aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-03-25 13:47:29 -0400
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-03-27 07:19:11 -0400
commitdbf7bff074d5fdc87c61b1b41d8e809109cf0bf8 (patch)
treea0adbbbc73b75dd97b8b134d1c4b289c20f2fa56
parente244a443bf72bccb44c75cadf04720101d1f313a (diff)
drm/i915: merge shmem_pread slow&fast-path
With the previous rewrite, they've become essential identical. v2: Simplify the page_do_bit17_swizzling logic as suggested by Chris Wilson. Tested-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
-rw-r--r--drivers/gpu/drm/i915/i915_gem.c108
1 files changed, 27 insertions, 81 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a2547528a9d4..1855e72859a8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -239,66 +239,6 @@ static int i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj)
239 obj->tiling_mode != I915_TILING_NONE; 239 obj->tiling_mode != I915_TILING_NONE;
240} 240}
241 241
242/**
243 * This is the fast shmem pread path, which attempts to copy_from_user directly
244 * from the backing pages of the object to the user's address space. On a
245 * fault, it fails so we can fall back to i915_gem_shmem_pwrite_slow().
246 */
247static int
248i915_gem_shmem_pread_fast(struct drm_device *dev,
249 struct drm_i915_gem_object *obj,
250 struct drm_i915_gem_pread *args,
251 struct drm_file *file)
252{
253 struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
254 ssize_t remain;
255 loff_t offset;
256 char __user *user_data;
257 int page_offset, page_length;
258
259 user_data = (char __user *) (uintptr_t) args->data_ptr;
260 remain = args->size;
261
262 offset = args->offset;
263
264 while (remain > 0) {
265 struct page *page;
266 char *vaddr;
267 int ret;
268
269 /* Operation in this page
270 *
271 * page_offset = offset within page
272 * page_length = bytes to copy for this page
273 */
274 page_offset = offset_in_page(offset);
275 page_length = remain;
276 if ((page_offset + remain) > PAGE_SIZE)
277 page_length = PAGE_SIZE - page_offset;
278
279 page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
280 if (IS_ERR(page))
281 return PTR_ERR(page);
282
283 vaddr = kmap_atomic(page);
284 ret = __copy_to_user_inatomic(user_data,
285 vaddr + page_offset,
286 page_length);
287 kunmap_atomic(vaddr);
288
289 mark_page_accessed(page);
290 page_cache_release(page);
291 if (ret)
292 return -EFAULT;
293
294 remain -= page_length;
295 user_data += page_length;
296 offset += page_length;
297 }
298
299 return 0;
300}
301
302static inline int 242static inline int
303__copy_to_user_swizzled(char __user *cpu_vaddr, 243__copy_to_user_swizzled(char __user *cpu_vaddr,
304 const char *gpu_vaddr, int gpu_offset, 244 const char *gpu_vaddr, int gpu_offset,
@@ -351,17 +291,11 @@ __copy_from_user_swizzled(char __user *gpu_vaddr, int gpu_offset,
351 return 0; 291 return 0;
352} 292}
353 293
354/**
355 * This is the fallback shmem pread path, which allocates temporary storage
356 * in kernel space to copy_to_user into outside of the struct_mutex, so we
357 * can copy out of the object's backing pages while holding the struct mutex
358 * and not take page faults.
359 */
360static int 294static int
361i915_gem_shmem_pread_slow(struct drm_device *dev, 295i915_gem_shmem_pread(struct drm_device *dev,
362 struct drm_i915_gem_object *obj, 296 struct drm_i915_gem_object *obj,
363 struct drm_i915_gem_pread *args, 297 struct drm_i915_gem_pread *args,
364 struct drm_file *file) 298 struct drm_file *file)
365{ 299{
366 struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping; 300 struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
367 char __user *user_data; 301 char __user *user_data;
@@ -369,6 +303,7 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
369 loff_t offset; 303 loff_t offset;
370 int shmem_page_offset, page_length, ret = 0; 304 int shmem_page_offset, page_length, ret = 0;
371 int obj_do_bit17_swizzling, page_do_bit17_swizzling; 305 int obj_do_bit17_swizzling, page_do_bit17_swizzling;
306 int hit_slowpath = 0;
372 307
373 user_data = (char __user *) (uintptr_t) args->data_ptr; 308 user_data = (char __user *) (uintptr_t) args->data_ptr;
374 remain = args->size; 309 remain = args->size;
@@ -377,8 +312,6 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
377 312
378 offset = args->offset; 313 offset = args->offset;
379 314
380 mutex_unlock(&dev->struct_mutex);
381
382 while (remain > 0) { 315 while (remain > 0) {
383 struct page *page; 316 struct page *page;
384 char *vaddr; 317 char *vaddr;
@@ -402,6 +335,20 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
402 page_do_bit17_swizzling = obj_do_bit17_swizzling && 335 page_do_bit17_swizzling = obj_do_bit17_swizzling &&
403 (page_to_phys(page) & (1 << 17)) != 0; 336 (page_to_phys(page) & (1 << 17)) != 0;
404 337
338 if (!page_do_bit17_swizzling) {
339 vaddr = kmap_atomic(page);
340 ret = __copy_to_user_inatomic(user_data,
341 vaddr + shmem_page_offset,
342 page_length);
343 kunmap_atomic(vaddr);
344 if (ret == 0)
345 goto next_page;
346 }
347
348 hit_slowpath = 1;
349
350 mutex_unlock(&dev->struct_mutex);
351
405 vaddr = kmap(page); 352 vaddr = kmap(page);
406 if (page_do_bit17_swizzling) 353 if (page_do_bit17_swizzling)
407 ret = __copy_to_user_swizzled(user_data, 354 ret = __copy_to_user_swizzled(user_data,
@@ -413,6 +360,8 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
413 page_length); 360 page_length);
414 kunmap(page); 361 kunmap(page);
415 362
363 mutex_lock(&dev->struct_mutex);
364next_page:
416 mark_page_accessed(page); 365 mark_page_accessed(page);
417 page_cache_release(page); 366 page_cache_release(page);
418 367
@@ -427,10 +376,11 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
427 } 376 }
428 377
429out: 378out:
430 mutex_lock(&dev->struct_mutex); 379 if (hit_slowpath) {
431 /* Fixup: Kill any reinstated backing storage pages */ 380 /* Fixup: Kill any reinstated backing storage pages */
432 if (obj->madv == __I915_MADV_PURGED) 381 if (obj->madv == __I915_MADV_PURGED)
433 i915_gem_object_truncate(obj); 382 i915_gem_object_truncate(obj);
383 }
434 384
435 return ret; 385 return ret;
436} 386}
@@ -486,11 +436,7 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
486 if (ret) 436 if (ret)
487 goto out; 437 goto out;
488 438
489 ret = -EFAULT; 439 ret = i915_gem_shmem_pread(dev, obj, args, file);
490 if (!i915_gem_object_needs_bit17_swizzle(obj))
491 ret = i915_gem_shmem_pread_fast(dev, obj, args, file);
492 if (ret == -EFAULT)
493 ret = i915_gem_shmem_pread_slow(dev, obj, args, file);
494 440
495out: 441out:
496 drm_gem_object_unreference(&obj->base); 442 drm_gem_object_unreference(&obj->base);