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
  32 void
  33 nouveau_dma_pre_init(struct nouveau_channel *chan)
  34 {
  35         struct drm_nouveau_private *dev_priv = chan->dev->dev_private;
  36         struct nouveau_bo *pushbuf = chan->pushbuf_bo;
  37
  38         if (dev_priv->card_type == NV_50) {
  39                 const int ib_size = pushbuf->bo.mem.size / 2;
  40
  41                 chan->dma.ib_base = (pushbuf->bo.mem.size - ib_size) >> 2;
  42                 chan->dma.ib_max = (ib_size / 8) - 1;
  43                 chan->dma.ib_put = 0;
  44                 chan->dma.ib_free = chan->dma.ib_max - chan->dma.ib_put;
  45
  46                 chan->dma.max = (pushbuf->bo.mem.size - ib_size) >> 2;
  47         } else {
  48                 chan->dma.max  = (pushbuf->bo.mem.size >> 2) - 2;
  49         }
  50
  51         chan->dma.put  = 0;
  52         chan->dma.cur  = chan->dma.put;
  53         chan->dma.free = chan->dma.max - chan->dma.cur;
  54 }
  55
  56 int
  57 nouveau_dma_init(struct nouveau_channel *chan)
  58 {
  59         struct drm_device *dev = chan->dev;
  60         struct drm_nouveau_private *dev_priv = dev->dev_private;
  61         struct nouveau_gpuobj *m2mf = NULL;
  62         struct nouveau_gpuobj *nvsw = NULL;
  63         int ret, i;
  64
  65         /* Create NV_MEMORY_TO_MEMORY_FORMAT for buffer moves */
  66         ret = nouveau_gpuobj_gr_new(chan, dev_priv->card_type < NV_50 ?
  67                                     0x0039 : 0x5039, &m2mf);
  68         if (ret)
  69                 return ret;
  70
  71         ret = nouveau_gpuobj_ref_add(dev, chan, NvM2MF, m2mf, NULL);
  72         if (ret)
  73                 return ret;
  74
  75         /* Create an NV_SW object for various sync purposes */
  76         ret = nouveau_gpuobj_sw_new(chan, NV_SW, &nvsw);
  77         if (ret)
  78                 return ret;
  79
  80         ret = nouveau_gpuobj_ref_add(dev, chan, NvSw, nvsw, NULL);
  81         if (ret)
  82                 return ret;
  83
  84         /* NV_MEMORY_TO_MEMORY_FORMAT requires a notifier object */
  85         ret = nouveau_notifier_alloc(chan, NvNotify0, 32, &chan->m2mf_ntfy);
  86         if (ret)
  87                 return ret;
  88
  89         /* Map push buffer */
  90         ret = nouveau_bo_map(chan->pushbuf_bo);
  91         if (ret)
  92                 return ret;
  93
  94         /* Map M2MF notifier object - fbcon. */
  95         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
  96                 ret = nouveau_bo_map(chan->notifier_bo);
  97                 if (ret)
  98                         return ret;
  99         }
 100
 101         /* Insert NOPS for NOUVEAU_DMA_SKIPS */
 102         ret = RING_SPACE(chan, NOUVEAU_DMA_SKIPS);
 103         if (ret)
 104                 return ret;
 105
 106         for (i = 0; i < NOUVEAU_DMA_SKIPS; i++)
 107                 OUT_RING(chan, 0);
 108
 109         /* Initialise NV_MEMORY_TO_MEMORY_FORMAT */
 110         ret = RING_SPACE(chan, 4);
 111         if (ret)
 112                 return ret;
 113         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_NAME, 1);
 114         OUT_RING(chan, NvM2MF);
 115         BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_DMA_NOTIFY, 1);
 116         OUT_RING(chan, NvNotify0);
 117
 118         /* Initialise NV_SW */
 119         ret = RING_SPACE(chan, 2);
 120         if (ret)
 121                 return ret;
 122         BEGIN_RING(chan, NvSubSw, 0, 1);
 123         OUT_RING(chan, NvSw);
 124
 125         /* Sit back and pray the channel works.. */
 126         FIRE_RING(chan);
 127
 128         return 0;
 129 }
 130
 131 void
 132 OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
 133 {
 134         bool is_iomem;
 135         u32 *mem = ttm_kmap_obj_virtual(&chan->pushbuf_bo->kmap, &is_iomem);
 136         mem = &mem[chan->dma.cur];
 137         if (is_iomem)
 138                 memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
 139         else
 140                 memcpy(mem, data, nr_dwords * 4);
 141         chan->dma.cur += nr_dwords;
 142 }
 143
 144 /* Fetch and adjust GPU GET pointer
 145  *
 146  * Returns:
 147  *  value >= 0, the adjusted GET pointer
 148  *  -EINVAL if GET pointer currently outside main push buffer
 149  *  -EBUSY if timeout exceeded
 150  */
 151 static inline int
 152 READ_GET(struct nouveau_channel *chan, uint32_t *prev_get, uint32_t *timeout)
 153 {
 154         uint32_t val;
 155
 156         val = nvchan_rd32(chan, chan->user_get);
 157
 158         /* reset counter as long as GET is still advancing, this is
 159          * to avoid misdetecting a GPU lockup if the GPU happens to
 160          * just be processing an operation that takes a long time
 161          */
 162         if (val != *prev_get) {
 163                 *prev_get = val;
 164                 *timeout = 0;
 165         }
 166
 167         if ((++*timeout & 0xff) == 0) {
 168                 DRM_UDELAY(1);
 169                 if (*timeout > 100000)
 170                         return -EBUSY;
 171         }
 172
 173         if (val < chan->pushbuf_base ||
 174             val > chan->pushbuf_base + (chan->dma.max << 2))
 175                 return -EINVAL;
 176
 177         return (val - chan->pushbuf_base) >> 2;
 178 }
 179
 180 void
 181 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
 182               int delta, int length)
 183 {
 184         struct nouveau_bo *pb = chan->pushbuf_bo;
 185         uint64_t offset = bo->bo.offset + delta;
 186         int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
 187
 188         BUG_ON(chan->dma.ib_free < 1);
 189         nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
 190         nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
 191
 192         chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
 193         nvchan_wr32(chan, 0x8c, chan->dma.ib_put);
 194         chan->dma.ib_free--;
 195 }
 196
 197 static int
 198 nv50_dma_push_wait(struct nouveau_channel *chan, int count)
 199 {
 200         uint32_t cnt = 0, prev_get = 0;
 201
 202         while (chan->dma.ib_free < count) {
 203                 uint32_t get = nvchan_rd32(chan, 0x88);
 204                 if (get != prev_get) {
 205                         prev_get = get;
 206                         cnt = 0;
 207                 }
 208
 209                 if ((++cnt & 0xff) == 0) {
 210                         DRM_UDELAY(1);
 211                         if (cnt > 100000)
 212                                 return -EBUSY;
 213                 }
 214
 215                 chan->dma.ib_free = get - chan->dma.ib_put;
 216                 if (chan->dma.ib_free <= 0)
 217                         chan->dma.ib_free += chan->dma.ib_max + 1;
 218         }
 219
 220         return 0;
 221 }
 222
 223 static int
 224 nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
 225 {
 226         uint32_t cnt = 0, prev_get = 0;
 227         int ret;
 228
 229         ret = nv50_dma_push_wait(chan, slots + 1);
 230         if (unlikely(ret))
 231                 return ret;
 232
 233         while (chan->dma.free < count) {
 234                 int get = READ_GET(chan, &prev_get, &cnt);
 235                 if (unlikely(get < 0)) {
 236                         if (get == -EINVAL)
 237                                 continue;
 238
 239                         return get;
 240                 }
 241
 242                 if (get <= chan->dma.cur) {
 243                         chan->dma.free = chan->dma.max - chan->dma.cur;
 244                         if (chan->dma.free >= count)
 245                                 break;
 246
 247                         FIRE_RING(chan);
 248                         do {
 249                                 get = READ_GET(chan, &prev_get, &cnt);
 250                                 if (unlikely(get < 0)) {
 251                                         if (get == -EINVAL)
 252                                                 continue;
 253                                         return get;
 254                                 }
 255                         } while (get == 0);
 256                         chan->dma.cur = 0;
 257                         chan->dma.put = 0;
 258                 }
 259
 260                 chan->dma.free = get - chan->dma.cur - 1;
 261         }
 262
 263         return 0;
 264 }
 265
 266 int
 267 nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
 268 {
 269         uint32_t prev_get = 0, cnt = 0;
 270         int get;
 271
 272         if (chan->dma.ib_max)
 273                 return nv50_dma_wait(chan, slots, size);
 274
 275         while (chan->dma.free < size) {
 276                 get = READ_GET(chan, &prev_get, &cnt);
 277                 if (unlikely(get == -EBUSY))
 278                         return -EBUSY;
 279
 280                 /* loop until we have a usable GET pointer.  the value
 281                  * we read from the GPU may be outside the main ring if
 282                  * PFIFO is processing a buffer called from the main ring,
 283                  * discard these values until something sensible is seen.
 284                  *
 285                  * the other case we discard GET is while the GPU is fetching
 286                  * from the SKIPS area, so the code below doesn't have to deal
 287                  * with some fun corner cases.
 288                  */
 289                 if (unlikely(get == -EINVAL) || get < NOUVEAU_DMA_SKIPS)
 290                         continue;
 291
 292                 if (get <= chan->dma.cur) {
 293                         /* engine is fetching behind us, or is completely
 294                          * idle (GET == PUT) so we have free space up until
 295                          * the end of the push buffer
 296                          *
 297                          * we can only hit that path once per call due to
 298                          * looping back to the beginning of the push buffer,
 299                          * we'll hit the fetching-ahead-of-us path from that
 300                          * point on.
 301                          *
 302                          * the *one* exception to that rule is if we read
 303                          * GET==PUT, in which case the below conditional will
 304                          * always succeed and break us out of the wait loop.
 305                          */
 306                         chan->dma.free = chan->dma.max - chan->dma.cur;
 307                         if (chan->dma.free >= size)
 308                                 break;
 309
 310                         /* not enough space left at the end of the push buffer,
 311                          * instruct the GPU to jump back to the start right
 312                          * after processing the currently pending commands.
 313                          */
 314                         OUT_RING(chan, chan->pushbuf_base | 0x20000000);
 315
 316                         /* wait for GET to depart from the skips area.
 317                          * prevents writing GET==PUT and causing a race
 318                          * condition that causes us to think the GPU is
 319                          * idle when it's not.
 320                          */
 321                         do {
 322                                 get = READ_GET(chan, &prev_get, &cnt);
 323                                 if (unlikely(get == -EBUSY))
 324                                         return -EBUSY;
 325                                 if (unlikely(get == -EINVAL))
 326                                         continue;
 327                         } while (get <= NOUVEAU_DMA_SKIPS);
 328                         WRITE_PUT(NOUVEAU_DMA_SKIPS);
 329
 330                         /* we're now submitting commands at the start of
 331                          * the push buffer.
 332                          */
 333                         chan->dma.cur  =
 334                         chan->dma.put  = NOUVEAU_DMA_SKIPS;
 335                 }
 336
 337                 /* engine fetching ahead of us, we have space up until the
 338                  * current GET pointer.  the "- 1" is to ensure there's
 339                  * space left to emit a jump back to the beginning of the
 340                  * push buffer if we require it.  we can never get GET == PUT
 341                  * here, so this is safe.
 342                  */
 343                 chan->dma.free = get - chan->dma.cur - 1;
 344         }
 345
 346         return 0;
 347 }
 348