drm/i915: rearrange mutex acquisition for pread
... to avoid the double acquisition along fast[er] paths.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1177ff5..efc6a4e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -265,14 +265,14 @@
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 @@
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 @@
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 @@
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);
- if (ret)
- goto fail_unlock;
-
- ret = i915_gem_object_set_cpu_read_domain_range(obj, args->offset,
+ ret = i915_gem_object_set_cpu_read_domain_range(obj,
+ args->offset,
args->size);
- if (ret != 0)
- goto fail_put_pages;
+ if (ret)
+ goto out;
+
+ do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
obj_priv = to_intel_bo(obj);
offset = args->offset;
@@ -548,11 +523,7 @@
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 @@
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 @@
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_shmem_pread_fast(dev, obj, args, file_priv);
- if (ret != 0)
- ret = i915_gem_shmem_pread_slow(dev, obj, args,
- file_priv);
- }
+ 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 == -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 @@
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;