Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 Red Hat Inc. |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 5 | * copy of this software and associated documentation files (the "Software"), |
| 6 | * to deal in the Software without restriction, including without limitation |
| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 8 | * and/or sell copies of the Software, and to permit persons to whom the |
| 9 | * Software is furnished to do so, subject to the following conditions: |
| 10 | * |
| 11 | * The above copyright notice and this permission notice shall be included in |
| 12 | * all copies or substantial portions of the Software. |
| 13 | * |
| 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| 18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 20 | * OTHER DEALINGS IN THE SOFTWARE. |
| 21 | * |
| 22 | * Authors: Ben Skeggs |
| 23 | */ |
| 24 | |
| 25 | #include "drmP.h" |
| 26 | #include "nouveau_drv.h" |
| 27 | #include "nouveau_mm.h" |
| 28 | #include "nouveau_vm.h" |
| 29 | |
| 30 | void |
| 31 | nouveau_vm_map_at(struct nouveau_vma *vma, u64 delta, struct nouveau_vram *vram) |
| 32 | { |
| 33 | struct nouveau_vm *vm = vma->vm; |
| 34 | struct nouveau_mm_node *r; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 35 | int big = vma->node->type != vm->spg_shift; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 36 | u32 offset = vma->node->offset + (delta >> 12); |
| 37 | u32 bits = vma->node->type - 12; |
| 38 | u32 pde = (offset >> vm->pgt_bits) - vm->fpde; |
| 39 | u32 pte = (offset & ((1 << vm->pgt_bits) - 1)) >> bits; |
| 40 | u32 max = 1 << (vm->pgt_bits - bits); |
| 41 | u32 end, len; |
| 42 | |
| 43 | list_for_each_entry(r, &vram->regions, rl_entry) { |
| 44 | u64 phys = (u64)r->offset << 12; |
| 45 | u32 num = r->length >> bits; |
| 46 | |
| 47 | while (num) { |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 48 | struct nouveau_gpuobj *pgt = vm->pgt[pde].obj[big]; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 49 | |
| 50 | end = (pte + num); |
| 51 | if (unlikely(end >= max)) |
| 52 | end = max; |
| 53 | len = end - pte; |
| 54 | |
| 55 | vm->map(vma, pgt, vram, pte, len, phys); |
| 56 | |
| 57 | num -= len; |
| 58 | pte += len; |
| 59 | if (unlikely(end >= max)) { |
| 60 | pde++; |
| 61 | pte = 0; |
| 62 | } |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | vm->flush(vm); |
| 67 | } |
| 68 | |
| 69 | void |
| 70 | nouveau_vm_map(struct nouveau_vma *vma, struct nouveau_vram *vram) |
| 71 | { |
| 72 | nouveau_vm_map_at(vma, 0, vram); |
| 73 | } |
| 74 | |
| 75 | void |
| 76 | nouveau_vm_map_sg(struct nouveau_vma *vma, u64 delta, u64 length, |
| 77 | dma_addr_t *list) |
| 78 | { |
| 79 | struct nouveau_vm *vm = vma->vm; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 80 | int big = vma->node->type != vm->spg_shift; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 81 | u32 offset = vma->node->offset + (delta >> 12); |
| 82 | u32 bits = vma->node->type - 12; |
| 83 | u32 num = length >> vma->node->type; |
| 84 | u32 pde = (offset >> vm->pgt_bits) - vm->fpde; |
| 85 | u32 pte = (offset & ((1 << vm->pgt_bits) - 1)) >> bits; |
| 86 | u32 max = 1 << (vm->pgt_bits - bits); |
| 87 | u32 end, len; |
| 88 | |
| 89 | while (num) { |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 90 | struct nouveau_gpuobj *pgt = vm->pgt[pde].obj[big]; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 91 | |
| 92 | end = (pte + num); |
| 93 | if (unlikely(end >= max)) |
| 94 | end = max; |
| 95 | len = end - pte; |
| 96 | |
| 97 | vm->map_sg(vma, pgt, pte, list, len); |
| 98 | |
| 99 | num -= len; |
| 100 | pte += len; |
| 101 | list += len; |
| 102 | if (unlikely(end >= max)) { |
| 103 | pde++; |
| 104 | pte = 0; |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | vm->flush(vm); |
| 109 | } |
| 110 | |
| 111 | void |
| 112 | nouveau_vm_unmap_at(struct nouveau_vma *vma, u64 delta, u64 length) |
| 113 | { |
| 114 | struct nouveau_vm *vm = vma->vm; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 115 | int big = vma->node->type != vm->spg_shift; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 116 | u32 offset = vma->node->offset + (delta >> 12); |
| 117 | u32 bits = vma->node->type - 12; |
| 118 | u32 num = length >> vma->node->type; |
| 119 | u32 pde = (offset >> vm->pgt_bits) - vm->fpde; |
| 120 | u32 pte = (offset & ((1 << vm->pgt_bits) - 1)) >> bits; |
| 121 | u32 max = 1 << (vm->pgt_bits - bits); |
| 122 | u32 end, len; |
| 123 | |
| 124 | while (num) { |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 125 | struct nouveau_gpuobj *pgt = vm->pgt[pde].obj[big]; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 126 | |
| 127 | end = (pte + num); |
| 128 | if (unlikely(end >= max)) |
| 129 | end = max; |
| 130 | len = end - pte; |
| 131 | |
| 132 | vm->unmap(pgt, pte, len); |
| 133 | |
| 134 | num -= len; |
| 135 | pte += len; |
| 136 | if (unlikely(end >= max)) { |
| 137 | pde++; |
| 138 | pte = 0; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | vm->flush(vm); |
| 143 | } |
| 144 | |
| 145 | void |
| 146 | nouveau_vm_unmap(struct nouveau_vma *vma) |
| 147 | { |
| 148 | nouveau_vm_unmap_at(vma, 0, (u64)vma->node->length << 12); |
| 149 | } |
| 150 | |
| 151 | static void |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 152 | nouveau_vm_unmap_pgt(struct nouveau_vm *vm, int big, u32 fpde, u32 lpde) |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 153 | { |
| 154 | struct nouveau_vm_pgd *vpgd; |
| 155 | struct nouveau_vm_pgt *vpgt; |
| 156 | struct nouveau_gpuobj *pgt; |
| 157 | u32 pde; |
| 158 | |
| 159 | for (pde = fpde; pde <= lpde; pde++) { |
| 160 | vpgt = &vm->pgt[pde - vm->fpde]; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 161 | if (--vpgt->refcount[big]) |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 162 | continue; |
| 163 | |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 164 | pgt = vpgt->obj[big]; |
| 165 | vpgt->obj[big] = NULL; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 166 | |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 167 | list_for_each_entry(vpgd, &vm->pgd_list, head) { |
| 168 | vm->map_pgt(vpgd->obj, pde, vpgt->obj); |
| 169 | } |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 170 | |
| 171 | mutex_unlock(&vm->mm->mutex); |
| 172 | nouveau_gpuobj_ref(NULL, &pgt); |
| 173 | mutex_lock(&vm->mm->mutex); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | static int |
| 178 | nouveau_vm_map_pgt(struct nouveau_vm *vm, u32 pde, u32 type) |
| 179 | { |
| 180 | struct nouveau_vm_pgt *vpgt = &vm->pgt[pde - vm->fpde]; |
| 181 | struct nouveau_vm_pgd *vpgd; |
| 182 | struct nouveau_gpuobj *pgt; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 183 | int big = (type != vm->spg_shift); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 184 | u32 pgt_size; |
| 185 | int ret; |
| 186 | |
| 187 | pgt_size = (1 << (vm->pgt_bits + 12)) >> type; |
| 188 | pgt_size *= 8; |
| 189 | |
| 190 | mutex_unlock(&vm->mm->mutex); |
| 191 | ret = nouveau_gpuobj_new(vm->dev, NULL, pgt_size, 0x1000, |
| 192 | NVOBJ_FLAG_ZERO_ALLOC, &pgt); |
| 193 | mutex_lock(&vm->mm->mutex); |
| 194 | if (unlikely(ret)) |
| 195 | return ret; |
| 196 | |
| 197 | /* someone beat us to filling the PDE while we didn't have the lock */ |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 198 | if (unlikely(vpgt->refcount[big]++)) { |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 199 | mutex_unlock(&vm->mm->mutex); |
| 200 | nouveau_gpuobj_ref(NULL, &pgt); |
| 201 | mutex_lock(&vm->mm->mutex); |
| 202 | return 0; |
| 203 | } |
| 204 | |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 205 | vpgt->obj[big] = pgt; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 206 | list_for_each_entry(vpgd, &vm->pgd_list, head) { |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 207 | vm->map_pgt(vpgd->obj, pde, vpgt->obj); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 208 | } |
| 209 | |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | int |
| 214 | nouveau_vm_get(struct nouveau_vm *vm, u64 size, u32 page_shift, |
| 215 | u32 access, struct nouveau_vma *vma) |
| 216 | { |
| 217 | u32 align = (1 << page_shift) >> 12; |
| 218 | u32 msize = size >> 12; |
| 219 | u32 fpde, lpde, pde; |
| 220 | int ret; |
| 221 | |
| 222 | mutex_lock(&vm->mm->mutex); |
| 223 | ret = nouveau_mm_get(vm->mm, page_shift, msize, 0, align, &vma->node); |
| 224 | if (unlikely(ret != 0)) { |
| 225 | mutex_unlock(&vm->mm->mutex); |
| 226 | return ret; |
| 227 | } |
| 228 | |
| 229 | fpde = (vma->node->offset >> vm->pgt_bits); |
| 230 | lpde = (vma->node->offset + vma->node->length - 1) >> vm->pgt_bits; |
| 231 | for (pde = fpde; pde <= lpde; pde++) { |
| 232 | struct nouveau_vm_pgt *vpgt = &vm->pgt[pde - vm->fpde]; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 233 | int big = (vma->node->type != vm->spg_shift); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 234 | |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 235 | if (likely(vpgt->refcount[big])) { |
| 236 | vpgt->refcount[big]++; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 237 | continue; |
| 238 | } |
| 239 | |
| 240 | ret = nouveau_vm_map_pgt(vm, pde, vma->node->type); |
| 241 | if (ret) { |
| 242 | if (pde != fpde) |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 243 | nouveau_vm_unmap_pgt(vm, big, fpde, pde - 1); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 244 | nouveau_mm_put(vm->mm, vma->node); |
| 245 | mutex_unlock(&vm->mm->mutex); |
| 246 | vma->node = NULL; |
| 247 | return ret; |
| 248 | } |
| 249 | } |
| 250 | mutex_unlock(&vm->mm->mutex); |
| 251 | |
| 252 | vma->vm = vm; |
| 253 | vma->offset = (u64)vma->node->offset << 12; |
| 254 | vma->access = access; |
| 255 | return 0; |
| 256 | } |
| 257 | |
| 258 | void |
| 259 | nouveau_vm_put(struct nouveau_vma *vma) |
| 260 | { |
| 261 | struct nouveau_vm *vm = vma->vm; |
| 262 | u32 fpde, lpde; |
| 263 | |
| 264 | if (unlikely(vma->node == NULL)) |
| 265 | return; |
| 266 | fpde = (vma->node->offset >> vm->pgt_bits); |
| 267 | lpde = (vma->node->offset + vma->node->length - 1) >> vm->pgt_bits; |
| 268 | |
| 269 | mutex_lock(&vm->mm->mutex); |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 270 | nouveau_vm_unmap_pgt(vm, vma->node->type != vm->spg_shift, fpde, lpde); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 271 | nouveau_mm_put(vm->mm, vma->node); |
| 272 | vma->node = NULL; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 273 | mutex_unlock(&vm->mm->mutex); |
| 274 | } |
| 275 | |
| 276 | int |
| 277 | nouveau_vm_new(struct drm_device *dev, u64 offset, u64 length, u64 mm_offset, |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 278 | struct nouveau_vm **pvm) |
| 279 | { |
| 280 | struct drm_nouveau_private *dev_priv = dev->dev_private; |
| 281 | struct nouveau_vm *vm; |
| 282 | u64 mm_length = (offset + length) - mm_offset; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 283 | u32 block, pgt_bits; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 284 | int ret; |
| 285 | |
| 286 | vm = kzalloc(sizeof(*vm), GFP_KERNEL); |
| 287 | if (!vm) |
| 288 | return -ENOMEM; |
| 289 | |
| 290 | if (dev_priv->card_type == NV_50) { |
| 291 | vm->map_pgt = nv50_vm_map_pgt; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 292 | vm->map = nv50_vm_map; |
| 293 | vm->map_sg = nv50_vm_map_sg; |
| 294 | vm->unmap = nv50_vm_unmap; |
| 295 | vm->flush = nv50_vm_flush; |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 296 | vm->spg_shift = 12; |
| 297 | vm->lpg_shift = 16; |
Ben Skeggs | 4c74eb7 | 2010-11-10 14:10:04 +1000 | [diff] [blame] | 298 | |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 299 | pgt_bits = 29; |
Ben Skeggs | 4c74eb7 | 2010-11-10 14:10:04 +1000 | [diff] [blame] | 300 | block = (1 << pgt_bits); |
| 301 | if (length < block) |
| 302 | block = length; |
| 303 | |
| 304 | } else |
| 305 | if (dev_priv->card_type == NV_C0) { |
| 306 | vm->map_pgt = nvc0_vm_map_pgt; |
| 307 | vm->map = nvc0_vm_map; |
| 308 | vm->map_sg = nvc0_vm_map_sg; |
| 309 | vm->unmap = nvc0_vm_unmap; |
| 310 | vm->flush = nvc0_vm_flush; |
| 311 | vm->spg_shift = 12; |
| 312 | vm->lpg_shift = 17; |
| 313 | pgt_bits = 27; |
| 314 | |
| 315 | /* Should be 4096 everywhere, this is a hack that's |
| 316 | * currently necessary to avoid an elusive bug that |
| 317 | * causes corruption when mixing small/large pages |
| 318 | */ |
| 319 | if (length < (1ULL << 40)) |
| 320 | block = 4096; |
| 321 | else { |
| 322 | block = (1 << pgt_bits); |
| 323 | if (length < block) |
| 324 | block = length; |
| 325 | } |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 326 | } else { |
| 327 | kfree(vm); |
| 328 | return -ENOSYS; |
| 329 | } |
| 330 | |
| 331 | vm->fpde = offset >> pgt_bits; |
| 332 | vm->lpde = (offset + length - 1) >> pgt_bits; |
| 333 | vm->pgt = kcalloc(vm->lpde - vm->fpde + 1, sizeof(*vm->pgt), GFP_KERNEL); |
| 334 | if (!vm->pgt) { |
| 335 | kfree(vm); |
| 336 | return -ENOMEM; |
| 337 | } |
| 338 | |
| 339 | INIT_LIST_HEAD(&vm->pgd_list); |
| 340 | vm->dev = dev; |
| 341 | vm->refcount = 1; |
| 342 | vm->pgt_bits = pgt_bits - 12; |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 343 | |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 344 | ret = nouveau_mm_init(&vm->mm, mm_offset >> 12, mm_length >> 12, |
| 345 | block >> 12); |
| 346 | if (ret) { |
| 347 | kfree(vm); |
| 348 | return ret; |
| 349 | } |
| 350 | |
| 351 | *pvm = vm; |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | static int |
| 356 | nouveau_vm_link(struct nouveau_vm *vm, struct nouveau_gpuobj *pgd) |
| 357 | { |
| 358 | struct nouveau_vm_pgd *vpgd; |
| 359 | int i; |
| 360 | |
| 361 | if (!pgd) |
| 362 | return 0; |
| 363 | |
| 364 | vpgd = kzalloc(sizeof(*vpgd), GFP_KERNEL); |
| 365 | if (!vpgd) |
| 366 | return -ENOMEM; |
| 367 | |
| 368 | nouveau_gpuobj_ref(pgd, &vpgd->obj); |
| 369 | |
| 370 | mutex_lock(&vm->mm->mutex); |
Ben Skeggs | 3ee0128 | 2010-12-15 11:04:39 +1000 | [diff] [blame] | 371 | for (i = vm->fpde; i <= vm->lpde; i++) |
| 372 | vm->map_pgt(pgd, i, vm->pgt[i - vm->fpde].obj); |
Ben Skeggs | a11c319 | 2010-08-27 10:00:25 +1000 | [diff] [blame] | 373 | list_add(&vpgd->head, &vm->pgd_list); |
| 374 | mutex_unlock(&vm->mm->mutex); |
| 375 | return 0; |
| 376 | } |
| 377 | |
| 378 | static void |
| 379 | nouveau_vm_unlink(struct nouveau_vm *vm, struct nouveau_gpuobj *pgd) |
| 380 | { |
| 381 | struct nouveau_vm_pgd *vpgd, *tmp; |
| 382 | |
| 383 | if (!pgd) |
| 384 | return; |
| 385 | |
| 386 | mutex_lock(&vm->mm->mutex); |
| 387 | list_for_each_entry_safe(vpgd, tmp, &vm->pgd_list, head) { |
| 388 | if (vpgd->obj != pgd) |
| 389 | continue; |
| 390 | |
| 391 | list_del(&vpgd->head); |
| 392 | nouveau_gpuobj_ref(NULL, &vpgd->obj); |
| 393 | kfree(vpgd); |
| 394 | } |
| 395 | mutex_unlock(&vm->mm->mutex); |
| 396 | } |
| 397 | |
| 398 | static void |
| 399 | nouveau_vm_del(struct nouveau_vm *vm) |
| 400 | { |
| 401 | struct nouveau_vm_pgd *vpgd, *tmp; |
| 402 | |
| 403 | list_for_each_entry_safe(vpgd, tmp, &vm->pgd_list, head) { |
| 404 | nouveau_vm_unlink(vm, vpgd->obj); |
| 405 | } |
| 406 | WARN_ON(nouveau_mm_fini(&vm->mm) != 0); |
| 407 | |
| 408 | kfree(vm->pgt); |
| 409 | kfree(vm); |
| 410 | } |
| 411 | |
| 412 | int |
| 413 | nouveau_vm_ref(struct nouveau_vm *ref, struct nouveau_vm **ptr, |
| 414 | struct nouveau_gpuobj *pgd) |
| 415 | { |
| 416 | struct nouveau_vm *vm; |
| 417 | int ret; |
| 418 | |
| 419 | vm = ref; |
| 420 | if (vm) { |
| 421 | ret = nouveau_vm_link(vm, pgd); |
| 422 | if (ret) |
| 423 | return ret; |
| 424 | |
| 425 | vm->refcount++; |
| 426 | } |
| 427 | |
| 428 | vm = *ptr; |
| 429 | *ptr = ref; |
| 430 | |
| 431 | if (vm) { |
| 432 | nouveau_vm_unlink(vm, pgd); |
| 433 | |
| 434 | if (--vm->refcount == 0) |
| 435 | nouveau_vm_del(vm); |
| 436 | } |
| 437 | |
| 438 | return 0; |
| 439 | } |