drivers/net/ethernet/intel/ixgbevf/mbx.c

   1 /*******************************************************************************
   2
   3   Intel 82599 Virtual Function driver
   4   Copyright(c) 1999 - 2015 Intel Corporation.
   5
   6   This program is free software; you can redistribute it and/or modify it
   7   under the terms and conditions of the GNU General Public License,
   8   version 2, as published by the Free Software Foundation.
   9
  10   This program is distributed in the hope it will be useful, but WITHOUT
  11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13   more details.
  14
  15   You should have received a copy of the GNU General Public License along with
  16   this program; if not, see <http://www.gnu.org/licenses/>.
  17
  18   The full GNU General Public License is included in this distribution in
  19   the file called "COPYING".
  20
  21   Contact Information:
  22   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  23   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24
  25 *******************************************************************************/
  26
  27 #include "mbx.h"
  28 #include "ixgbevf.h"
  29
  30 /**
  31  *  ixgbevf_poll_for_msg - Wait for message notification
  32  *  @hw: pointer to the HW structure
  33  *
  34  *  returns 0 if it successfully received a message notification
  35  **/
  36 static s32 ixgbevf_poll_for_msg(struct ixgbe_hw *hw)
  37 {
  38         struct ixgbe_mbx_info *mbx = &hw->mbx;
  39         int countdown = mbx->timeout;
  40
  41         while (countdown && mbx->ops.check_for_msg(hw)) {
  42                 countdown--;
  43                 udelay(mbx->udelay);
  44         }
  45
  46         /* if we failed, all future posted messages fail until reset */
  47         if (!countdown)
  48                 mbx->timeout = 0;
  49
  50         return countdown ? 0 : IXGBE_ERR_MBX;
  51 }
  52
  53 /**
  54  *  ixgbevf_poll_for_ack - Wait for message acknowledgment
  55  *  @hw: pointer to the HW structure
  56  *
  57  *  returns 0 if it successfully received a message acknowledgment
  58  **/
  59 static s32 ixgbevf_poll_for_ack(struct ixgbe_hw *hw)
  60 {
  61         struct ixgbe_mbx_info *mbx = &hw->mbx;
  62         int countdown = mbx->timeout;
  63
  64         while (countdown && mbx->ops.check_for_ack(hw)) {
  65                 countdown--;
  66                 udelay(mbx->udelay);
  67         }
  68
  69         /* if we failed, all future posted messages fail until reset */
  70         if (!countdown)
  71                 mbx->timeout = 0;
  72
  73         return countdown ? 0 : IXGBE_ERR_MBX;
  74 }
  75
  76 /**
  77  *  ixgbevf_read_posted_mbx - Wait for message notification and receive message
  78  *  @hw: pointer to the HW structure
  79  *  @msg: The message buffer
  80  *  @size: Length of buffer
  81  *
  82  *  returns 0 if it successfully received a message notification and
  83  *  copied it into the receive buffer.
  84  **/
  85 static s32 ixgbevf_read_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
  86 {
  87         struct ixgbe_mbx_info *mbx = &hw->mbx;
  88         s32 ret_val = IXGBE_ERR_MBX;
  89
  90         if (!mbx->ops.read)
  91                 goto out;
  92
  93         ret_val = ixgbevf_poll_for_msg(hw);
  94
  95         /* if ack received read message, otherwise we timed out */
  96         if (!ret_val)
  97                 ret_val = mbx->ops.read(hw, msg, size);
  98 out:
  99         return ret_val;
 100 }
 101
 102 /**
 103  *  ixgbevf_write_posted_mbx - Write a message to the mailbox, wait for ack
 104  *  @hw: pointer to the HW structure
 105  *  @msg: The message buffer
 106  *  @size: Length of buffer
 107  *
 108  *  returns 0 if it successfully copied message into the buffer and
 109  *  received an ack to that message within delay * timeout period
 110  **/
 111 static s32 ixgbevf_write_posted_mbx(struct ixgbe_hw *hw, u32 *msg, u16 size)
 112 {
 113         struct ixgbe_mbx_info *mbx = &hw->mbx;
 114         s32 ret_val = IXGBE_ERR_MBX;
 115
 116         /* exit if either we can't write or there isn't a defined timeout */
 117         if (!mbx->ops.write || !mbx->timeout)
 118                 goto out;
 119
 120         /* send msg */
 121         ret_val = mbx->ops.write(hw, msg, size);
 122
 123         /* if msg sent wait until we receive an ack */
 124         if (!ret_val)
 125                 ret_val = ixgbevf_poll_for_ack(hw);
 126 out:
 127         return ret_val;
 128 }
 129
 130 /**
 131  *  ixgbevf_read_v2p_mailbox - read v2p mailbox
 132  *  @hw: pointer to the HW structure
 133  *
 134  *  This function is used to read the v2p mailbox without losing the read to
 135  *  clear status bits.
 136  **/
 137 static u32 ixgbevf_read_v2p_mailbox(struct ixgbe_hw *hw)
 138 {
 139         u32 v2p_mailbox = IXGBE_READ_REG(hw, IXGBE_VFMAILBOX);
 140
 141         v2p_mailbox |= hw->mbx.v2p_mailbox;
 142         hw->mbx.v2p_mailbox |= v2p_mailbox & IXGBE_VFMAILBOX_R2C_BITS;
 143
 144         return v2p_mailbox;
 145 }
 146
 147 /**
 148  *  ixgbevf_check_for_bit_vf - Determine if a status bit was set
 149  *  @hw: pointer to the HW structure
 150  *  @mask: bitmask for bits to be tested and cleared
 151  *
 152  *  This function is used to check for the read to clear bits within
 153  *  the V2P mailbox.
 154  **/
 155 static s32 ixgbevf_check_for_bit_vf(struct ixgbe_hw *hw, u32 mask)
 156 {
 157         u32 v2p_mailbox = ixgbevf_read_v2p_mailbox(hw);
 158         s32 ret_val = IXGBE_ERR_MBX;
 159
 160         if (v2p_mailbox & mask)
 161                 ret_val = 0;
 162
 163         hw->mbx.v2p_mailbox &= ~mask;
 164
 165         return ret_val;
 166 }
 167
 168 /**
 169  *  ixgbevf_check_for_msg_vf - checks to see if the PF has sent mail
 170  *  @hw: pointer to the HW structure
 171  *
 172  *  returns 0 if the PF has set the Status bit or else ERR_MBX
 173  **/
 174 static s32 ixgbevf_check_for_msg_vf(struct ixgbe_hw *hw)
 175 {
 176         s32 ret_val = IXGBE_ERR_MBX;
 177
 178         if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFSTS)) {
 179                 ret_val = 0;
 180                 hw->mbx.stats.reqs++;
 181         }
 182
 183         return ret_val;
 184 }
 185
 186 /**
 187  *  ixgbevf_check_for_ack_vf - checks to see if the PF has ACK'd
 188  *  @hw: pointer to the HW structure
 189  *
 190  *  returns 0 if the PF has set the ACK bit or else ERR_MBX
 191  **/
 192 static s32 ixgbevf_check_for_ack_vf(struct ixgbe_hw *hw)
 193 {
 194         s32 ret_val = IXGBE_ERR_MBX;
 195
 196         if (!ixgbevf_check_for_bit_vf(hw, IXGBE_VFMAILBOX_PFACK)) {
 197                 ret_val = 0;
 198                 hw->mbx.stats.acks++;
 199         }
 200
 201         return ret_val;
 202 }
 203
 204 /**
 205  *  ixgbevf_check_for_rst_vf - checks to see if the PF has reset
 206  *  @hw: pointer to the HW structure
 207  *
 208  *  returns true if the PF has set the reset done bit or else false
 209  **/
 210 static s32 ixgbevf_check_for_rst_vf(struct ixgbe_hw *hw)
 211 {
 212         s32 ret_val = IXGBE_ERR_MBX;
 213
 214         if (!ixgbevf_check_for_bit_vf(hw, (IXGBE_VFMAILBOX_RSTD |
 215                                            IXGBE_VFMAILBOX_RSTI))) {
 216                 ret_val = 0;
 217                 hw->mbx.stats.rsts++;
 218         }
 219
 220         return ret_val;
 221 }
 222
 223 /**
 224  *  ixgbevf_obtain_mbx_lock_vf - obtain mailbox lock
 225  *  @hw: pointer to the HW structure
 226  *
 227  *  return 0 if we obtained the mailbox lock
 228  **/
 229 static s32 ixgbevf_obtain_mbx_lock_vf(struct ixgbe_hw *hw)
 230 {
 231         s32 ret_val = IXGBE_ERR_MBX;
 232
 233         /* Take ownership of the buffer */
 234         IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_VFU);
 235
 236         /* reserve mailbox for VF use */
 237         if (ixgbevf_read_v2p_mailbox(hw) & IXGBE_VFMAILBOX_VFU)
 238                 ret_val = 0;
 239
 240         return ret_val;
 241 }
 242
 243 /**
 244  *  ixgbevf_write_mbx_vf - Write a message to the mailbox
 245  *  @hw: pointer to the HW structure
 246  *  @msg: The message buffer
 247  *  @size: Length of buffer
 248  *
 249  *  returns 0 if it successfully copied message into the buffer
 250  **/
 251 static s32 ixgbevf_write_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
 252 {
 253         s32 ret_val;
 254         u16 i;
 255
 256         /* lock the mailbox to prevent PF/VF race condition */
 257         ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
 258         if (ret_val)
 259                 goto out_no_write;
 260
 261         /* flush msg and acks as we are overwriting the message buffer */
 262         ixgbevf_check_for_msg_vf(hw);
 263         ixgbevf_check_for_ack_vf(hw);
 264
 265         /* copy the caller specified message to the mailbox memory buffer */
 266         for (i = 0; i < size; i++)
 267                 IXGBE_WRITE_REG_ARRAY(hw, IXGBE_VFMBMEM, i, msg[i]);
 268
 269         /* update stats */
 270         hw->mbx.stats.msgs_tx++;
 271
 272         /* Drop VFU and interrupt the PF to tell it a message has been sent */
 273         IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_REQ);
 274
 275 out_no_write:
 276         return ret_val;
 277 }
 278
 279 /**
 280  *  ixgbevf_read_mbx_vf - Reads a message from the inbox intended for VF
 281  *  @hw: pointer to the HW structure
 282  *  @msg: The message buffer
 283  *  @size: Length of buffer
 284  *
 285  *  returns 0 if it successfully read message from buffer
 286  **/
 287 static s32 ixgbevf_read_mbx_vf(struct ixgbe_hw *hw, u32 *msg, u16 size)
 288 {
 289         s32 ret_val = 0;
 290         u16 i;
 291
 292         /* lock the mailbox to prevent PF/VF race condition */
 293         ret_val = ixgbevf_obtain_mbx_lock_vf(hw);
 294         if (ret_val)
 295                 goto out_no_read;
 296
 297         /* copy the message from the mailbox memory buffer */
 298         for (i = 0; i < size; i++)
 299                 msg[i] = IXGBE_READ_REG_ARRAY(hw, IXGBE_VFMBMEM, i);
 300
 301         /* Acknowledge receipt and release mailbox, then we're done */
 302         IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);
 303
 304         /* update stats */
 305         hw->mbx.stats.msgs_rx++;
 306
 307 out_no_read:
 308         return ret_val;
 309 }
 310
 311 /**
 312  *  ixgbevf_init_mbx_params_vf - set initial values for VF mailbox
 313  *  @hw: pointer to the HW structure
 314  *
 315  *  Initializes the hw->mbx struct to correct values for VF mailbox
 316  */
 317 static s32 ixgbevf_init_mbx_params_vf(struct ixgbe_hw *hw)
 318 {
 319         struct ixgbe_mbx_info *mbx = &hw->mbx;
 320
 321         /* start mailbox as timed out and let the reset_hw call set the timeout
 322          * value to begin communications
 323          */
 324         mbx->timeout = 0;
 325         mbx->udelay = IXGBE_VF_MBX_INIT_DELAY;
 326
 327         mbx->size = IXGBE_VFMAILBOX_SIZE;
 328
 329         mbx->stats.msgs_tx = 0;
 330         mbx->stats.msgs_rx = 0;
 331         mbx->stats.reqs = 0;
 332         mbx->stats.acks = 0;
 333         mbx->stats.rsts = 0;
 334
 335         return 0;
 336 }
 337
 338 const struct ixgbe_mbx_operations ixgbevf_mbx_ops = {
 339         .init_params    = ixgbevf_init_mbx_params_vf,
 340         .read           = ixgbevf_read_mbx_vf,
 341         .write          = ixgbevf_write_mbx_vf,
 342         .read_posted    = ixgbevf_read_posted_mbx,
 343         .write_posted   = ixgbevf_write_posted_mbx,
 344         .check_for_msg  = ixgbevf_check_for_msg_vf,
 345         .check_for_ack  = ixgbevf_check_for_ack_vf,
 346         .check_for_rst  = ixgbevf_check_for_rst_vf,
 347 };
 348
 349 /* Mailbox operations when running on Hyper-V.
 350  * On Hyper-V, PF/VF communication is not through the
 351  * hardware mailbox; this communication is through
 352  * a software mediated path.
 353  * Most mail box operations are noop while running on
 354  * Hyper-V.
 355  */
 356 const struct ixgbe_mbx_operations ixgbevf_hv_mbx_ops = {
 357         .init_params    = ixgbevf_init_mbx_params_vf,
 358         .check_for_rst  = ixgbevf_check_for_rst_vf,
 359 };