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, &chan->m2mf_ntfy);
  87         if (ret)
  88                 return ret;
  89
  90         /* Insert NOPS for NOUVEAU_DMA_SKIPS */
  91         ret = RING_SPACE(chan, NOUVEAU_DMA_SKIPS);
  92         if (ret)
  93                 return ret;
  94
  95         for (i = 0; i < NOUVEAU_DMA_SKIPS; i++)
  96                 OUT_RING(chan, 0);
  97
  98         /* Initialise NV_MEMORY_TO_MEMORY_FORMAT */
  99         ret = RING_SPACE(chan, 4);
 100         if (ret)
 101                 return ret;
 102         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_NAME, 1);
 103         OUT_RING(chan, NvM2MF);
 104         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_DMA_NOTIFY, 1);
 105         OUT_RING(chan, NvNotify0);
 106
 107         /* Sit back and pray the channel works.. */
 108         FIRE_RING(chan);
 109
 110         return 0;
 111 }
 112
 113 void
 114 OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
 115 {
 116         bool is_iomem;
 117         u32 *mem = ttm_kmap_obj_virtual(&chan->pushbuf_bo->kmap, &is_iomem);
 118         mem = &mem[chan->dma.cur];
 119         if (is_iomem)
 120                 memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
 121         else
 122                 memcpy(mem, data, nr_dwords * 4);
 123         chan->dma.cur += nr_dwords;
 124 }
 125
 126 /* Fetch and adjust GPU GET pointer
 127  *
 128  * Returns:
 129  *  value >= 0, the adjusted GET pointer
 130  *  -EINVAL if GET pointer currently outside main push buffer
 131  *  -EBUSY if timeout exceeded
 132  */
 133 static inline int
 134 READ_GET(struct nouveau_channel *chan, uint32_t *prev_get, uint32_t *timeout)
 135 {
 136         uint32_t val;
 137
 138         val = nvchan_rd32(chan, chan->user_get);
 139
 140         /* reset counter as long as GET is still advancing, this is
 141          * to avoid misdetecting a GPU lockup if the GPU happens to
 142          * just be processing an operation that takes a long time
 143          */
 144         if (val != *prev_get) {
 145                 *prev_get = val;
 146                 *timeout = 0;
 147         }
 148
 149         if ((++*timeout & 0xff) == 0) {
 150                 DRM_UDELAY(1);
 151                 if (*timeout > 100000)
 152                         return -EBUSY;
 153         }
 154
 155         if (val < chan->pushbuf_base ||
 156             val > chan->pushbuf_base + (chan->dma.max << 2))
 157                 return -EINVAL;
 158
 159         return (val - chan->pushbuf_base) >> 2;
 160 }
 161
 162 void
 163 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
 164               int delta, int length)
 165 {
 166         struct nouveau_bo *pb = chan->pushbuf_bo;
 167         uint64_t offset = bo->bo.offset + delta;
 168         int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
 169
 170         BUG_ON(chan->dma.ib_free < 1);
 171         nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
 172         nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
 173
 174         chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
 175
 176         DRM_MEMORYBARRIER();
 177         /* Flush writes. */
 178         nouveau_bo_rd32(pb, 0);
 179
 180         nvchan_wr32(chan, 0x8c, chan->dma.ib_put);
 181         chan->dma.ib_free--;
 182 }
 183
 184 static int
 185 nv50_dma_push_wait(struct nouveau_channel *chan, int count)
 186 {
 187         uint32_t cnt = 0, prev_get = 0;
 188
 189         while (chan->dma.ib_free < count) {
 190                 uint32_t get = nvchan_rd32(chan, 0x88);
 191                 if (get != prev_get) {
 192                         prev_get = get;
 193                         cnt = 0;
 194                 }
 195
 196                 if ((++cnt & 0xff) == 0) {
 197                         DRM_UDELAY(1);
 198                         if (cnt > 100000)
 199                                 return -EBUSY;
 200                 }
 201
 202                 chan->dma.ib_free = get - chan->dma.ib_put;
 203                 if (chan->dma.ib_free <= 0)
 204                         chan->dma.ib_free += chan->dma.ib_max;
 205         }
 206
 207         return 0;
 208 }
 209
 210 static int
 211 nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
 212 {
 213         uint32_t cnt = 0, prev_get = 0;
 214         int ret;
 215
 216         ret = nv50_dma_push_wait(chan, slots + 1);
 217         if (unlikely(ret))
 218                 return ret;
 219
 220         while (chan->dma.free < count) {
 221                 int get = READ_GET(chan, &prev_get, &cnt);
 222                 if (unlikely(get < 0)) {
 223                         if (get == -EINVAL)
 224                                 continue;
 225
 226                         return get;
 227                 }
 228
 229                 if (get <= chan->dma.cur) {
 230                         chan->dma.free = chan->dma.max - chan->dma.cur;
 231                         if (chan->dma.free >= count)
 232                                 break;
 233
 234                         FIRE_RING(chan);
 235                         do {
 236                                 get = READ_GET(chan, &prev_get, &cnt);
 237                                 if (unlikely(get < 0)) {
 238                                         if (get == -EINVAL)
 239                                                 continue;
 240                                         return get;
 241                                 }
 242                         } while (get == 0);
 243                         chan->dma.cur = 0;
 244                         chan->dma.put = 0;
 245                 }
 246
 247                 chan->dma.free = get - chan->dma.cur - 1;
 248         }
 249
 250         return 0;
 251 }
 252
 253 int
 254 nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
 255 {
 256         uint32_t prev_get = 0, cnt = 0;
 257         int get;
 258
 259         if (chan->dma.ib_max)
 260                 return nv50_dma_wait(chan, slots, size);
 261
 262         while (chan->dma.free < size) {
 263                 get = READ_GET(chan, &prev_get, &cnt);
 264                 if (unlikely(get == -EBUSY))
 265                         return -EBUSY;
 266
 267                 /* loop until we have a usable GET pointer.  the value
 268                  * we read from the GPU may be outside the main ring if
 269                  * PFIFO is processing a buffer called from the main ring,
 270                  * discard these values until something sensible is seen.
 271                  *
 272                  * the other case we discard GET is while the GPU is fetching
 273                  * from the SKIPS area, so the code below doesn't have to deal
 274                  * with some fun corner cases.
 275                  */
 276                 if (unlikely(get == -EINVAL) || get < NOUVEAU_DMA_SKIPS)
 277                         continue;
 278
 279                 if (get <= chan->dma.cur) {
 280                         /* engine is fetching behind us, or is completely
 281                          * idle (GET == PUT) so we have free space up until
 282                          * the end of the push buffer
 283                          *
 284                          * we can only hit that path once per call due to
 285                          * looping back to the beginning of the push buffer,
 286                          * we'll hit the fetching-ahead-of-us path from that
 287                          * point on.
 288                          *
 289                          * the *one* exception to that rule is if we read
 290                          * GET==PUT, in which case the below conditional will
 291                          * always succeed and break us out of the wait loop.
 292                          */
 293                         chan->dma.free = chan->dma.max - chan->dma.cur;
 294                         if (chan->dma.free >= size)
 295                                 break;
 296
 297                         /* not enough space left at the end of the push buffer,
 298                          * instruct the GPU to jump back to the start right
 299                          * after processing the currently pending commands.
 300                          */
 301                         OUT_RING(chan, chan->pushbuf_base | 0x20000000);
 302
 303                         /* wait for GET to depart from the skips area.
 304                          * prevents writing GET==PUT and causing a race
 305                          * condition that causes us to think the GPU is
 306                          * idle when it's not.
 307                          */
 308                         do {
 309                                 get = READ_GET(chan, &prev_get, &cnt);
 310                                 if (unlikely(get == -EBUSY))
 311                                         return -EBUSY;
 312                                 if (unlikely(get == -EINVAL))
 313                                         continue;
 314                         } while (get <= NOUVEAU_DMA_SKIPS);
 315                         WRITE_PUT(NOUVEAU_DMA_SKIPS);
 316
 317                         /* we're now submitting commands at the start of
 318                          * the push buffer.
 319                          */
 320                         chan->dma.cur  =
 321                         chan->dma.put  = NOUVEAU_DMA_SKIPS;
 322                 }
 323
 324                 /* engine fetching ahead of us, we have space up until the
 325                  * current GET pointer.  the "- 1" is to ensure there's
 326                  * space left to emit a jump back to the beginning of the
 327                  * push buffer if we require it.  we can never get GET == PUT
 328                  * here, so this is safe.
 329                  */
 330                 chan->dma.free = get - chan->dma.cur - 1;
 331         }
 332
 333         return 0;
 334 }
 335