drivers/gpu/drm/nouveau/nouveau_dma.c

   1 /*
   2  * Copyright (C) 2007 Ben Skeggs.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial
  15  * portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  */
  26
  27 #include "drmP.h"
  28 #include "drm.h"
  29 #include "nouveau_drv.h"
  30 #include "nouveau_dma.h"
  31 #include "nouveau_ramht.h"
  32
  33 void
  34 nouveau_dma_pre_init(struct nouveau_channel *chan)
  35 {
  36         struct drm_nouveau_private *dev_priv = chan->dev->dev_private;
  37         struct nouveau_bo *pushbuf = chan->pushbuf_bo;
  38
  39         if (dev_priv->card_type >= NV_50) {
  40                 const int ib_size = pushbuf->bo.mem.size / 2;
  41
  42                 chan->dma.ib_base = (pushbuf->bo.mem.size - ib_size) >> 2;
  43                 chan->dma.ib_max = (ib_size / 8) - 1;
  44                 chan->dma.ib_put = 0;
  45                 chan->dma.ib_free = chan->dma.ib_max - chan->dma.ib_put;
  46
  47                 chan->dma.max = (pushbuf->bo.mem.size - ib_size) >> 2;
  48         } else {
  49                 chan->dma.max  = (pushbuf->bo.mem.size >> 2) - 2;
  50         }
  51
  52         chan->dma.put  = 0;
  53         chan->dma.cur  = chan->dma.put;
  54         chan->dma.free = chan->dma.max - chan->dma.cur;
  55 }
  56
  57 int
  58 nouveau_dma_init(struct nouveau_channel *chan)
  59 {
  60         struct drm_device *dev = chan->dev;
  61         struct drm_nouveau_private *dev_priv = dev->dev_private;
  62         int ret, i;
  63
  64         if (dev_priv->card_type >= NV_C0) {
  65                 ret = nouveau_gpuobj_gr_new(chan, 0x9039, 0x9039);
  66                 if (ret)
  67                         return ret;
  68
  69                 ret = RING_SPACE(chan, 2);
  70                 if (ret)
  71                         return ret;
  72
  73                 BEGIN_NVC0(chan, 2, NvSubM2MF, 0x0000, 1);
  74                 OUT_RING  (chan, 0x00009039);
  75                 FIRE_RING (chan);
  76                 return 0;
  77         }
  78
  79         /* Create NV_MEMORY_TO_MEMORY_FORMAT for buffer moves */
  80         ret = nouveau_gpuobj_gr_new(chan, NvM2MF, dev_priv->card_type < NV_50 ?
  81                                     0x0039 : 0x5039);
  82         if (ret)
  83                 return ret;
  84
  85         /* NV_MEMORY_TO_MEMORY_FORMAT requires a notifier object */
  86         ret = nouveau_notifier_alloc(chan, NvNotify0, 32, 0xfd0, 0x1000,
  87                                      &chan->m2mf_ntfy);
  88         if (ret)
  89                 return ret;
  90
  91         /* Insert NOPS for NOUVEAU_DMA_SKIPS */
  92         ret = RING_SPACE(chan, NOUVEAU_DMA_SKIPS);
  93         if (ret)
  94                 return ret;
  95
  96         for (i = 0; i < NOUVEAU_DMA_SKIPS; i++)
  97                 OUT_RING(chan, 0);
  98
  99         /* Initialise NV_MEMORY_TO_MEMORY_FORMAT */
 100         ret = RING_SPACE(chan, 4);
 101         if (ret)
 102                 return ret;
 103         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_NAME, 1);
 104         OUT_RING(chan, NvM2MF);
 105         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_DMA_NOTIFY, 1);
 106         OUT_RING(chan, NvNotify0);
 107
 108         /* Sit back and pray the channel works.. */
 109         FIRE_RING(chan);
 110
 111         return 0;
 112 }
 113
 114 void
 115 OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
 116 {
 117         bool is_iomem;
 118         u32 *mem = ttm_kmap_obj_virtual(&chan->pushbuf_bo->kmap, &is_iomem);
 119         mem = &mem[chan->dma.cur];
 120         if (is_iomem)
 121                 memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
 122         else
 123                 memcpy(mem, data, nr_dwords * 4);
 124         chan->dma.cur += nr_dwords;
 125 }
 126
 127 /* Fetch and adjust GPU GET pointer
 128  *
 129  * Returns:
 130  *  value >= 0, the adjusted GET pointer
 131  *  -EINVAL if GET pointer currently outside main push buffer
 132  *  -EBUSY if timeout exceeded
 133  */
 134 static inline int
 135 READ_GET(struct nouveau_channel *chan, uint32_t *prev_get, uint32_t *timeout)
 136 {
 137         uint32_t val;
 138
 139         val = nvchan_rd32(chan, chan->user_get);
 140
 141         /* reset counter as long as GET is still advancing, this is
 142          * to avoid misdetecting a GPU lockup if the GPU happens to
 143          * just be processing an operation that takes a long time
 144          */
 145         if (val != *prev_get) {
 146                 *prev_get = val;
 147                 *timeout = 0;
 148         }
 149
 150         if ((++*timeout & 0xff) == 0) {
 151                 DRM_UDELAY(1);
 152                 if (*timeout > 100000)
 153                         return -EBUSY;
 154         }
 155
 156         if (val < chan->pushbuf_base ||
 157             val > chan->pushbuf_base + (chan->dma.max << 2))
 158                 return -EINVAL;
 159
 160         return (val - chan->pushbuf_base) >> 2;
 161 }
 162
 163 void
 164 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
 165               int delta, int length)
 166 {
 167         struct nouveau_bo *pb = chan->pushbuf_bo;
 168         uint64_t offset = bo->bo.offset + delta;
 169         int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
 170
 171         BUG_ON(chan->dma.ib_free < 1);
 172         nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
 173         nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
 174
 175         chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
 176
 177         DRM_MEMORYBARRIER();
 178         /* Flush writes. */
 179         nouveau_bo_rd32(pb, 0);
 180
 181         nvchan_wr32(chan, 0x8c, chan->dma.ib_put);
 182         chan->dma.ib_free--;
 183 }
 184
 185 static int
 186 nv50_dma_push_wait(struct nouveau_channel *chan, int count)
 187 {
 188         uint32_t cnt = 0, prev_get = 0;
 189
 190         while (chan->dma.ib_free < count) {
 191                 uint32_t get = nvchan_rd32(chan, 0x88);
 192                 if (get != prev_get) {
 193                         prev_get = get;
 194                         cnt = 0;
 195                 }
 196
 197                 if ((++cnt & 0xff) == 0) {
 198                         DRM_UDELAY(1);
 199                         if (cnt > 100000)
 200                                 return -EBUSY;
 201                 }
 202
 203                 chan->dma.ib_free = get - chan->dma.ib_put;
 204                 if (chan->dma.ib_free <= 0)
 205                         chan->dma.ib_free += chan->dma.ib_max;
 206         }
 207
 208         return 0;
 209 }
 210
 211 static int
 212 nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
 213 {
 214         uint32_t cnt = 0, prev_get = 0;
 215         int ret;
 216
 217         ret = nv50_dma_push_wait(chan, slots + 1);
 218         if (unlikely(ret))
 219                 return ret;
 220
 221         while (chan->dma.free < count) {
 222                 int get = READ_GET(chan, &prev_get, &cnt);
 223                 if (unlikely(get < 0)) {
 224                         if (get == -EINVAL)
 225                                 continue;
 226
 227                         return get;
 228                 }
 229
 230                 if (get <= chan->dma.cur) {
 231                         chan->dma.free = chan->dma.max - chan->dma.cur;
 232                         if (chan->dma.free >= count)
 233                                 break;
 234
 235                         FIRE_RING(chan);
 236                         do {
 237                                 get = READ_GET(chan, &prev_get, &cnt);
 238                                 if (unlikely(get < 0)) {
 239                                         if (get == -EINVAL)
 240                                                 continue;
 241                                         return get;
 242                                 }
 243                         } while (get == 0);
 244                         chan->dma.cur = 0;
 245                         chan->dma.put = 0;
 246                 }
 247
 248                 chan->dma.free = get - chan->dma.cur - 1;
 249         }
 250
 251         return 0;
 252 }
 253
 254 int
 255 nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
 256 {
 257         uint32_t prev_get = 0, cnt = 0;
 258         int get;
 259
 260         if (chan->dma.ib_max)
 261                 return nv50_dma_wait(chan, slots, size);
 262
 263         while (chan->dma.free < size) {
 264                 get = READ_GET(chan, &prev_get, &cnt);
 265                 if (unlikely(get == -EBUSY))
 266                         return -EBUSY;
 267
 268                 /* loop until we have a usable GET pointer.  the value
 269                  * we read from the GPU may be outside the main ring if
 270                  * PFIFO is processing a buffer called from the main ring,
 271                  * discard these values until something sensible is seen.
 272                  *
 273                  * the other case we discard GET is while the GPU is fetching
 274                  * from the SKIPS area, so the code below doesn't have to deal
 275                  * with some fun corner cases.
 276                  */
 277                 if (unlikely(get == -EINVAL) || get < NOUVEAU_DMA_SKIPS)
 278                         continue;
 279
 280                 if (get <= chan->dma.cur) {
 281                         /* engine is fetching behind us, or is completely
 282                          * idle (GET == PUT) so we have free space up until
 283                          * the end of the push buffer
 284                          *
 285                          * we can only hit that path once per call due to
 286                          * looping back to the beginning of the push buffer,
 287                          * we'll hit the fetching-ahead-of-us path from that
 288                          * point on.
 289                          *
 290                          * the *one* exception to that rule is if we read
 291                          * GET==PUT, in which case the below conditional will
 292                          * always succeed and break us out of the wait loop.
 293                          */
 294                         chan->dma.free = chan->dma.max - chan->dma.cur;
 295                         if (chan->dma.free >= size)
 296                                 break;
 297
 298                         /* not enough space left at the end of the push buffer,
 299                          * instruct the GPU to jump back to the start right
 300                          * after processing the currently pending commands.
 301                          */
 302                         OUT_RING(chan, chan->pushbuf_base | 0x20000000);
 303
 304                         /* wait for GET to depart from the skips area.
 305                          * prevents writing GET==PUT and causing a race
 306                          * condition that causes us to think the GPU is
 307                          * idle when it's not.
 308                          */
 309                         do {
 310                                 get = READ_GET(chan, &prev_get, &cnt);
 311                                 if (unlikely(get == -EBUSY))
 312                                         return -EBUSY;
 313                                 if (unlikely(get == -EINVAL))
 314                                         continue;
 315                         } while (get <= NOUVEAU_DMA_SKIPS);
 316                         WRITE_PUT(NOUVEAU_DMA_SKIPS);
 317
 318                         /* we're now submitting commands at the start of
 319                          * the push buffer.
 320                          */
 321                         chan->dma.cur  =
 322                         chan->dma.put  = NOUVEAU_DMA_SKIPS;
 323                 }
 324
 325                 /* engine fetching ahead of us, we have space up until the
 326                  * current GET pointer.  the "- 1" is to ensure there's
 327                  * space left to emit a jump back to the beginning of the
 328                  * push buffer if we require it.  we can never get GET == PUT
 329                  * here, so this is safe.
 330                  */
 331                 chan->dma.free = get - chan->dma.cur - 1;
 332         }
 333
 334         return 0;
 335 }
 336