drm/i915: Rearrange acquisition of mutex during pwrite
... to avoid reacquiring it to drop the object reference count on
exit. Note we have to make sure we now drop (and reacquire) the lock
around acquiring the mm semaphore on the slow 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 b44c09a..1177ff5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -635,9 +635,7 @@
unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + page_offset,
user_data, length);
io_mapping_unmap_atomic(vaddr_atomic, KM_USER0);
- if (unwritten)
- return -EFAULT;
- return 0;
+ return unwritten;
}
/* Here's the write path which can sleep for
@@ -670,14 +668,14 @@
char __user *data,
int length)
{
- int unwritten;
char *vaddr;
+ int ret;
vaddr = kmap_atomic(pages[page_base >> PAGE_SHIFT], KM_USER0);
- unwritten = __copy_from_user_inatomic(vaddr + page_offset, data, length);
+ ret = __copy_from_user_inatomic(vaddr + page_offset, data, length);
kunmap_atomic(vaddr, KM_USER0);
- return unwritten ? -EFAULT : 0;
+ return ret;
}
/**
@@ -695,24 +693,10 @@
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_pin(obj, 0);
- if (ret) {
- mutex_unlock(&dev->struct_mutex);
- return ret;
- }
- ret = i915_gem_object_set_to_gtt_domain(obj, 1);
- if (ret)
- goto fail;
-
obj_priv = to_intel_bo(obj);
offset = obj_priv->gtt_offset + args->offset;
@@ -729,26 +713,21 @@
if ((page_offset + remain) > PAGE_SIZE)
page_length = PAGE_SIZE - page_offset;
- ret = fast_user_write (dev_priv->mm.gtt_mapping, page_base,
- page_offset, user_data, page_length);
-
/* If we get a fault while copying data, then (presumably) our
* source page isn't available. Return the error and we'll
* retry in the slow path.
*/
- if (ret)
- goto fail;
+ if (fast_user_write(dev_priv->mm.gtt_mapping, page_base,
+ page_offset, user_data, page_length))
+
+ return -EFAULT;
remain -= page_length;
user_data += page_length;
offset += page_length;
}
-fail:
- i915_gem_object_unpin(obj);
- mutex_unlock(&dev->struct_mutex);
-
- return ret;
+ return 0;
}
/**
@@ -785,30 +764,24 @@
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, 0, 0, user_pages, NULL);
up_read(&mm->mmap_sem);
+ mutex_lock(&dev->struct_mutex);
if (pinned_pages < num_pages) {
ret = -EFAULT;
goto out_unpin_pages;
}
- ret = i915_mutex_lock_interruptible(dev);
- if (ret)
- goto out_unpin_pages;
-
- ret = i915_gem_object_pin(obj, 0);
- if (ret)
- goto out_unlock;
-
ret = i915_gem_object_set_to_gtt_domain(obj, 1);
if (ret)
- goto out_unpin_object;
+ goto out_unpin_pages;
obj_priv = to_intel_bo(obj);
offset = obj_priv->gtt_offset + args->offset;
@@ -844,10 +817,6 @@
data_ptr += page_length;
}
-out_unpin_object:
- i915_gem_object_unpin(obj);
-out_unlock:
- mutex_unlock(&dev->struct_mutex);
out_unpin_pages:
for (i = 0; i < pinned_pages; i++)
page_cache_release(user_pages[i]);
@@ -870,23 +839,10 @@
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_to_cpu_domain(obj, 1);
- if (ret != 0)
- goto fail_put_pages;
-
obj_priv = to_intel_bo(obj);
offset = args->offset;
obj_priv->dirty = 1;
@@ -904,23 +860,17 @@
if ((page_offset + remain) > PAGE_SIZE)
page_length = PAGE_SIZE - page_offset;
- ret = fast_shmem_write(obj_priv->pages,
+ if (fast_shmem_write(obj_priv->pages,
page_base, page_offset,
- user_data, page_length);
- if (ret)
- goto fail_put_pages;
+ 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;
}
/**
@@ -962,28 +912,22 @@
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, 0, 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_to_cpu_domain(obj, 1);
- 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;
@@ -1029,11 +973,7 @@
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++)
page_cache_release(user_pages[i]);
drm_free_large(user_pages);
@@ -1048,18 +988,24 @@
*/
int
i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
- struct drm_file *file_priv)
+ struct drm_file *file)
{
struct drm_i915_gem_pwrite *args = data;
struct drm_gem_object *obj;
struct drm_i915_gem_object *obj_priv;
int ret = 0;
- obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+ obj = drm_gem_object_lookup(dev, file, args->handle);
if (obj == NULL)
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 destination. */
if (args->offset > obj->size || args->size > obj->size - args->offset) {
ret = -EINVAL;
@@ -1090,32 +1036,46 @@
* perspective, requiring manual detiling by the client.
*/
if (obj_priv->phys_obj)
- ret = i915_gem_phys_pwrite(dev, obj, args, file_priv);
+ ret = i915_gem_phys_pwrite(dev, obj, args, file);
else if (obj_priv->tiling_mode == I915_TILING_NONE &&
obj_priv->gtt_space &&
obj->write_domain != I915_GEM_DOMAIN_CPU) {
- ret = i915_gem_gtt_pwrite_fast(dev, obj, args, file_priv);
- if (ret == -EFAULT) {
- ret = i915_gem_gtt_pwrite_slow(dev, obj, args,
- file_priv);
- }
- } else if (i915_gem_object_needs_bit17_swizzle(obj)) {
- ret = i915_gem_shmem_pwrite_slow(dev, obj, args, file_priv);
+ ret = i915_gem_object_pin(obj, 0);
+ if (ret)
+ goto out;
+
+ ret = i915_gem_object_set_to_gtt_domain(obj, 1);
+ if (ret)
+ goto out_unpin;
+
+ ret = i915_gem_gtt_pwrite_fast(dev, obj, args, file);
+ if (ret == -EFAULT)
+ ret = i915_gem_gtt_pwrite_slow(dev, obj, args, file);
+
+out_unpin:
+ i915_gem_object_unpin(obj);
} else {
- ret = i915_gem_shmem_pwrite_fast(dev, obj, args, file_priv);
- if (ret == -EFAULT) {
- ret = i915_gem_shmem_pwrite_slow(dev, obj, args,
- file_priv);
- }
+ ret = i915_gem_object_get_pages_or_evict(obj);
+ if (ret)
+ goto out;
+
+ ret = i915_gem_object_set_to_cpu_domain(obj, 1);
+ if (ret)
+ goto out_put;
+
+ ret = -EFAULT;
+ if (!i915_gem_object_needs_bit17_swizzle(obj))
+ ret = i915_gem_shmem_pwrite_fast(dev, obj, args, file);
+ if (ret == -EFAULT)
+ ret = i915_gem_shmem_pwrite_slow(dev, obj, args, file);
+
+out_put:
+ i915_gem_object_put_pages(obj);
}
-#if WATCH_PWRITE
- if (ret)
- DRM_INFO("pwrite failed %d\n", ret);
-#endif
-
out:
- drm_gem_object_unreference_unlocked(obj);
+ drm_gem_object_unreference(obj);
+ mutex_unlock(&dev->struct_mutex);
return ret;
}