[Intel-gfx] [PATCH 2/2] drm/i915: pwrite/pread do not require obj->base.filp, just pages

[Tvrtko Ursulin]

On 20/06/16 10:31, Chris Wilson wrote:
> The idea behind relaxing the restriction for pread/pwrite was to handle
> !obj->base.flip, i.e. non-shmemfs backed objects, which only requires
> that the object provide struct pages.
>
> v2: Remove excess (). Note enough editing after copy'n'paste.
> v3: Use new i915_gem_object_has_struct_page()
>
> Testcase: igt/prime_vgem/read
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Ankitprasad Sharma <ankitprasad.r.sharma at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 7f6879cc82fb..604989b81131 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -760,7 +760,7 @@ i915_gem_shmem_pread(struct drm_device *dev,
>   	int needs_clflush = 0;
>   	struct sg_page_iter sg_iter;
>
> -	if (!obj->base.filp)
> +	if (!i915_gem_object_has_struct_page(obj))
>   		return -ENODEV;
>
>   	user_data = u64_to_user_ptr(args->data_ptr);
> @@ -1298,7 +1298,8 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
>   	 * pread/pwrite currently are reading and writing from the CPU
>   	 * perspective, requiring manual detiling by the client.
>   	 */
> -	if (!obj->base.filp || cpu_write_needs_clflush(obj)) {
> +	if (!i915_gem_object_has_struct_page(obj) ||
> +	    cpu_write_needs_clflush(obj)) {
>   		ret = i915_gem_gtt_pwrite_fast(dev_priv, obj, args, file);
>   		/* Note that the gtt paths might fail with non-page-backed user
>   		 * pointers (e.g. gtt mappings when moving data between
> @@ -1308,7 +1309,7 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
>   	if (ret == -EFAULT) {
>   		if (obj->phys_handle)
>   			ret = i915_gem_phys_pwrite(obj, args, file);
> -		else if (obj->base.filp)
> +		else if (i915_gem_object_has_struct_page(obj))
>   			ret = i915_gem_shmem_pwrite(dev, obj, args, file);
>   		else
>   			ret = -ENODEV;
>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko