With the previous rewrite, they've become essential identical.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/i915/i915_gem.c | 108 ++++++++++----------------------------- 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 52fc0b5..5eec933 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -277,66 +277,6 @@ slow_shmem_copy(struct page *dst_page, kunmap(dst_page); }
-/** - * This is the fast shmem pread path, which attempts to copy_from_user directly - * from the backing pages of the object to the user's address space. On a - * fault, it fails so we can fall back to i915_gem_shmem_pwrite_slow(). - */ -static int -i915_gem_shmem_pread_fast(struct drm_device *dev, - struct drm_i915_gem_object *obj, - struct drm_i915_gem_pread *args, - struct drm_file *file) -{ - struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping; - ssize_t remain; - loff_t offset; - char __user *user_data; - int page_offset, page_length; - - user_data = (char __user *) (uintptr_t) args->data_ptr; - remain = args->size; - - offset = args->offset; - - while (remain > 0) { - struct page *page; - char *vaddr; - int ret; - - /* Operation in this page - * - * page_offset = offset within page - * page_length = bytes to copy for this page - */ - page_offset = offset_in_page(offset); - page_length = remain; - if ((page_offset + remain) > PAGE_SIZE) - page_length = PAGE_SIZE - page_offset; - - page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT); - if (IS_ERR(page)) - return PTR_ERR(page); - - vaddr = kmap_atomic(page); - ret = __copy_to_user_inatomic(user_data, - vaddr + page_offset, - page_length); - kunmap_atomic(vaddr); - - mark_page_accessed(page); - page_cache_release(page); - if (ret) - return -EFAULT; - - remain -= page_length; - user_data += page_length; - offset += page_length; - } - - return 0; -} - static inline int __copy_to_user_swizzled(char __user *cpu_vaddr, const char *gpu_vaddr, int gpu_offset, @@ -389,17 +329,11 @@ __copy_from_user_swizzled(char __user *gpu_vaddr, int gpu_offset, return 0; }
-/** - * This is the fallback shmem pread path, which allocates temporary storage - * in kernel space to copy_to_user into outside of the struct_mutex, so we - * can copy out of the object's backing pages while holding the struct mutex - * and not take page faults. - */ static int -i915_gem_shmem_pread_slow(struct drm_device *dev, - struct drm_i915_gem_object *obj, - struct drm_i915_gem_pread *args, - struct drm_file *file) +i915_gem_shmem_pread(struct drm_device *dev, + struct drm_i915_gem_object *obj, + struct drm_i915_gem_pread *args, + struct drm_file *file) { struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping; char __user *user_data; @@ -407,6 +341,7 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, loff_t offset; int shmem_page_offset, page_length, ret; int obj_do_bit17_swizzling, page_do_bit17_swizzling; + int hit_slowpath = 0;
user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; @@ -415,8 +350,6 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
offset = args->offset;
- mutex_unlock(&dev->struct_mutex); - while (remain > 0) { struct page *page; char *vaddr; @@ -439,6 +372,20 @@ i915_gem_shmem_pread_slow(struct drm_device *dev,
page_do_bit17_swizzling = (page_to_phys(page) & (1 << 17)) == 0;
+ if (!obj_do_bit17_swizzling || !page_do_bit17_swizzling) { + vaddr = kmap_atomic(page); + ret = __copy_to_user_inatomic(user_data, + vaddr + shmem_page_offset, + page_length); + kunmap_atomic(vaddr); + if (ret == 0) + goto next_page; + } + + hit_slowpath = 1; + + mutex_unlock(&dev->struct_mutex); + vaddr = kmap(page); if (obj_do_bit17_swizzling && page_do_bit17_swizzling) ret = __copy_to_user_swizzled(user_data, @@ -450,6 +397,8 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, page_length); kunmap(page);
+ mutex_lock(&dev->struct_mutex); +next_page: mark_page_accessed(page); page_cache_release(page);
@@ -464,10 +413,11 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, }
out: - mutex_lock(&dev->struct_mutex); - /* Fixup: Kill any reinstated backing storage pages */ - if (obj->madv == __I915_MADV_PURGED) - i915_gem_object_truncate(obj); + if (hit_slowpath) { + /* Fixup: Kill any reinstated backing storage pages */ + if (obj->madv == __I915_MADV_PURGED) + i915_gem_object_truncate(obj); + }
return ret; } @@ -523,11 +473,7 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, if (ret) goto out;
- ret = -EFAULT; - if (!i915_gem_object_needs_bit17_swizzle(obj)) - ret = i915_gem_shmem_pread_fast(dev, obj, args, file); - if (ret == -EFAULT) - ret = i915_gem_shmem_pread_slow(dev, obj, args, file); + ret = i915_gem_shmem_pread(dev, obj, args, file);
out: drm_gem_object_unreference(&obj->base);