drm/i915/uapi: convert drm_i915_gem_caching to kernel doc

Convert all the drm_i915_gem_caching bits to proper kernel doc.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210705135310.1502437-2-matthew.auld@intel.com
This commit is contained in:
Matthew Auld 2021-07-05 14:53:07 +01:00
parent 3101e9952b
commit 289f5a7200

View File

@ -1363,43 +1363,50 @@ struct drm_i915_gem_busy {
};
/**
* I915_CACHING_NONE
* struct drm_i915_gem_caching - Set or get the caching for given object
* handle.
*
* GPU access is not coherent with cpu caches. Default for machines without an
* LLC.
* Allow userspace to control the GTT caching bits for a given object when the
* object is later mapped through the ppGTT(or GGTT on older platforms lacking
* ppGTT support, or if the object is used for scanout). Note that this might
* require unbinding the object from the GTT first, if its current caching value
* doesn't match.
*/
#define I915_CACHING_NONE 0
/**
* I915_CACHING_CACHED
*
* GPU access is coherent with cpu caches and furthermore the data is cached in
* last-level caches shared between cpu cores and the gpu GT. Default on
* machines with HAS_LLC.
*/
#define I915_CACHING_CACHED 1
/**
* I915_CACHING_DISPLAY
*
* Special GPU caching mode which is coherent with the scanout engines.
* Transparently falls back to I915_CACHING_NONE on platforms where no special
* cache mode (like write-through or gfdt flushing) is available. The kernel
* automatically sets this mode when using a buffer as a scanout target.
* Userspace can manually set this mode to avoid a costly stall and clflush in
* the hotpath of drawing the first frame.
*/
#define I915_CACHING_DISPLAY 2
struct drm_i915_gem_caching {
/**
* Handle of the buffer to set/get the caching level of. */
* @handle: Handle of the buffer to set/get the caching level.
*/
__u32 handle;
/**
* Cacheing level to apply or return value
* @caching: The GTT caching level to apply or possible return value.
*
* bits0-15 are for generic caching control (i.e. the above defined
* values). bits16-31 are reserved for platform-specific variations
* (e.g. l3$ caching on gen7). */
* The supported @caching values:
*
* I915_CACHING_NONE:
*
* GPU access is not coherent with CPU caches. Default for machines
* without an LLC. This means manual flushing might be needed, if we
* want GPU access to be coherent.
*
* I915_CACHING_CACHED:
*
* GPU access is coherent with CPU caches and furthermore the data is
* cached in last-level caches shared between CPU cores and the GPU GT.
*
* I915_CACHING_DISPLAY:
*
* Special GPU caching mode which is coherent with the scanout engines.
* Transparently falls back to I915_CACHING_NONE on platforms where no
* special cache mode (like write-through or gfdt flushing) is
* available. The kernel automatically sets this mode when using a
* buffer as a scanout target. Userspace can manually set this mode to
* avoid a costly stall and clflush in the hotpath of drawing the first
* frame.
*/
#define I915_CACHING_NONE 0
#define I915_CACHING_CACHED 1
#define I915_CACHING_DISPLAY 2
__u32 caching;
};