array_index = 0;
 107         int number_of_bits = number_of_bytes * 8;
 108         u16 remainder = 0;
 109
 110         while (number_of_bits != 0) {
 111                 number_of_bits--;
 112                 remainder <<= 1;
 113                 remainder |= (data[array_index] & bitmask) >> bitshift;
 114                 bitmask >>= 1;
 115                 bitshift--;
 116                 if (bitmask == 0) {
 117                         bitmask = 0x80;
 118                         bitshift = 7;
 119                         array_index++;
 120                 }
 121                 if ((remainder & 0x100) == 0x100)
 122                         remainder ^= 0xd5;
 123         }
 124
 125         number_of_bits = 8;
 126         while (number_of_bits != 0) {
 127                 number_of_bits--;
 128                 remainder <<= 1;
 129                 if ((remainder & 0x100) != 0)
 130                         remainder ^= 0xd5;
 131         }
 132
 133         return remainder & 0xff;
 134 }
 135 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
 136 {
 137         u8 size = 3;
 138         size += (hdr->lct / 2);
 139         return size;
 140 }
 141
 142 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 143                                            u8 *buf, int *len)
 144 {
 145         int idx = 0;
 146         int i;
 147         u8 crc4;
 148         buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
 149         for (i = 0; i < (hdr->lct / 2); i++)
 150                 buf[idx++] = hdr->rad[i];
 151         buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
 152                 (hdr->msg_len & 0x3f);
 153         buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
 154
 155         crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
 156         buf[idx - 1] |= (crc4 & 0xf);
 157
 158         *len = idx;
 159 }
 160
 161 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 162                                            u8 *buf, int buflen, u8 *hdrlen)
 163 {
 164         u8 crc4;
 165         u8 len;
 166         int i;
 167         u8 idx;
 168         if (buf[0] == 0)
 169                 return false;
 170         len = 3;
 171         len += ((buf[0] & 0xf0) >> 4) / 2;
 172         if (len > buflen)
 173                 return false;
 174         crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
 175
 176         if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
 177                 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
 178                 return false;
 179         }
 180
 181         hdr->lct = (buf[0] & 0xf0) >> 4;
 182         hdr->lcr = (buf[0] & 0xf);
 183         idx = 1;
 184         for (i = 0; i < (hdr->lct / 2); i++)
 185                 hdr->rad[i] = buf[idx++];
 186         hdr->broadcast = (buf[idx] >> 7) & 0x1;
 187         hdr->path_msg = (buf[idx] >> 6) & 0x1;
 188         hdr->msg_len = buf[idx] & 0x3f;
 189         idx++;
 190         hdr->somt = (buf[idx] >> 7) & 0x1;
 191         hdr->eomt = (buf[idx] >> 6) & 0x1;
 192         hdr->seqno = (buf[idx] >> 4) & 0x1;
 193         idx++;
 194         *hdrlen = idx;
 195         return true;
 196 }
 197
 198 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
 199                                        struct drm_dp_sideband_msg_tx *raw)
 200 {
 201         int idx = 0;
 202         int i;
 203         u8 *buf = raw->msg;
 204         buf[idx++] = req->req_type & 0x7f;
 205
 206         switch (req->req_type) {
 207         case DP_ENUM_PATH_RESOURCES:
 208                 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 209                 idx++;
 210                 break;
 211         case DP_ALLOCATE_PAYLOAD:
 212                 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
 213                         (req->u.allocate_payload.number_sdp_streams & 0xf);
 214                 idx++;
 215                 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
 216                 idx++;
 217                 buf[idx] = (req->u.allocate_payload.pbn >> 8);
 218                 idx++;
 219                 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
 220                 idx++;
 221                 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
 222                         buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
 223                                 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
 224                         idx++;
 225                 }
 226                 if (req->u.allocate_payload.number_sdp_streams & 1) {
 227                         i = req->u.allocate_payload.number_sdp_streams - 1;
 228                         buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
 229                         idx++;
 230                 }
 231                 break;
 232         case DP_QUERY_PAYLOAD:
 233                 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
 234                 idx++;
 235                 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
 236                 idx++;
 237                 break;
 238         case DP_REMOTE_DPCD_READ:
 239                 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
 240                 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
 241                 idx++;
 242                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
 243                 idx++;
 244                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
 245                 idx++;
 246                 buf[idx] = (req->u.dpcd_read.num_bytes);
 247                 idx++;
 248                 break;
 249
 250         case DP_REMOTE_DPCD_WRITE:
 251                 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
 252                 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
 253                 idx++;
 254                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
 255                 idx++;
 256                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
 257                 idx++;
 258                 buf[idx] = (req->u.dpcd_write.num_bytes);
 259                 idx++;
 260                 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
 261                 idx += req->u.dpcd_write.num_bytes;
 262                 break;
 263         case DP_REMOTE_I2C_READ:
 264                 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
 265                 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
 266                 idx++;
 267                 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
 268                         buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
 269                         idx++;
 270                         buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
 271                         idx++;
 272                         memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
 273                         idx += req->u.i2c_read.transactions[i].num_bytes;
 274
 275                         buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
 276                         buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
 277                         idx++;
 278                 }
 279                 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
 280                 idx++;
 281                 buf[idx] = (req->u.i2c_read.num_bytes_read);
 282                 idx++;
 283                 break;
 284
 285         case DP_REMOTE_I2C_WRITE:
 286                 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
 287                 idx++;
 288                 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
 289                 idx++;
 290                 buf[idx] = (req->u.i2c_write.num_bytes);
 291                 idx++;
 292                 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
 293                 idx += req->u.i2c_write.num_bytes;
 294                 break;
 295         }
 296         raw->cur_len = idx;
 297 }
 298
 299 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
 300 {
 301         u8 crc4;
 302         crc4 = drm_dp_msg_data_crc4(msg, len);
 303         msg[len] = crc4;
 304 }
 305
 306 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
 307                                          struct drm_dp_sideband_msg_tx *raw)
 308 {
 309         int idx = 0;
 310         u8 *buf = raw->msg;
 311
 312         buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
 313
 314         raw->cur_len = idx;
 315 }
 316
 317 /* this adds a chunk of msg to the builder to get the final msg */
 318 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 319                                       u8 *replybuf, u8 replybuflen, bool hdr)
 320 {
 321         int ret;
 322         u8 crc4;
 323
 324         if (hdr) {
 325                 u8 hdrlen;
 326                 struct drm_dp_sideband_msg_hdr recv_hdr;
 327                 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
 328                 if (ret == false) {
 329                         print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
 330                         return false;
 331                 }
 332
 333                 /* get length contained in this portion */
 334                 msg->curchunk_len = recv_hdr.msg_len;
 335                 msg->curchunk_hdrlen = hdrlen;
 336
 337                 /* we have already gotten an somt - don't bother parsing */
 338                 if (recv_hdr.somt && msg->have_somt)
 339                         return false;
 340
 341                 if (recv_hdr.somt) {
 342                         memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
 343                         msg->have_somt = true;
 344                 }
 345                 if (recv_hdr.eomt)
 346                         msg->have_eomt = true;
 347
 348                 /* copy the bytes for the remainder of this header chunk */
 349                 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
 350                 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
 351         } else {
 352                 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 353                 msg->curchunk_idx += replybuflen;
 354         }
 355
 356         if (msg->curchunk_idx >= msg->curchunk_len) {
 357                 /* do CRC */
 358                 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
 359                 /* copy chunk into bigger msg */
 360                 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 361                 msg->curlen += msg->curchunk_len - 1;
 362         }
 363         return true;
 364 }
 365
 366 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
 367                                                struct drm_dp_sideband_msg_reply_body *repmsg)
 368 {
 369         int idx = 1;
 370         int i;
 371         memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
 372         idx += 16;
 373         repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
 374         idx++;
 375         if (idx > raw->curlen)
 376                 goto fail_len;
 377         for (i = 0; i < repmsg->u.link_addr.nports; i++) {
 378                 if (raw->msg[idx] & 0x80)
 379                         repmsg->u.link_addr.ports[i].input_port = 1;
 380
 381                 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
 382                 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
 383
 384                 idx++;
 385                 if (idx > raw->curlen)
 386                         goto fail_len;
 387                 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
 388                 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
 389                 if (repmsg->u.link_addr.ports[i].input_port == 0)
 390                         repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 391                 idx++;
 392                 if (idx > raw->curlen)
 393                         goto fail_len;
 394                 if (repmsg->u.link_addr.ports[i].input_port == 0) {
 395                         repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
 396                         idx++;
 397                         if (idx > raw->curlen)
 398                                 goto fail_len;
 399                         memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
 400                         idx += 16;
 401                         if (idx > raw->curlen)
 402                                 goto fail_len;
 403                         repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
 404                         repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
 405                         idx++;
 406
 407                 }
 408                 if (idx > raw->curlen)
 409                         goto fail_len;
 410         }
 411
 412         return true;
 413 fail_len:
 414         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 415         return false;
 416 }
 417
 418 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
 419                                                    struct drm_dp_sideband_msg_reply_body *repmsg)
 420 {
 421         int idx = 1;
 422         repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
 423         idx++;
 424         if (idx > raw->curlen)
 425                 goto fail_len;
 426         repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 427         if (idx > raw->curlen)
 428                 goto fail_len;
 429
 430         memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
 431         return true;
 432 fail_len:
 433         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 434         return false;
 435 }
 436
 437 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
 438                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 439 {
 440         int idx = 1;
 441         repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
 442         idx++;
 443         if (idx > raw->curlen)
 444                 goto fail_len;
 445         return true;
 446 fail_len:
 447         DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
 448         return false;
 449 }
 450
 451 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
 452                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 453 {
 454         int idx = 1;
 455
 456         repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
 457         idx++;
 458         if (idx > raw->curlen)
 459                 goto fail_len;
 460         repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 461         idx++;
 462         /* TODO check */
 463         memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 464         return true;
 465 fail_len:
 466         DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
 467         return false;
 468 }
 469
 470 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
 471                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 472 {
 473         int idx = 1;
 474         repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 475         idx++;
 476         if (idx > raw->curlen)
 477                 goto fail_len;
 478         repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 479         idx += 2;
 480         if (idx > raw->curlen)
 481                 goto fail_len;
 482         repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 483         idx += 2;
 484         if (idx > raw->curlen)
 485                 goto fail_len;
 486         return true;
 487 fail_len:
 488         DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
 489         return false;
 490 }
 491
 492 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 493                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 494 {
 495         int idx = 1;
 496         repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 497         idx++;
 498         if (idx > raw->curlen)
 499                 goto fail_len;
 500         repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 501         idx++;
 502         if (idx > raw->curlen)
 503                 goto fail_len;
 504         repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 505         idx += 2;
 506         if (idx > raw->curlen)
 507                 goto fail_len;
 508         return true;
 509 fail_len:
 510         DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
 511         return false;
 512 }
 513
 514 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 515                                                     struct drm_dp_sideband_msg_reply_body *repmsg)
 516 {
 517         int idx = 1;
 518         repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 519         idx++;
 520         if (idx > raw->curlen)
 521                 goto fail_len;
 522         repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 523         idx += 2;
 524         if (idx > raw->curlen)
 525                 goto fail_len;
 526         return true;
 527 fail_len:
 528         DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
 529         return false;
 530 }
 531
 532 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
 533                                         struct drm_dp_sideband_msg_reply_body *msg)
 534 {
 535         memset(msg, 0, sizeof(*msg));
 536         msg->reply_type = (raw->msg[0] & 0x80) >> 7;
 537         msg->req_type = (raw->msg[0] & 0x7f);
 538
 539         if (msg->reply_type) {
 540                 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
 541                 msg->u.nak.reason = raw->msg[17];
 542                 msg->u.nak.nak_data = raw->msg[18];
 543                 return false;
 544         }
 545
 546         switch (msg->req_type) {
 547         case DP_LINK_ADDRESS:
 548                 return drm_dp_sideband_parse_link_address(raw, msg);
 549         case DP_QUERY_PAYLOAD:
 550                 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
 551         case DP_REMOTE_DPCD_READ:
 552                 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
 553         case DP_REMOTE_DPCD_WRITE:
 554                 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
 555         case DP_REMOTE_I2C_READ:
 556                 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
 557         case DP_ENUM_PATH_RESOURCES:
 558                 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
 559         case DP_ALLOCATE_PAYLOAD:
 560                 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
 561         default:
 562                 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
 563                 return false;
 564         }
 565 }
 566
 567 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
 568                                                            struct drm_dp_sideband_msg_req_body *msg)
 569 {
 570         int idx = 1;
 571
 572         msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 573         idx++;
 574         if (idx > raw->curlen)
 575                 goto fail_len;
 576
 577         memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
 578         idx += 16;
 579         if (idx > raw->curlen)
 580                 goto fail_len;
 581
 582         msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
 583         msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 584         msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
 585         msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
 586         msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
 587         idx++;
 588         return true;
 589 fail_len:
 590         DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
 591         return false;
 592 }
 593
 594 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
 595                                                            struct drm_dp_sideband_msg_req_body *msg)
 596 {
 597         int idx = 1;
 598
 599         msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 600         idx++;
 601         if (idx > raw->curlen)
 602                 goto fail_len;
 603
 604         memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
 605         idx += 16;
 606         if (idx > raw->curlen)
 607                 goto fail_len;
 608
 609         msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 610         idx++;
 611         return true;
 612 fail_len:
 613         DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
 614         return false;
 615 }
 616
 617 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 618                                       struct drm_dp_sideband_msg_req_body *msg)
 619 {
 620         memset(msg, 0, sizeof(*msg));
 621         msg->req_type = (raw->msg[0] & 0x7f);
 622
 623         switch (msg->req_type) {
 624         case DP_CONNECTION_STATUS_NOTIFY:
 625                 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
 626         case DP_RESOURCE_STATUS_NOTIFY:
 627                 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
 628         default:
 629                 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
 630                 return false;
 631         }
 632 }
 633
 634 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 635 {
 636         struct drm_dp_sideband_msg_req_body req;
 637
 638         req.req_type = DP_REMOTE_DPCD_WRITE;
 639         req.u.dpcd_write.port_number = port_num;
 640         req.u.dpcd_write.dpcd_address = offset;
 641         req.u.dpcd_write.num_bytes = num_bytes;
 642         req.u.dpcd_write.bytes = bytes;
 643         drm_dp_encode_sideband_req(&req, msg);
 644
 645         return 0;
 646 }
 647
 648 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
 649 {
 650         struct drm_dp_sideband_msg_req_body req;
 651
 652         req.req_type = DP_LINK_ADDRESS;
 653         drm_dp_encode_sideband_req(&req, msg);
 654         return 0;
 655 }
 656
 657 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
 658 {
 659         struct drm_dp_sideband_msg_req_body req;
 660
 661         req.req_type = DP_ENUM_PATH_RESOURCES;
 662         req.u.port_num.port_number = port_num;
 663         drm_dp_encode_sideband_req(&req, msg);
 664         msg->path_msg = true;
 665         return 0;
 666 }
 667
 668 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
 669                                   u8 vcpi, uint16_t pbn,
 670                                   u8 number_sdp_streams,
 671                                   u8 *sdp_stream_sink)
 672 {
 673         struct drm_dp_sideband_msg_req_body req;
 674         memset(&req, 0, sizeof(req));
 675         req.req_type = DP_ALLOCATE_PAYLOAD;
 676         req.u.allocate_payload.port_number = port_num;
 677         req.u.allocate_payload.vcpi = vcpi;
 678         req.u.allocate_payload.pbn = pbn;
 679         req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
 680         memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
 681                    number_sdp_streams);
 682         drm_dp_encode_sideband_req(&req, msg);
 683         msg->path_msg = true;
 684         return 0;
 685 }
 686
 687 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 688                                         struct drm_dp_vcpi *vcpi)
 689 {
 690         int ret, vcpi_ret;
 691
 692         mutex_lock(&mgr->payload_lock);
 693         ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 694         if (ret > mgr->max_payloads) {
 695                 ret = -EINVAL;
 696                 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 697                 goto out_unlock;
 698         }
 699
 700         vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 701         if (vcpi_ret > mgr->max_payloads) {
 702                 ret = -EINVAL;
 703                 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 704                 goto out_unlock;
 705         }
 706
 707         set_bit(ret, &mgr->payload_mask);
 708         set_bit(vcpi_ret, &mgr->vcpi_mask);
 709         vcpi->vcpi = vcpi_ret + 1;
 710         mgr->proposed_vcpis[ret - 1] = vcpi;
 711 out_unlock:
 712         mutex_unlock(&mgr->payload_lock);
 713         return ret;
 714 }
 715
 716 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 717                                       int vcpi)
 718 {
 719         int i;
 720         if (vcpi == 0)
 721                 return;
 722
 723         mutex_lock(&mgr->payload_lock);
 724         DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 725         clear_bit(vcpi - 1, &mgr->vcpi_mask);
 726
 727         for (i = 0; i < mgr->max_payloads; i++) {
 728                 if (mgr->proposed_vcpis[i])
 729                         if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 730                                 mgr->proposed_vcpis[i] = NULL;
 731                                 clear_bit(i + 1, &mgr->payload_mask);
 732                         }
 733         }
 734         mutex_unlock(&mgr->payload_lock);
 735 }
 736
 737 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 738                               struct drm_dp_sideband_msg_tx *txmsg)
 739 {
 740         unsigned int state;
 741
 742         /*
 743          * All updates to txmsg->state are protected by mgr->qlock, and the two
 744          * cases we check here are terminal states. For those the barriers
 745          * provided by the wake_up/wait_event pair are enough.
 746          */
 747         state = READ_ONCE(txmsg->state);
 748         return (state == DRM_DP_SIDEBAND_TX_RX ||
 749                 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 750 }
 751
 752 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 753                                     struct drm_dp_sideband_msg_tx *txmsg)
 754 {
 755         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 756         int ret;
 757
 758         ret = wait_event_timeout(mgr->tx_waitq,
 759                                  check_txmsg_state(mgr, txmsg),
 760                                  (4 * HZ));
 761         mutex_lock(&mstb->mgr->qlock);
 762         if (ret > 0) {
 763                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 764                         ret = -EIO;
 765                         goto out;
 766                 }
 767         } else {
 768                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 769
 770                 /* dump some state */
 771                 ret = -EIO;
 772
 773                 /* remove from q */
 774                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 775                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 776                         list_del(&txmsg->next);
 777                 }
 778
 779                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 780                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 781                         mstb->tx_slots[txmsg->seqno] = NULL;
 782                 }
 783         }
 784 out:
 785         mutex_unlock(&mgr->qlock);
 786
 787         return ret;
 788 }
 789
 790 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 791 {
 792         struct drm_dp_mst_branch *mstb;
 793
 794         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 795         if (!mstb)
 796                 return NULL;
 797
 798         mstb->lct = lct;
 799         if (lct > 1)
 800                 memcpy(mstb->rad, rad, lct / 2);
 801         INIT_LIST_HEAD(&mstb->ports);
 802         kref_init(&mstb->kref);
 803         return mstb;
 804 }
 805
 806 static void drm_dp_free_mst_port(struct kref *kref);
 807
 808 static void drm_dp_free_mst_branch_device(struct kref *kref)
 809 {
 810         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 811         if (mstb->port_parent) {
 812                 if (list_empty(&mstb->port_parent->next))
 813                         kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
 814         }
 815         kfree(mstb);
 816 }
 817
 818 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 819 {
 820         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 821         struct drm_dp_mst_port *port, *tmp;
 822         bool wake_tx = false;
 823
 824         /*
 825          * init kref again to be used by ports to remove mst branch when it is
 826          * not needed anymore
 827          */
 828         kref_init(kref);
 829
 830         if (mstb->port_parent && list_empty(&mstb->port_parent->next))
 831                 kref_get(&mstb->port_parent->kref);
 832
 833         /*
 834          * destroy all ports - don't need lock
 835          * as there are no more references to the mst branch
 836          * device at this point.
 837          */
 838         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 839                 list_del(&port->next);
 840                 drm_dp_put_port(port);
 841         }
 842
 843         /* drop any tx slots msg */
 844         mutex_lock(&mstb->mgr->qlock);
 845         if (mstb->tx_slots[0]) {
 846                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 847                 mstb->tx_slots[0] = NULL;
 848                 wake_tx = true;
 849         }
 850         if (mstb->tx_slots[1]) {
 851                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 852                 mstb->tx_slots[1] = NULL;
 853                 wake_tx = true;
 854         }
 855         mutex_unlock(&mstb->mgr->qlock);
 856
 857         if (wake_tx)
 858                 wake_up_all(&mstb->mgr->tx_waitq);
 859
 860         kref_put(kref, drm_dp_free_mst_branch_device);
 861 }
 862
 863 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 864 {
 865         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 866 }
 867
 868
 869 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 870 {
 871         struct drm_dp_mst_branch *mstb;
 872
 873         switch (old_pdt) {
 874         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 875         case DP_PEER_DEVICE_SST_SINK:
 876                 /* remove i2c over sideband */
 877                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 878                 break;
 879         case DP_PEER_DEVICE_MST_BRANCHING:
 880                 mstb = port->mstb;
 881                 port->mstb = NULL;
 882                 drm_dp_put_mst_branch_device(mstb);
 883                 break;
 884         }
 885 }
 886
 887 static void drm_dp_destroy_port(struct kref *kref)
 888 {
 889         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 890         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 891
 892         if (!port->input) {
 893                 port->vcpi.num_slots = 0;
 894
 895                 kfree(port->cached_edid);
 896
 897                 /*
 898                  * The only time we don't have a connector
 899                  * on an output port is if the connector init
 900                  * fails.
 901                  */
 902                 if (port->connector) {
 903                         /* we can't destroy the connector here, as
 904                          * we might be holding the mode_config.mutex
 905                          * from an EDID retrieval */
 906
 907                         mutex_lock(&mgr->destroy_connector_lock);
 908                         kref_get(&port->parent->kref);
 909                         list_add(&port->next, &mgr->destroy_connector_list);
 910                         mutex_unlock(&mgr->destroy_connector_lock);
 911                         schedule_work(&mgr->destroy_connector_work);
 912                         return;
 913                 }
 914                 /* no need to clean up vcpi
 915                  * as if we have no connector we never setup a vcpi */
 916                 drm_dp_port_teardown_pdt(port, port->pdt);
 917                 port->pdt = DP_PEER_DEVICE_NONE;
 918         }
 919         kfree(port);
 920 }
 921
 922 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 923 {
 924         kref_put(&port->kref, drm_dp_destroy_port);
 925 }
 926
 927 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
 928 {
 929         struct drm_dp_mst_port *port;
 930         struct drm_dp_mst_branch *rmstb;
 931         if (to_find == mstb) {
 932                 kref_get(&mstb->kref);
 933                 return mstb;
 934         }
 935         list_for_each_entry(port, &mstb->ports, next) {
 936                 if (port->mstb) {
 937                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 938                         if (rmstb)
 939                                 return rmstb;
 940                 }
 941         }
 942         return NULL;
 943 }
 944
 945 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
 946 {
 947         struct drm_dp_mst_branch *rmstb = NULL;
 948         mutex_lock(&mgr->lock);
 949         if (mgr->mst_primary)
 950                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 951         mutex_unlock(&mgr->lock);
 952         return rmstb;
 953 }
 954
 955 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
 956 {
 957         struct drm_dp_mst_port *port, *mport;
 958
 959         list_for_each_entry(port, &mstb->ports, next) {
 960                 if (port == to_find) {
 961                         kref_get(&port->kref);
 962                         return port;
 963                 }
 964                 if (port->mstb) {
 965                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 966                         if (mport)
 967                                 return mport;
 968                 }
 969         }
 970         return NULL;
 971 }
 972
 973 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 974 {
 975         struct drm_dp_mst_port *rport = NULL;
 976         mutex_lock(&mgr->lock);
 977         if (mgr->mst_primary)
 978                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 979         mutex_unlock(&mgr->lock);
 980         return rport;
 981 }
 982
 983 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 984 {
 985         struct drm_dp_mst_port *port;
 986
 987         list_for_each_entry(port, &mstb->ports, next) {
 988                 if (port->port_num == port_num) {
 989                         kref_get(&port->kref);
 990                         return port;
 991                 }
 992         }
 993
 994         return NULL;
 995 }
 996
 997 /*
 998  * calculate a new RAD for this MST branch device
 999  * if parent has an LCT of 2 then it has 1 nibble of RAD,
1000  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1001  */
1002 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1003                                  u8 *rad)
1004 {
1005         int parent_lct = port->parent->lct;
1006         int shift = 4;
1007         int idx = (parent_lct - 1) / 2;
1008         if (parent_lct > 1) {
1009                 memcpy(rad, port->parent->rad, idx + 1);
1010                 shift = (parent_lct % 2) ? 4 : 0;
1011         } else
1012                 rad[0] = 0;
1013
1014         rad[idx] |= port->port_num << shift;
1015         return parent_lct + 1;
1016 }
1017
1018 /*
1019  * return sends link address for new mstb
1020  */
1021 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1022 {
1023         int ret;
1024         u8 rad[6], lct;
1025         bool send_link = false;
1026         switch (port->pdt) {
1027         case DP_PEER_DEVICE_DP_LEGACY_CONV:
1028         case DP_PEER_DEVICE_SST_SINK:
1029                 /* add i2c over sideband */
1030                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1031                 break;
1032         case DP_PEER_DEVICE_MST_BRANCHING:
1033                 lct = drm_dp_calculate_rad(port, rad);
1034
1035                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1036                 port->mstb->mgr = port->mgr;
1037                 port->mstb->port_parent = port;
1038
1039                 send_link = true;
1040                 break;
1041         }
1042         return send_link;
1043 }
1044
1045 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1046 {
1047         int ret;
1048
1049         memcpy(mstb->guid, guid, 16);
1050
1051         if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1052                 if (mstb->port_parent) {
1053                         ret = drm_dp_send_dpcd_write(
1054                                         mstb->mgr,
1055                                         mstb->port_parent,
1056                                         DP_GUID,
1057                                         16,
1058                                         mstb->guid);
1059                 } else {
1060
1061                         ret = drm_dp_dpcd_write(
1062                                         mstb->mgr->aux,
1063                                         DP_GUID,
1064                                         mstb->guid,
1065                                         16);
1066                 }
1067         }
1068 }
1069
1070 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1071                                 int pnum,
1072                                 char *proppath,
1073                                 size_t proppath_size)
1074 {
1075         int i;
1076         char temp[8];
1077         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1078         for (i = 0; i < (mstb->lct - 1); i++) {
1079                 int shift = (i % 2) ? 0 : 4;
1080                 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1081                 snprintf(temp, sizeof(temp), "-%d", port_num);
1082                 strlcat(proppath, temp, proppath_size);
1083         }
1084         snprintf(temp, sizeof(temp), "-%d", pnum);
1085         strlcat(proppath, temp, proppath_size);
1086 }
1087
1088 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1089                             struct drm_device *dev,
1090                             struct drm_dp_link_addr_reply_port *port_msg)
1091 {
1092         struct drm_dp_mst_port *port;
1093         bool ret;
1094         bool created = false;
1095         int old_pdt = 0;
1096         int old_ddps = 0;
1097         port = drm_dp_get_port(mstb, port_msg->port_number);
1098         if (!port) {
1099                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1100                 if (!port)
1101                         return;
1102                 kref_init(&port->kref);
1103                 port->parent = mstb;
1104                 port->port_num = port_msg->port_number;
1105                 port->mgr = mstb->mgr;
1106                 port->aux.name = "DPMST";
1107                 port->aux.dev = dev->dev;
1108                 created = true;
1109         } else {
1110                 old_pdt = port->pdt;
1111                 old_ddps = port->ddps;
1112         }
1113
1114         port->pdt = port_msg->peer_device_type;
1115         port->input = port_msg->input_port;
1116         port->mcs = port_msg->mcs;
1117         port->ddps = port_msg->ddps;
1118         port->ldps = port_msg->legacy_device_plug_status;
1119         port->dpcd_rev = port_msg->dpcd_revision;
1120         port->num_sdp_streams = port_msg->num_sdp_streams;
1121         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1122
1123         /* manage mstb port lists with mgr lock - take a reference
1124            for this list */
1125         if (created) {
1126                 mutex_lock(&mstb->mgr->lock);
1127                 kref_get(&port->kref);
1128                 list_add(&port->next, &mstb->ports);
1129                 mutex_unlock(&mstb->mgr->lock);
1130         }
1131
1132         if (old_ddps != port->ddps) {
1133                 if (port->ddps) {
1134                         if (!port->input)
1135                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1136                 } else {
1137                         port->available_pbn = 0;
1138                         }
1139         }
1140
1141         if (old_pdt != port->pdt && !port->input) {
1142                 drm_dp_port_teardown_pdt(port, old_pdt);
1143
1144                 ret = drm_dp_port_setup_pdt(port);
1145                 if (ret == true)
1146                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1147         }
1148
1149         if (created && !port->input) {
1150                 char proppath[255];
1151
1152                 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1153                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1154                 if (!port->connector) {
1155                         /* remove it from the port list */
1156                         mutex_lock(&mstb->mgr->lock);
1157                         list_del(&port->next);
1158                         mutex_unlock(&mstb->mgr->lock);
1159                         /* drop port list reference */
1160                         drm_dp_put_port(port);
1161                         goto out;
1162                 }
1163                 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1164                      port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1165                     port->port_num >= DP_MST_LOGICAL_PORT_0) {
1166                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1167                         drm_mode_connector_set_tile_property(port->connector);
1168                 }
1169                 (*mstb->mgr->cbs->register_connector)(port->connector);
1170         }
1171
1172 out:
1173         /* put reference to this port */
1174         drm_dp_put_port(port);
1175 }
1176
1177 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1178                                struct drm_dp_connection_status_notify *conn_stat)
1179 {
1180         struct drm_dp_mst_port *port;
1181         int old_pdt;
1182         int old_ddps;
1183         bool dowork = false;
1184         port = drm_dp_get_port(mstb, conn_stat->port_number);
1185         if (!port)
1186                 return;
1187
1188         old_ddps = port->ddps;
1189         old_pdt = port->pdt;
1190         port->pdt = conn_stat->peer_device_type;
1191         port->mcs = conn_stat->message_capability_status;
1192         port->ldps = conn_stat->legacy_device_plug_status;
1193         port->ddps = conn_stat->displayport_device_plug_status;
1194
1195         if (old_ddps != port->ddps) {
1196                 if (port->ddps) {
1197                         dowork = true;
1198                 } else {
1199                         port->available_pbn = 0;
1200                 }
1201         }
1202         if (old_pdt != port->pdt && !port->input) {
1203                 drm_dp_port_teardown_pdt(port, old_pdt);
1204
1205                 if (drm_dp_port_setup_pdt(port))
1206                         dowork = true;
1207         }
1208
1209         drm_dp_put_port(port);
1210         if (dowork)
1211                 queue_work(system_long_wq, &mstb->mgr->work);
1212
1213 }
1214
1215 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1216                                                                u8 lct, u8 *rad)
1217 {
1218         struct drm_dp_mst_branch *mstb;
1219         struct drm_dp_mst_port *port;
1220         int i;
1221         /* find the port by iterating down */
1222
1223         mutex_lock(&mgr->lock);
1224         mstb = mgr->mst_primary;
1225
1226         for (i = 0; i < lct - 1; i++) {
1227                 int shift = (i % 2) ? 0 : 4;
1228                 int port_num = (rad[i / 2] >> shift) & 0xf;
1229
1230                 list_for_each_entry(port, &mstb->ports, next) {
1231                         if (port->port_num == port_num) {
1232                                 mstb = port->mstb;
1233                                 if (!mstb) {
1234                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1235                                         goto out;
1236                                 }
1237
1238                                 break;
1239                         }
1240                 }
1241         }
1242         kref_get(&mstb->kref);
1243 out:
1244         mutex_unlock(&mgr->lock);
1245         return mstb;
1246 }
1247
1248 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1249         struct drm_dp_mst_branch *mstb,
1250         uint8_t *guid)
1251 {
1252         struct drm_dp_mst_branch *found_mstb;
1253         struct drm_dp_mst_port *port;
1254
1255         if (memcmp(mstb->guid, guid, 16) == 0)
1256                 return mstb;
1257
1258
1259         list_for_each_entry(port, &mstb->ports, next) {
1260                 if (!port->mstb)
1261                         continue;
1262
1263                 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1264
1265                 if (found_mstb)
1266                         return found_mstb;
1267         }
1268
1269         return NULL;
1270 }
1271
1272 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1273         struct drm_dp_mst_topology_mgr *mgr,
1274         uint8_t *guid)
1275 {
1276         struct drm_dp_mst_branch *mstb;
1277
1278         /* find the port by iterating down */
1279         mutex_lock(&mgr->lock);
1280
1281         mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1282
1283         if (mstb)
1284                 kref_get(&mstb->kref);
1285
1286         mutex_unlock(&mgr->lock);
1287         return mstb;
1288 }
1289
1290 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1291                                                struct drm_dp_mst_branch *mstb)
1292 {
1293         struct drm_dp_mst_port *port;
1294         struct drm_dp_mst_branch *mstb_child;
1295         if (!mstb->link_address_sent)
1296                 drm_dp_send_link_address(mgr, mstb);
1297
1298         list_for_each_entry(port, &mstb->ports, next) {
1299                 if (port->input)
1300                         continue;
1301
1302                 if (!port->ddps)
1303                         continue;
1304
1305                 if (!port->available_pbn)
1306                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1307
1308                 if (port->mstb) {
1309                         mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1310                         if (mstb_child) {
1311                                 drm_dp_check_and_send_link_address(mgr, mstb_child);
1312                                 drm_dp_put_mst_branch_device(mstb_child);
1313                         }
1314                 }
1315         }
1316 }
1317
1318 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1319 {
1320         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1321         struct drm_dp_mst_branch *mstb;
1322
1323         mutex_lock(&mgr->lock);
1324         mstb = mgr->mst_primary;
1325         if (mstb) {
1326                 kref_get(&mstb->kref);
1327         }
1328         mutex_unlock(&mgr->lock);
1329         if (mstb) {
1330                 drm_dp_check_and_send_link_address(mgr, mstb);
1331                 drm_dp_put_mst_branch_device(mstb);
1332         }
1333 }
1334
1335 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1336                                  u8 *guid)
1337 {
1338         static u8 zero_guid[16];
1339
1340         if (!memcmp(guid, zero_guid, 16)) {
1341                 u64 salt = get_jiffies_64();
1342                 memcpy(&guid[0], &salt, sizeof(u64));
1343                 memcpy(&guid[8], &salt, sizeof(u64));
1344                 return false;
1345         }
1346         return true;
1347 }
1348
1349 #if 0
1350 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1351 {
1352         struct drm_dp_sideband_msg_req_body req;
1353
1354         req.req_type = DP_REMOTE_DPCD_READ;
1355         req.u.dpcd_read.port_number = port_num;
1356         req.u.dpcd_read.dpcd_address = offset;
1357         req.u.dpcd_read.num_bytes = num_bytes;
1358         drm_dp_encode_sideband_req(&req, msg);
1359
1360         return 0;
1361 }
1362 #endif
1363
1364 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1365                                     bool up, u8 *msg, int len)
1366 {
1367         int ret;
1368         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1369         int tosend, total, offset;
1370         int retries = 0;
1371
1372 retry:
1373         total = len;
1374         offset = 0;
1375         do {
1376                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1377
1378                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1379                                         &msg[offset],
1380                                         tosend);
1381                 if (ret != tosend) {
1382                         if (ret == -EIO && retries < 5) {
1383                                 retries++;
1384                                 goto retry;
1385                         }
1386                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1387
1388                         return -EIO;
1389                 }
1390                 offset += tosend;
1391                 total -= tosend;
1392         } while (total > 0);
1393         return 0;
1394 }
1395
1396 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1397                                   struct drm_dp_sideband_msg_tx *txmsg)
1398 {
1399         struct drm_dp_mst_branch *mstb = txmsg->dst;
1400         u8 req_type;
1401
1402         /* both msg slots are full */
1403         if (txmsg->seqno == -1) {
1404                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1405                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1406                         return -EAGAIN;
1407                 }
1408                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1409                         txmsg->seqno = mstb->last_seqno;
1410                         mstb->last_seqno ^= 1;
1411                 } else if (mstb->tx_slots[0] == NULL)
1412                         txmsg->seqno = 0;
1413                 else
1414                         txmsg->seqno = 1;
1415                 mstb->tx_slots[txmsg->seqno] = txmsg;
1416         }
1417
1418         req_type = txmsg->msg[0] & 0x7f;
1419         if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1420                 req_type == DP_RESOURCE_STATUS_NOTIFY)
1421                 hdr->broadcast = 1;
1422         else
1423                 hdr->broadcast = 0;
1424         hdr->path_msg = txmsg->path_msg;
1425         hdr->lct = mstb->lct;
1426         hdr->lcr = mstb->lct - 1;
1427         if (mstb->lct > 1)
1428                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1429         hdr->seqno = txmsg->seqno;
1430         return 0;
1431 }
1432 /*
1433  * process a single block of the next message in the sideband queue
1434  */
1435 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1436                                    struct drm_dp_sideband_msg_tx *txmsg,
1437                                    bool up)
1438 {
1439         u8 chunk[48];
1440         struct drm_dp_sideband_msg_hdr hdr;
1441         int len, space, idx, tosend;
1442         int ret;
1443
1444         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1445
1446         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1447                 txmsg->seqno = -1;
1448                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1449         }
1450
1451         /* make hdr from dst mst - for replies use seqno
1452            otherwise assign one */
1453         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1454         if (ret < 0)
1455                 return ret;
1456
1457         /* amount left to send in this message */
1458         len = txmsg->cur_len - txmsg->cur_offset;
1459
1460         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1461         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1462
1463         tosend = min(len, space);
1464         if (len == txmsg->cur_len)
1465                 hdr.somt = 1;
1466         if (space >= len)
1467                 hdr.eomt = 1;
1468
1469
1470         hdr.msg_len = tosend + 1;
1471         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1472         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1473         /* add crc at end */
1474         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1475         idx += tosend + 1;
1476
1477         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1478         if (ret) {
1479                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1480                 return ret;
1481         }
1482
1483         txmsg->cur_offset += tosend;
1484         if (txmsg->cur_offset == txmsg->cur_len) {
1485                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1486                 return 1;
1487         }
1488         return 0;
1489 }
1490
1491 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1492 {
1493         struct drm_dp_sideband_msg_tx *txmsg;
1494         int ret;
1495
1496         WARN_ON(!mutex_is_locked(&mgr->qlock));
1497
1498         /* construct a chunk from the first msg in the tx_msg queue */
1499         if (list_empty(&mgr->tx_msg_downq))
1500                 return;
1501
1502         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1503         ret = process_single_tx_qlock(mgr, txmsg, false);
1504         if (ret == 1) {
1505                 /* txmsg is sent it should be in the slots now */
1506                 list_del(&txmsg->next);
1507         } else if (ret) {
1508                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1509                 list_del(&txmsg->next);
1510                 if (txmsg->seqno != -1)
1511                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1512                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1513                 wake_up_all(&mgr->tx_waitq);
1514         }
1515 }
1516
1517 /* called holding qlock */
1518 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1519                                        struct drm_dp_sideband_msg_tx *txmsg)
1520 {
1521         int ret;
1522
1523         /* construct a chunk from the first msg in the tx_msg queue */
1524         ret = process_single_tx_qlock(mgr, txmsg, true);
1525
1526         if (ret != 1)
1527                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1528
1529         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1530 }
1531
1532 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1533                                  struct drm_dp_sideband_msg_tx *txmsg)
1534 {
1535         mutex_lock(&mgr->qlock);
1536         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1537         if (list_is_singular(&mgr->tx_msg_downq))
1538                 process_single_down_tx_qlock(mgr);
1539         mutex_unlock(&mgr->qlock);
1540 }
1541
1542 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1543                                      struct drm_dp_mst_branch *mstb)
1544 {
1545         int len;
1546         struct drm_dp_sideband_msg_tx *txmsg;
1547         int ret;
1548
1549         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1550         if (!txmsg)
1551                 return;
1552
1553         txmsg->dst = mstb;
1554         len = build_link_address(txmsg);
1555
1556         mstb->link_address_sent = true;
1557         drm_dp_queue_down_tx(mgr, txmsg);
1558
1559         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1560         if (ret > 0) {
1561                 int i;
1562
1563                 if (txmsg->reply.reply_type == 1)
1564                         DRM_DEBUG_KMS("link address nak received\n");
1565                 else {
1566                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1567                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1568                                 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
1569                                        txmsg->reply.u.link_addr.ports[i].input_port,
1570                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1571                                        txmsg->reply.u.link_addr.ports[i].port_number,
1572                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1573                                        txmsg->reply.u.link_addr.ports[i].mcs,
1574                                        txmsg->reply.u.link_addr.ports[i].ddps,
1575                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1576                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1577                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1578                         }
1579
1580                         drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1581
1582                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1583                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1584                         }
1585                         (*mgr->cbs->hotplug)(mgr);
1586                 }
1587         } else {
1588                 mstb->link_address_sent = false;
1589                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1590         }
1591
1592         kfree(txmsg);
1593 }
1594
1595 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1596                                            struct drm_dp_mst_branch *mstb,
1597                                            struct drm_dp_mst_port *port)
1598 {
1599         int len;
1600         struct drm_dp_sideband_msg_tx *txmsg;
1601         int ret;
1602
1603         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1604         if (!txmsg)
1605                 return -ENOMEM;
1606
1607         txmsg->dst = mstb;
1608         len = build_enum_path_resources(txmsg, port->port_num);
1609
1610         drm_dp_queue_down_tx(mgr, txmsg);
1611
1612         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1613         if (ret > 0) {
1614                 if (txmsg->reply.reply_type == 1)
1615                         DRM_DEBUG_KMS("enum path resources nak received\n");
1616                 else {
1617                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1618                                 DRM_ERROR("got incorrect port in response\n");
1619                         DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
1620                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1621                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1622                 }
1623         }
1624
1625         kfree(txmsg);
1626         return 0;
1627 }
1628
1629 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1630 {
1631         if (!mstb->port_parent)
1632                 return NULL;
1633
1634         if (mstb->port_parent->mstb != mstb)
1635                 return mstb->port_parent;
1636
1637         return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1638 }
1639
1640 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1641                                                                          struct drm_dp_mst_branch *mstb,
1642                                                                          int *port_num)
1643 {
1644         struct drm_dp_mst_branch *rmstb = NULL;
1645         struct drm_dp_mst_port *found_port;
1646         mutex_lock(&mgr->lock);
1647         if (mgr->mst_primary) {
1648                 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1649
1650                 if (found_port) {
1651                         rmstb = found_port->parent;
1652                         kref_get(&rmstb->kref);
1653                         *port_num = found_port->port_num;
1654                 }
1655         }
1656         mutex_unlock(&mgr->lock);
1657         return rmstb;
1658 }
1659
1660 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1661                                    struct drm_dp_mst_port *port,
1662                                    int id,
1663                                    int pbn)
1664 {
1665         struct drm_dp_sideband_msg_tx *txmsg;
1666         struct drm_dp_mst_branch *mstb;
1667         int len, ret, port_num;
1668         u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1669         int i;
1670
1671         port = drm_dp_get_validated_port_ref(mgr, port);
1672         if (!port)
1673                 return -EINVAL;
1674
1675         port_num = port->port_num;
1676         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1677         if (!mstb) {
1678                 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1679
1680                 if (!mstb) {
1681                         drm_dp_put_port(port);
1682                         return -EINVAL;
1683                 }
1684         }
1685
1686         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1687         if (!txmsg) {
1688                 ret = -ENOMEM;
1689                 goto fail_put;
1690         }
1691
1692         for (i = 0; i < port->num_sdp_streams; i++)
1693                 sinks[i] = i;
1694
1695         txmsg->dst = mstb;
1696         len = build_allocate_payload(txmsg, port_num,
1697                                      id,
1698                                      pbn, port->num_sdp_streams, sinks);
1699
1700         drm_dp_queue_down_tx(mgr, txmsg);
1701
1702         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1703         if (ret > 0) {
1704                 if (txmsg->reply.reply_type == 1) {
1705                         ret = -EINVAL;
1706                 } else
1707                         ret = 0;
1708         }
1709         kfree(txmsg);
1710 fail_put:
1711         drm_dp_put_mst_branch_device(mstb);
1712         drm_dp_put_port(port);
1713         return ret;
1714 }
1715
1716 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1717                                        int id,
1718                                        struct drm_dp_payload *payload)
1719 {
1720         int ret;
1721
1722         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1723         if (ret < 0) {
1724                 payload->payload_state = 0;
1725                 return ret;
1726         }
1727         payload->payload_state = DP_PAYLOAD_LOCAL;
1728         return 0;
1729 }
1730
1731 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1732                                        struct drm_dp_mst_port *port,
1733                                        int id,
1734                                        struct drm_dp_payload *payload)
1735 {
1736         int ret;
1737         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1738         if (ret < 0)
1739                 return ret;
1740         payload->payload_state = DP_PAYLOAD_REMOTE;
1741         return ret;
1742 }
1743
1744 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1745                                         struct drm_dp_mst_port *port,
1746                                         int id,
1747                                         struct drm_dp_payload *payload)
1748 {
1749         DRM_DEBUG_KMS("\n");
1750         /* its okay for these to fail */
1751         if (port) {
1752                 drm_dp_payload_send_msg(mgr, port, id, 0);
1753         }
1754
1755         drm_dp_dpcd_write_payload(mgr, id, payload);
1756         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1757         return 0;
1758 }
1759
1760 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1761                                         int id,
1762                                         struct drm_dp_payload *payload)
1763 {
1764         payload->payload_state = 0;
1765         return 0;
1766 }
1767
1768 /**
1769  * drm_dp_update_payload_part1() - Execute payload update part 1
1770  * @mgr: manager to use.
1771  *
1772  * This iterates over all proposed virtual channels, and tries to
1773  * allocate space in the link for them. For 0->slots transitions,
1774  * this step just writes the VCPI to the MST device. For slots->0
1775  * transitions, this writes the updated VCPIs and removes the
1776  * remote VC payloads.
1777  *
1778  * after calling this the driver should generate ACT and payload
1779  * packets.
1780  */
1781 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1782 {
1783         int i, j;
1784         int cur_slots = 1;
1785         struct drm_dp_payload req_payload;
1786         struct drm_dp_mst_port *port;
1787
1788         mutex_lock(&mgr->payload_lock);
1789         for (i = 0; i < mgr->max_payloads; i++) {
1790                 /* solve the current payloads - compare to the hw ones
1791                    - update the hw view */
1792                 req_payload.start_slot = cur_slots;
1793                 if (mgr->proposed_vcpis[i]) {
1794                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1795                         port = drm_dp_get_validated_port_ref(mgr, port);
1796                         if (!port) {
1797                                 mutex_unlock(&mgr->payload_lock);
1798                                 return -EINVAL;
1799                         }
1800                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1801                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1802                 } else {
1803                         port = NULL;
1804                         req_payload.num_slots = 0;
1805                 }
1806
1807                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1808                         mgr->payloads[i].start_slot = req_payload.start_slot;
1809                 }
1810                 /* work out what is required to happen with this payload */
1811                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1812
1813                         /* need to push an update for this payload */
1814                         if (req_payload.num_slots) {
1815                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1816                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1817                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1818                         } else if (mgr->payloads[i].num_slots) {
1819                                 mgr->payloads[i].num_slots = 0;
1820                                 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1821                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1822                                 mgr->payloads[i].start_slot = 0;
1823                         }
1824                         mgr->payloads[i].payload_state = req_payload.payload_state;
1825                 }
1826                 cur_slots += req_payload.num_slots;
1827
1828                 if (port)
1829                         drm_dp_put_port(port);
1830         }
1831
1832         for (i = 0; i < mgr->max_payloads; i++) {
1833                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1834                         DRM_DEBUG_KMS("removing payload %d\n", i);
1835                         for (j = i; j < mgr->max_payloads - 1; j++) {
1836                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1837                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1838                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1839                                         set_bit(j + 1, &mgr->payload_mask);
1840                                 } else {
1841                                         clear_bit(j + 1, &mgr->payload_mask);
1842                                 }
1843                         }
1844                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1845                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1846                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1847
1848                 }
1849         }
1850         mutex_unlock(&mgr->payload_lock);
1851
1852         return 0;
1853 }
1854 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1855
1856 /**
1857  * drm_dp_update_payload_part2() - Execute payload update part 2
1858  * @mgr: manager to use.
1859  *
1860  * This iterates over all proposed virtual channels, and tries to
1861  * allocate space in the link for them. For 0->slots transitions,
1862  * this step writes the remote VC payload commands. For slots->0
1863  * this just resets some internal state.
1864  */
1865 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1866 {
1867         struct drm_dp_mst_port *port;
1868         int i;
1869         int ret = 0;
1870         mutex_lock(&mgr->payload_lock);
1871         for (i = 0; i < mgr->max_payloads; i++) {
1872
1873                 if (!mgr->proposed_vcpis[i])
1874                         continue;
1875
1876                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1877
1878                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1879                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1880                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1881                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1882                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1883                 }
1884                 if (ret) {
1885                         mutex_unlock(&mgr->payload_lock);
1886                         return ret;
1887                 }
1888         }
1889         mutex_unlock(&mgr->payload_lock);
1890         return 0;
1891 }
1892 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1893
1894 #if 0 /* unused as of yet */
1895 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1896                                  struct drm_dp_mst_port *port,
1897                                  int offset, int size)
1898 {
1899         int len;
1900         struct drm_dp_sideband_msg_tx *txmsg;
1901
1902         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1903         if (!txmsg)
1904                 return -ENOMEM;
1905
1906         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1907         txmsg->dst = port->parent;
1908
1909         drm_dp_queue_down_tx(mgr, txmsg);
1910
1911         return 0;
1912 }
1913 #endif
1914
1915 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1916                                   struct drm_dp_mst_port *port,
1917                                   int offset, int size, u8 *bytes)
1918 {
1919         int len;
1920         int ret;
1921         struct drm_dp_sideband_msg_tx *txmsg;
1922         struct drm_dp_mst_branch *mstb;
1923
1924         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1925         if (!mstb)
1926                 return -EINVAL;
1927
1928         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1929         if (!txmsg) {
1930                 ret = -ENOMEM;
1931                 goto fail_put;
1932         }
1933
1934         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1935         txmsg->dst = mstb;
1936
1937         drm_dp_queue_down_tx(mgr, txmsg);
1938
1939         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1940         if (ret > 0) {
1941                 if (txmsg->reply.reply_type == 1) {
1942                         ret = -EINVAL;
1943                 } else
1944                         ret = 0;
1945         }
1946         kfree(txmsg);
1947 fail_put:
1948         drm_dp_put_mst_branch_device(mstb);
1949         return ret;
1950 }
1951
1952 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1953 {
1954         struct drm_dp_sideband_msg_reply_body reply;
1955
1956         reply.reply_type = 0;
1957         reply.req_type = req_type;
1958         drm_dp_encode_sideband_reply(&reply, msg);
1959         return 0;
1960 }
1961
1962 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1963                                     struct drm_dp_mst_branch *mstb,
1964                                     int req_type, int seqno, bool broadcast)
1965 {
1966         struct drm_dp_sideband_msg_tx *txmsg;
1967
1968         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1969         if (!txmsg)
1970                 return -ENOMEM;
1971
1972         txmsg->dst = mstb;
1973         txmsg->seqno = seqno;
1974         drm_dp_encode_up_ack_reply(txmsg, req_type);
1975
1976         mutex_lock(&mgr->qlock);
1977
1978         process_single_up_tx_qlock(mgr, txmsg);
1979
1980         mutex_unlock(&mgr->qlock);
1981
1982         kfree(txmsg);
1983         return 0;
1984 }
1985
1986 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1987                                      int dp_link_count,
1988                                      int *out)
1989 {
1990         switch (dp_link_bw) {
1991         default:
1992                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1993                               dp_link_bw, dp_link_count);
1994                 return false;
1995
1996         case DP_LINK_BW_1_62:
1997                 *out = 3 * dp_link_count;
1998                 break;
1999         case DP_LINK_BW_2_7:
2000                 *out = 5 * dp_link_count;
2001                 break;
2002         case DP_LINK_BW_5_4:
2003                 *out = 10 * dp_link_count;
2004                 break;
2005         }
2006         return true;
2007 }
2008
2009 /**
2010  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2011  * @mgr: manager to set state for
2012  * @mst_state: true to enable MST on this connector - false to disable.
2013  *
2014  * This is called by the driver when it detects an MST capable device plugged
2015  * into a DP MST capable port, or when a DP MST capable device is unplugged.
2016  */
2017 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2018 {
2019         int ret = 0;
2020         struct drm_dp_mst_branch *mstb = NULL;
2021
2022         mutex_lock(&mgr->lock);
2023         if (mst_state == mgr->mst_state)
2024                 goto out_unlock;
2025
2026         mgr->mst_state = mst_state;
2027         /* set the device into MST mode */
2028         if (mst_state) {
2029                 WARN_ON(mgr->mst_primary);
2030
2031                 /* get dpcd info */
2032                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2033                 if (ret != DP_RECEIVER_CAP_SIZE) {
2034                         DRM_DEBUG_KMS("failed to read DPCD\n");
2035                         goto out_unlock;
2036                 }
2037
2038                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2039                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2040                                               &mgr->pbn_div)) {
2041                         ret = -EINVAL;
2042                         goto out_unlock;
2043                 }
2044
2045                 /* add initial branch device at LCT 1 */
2046                 mstb = drm_dp_add_mst_branch_device(1, NULL);
2047                 if (mstb == NULL) {
2048                         ret = -ENOMEM;
2049                         goto out_unlock;
2050                 }
2051                 mstb->mgr = mgr;
2052
2053                 /* give this the main reference */
2054                 mgr->mst_primary = mstb;
2055                 kref_get(&mgr->mst_primary->kref);
2056
2057                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2058                                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2059                 if (ret < 0) {
2060                         goto out_unlock;
2061                 }
2062
2063                 {
2064                         struct drm_dp_payload reset_pay;
2065                         reset_pay.start_slot = 0;
2066                         reset_pay.num_slots = 0x3f;
2067                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2068                 }
2069
2070                 queue_work(system_long_wq, &mgr->work);
2071
2072                 ret = 0;
2073         } else {
2074                 /* disable MST on the device */
2075                 mstb = mgr->mst_primary;
2076                 mgr->mst_primary = NULL;
2077                 /* this can fail if the device is gone */
2078                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2079                 ret = 0;
2080                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2081                 mgr->payload_mask = 0;
2082                 set_bit(0, &mgr->payload_mask);
2083                 mgr->vcpi_mask = 0;
2084         }
2085
2086 out_unlock:
2087         mutex_unlock(&mgr->lock);
2088         if (mstb)
2089                 drm_dp_put_mst_branch_device(mstb);
2090         return ret;
2091
2092 }
2093 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2094
2095 /**
2096  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2097  * @mgr: manager to suspend
2098  *
2099  * This function tells the MST device that we can't handle UP messages
2100  * anymore. This should stop it from sending any since we are suspended.
2101  */
2102 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2103 {
2104         mutex_lock(&mgr->lock);
2105         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2106                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2107         mutex_unlock(&mgr->lock);
2108         flush_work(&mgr->work);
2109         flush_work(&mgr->destroy_connector_work);
2110 }
2111 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2112
2113 /**
2114  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2115  * @mgr: manager to resume
2116  *
2117  * This will fetch DPCD and see if the device is still there,
2118  * if it is, it will rewrite the MSTM control bits, and return.
2119  *
2120  * if the device fails this returns -1, and the driver should do
2121  * a full MST reprobe, in case we were undocked.
2122  */
2123 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2124 {
2125         int ret = 0;
2126
2127         mutex_lock(&mgr->lock);
2128
2129         if (mgr->mst_primary) {
2130                 int sret;
2131                 u8 guid[16];
2132
2133                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2134                 if (sret != DP_RECEIVER_CAP_SIZE) {
2135                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2136                         ret = -1;
2137                         goto out_unlock;
2138                 }
2139
2140                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2141                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2142                 if (ret < 0) {
2143                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2144                         ret = -1;
2145                         goto out_unlock;
2146                 }
2147
2148                 /* Some hubs forget their guids after they resume */
2149                 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2150                 if (sret != 16) {
2151                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2152                         ret = -1;
2153                         goto out_unlock;
2154                 }
2155                 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2156
2157                 ret = 0;
2158         } else
2159                 ret = -1;
2160
2161 out_unlock:
2162         mutex_unlock(&mgr->lock);
2163         return ret;
2164 }
2165 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2166
2167 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2168 {
2169         int len;
2170         u8 replyblock[32];
2171         int replylen, origlen, curreply;
2172         int ret;
2173         struct drm_dp_sideband_msg_rx *msg;
2174         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2175         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2176
2177         len = min(mgr->max_dpcd_transaction_bytes, 16);
2178         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2179                                replyblock, len);
2180         if (ret != len) {
2181                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2182                 return;
2183         }
2184         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2185         if (!ret) {
2186                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2187                 return;
2188         }
2189         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2190
2191         origlen = replylen;
2192         replylen -= len;
2193         curreply = len;
2194         while (replylen > 0) {
2195                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2196                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2197                                     replyblock, len);
2198                 if (ret != len) {
2199                         DRM_DEBUG_KMS("failed to read a chunk\n");
2200                 }
2201                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2202                 if (ret == false)
2203                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2204                 curreply += len;
2205                 replylen -= len;
2206         }
2207 }
2208
2209 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2210 {
2211         int ret = 0;
2212
2213         drm_dp_get_one_sb_msg(mgr, false);
2214
2215         if (mgr->down_rep_recv.have_eomt) {
2216                 struct drm_dp_sideband_msg_tx *txmsg;
2217                 struct drm_dp_mst_branch *mstb;
2218                 int slot = -1;
2219                 mstb = drm_dp_get_mst_branch_device(mgr,
2220                                                     mgr->down_rep_recv.initial_hdr.lct,
2221                                                     mgr->down_rep_recv.initial_hdr.rad);
2222
2223                 if (!mstb) {
2224                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2225                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2226                         return 0;
2227                 }
2228
2229                 /* find the message */
2230                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2231                 mutex_lock(&mgr->qlock);
2232                 txmsg = mstb->tx_slots[slot];
2233                 /* remove from slots */
2234                 mutex_unlock(&mgr->qlock);
2235
2236                 if (!txmsg) {
2237                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2238                                mstb,
2239                                mgr->down_rep_recv.initial_hdr.seqno,
2240                                mgr->down_rep_recv.initial_hdr.lct,
2241                                       mgr->down_rep_recv.initial_hdr.rad[0],
2242                                       mgr->down_rep_recv.msg[0]);
2243                         drm_dp_put_mst_branch_device(mstb);
2244                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2245                         return 0;
2246                 }
2247
2248                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2249                 if (txmsg->reply.reply_type == 1) {
2250                         DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2251                 }
2252
2253                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2254                 drm_dp_put_mst_branch_device(mstb);
2255
2256                 mutex_lock(&mgr->qlock);
2257                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2258                 mstb->tx_slots[slot] = NULL;
2259                 mutex_unlock(&mgr->qlock);
2260
2261                 wake_up_all(&mgr->tx_waitq);
2262         }
2263         return ret;
2264 }
2265
2266 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2267 {
2268         int ret = 0;
2269         drm_dp_get_one_sb_msg(mgr, true);
2270
2271         if (mgr->up_req_recv.have_eomt) {
2272                 struct drm_dp_sideband_msg_req_body msg;
2273                 struct drm_dp_mst_branch *mstb = NULL;
2274                 bool seqno;
2275
2276                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2277                         mstb = drm_dp_get_mst_branch_device(mgr,
2278                                                             mgr->up_req_recv.initial_hdr.lct,
2279                                                             mgr->up_req_recv.initial_hdr.rad);
2280                         if (!mstb) {
2281                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2282                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2283                                 return 0;
2284                         }
2285                 }
2286
2287                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2288                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2289
2290                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2291                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2292
2293                         if (!mstb)
2294                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2295
2296                         if (!mstb) {
2297                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2298                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2299                                 return 0;
2300                         }
2301
2302                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2303
2304                         DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
2305                         (*mgr->cbs->hotplug)(mgr);
2306
2307                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2308                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2309                         if (!mstb)
2310                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2311
2312                         if (!mstb) {
2313                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2314                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2315                                 return 0;
2316                         }
2317
2318                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2319                 }
2320
2321                 drm_dp_put_mst_branch_device(mstb);
2322                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2323         }
2324         return ret;
2325 }
2326
2327 /**
2328  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2329  * @mgr: manager to notify irq for.
2330  * @esi: 4 bytes from SINK_COUNT_ESI
2331  * @handled: whether the hpd interrupt was consumed or not
2332  *
2333  * This should be called from the driver when it detects a short IRQ,
2334  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2335  * topology manager will process the sideband messages received as a result
2336  * of this.
2337  */
2338 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2339 {
2340         int ret = 0;
2341         int sc;
2342         *handled = false;
2343         sc = esi[0] & 0x3f;
2344
2345         if (sc != mgr->sink_count) {
2346                 mgr->sink_count = sc;
2347                 *handled = true;
2348         }
2349
2350         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2351                 ret = drm_dp_mst_handle_down_rep(mgr);
2352                 *handled = true;
2353         }
2354
2355         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2356                 ret |= drm_dp_mst_handle_up_req(mgr);
2357                 *handled = true;
2358         }
2359
2360         drm_dp_mst_kick_tx(mgr);
2361         return ret;
2362 }
2363 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2364
2365 /**
2366  * drm_dp_mst_detect_port() - get connection status for an MST port
2367  * @connector: DRM connector for this port
2368  * @mgr: manager for this port
2369  * @port: unverified pointer to a port
2370  *
2371  * This returns the current connection state for a port. It validates the
2372  * port pointer still exists so the caller doesn't require a reference
2373  */
2374 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2375                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2376 {
2377         enum drm_connector_status status = connector_status_disconnected;
2378
2379         /* we need to search for the port in the mgr in case its gone */
2380         port = drm_dp_get_validated_port_ref(mgr, port);
2381         if (!port)
2382                 return connector_status_disconnected;
2383
2384         if (!port->ddps)
2385                 goto out;
2386
2387         switch (port->pdt) {
2388         case DP_PEER_DEVICE_NONE:
2389         case DP_PEER_DEVICE_MST_BRANCHING:
2390                 break;
2391
2392         case DP_PEER_DEVICE_SST_SINK:
2393                 status = connector_status_connected;
2394                 /* for logical ports - cache the EDID */
2395                 if (port->port_num >= 8 && !port->cached_edid) {
2396                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2397                 }
2398                 break;
2399         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2400                 if (port->ldps)
2401                         status = connector_status_connected;
2402                 break;
2403         }
2404 out:
2405         drm_dp_put_port(port);
2406         return status;
2407 }
2408 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2409
2410 /**
2411  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2412  * @mgr: manager for this port
2413  * @port: unverified pointer to a port.
2414  *
2415  * This returns whether the port supports audio or not.
2416  */
2417 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2418                                         struct drm_dp_mst_port *port)
2419 {
2420         bool ret = false;
2421
2422         port = drm_dp_get_validated_port_ref(mgr, port);
2423         if (!port)
2424                 return ret;
2425         ret = port->has_audio;
2426         drm_dp_put_port(port);
2427         return ret;
2428 }
2429 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2430
2431 /**
2432  * drm_dp_mst_get_edid() - get EDID for an MST port
2433  * @connector: toplevel connector to get EDID for
2434  * @mgr: manager for this port
2435  * @port: unverified pointer to a port.
2436  *
2437  * This returns an EDID for the port connected to a connector,
2438  * It validates the pointer still exists so the caller doesn't require a
2439  * reference.
2440  */
2441 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2442 {
2443         struct edid *edid = NULL;
2444
2445         /* we need to search for the port in the mgr in case its gone */
2446         port = drm_dp_get_validated_port_ref(mgr, port);
2447         if (!port)
2448                 return NULL;
2449
2450         if (port->cached_edid)
2451                 edid = drm_edid_duplicate(port->cached_edid);
2452         else {
2453                 edid = drm_get_edid(connector, &port->aux.ddc);
2454                 drm_mode_connector_set_tile_property(connector);
2455         }
2456         port->has_audio = drm_detect_monitor_audio(edid);
2457         drm_dp_put_port(port);
2458         return edid;
2459 }
2460 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2461
2462 /**
2463  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2464  * @mgr: manager to use
2465  * @pbn: payload bandwidth to convert into slots.
2466  */
2467 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2468                            int pbn)
2469 {
2470         int num_slots;
2471
2472         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2473
2474         /* max. time slots - one slot for MTP header */
2475         if (num_slots > 63)
2476                 return -ENOSPC;
2477         return num_slots;
2478 }
2479 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2480
2481 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2482                             struct drm_dp_vcpi *vcpi, int pbn, int slots)
2483 {
2484         int ret;
2485
2486         /* max. time slots - one slot for MTP header */
2487         if (slots > 63)
2488                 return -ENOSPC;
2489
2490         vcpi->pbn = pbn;
2491         vcpi->aligned_pbn = slots * mgr->pbn_div;
2492         vcpi->num_slots = slots;
2493
2494         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2495         if (ret < 0)
2496                 return ret;
2497         return 0;
2498 }
2499
2500 /**
2501  * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
2502  * @state: global atomic state
2503  * @mgr: MST topology manager for the port
2504  * @port: port to find vcpi slots for
2505  * @pbn: bandwidth required for the mode in PBN
2506  *
2507  * RETURNS:
2508  * Total slots in the atomic state assigned for this port or error
2509  */
2510 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
2511                                   struct drm_dp_mst_topology_mgr *mgr,
2512                                   struct drm_dp_mst_port *port, int pbn)
2513 {
2514         struct drm_dp_mst_topology_state *topology_state;
2515         int req_slots;
2516
2517         topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2518         if (topology_state == NULL)
2519                 return -ENOMEM;
2520
2521         port = drm_dp_get_validated_port_ref(mgr, port);
2522         if (port == NULL)
2523                 return -EINVAL;
2524         req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2525         DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
2526                         req_slots, topology_state->avail_slots);
2527
2528         if (req_slots > topology_state->avail_slots) {
2529                 drm_dp_put_port(port);
2530                 return -ENOSPC;
2531         }
2532
2533         topology_state->avail_slots -= req_slots;
2534         DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
2535
2536         drm_dp_put_port(port);
2537         return req_slots;
2538 }
2539 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
2540
2541 /**
2542  * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
2543  * @state: global atomic state
2544  * @mgr: MST topology manager for the port
2545  * @slots: number of vcpi slots to release
2546  *
2547  * RETURNS:
2548  * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or
2549  * negative error code
2550  */
2551 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
2552                                      struct drm_dp_mst_topology_mgr *mgr,
2553                                      int slots)
2554 {
2555         struct drm_dp_mst_topology_state *topology_state;
2556
2557         topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2558         if (topology_state == NULL)
2559                 return -ENOMEM;
2560
2561         /* We cannot rely on port->vcpi.num_slots to update
2562          * topology_state->avail_slots as the port may not exist if the parent
2563          * branch device was unplugged. This should be fixed by tracking
2564          * per-port slot allocation in drm_dp_mst_topology_state instead of
2565          * depending on the caller to tell us how many slots to release.
2566          */
2567         topology_state->avail_slots += slots;
2568         DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
2569                         slots, topology_state->avail_slots);
2570
2571         return 0;
2572 }
2573 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
2574
2575 /**
2576  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2577  * @mgr: manager for this port
2578  * @port: port to allocate a virtual channel for.
2579  * @pbn: payload bandwidth number to request
2580  * @slots: returned number of slots for this PBN.
2581  */
2582 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2583                               struct drm_dp_mst_port *port, int pbn, int slots)
2584 {
2585         int ret;
2586
2587         port = drm_dp_get_validated_port_ref(mgr, port);
2588         if (!port)
2589                 return false;
2590
2591         if (slots < 0)
2592                 return false;
2593
2594         if (port->vcpi.vcpi > 0) {
2595                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2596                 if (pbn == port->vcpi.pbn) {
2597                         drm_dp_put_port(port);
2598                         return true;
2599                 }
2600         }
2601
2602         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
2603         if (ret) {
2604                 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
2605                                 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
2606                 goto out;
2607         }
2608         DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
2609                         pbn, port->vcpi.num_slots);
2610
2611         drm_dp_put_port(port);
2612         return true;
2613 out:
2614         return false;
2615 }
2616 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2617
2618 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2619 {
2620         int slots = 0;
2621         port = drm_dp_get_validated_port_ref(mgr, port);
2622         if (!port)
2623                 return slots;
2624
2625         slots = port->vcpi.num_slots;
2626         drm_dp_put_port(port);
2627         return slots;
2628 }
2629 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2630
2631 /**
2632  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2633  * @mgr: manager for this port
2634  * @port: unverified pointer to a port.
2635  *
2636  * This just resets the number of slots for the ports VCPI for later programming.
2637  */
2638 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2639 {
2640         port = drm_dp_get_validated_port_ref(mgr, port);
2641         if (!port)
2642                 return;
2643         port->vcpi.num_slots = 0;
2644         drm_dp_put_port(port);
2645 }
2646 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2647
2648 /**
2649  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2650  * @mgr: manager for this port
2651  * @port: unverified port to deallocate vcpi for
2652  */
2653 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2654 {
2655         port = drm_dp_get_validated_port_ref(mgr, port);
2656         if (!port)
2657                 return;
2658
2659         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2660         port->vcpi.num_slots = 0;
2661         port->vcpi.pbn = 0;
2662         port->vcpi.aligned_pbn = 0;
2663         port->vcpi.vcpi = 0;
2664         drm_dp_put_port(port);
2665 }
2666 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2667
2668 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2669                                      int id, struct drm_dp_payload *payload)
2670 {
2671         u8 payload_alloc[3], status;
2672         int ret;
2673         int retries = 0;
2674
2675         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2676                            DP_PAYLOAD_TABLE_UPDATED);
2677
2678         payload_alloc[0] = id;
2679         payload_alloc[1] = payload->start_slot;
2680         payload_alloc[2] = payload->num_slots;
2681
2682         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2683         if (ret != 3) {
2684                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2685                 goto fail;
2686         }
2687
2688 retry:
2689         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2690         if (ret < 0) {
2691                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2692                 goto fail;
2693         }
2694
2695         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2696                 retries++;
2697                 if (retries < 20) {
2698                         usleep_range(10000, 20000);
2699                         goto retry;
2700                 }
2701                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2702                 ret = -EINVAL;
2703                 goto fail;
2704         }
2705         ret = 0;
2706 fail:
2707         return ret;
2708 }
2709
2710
2711 /**
2712  * drm_dp_check_act_status() - Check ACT handled status.
2713  * @mgr: manager to use
2714  *
2715  * Check the payload status bits in the DPCD for ACT handled completion.
2716  */
2717 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2718 {
2719         u8 status;
2720         int ret;
2721         int count = 0;
2722
2723         do {
2724                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2725
2726                 if (ret < 0) {
2727                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2728                         goto fail;
2729                 }
2730
2731                 if (status & DP_PAYLOAD_ACT_HANDLED)
2732                         break;
2733                 count++;
2734                 udelay(100);
2735
2736         } while (count < 30);
2737
2738         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2739                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2740                 ret = -EINVAL;
2741                 goto fail;
2742         }
2743         return 0;
2744 fail:
2745         return ret;
2746 }
2747 EXPORT_SYMBOL(drm_dp_check_act_status);
2748
2749 /**
2750  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2751  * @clock: dot clock for the mode
2752  * @bpp: bpp for the mode.
2753  *
2754  * This uses the formula in the spec to calculate the PBN value for a mode.
2755  */
2756 int drm_dp_calc_pbn_mode(int clock, int bpp)
2757 {
2758         u64 kbps;
2759         s64 peak_kbps;
2760         u32 numerator;
2761         u32 denominator;
2762
2763         kbps = clock * bpp;
2764
2765         /*
2766          * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2767          * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2768          * common multiplier to render an integer PBN for all link rate/lane
2769          * counts combinations
2770          * calculate
2771          * peak_kbps *= (1006/1000)
2772          * peak_kbps *= (64/54)
2773          * peak_kbps *= 8    convert to bytes
2774          */
2775
2776         numerator = 64 * 1006;
2777         denominator = 54 * 8 * 1000 * 1000;
2778
2779         kbps *= numerator;
2780         peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2781
2782         return drm_fixp2int_ceil(peak_kbps);
2783 }
2784 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2785
2786 static int test_calc_pbn_mode(void)
2787 {
2788         int ret;
2789         ret = drm_dp_calc_pbn_mode(154000, 30);
2790         if (ret != 689) {
2791                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2792                                 154000, 30, 689, ret);
2793                 return -EINVAL;
2794         }
2795         ret = drm_dp_calc_pbn_mode(234000, 30);
2796         if (ret != 1047) {
2797                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2798                                 234000, 30, 1047, ret);
2799                 return -EINVAL;
2800         }
2801         ret = drm_dp_calc_pbn_mode(297000, 24);
2802         if (ret != 1063) {
2803                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2804                                 297000, 24, 1063, ret);
2805                 return -EINVAL;
2806         }
2807         return 0;
2808 }
2809
2810 /* we want to kick the TX after we've ack the up/down IRQs. */
2811 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2812 {
2813         queue_work(system_long_wq, &mgr->tx_work);
2814 }
2815
2816 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2817                                  struct drm_dp_mst_branch *mstb)
2818 {
2819         struct drm_dp_mst_port *port;
2820         int tabs = mstb->lct;
2821         char prefix[10];
2822         int i;
2823
2824         for (i = 0; i < tabs; i++)
2825                 prefix[i] = '\t';
2826         prefix[i] = '\0';
2827
2828         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2829         list_for_each_entry(port, &mstb->ports, next) {
2830                 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2831                 if (port->mstb)
2832                         drm_dp_mst_dump_mstb(m, port->mstb);
2833         }
2834 }
2835
2836 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2837                                   char *buf)
2838 {
2839         int i;
2840
2841         for (i = 0; i < 64; i += 16) {
2842                 if (drm_dp_dpcd_read(mgr->aux,
2843                                      DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
2844                                      &buf[i], 16) != 16)
2845                         return false;
2846         }
2847         return true;
2848 }
2849
2850 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2851                                struct drm_dp_mst_port *port, char *name,
2852                                int namelen)
2853 {
2854         struct edid *mst_edid;
2855
2856         mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2857         drm_edid_get_monitor_name(mst_edid, name, namelen);
2858 }
2859
2860 /**
2861  * drm_dp_mst_dump_topology(): dump topology to seq file.
2862  * @m: seq_file to dump output to
2863  * @mgr: manager to dump current topology for.
2864  *
2865  * helper to dump MST topology to a seq file for debugfs.
2866  */
2867 void drm_dp_mst_dump_topology(struct seq_file *m,
2868                               struct drm_dp_mst_topology_mgr *mgr)
2869 {
2870         int i;
2871         struct drm_dp_mst_port *port;
2872
2873         mutex_lock(&mgr->lock);
2874         if (mgr->mst_primary)
2875                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2876
2877         /* dump VCPIs */
2878         mutex_unlock(&mgr->lock);
2879
2880         mutex_lock(&mgr->payload_lock);
2881         seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2882                 mgr->max_payloads);
2883
2884         for (i = 0; i < mgr->max_payloads; i++) {
2885                 if (mgr->proposed_vcpis[i]) {
2886                         char name[14];
2887
2888                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2889                         fetch_monitor_name(mgr, port, name, sizeof(name));
2890                         seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
2891                                    port->port_num, port->vcpi.vcpi,
2892                                    port->vcpi.num_slots,
2893                                    (*name != 0) ? name :  "Unknown");
2894                 } else
2895                         seq_printf(m, "vcpi %d:unused\n", i);
2896         }
2897         for (i = 0; i < mgr->max_payloads; i++) {
2898                 seq_printf(m, "payload %d: %d, %d, %d\n",
2899                            i,
2900                            mgr->payloads[i].payload_state,
2901                            mgr->payloads[i].start_slot,
2902                            mgr->payloads[i].num_slots);
2903
2904
2905         }
2906         mutex_unlock(&mgr->payload_lock);
2907
2908         mutex_lock(&mgr->lock);
2909         if (mgr->mst_primary) {
2910                 u8 buf[64];
2911                 int ret;
2912
2913                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2914                 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
2915                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2916                 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
2917                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2918                 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
2919
2920                 /* dump the standard OUI branch header */
2921                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2922                 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
2923                 for (i = 0x3; i < 0x8 && buf[i]; i++)
2924                         seq_printf(m, "%c", buf[i]);
2925                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
2926                            buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2927                 if (dump_dp_payload_table(mgr, buf))
2928                         seq_printf(m, "payload table: %*ph\n", 63, buf);
2929
2930         }
2931
2932         mutex_unlock(&mgr->lock);
2933
2934 }
2935 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2936
2937 static void drm_dp_tx_work(struct work_struct *work)
2938 {
2939         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2940
2941         mutex_lock(&mgr->qlock);
2942         if (!list_empty(&mgr->tx_msg_downq))
2943                 process_single_down_tx_qlock(mgr);
2944         mutex_unlock(&mgr->qlock);
2945 }
2946
2947 static void drm_dp_free_mst_port(struct kref *kref)
2948 {
2949         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2950         kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2951         kfree(port);
2952 }
2953
2954 static void drm_dp_destroy_connector_work(struct work_struct *work)
2955 {
2956         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2957         struct drm_dp_mst_port *port;
2958         bool send_hotplug = false;
2959         /*
2960          * Not a regular list traverse as we have to drop the destroy
2961          * connector lock before destroying the connector, to avoid AB->BA
2962          * ordering between this lock and the config mutex.
2963          */
2964         for (;;) {
2965                 mutex_lock(&mgr->destroy_connector_lock);
2966                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2967                 if (!port) {
2968                         mutex_unlock(&mgr->destroy_connector_lock);
2969                         break;
2970                 }
2971                 list_del(&port->next);
2972                 mutex_unlock(&mgr->destroy_connector_lock);
2973
2974                 kref_init(&port->kref);
2975                 INIT_LIST_HEAD(&port->next);
2976
2977                 mgr->cbs->destroy_connector(mgr, port->connector);
2978
2979                 drm_dp_port_teardown_pdt(port, port->pdt);
2980                 port->pdt = DP_PEER_DEVICE_NONE;
2981
2982                 if (!port->input && port->vcpi.vcpi > 0) {
2983                         drm_dp_mst_reset_vcpi_slots(mgr, port);
2984                         drm_dp_update_payload_part1(mgr);
2985                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2986                 }
2987
2988                 kref_put(&port->kref, drm_dp_free_mst_port);
2989                 send_hotplug = true;
2990         }
2991         if (send_hotplug)
2992                 (*mgr->cbs->hotplug)(mgr);
2993 }
2994
2995 void *drm_dp_mst_duplicate_state(struct drm_atomic_state *state, void *obj)
2996 {
2997         struct drm_dp_mst_topology_mgr *mgr = obj;
2998         struct drm_dp_mst_topology_state *new_mst_state;
2999
3000         if (WARN_ON(!mgr->state))
3001                 return NULL;
3002
3003         new_mst_state = kmemdup(mgr->state, sizeof(*new_mst_state), GFP_KERNEL);
3004         if (new_mst_state)
3005                 new_mst_state->state = state;
3006         return new_mst_state;
3007 }
3008
3009 void drm_dp_mst_swap_state(void *obj, void **obj_state_ptr)
3010 {
3011         struct drm_dp_mst_topology_mgr *mgr = obj;
3012         struct drm_dp_mst_topology_state **topology_state_ptr;
3013
3014         topology_state_ptr = (struct drm_dp_mst_topology_state **)obj_state_ptr;
3015
3016         mgr->state->state = (*topology_state_ptr)->state;
3017         swap(*topology_state_ptr, mgr->state);
3018         mgr->state->state = NULL;
3019 }
3020
3021 void drm_dp_mst_destroy_state(void *obj_state)
3022 {
3023         kfree(obj_state);
3024 }
3025
3026 static const struct drm_private_state_funcs mst_state_funcs = {
3027         .duplicate_state = drm_dp_mst_duplicate_state,
3028         .swap_state = drm_dp_mst_swap_state,
3029         .destroy_state = drm_dp_mst_destroy_state,
3030 };
3031
3032 /**
3033  * drm_atomic_get_mst_topology_state: get MST topology state
3034  *
3035  * @state: global atomic state
3036  * @mgr: MST topology manager, also the private object in this case
3037  *
3038  * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3039  * state vtable so that the private object state returned is that of a MST
3040  * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3041  * to care of the locking, so warn if don't hold the connection_mutex.
3042  *
3043  * RETURNS:
3044  *
3045  * The MST topology state or error pointer.
3046  */
3047 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3048                                                                     struct drm_dp_mst_topology_mgr *mgr)
3049 {
3050         struct drm_device *dev = mgr->dev;
3051
3052         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
3053         return drm_atomic_get_private_obj_state(state, mgr,
3054                                                 &mst_state_funcs);
3055 }
3056 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3057
3058 /**
3059  * drm_dp_mst_topology_mgr_init - initialise a topology manager
3060  * @mgr: manager struct to initialise
3061  * @dev: device providing this structure - for i2c addition.
3062  * @aux: DP helper aux channel to talk to this device
3063  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3064  * @max_payloads: maximum number of payloads this GPU can source
3065  * @conn_base_id: the connector object ID the MST device is connected to.
3066  *
3067  * Return 0 for success, or negative error code on failure
3068  */
3069 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
3070                                  struct drm_device *dev, struct drm_dp_aux *aux,
3071                                  int max_dpcd_transaction_bytes,
3072                                  int max_payloads, int conn_base_id)
3073 {
3074         mutex_init(&mgr->lock);
3075         mutex_init(&mgr->qlock);
3076         mutex_init(&mgr->payload_lock);
3077         mutex_init(&mgr->destroy_connector_lock);
3078         INIT_LIST_HEAD(&mgr->tx_msg_downq);
3079         INIT_LIST_HEAD(&mgr->destroy_connector_list);
3080         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3081         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
3082         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
3083         init_waitqueue_head(&mgr->tx_waitq);
3084         mgr->dev = dev;
3085         mgr->aux = aux;
3086         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3087         mgr->max_payloads = max_payloads;
3088         mgr->conn_base_id = conn_base_id;
3089         if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3090             max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3091                 return -EINVAL;
3092         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3093         if (!mgr->payloads)
3094                 return -ENOMEM;
3095         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3096         if (!mgr->proposed_vcpis)
3097                 return -ENOMEM;
3098         set_bit(0, &mgr->payload_mask);
3099         if (test_calc_pbn_mode() < 0)
3100                 DRM_ERROR("MST PBN self-test failed\n");
3101
3102         mgr->state = kzalloc(sizeof(*mgr->state), GFP_KERNEL);
3103         if (mgr->state == NULL)
3104                 return -ENOMEM;
3105         mgr->state->mgr = mgr;
3106
3107         /* max. time slots - one slot for MTP header */
3108         mgr->state->avail_slots = 63;
3109         mgr->funcs = &mst_state_funcs;
3110
3111         return 0;
3112 }
3113 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3114
3115 /**
3116  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3117  * @mgr: manager to destroy
3118  */
3119 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3120 {
3121         flush_work(&mgr->work);
3122         flush_work(&mgr->destroy_connector_work);
3123         mutex_lock(&mgr->payload_lock);
3124         kfree(mgr->payloads);
3125         mgr->payloads = NULL;
3126         kfree(mgr->proposed_vcpis);
3127         mgr->proposed_vcpis = NULL;
3128         mutex_unlock(&mgr->payload_lock);
3129         mgr->dev = NULL;
3130         mgr->aux = NULL;
3131         kfree(mgr->state);
3132         mgr->state = NULL;
3133         mgr->funcs = NULL;
3134 }
3135 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3136
3137 /* I2C device */
3138 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3139                                int num)
3140 {
3141         struct drm_dp_aux *aux = adapter->algo_data;
3142         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3143         struct drm_dp_mst_branch *mstb;
3144         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3145         unsigned int i;
3146         bool reading = false;
3147         struct drm_dp_sideband_msg_req_body msg;
3148         struct drm_dp_sideband_msg_tx *txmsg = NULL;
3149         int ret;
3150
3151         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3152         if (!mstb)
3153                 return -EREMOTEIO;
3154
3155         /* construct i2c msg */
3156         /* see if last msg is a read */
3157         if (msgs[num - 1].flags & I2C_M_RD)
3158                 reading = true;
3159
3160         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3161                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3162                 ret = -EIO;
3163                 goto out;
3164         }
3165
3166         memset(&msg, 0, sizeof(msg));
3167         msg.req_type = DP_REMOTE_I2C_READ;
3168         msg.u.i2c_read.num_transactions = num - 1;
3169         msg.u.i2c_read.port_number = port->port_num;
3170         for (i = 0; i < num - 1; i++) {
3171                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3172                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3173                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3174         }
3175         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3176         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3177
3178         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3179         if (!txmsg) {
3180                 ret = -ENOMEM;
3181                 goto out;
3182         }
3183
3184         txmsg->dst = mstb;
3185         drm_dp_encode_sideband_req(&msg, txmsg);
3186
3187         drm_dp_queue_down_tx(mgr, txmsg);
3188
3189         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3190         if (ret > 0) {
3191
3192                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3193                         ret = -EREMOTEIO;
3194                         goto out;
3195                 }
3196                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3197                         ret = -EIO;
3198                         goto out;
3199                 }
3200                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3201                 ret = num;
3202         }
3203 out:
3204         kfree(txmsg);
3205         drm_dp_put_mst_branch_device(mstb);
3206         return ret;
3207 }
3208
3209 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3210 {
3211         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3212                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3213                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3214                I2C_FUNC_10BIT_ADDR;
3215 }
3216
3217 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3218         .functionality = drm_dp_mst_i2c_functionality,
3219         .master_xfer = drm_dp_mst_i2c_xfer,
3220 };
3221
3222 /**
3223  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3224  * @aux: DisplayPort AUX channel
3225  *
3226  * Returns 0 on success or a negative error code on failure.
3227  */
3228 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3229 {
3230         aux->ddc.algo = &drm_dp_mst_i2c_algo;
3231         aux->ddc.algo_data = aux;
3232         aux->ddc.retries = 3;
3233
3234         aux->ddc.class = I2C_CLASS_DDC;
3235         aux->ddc.owner = THIS_MODULE;
3236         aux->ddc.dev.parent = aux->dev;
3237         aux->ddc.dev.of_node = aux->dev->of_node;
3238
3239         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3240                 sizeof(aux->ddc.name));
3241
3242         return i2c_add_adapter(&aux->ddc);
3243 }
3244
3245 /**
3246  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3247  * @aux: DisplayPort AUX channel
3248  */
3249 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3250 {
3251         i2c_del_adapter(&aux->ddc);
3252 }