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drm/i915: merge shmem_pwrite 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>
hifive-unleashed-5.1
Daniel Vetter 2012-03-25 19:47:28 +02:00
parent dabdfe021a
commit e244a443bf
1 changed files with 33 additions and 93 deletions
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126
drivers/gpu/drm/i915/i915_gem.c
View File

@ -691,84 +691,11 @@ out_unpin_pages:
return ret;
}
/**
* This is the fast shmem pwrite path, which attempts to directly
* copy_from_user into the kmapped pages backing the object.
*/
static int
i915_gem_shmem_pwrite_fast(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *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;
obj->dirty = 1;
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_from_user_inatomic(vaddr + page_offset,
user_data,
page_length);
kunmap_atomic(vaddr);
set_page_dirty(page);
mark_page_accessed(page);
page_cache_release(page);
/* 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)
return -EFAULT;
remain -= page_length;
user_data += page_length;
offset += page_length;
}
return 0;
}
/**
* This is the fallback shmem pwrite path, which uses get_user_pages to pin
* the memory and maps it using kmap_atomic for copying.
*
* This avoids taking mmap_sem for faulting on the user's address while the
* struct_mutex is held.
*/
static int
i915_gem_shmem_pwrite_slow(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file)
i915_gem_shmem_pwrite(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file)
{
struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
ssize_t remain;
@ -776,6 +703,7 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev,
char __user *user_data;
int shmem_page_offset, page_length, ret = 0;
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;
@ -785,8 +713,6 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev,
offset = args->offset;
obj->dirty = 1;
mutex_unlock(&dev->struct_mutex);
while (remain > 0) {
struct page *page;
char *vaddr;
@ -811,6 +737,21 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev,
page_do_bit17_swizzling = obj_do_bit17_swizzling &&
(page_to_phys(page) & (1 << 17)) != 0;
if (!page_do_bit17_swizzling) {
vaddr = kmap_atomic(page);
ret = __copy_from_user_inatomic(vaddr + shmem_page_offset,
user_data,
page_length);
kunmap_atomic(vaddr);
if (ret == 0)
goto next_page;
}
hit_slowpath = 1;
mutex_unlock(&dev->struct_mutex);
vaddr = kmap(page);
if (page_do_bit17_swizzling)
ret = __copy_from_user_swizzled(vaddr, shmem_page_offset,
@ -822,6 +763,8 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev,
page_length);
kunmap(page);
mutex_lock(&dev->struct_mutex);
next_page:
set_page_dirty(page);
mark_page_accessed(page);
page_cache_release(page);
@ -837,15 +780,16 @@ i915_gem_shmem_pwrite_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);
/* and flush dirty cachelines in case the object isn't in the cpu write
* domain anymore. */
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
i915_gem_clflush_object(obj);
intel_gtt_chipset_flush();
if (hit_slowpath) {
/* Fixup: Kill any reinstated backing storage pages */
if (obj->madv == __I915_MADV_PURGED)
i915_gem_object_truncate(obj);
/* and flush dirty cachelines in case the object isn't in the cpu write
* domain anymore. */
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
i915_gem_clflush_object(obj);
intel_gtt_chipset_flush();
}
}
return ret;
@ -939,11 +883,7 @@ out_unpin:
if (ret)
goto out;
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);
ret = i915_gem_shmem_pwrite(dev, obj, args, file);
out:
drm_gem_object_unreference(&obj->base);