From 4f27b75d56334f33cbccff5da8372dc4aba122ba Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 14 Oct 2010 15:26:45 +0100 Subject: [PATCH] drm/i915: rearrange mutex acquisition for pread ... to avoid the double acquisition along fast[er] paths. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/i915_gem.c | 99 ++++++++++++++------------------- 1 file changed, 43 insertions(+), 56 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 1177ff577914..efc6a4e3b1d2 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -265,14 +265,14 @@ fast_shmem_read(struct page **pages, char __user *data, int length) { - int unwritten; char *vaddr; + int ret; vaddr = kmap_atomic(pages[page_base >> PAGE_SHIFT], KM_USER0); - unwritten = __copy_to_user_inatomic(data, vaddr + page_offset, length); + ret = __copy_to_user_inatomic(data, vaddr + page_offset, length); kunmap_atomic(vaddr, KM_USER0); - return unwritten ? -EFAULT : 0; + return ret; } static int i915_gem_object_needs_bit17_swizzle(struct drm_gem_object *obj) @@ -366,24 +366,10 @@ i915_gem_shmem_pread_fast(struct drm_device *dev, struct drm_gem_object *obj, loff_t offset, page_base; char __user *user_data; int page_offset, page_length; - int ret; user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; - ret = i915_mutex_lock_interruptible(dev); - if (ret) - return ret; - - ret = i915_gem_object_get_pages(obj, 0); - if (ret != 0) - goto fail_unlock; - - ret = i915_gem_object_set_cpu_read_domain_range(obj, args->offset, - args->size); - if (ret != 0) - goto fail_put_pages; - obj_priv = to_intel_bo(obj); offset = args->offset; @@ -400,23 +386,17 @@ i915_gem_shmem_pread_fast(struct drm_device *dev, struct drm_gem_object *obj, if ((page_offset + remain) > PAGE_SIZE) page_length = PAGE_SIZE - page_offset; - ret = fast_shmem_read(obj_priv->pages, - page_base, page_offset, - user_data, page_length); - if (ret) - goto fail_put_pages; + if (fast_shmem_read(obj_priv->pages, + page_base, page_offset, + user_data, page_length)) + return -EFAULT; remain -= page_length; user_data += page_length; offset += page_length; } -fail_put_pages: - i915_gem_object_put_pages(obj); -fail_unlock: - mutex_unlock(&dev->struct_mutex); - - return ret; + return 0; } static int @@ -477,33 +457,28 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, struct drm_gem_object *obj, last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE; num_pages = last_data_page - first_data_page + 1; - user_pages = drm_calloc_large(num_pages, sizeof(struct page *)); + user_pages = drm_malloc_ab(num_pages, sizeof(struct page *)); if (user_pages == NULL) return -ENOMEM; + mutex_unlock(&dev->struct_mutex); down_read(&mm->mmap_sem); pinned_pages = get_user_pages(current, mm, (uintptr_t)args->data_ptr, num_pages, 1, 0, user_pages, NULL); up_read(&mm->mmap_sem); + mutex_lock(&dev->struct_mutex); if (pinned_pages < num_pages) { ret = -EFAULT; - goto fail_put_user_pages; + goto out; } - do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj); - - ret = i915_mutex_lock_interruptible(dev); - if (ret) - goto fail_put_user_pages; - - ret = i915_gem_object_get_pages_or_evict(obj); + ret = i915_gem_object_set_cpu_read_domain_range(obj, + args->offset, + args->size); if (ret) - goto fail_unlock; + goto out; - ret = i915_gem_object_set_cpu_read_domain_range(obj, args->offset, - args->size); - if (ret != 0) - goto fail_put_pages; + do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj); obj_priv = to_intel_bo(obj); offset = args->offset; @@ -548,11 +523,7 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, struct drm_gem_object *obj, offset += page_length; } -fail_put_pages: - i915_gem_object_put_pages(obj); -fail_unlock: - mutex_unlock(&dev->struct_mutex); -fail_put_user_pages: +out: for (i = 0; i < pinned_pages; i++) { SetPageDirty(user_pages[i]); page_cache_release(user_pages[i]); @@ -581,6 +552,12 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, return -ENOENT; obj_priv = to_intel_bo(obj); + ret = i915_mutex_lock_interruptible(dev); + if (ret) { + drm_gem_object_unreference_unlocked(obj); + return ret; + } + /* Bounds check source. */ if (args->offset > obj->size || args->size > obj->size - args->offset) { ret = -EINVAL; @@ -604,17 +581,27 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, goto out; } - if (i915_gem_object_needs_bit17_swizzle(obj)) { - ret = i915_gem_shmem_pread_slow(dev, obj, args, file_priv); - } else { + ret = i915_gem_object_get_pages_or_evict(obj); + if (ret) + goto out; + + ret = i915_gem_object_set_cpu_read_domain_range(obj, + args->offset, + args->size); + if (ret) + goto out_put; + + ret = -EFAULT; + if (!i915_gem_object_needs_bit17_swizzle(obj)) ret = i915_gem_shmem_pread_fast(dev, obj, args, file_priv); - if (ret != 0) - ret = i915_gem_shmem_pread_slow(dev, obj, args, - file_priv); - } + if (ret == -EFAULT) + ret = i915_gem_shmem_pread_slow(dev, obj, args, file_priv); +out_put: + i915_gem_object_put_pages(obj); out: - drm_gem_object_unreference_unlocked(obj); + drm_gem_object_unreference(obj); + mutex_unlock(&dev->struct_mutex); return ret; } @@ -908,7 +895,7 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev, struct drm_gem_object *obj, last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE; num_pages = last_data_page - first_data_page + 1; - user_pages = drm_calloc_large(num_pages, sizeof(struct page *)); + user_pages = drm_malloc_ab(num_pages, sizeof(struct page *)); if (user_pages == NULL) return -ENOMEM; -- 2.20.1