Commit 3f4309cb authored by Matthew Auld's avatar Matthew Auld
Browse files

drm/i915/uapi: add probed_cpu_visible_size 



Userspace wants to know the size of CPU visible portion of device
local-memory, and on small BAR devices the probed_size is no longer
enough. In Vulkan, for example, it would like to know the size in bytes
for CPU visible VkMemoryHeap. We already track the io_size for each
region, so plumb that through to the region query.

v2: Drop the ( -1 = unknown ) stuff, which is confusing since nothing
can currently ever return such a value.

Testcase: igt@i915_query@query-regions-sanity-check
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Acked-by: default avatarNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220629174350.384910-2-matthew.auld@intel.com
parent fff1d972

drivers/gpu/drm/i915/i915_query.c

+6 −0
Original line number Diff line number Diff line
@@ -498,6 +498,12 @@ static int query_memregion_info(struct drm_i915_private *i915, 
		info.region.memory_class = mr->type;

		info.region.memory_instance = mr->instance;

		info.probed_size = mr->total;



		if (mr->type == INTEL_MEMORY_LOCAL)

			info.probed_cpu_visible_size = mr->io_size;

		else

			info.probed_cpu_visible_size = mr->total;



		info.unallocated_size = mr->avail;



		if (__copy_to_user(info_ptr, &info, sizeof(info)))

include/uapi/drm/i915_drm.h

+42 −34
Original line number Diff line number Diff line
@@ -3207,36 +3207,6 @@ struct drm_i915_gem_memory_class_instance { 
 * struct drm_i915_memory_region_info - Describes one region as known to the

 * driver.

 *

 * Note that we reserve some stuff here for potential future work. As an example

 * we might want expose the capabilities for a given region, which could include

 * things like if the region is CPU mappable/accessible, what are the supported

 * mapping types etc.

 *

 * Note that to extend struct drm_i915_memory_region_info and struct

 * drm_i915_query_memory_regions in the future the plan is to do the following:

 *

 * .. code-block:: C

 *

 *	struct drm_i915_memory_region_info {

 *		struct drm_i915_gem_memory_class_instance region;

 *		union {

 *			__u32 rsvd0;

 *			__u32 new_thing1;

 *		};

 *		...

 *		union {

 *			__u64 rsvd1[8];

 *			struct {

 *				__u64 new_thing2;

 *				__u64 new_thing3;

 *				...

 *			};

 *		};

 *	};

 *

 * With this things should remain source compatible between versions for

 * userspace, even as we add new fields.

 *

 * Note this is using both struct drm_i915_query_item and struct drm_i915_query.

 * For this new query we are adding the new query id DRM_I915_QUERY_MEMORY_REGIONS

 * at &drm_i915_query_item.query_id.
@@ -3248,14 +3218,52 @@ struct drm_i915_memory_region_info { 
	/** @rsvd0: MBZ */

	__u32 rsvd0;



	/** @probed_size: Memory probed by the driver (-1 = unknown) */

	/**

	 * @probed_size: Memory probed by the driver

	 *

	 * Note that it should not be possible to ever encounter a zero value

	 * here, also note that no current region type will ever return -1 here.

	 * Although for future region types, this might be a possibility. The

	 * same applies to the other size fields.

	 */

	__u64 probed_size;



	/** @unallocated_size: Estimate of memory remaining (-1 = unknown) */

	/** @unallocated_size: Estimate of memory remaining */

	__u64 unallocated_size;



	union {

		/** @rsvd1: MBZ */

		__u64 rsvd1[8];

		struct {

			/**

			 * @probed_cpu_visible_size: Memory probed by the driver

			 * that is CPU accessible.

			 *

			 * This will be always be <= @probed_size, and the

			 * remainder (if there is any) will not be CPU

			 * accessible.

			 *

			 * On systems without small BAR, the @probed_size will

			 * always equal the @probed_cpu_visible_size, since all

			 * of it will be CPU accessible.

			 *

			 * Note this is only tracked for

			 * I915_MEMORY_CLASS_DEVICE regions (for other types the

			 * value here will always equal the @probed_size).

			 *

			 * Note that if the value returned here is zero, then

			 * this must be an old kernel which lacks the relevant

			 * small-bar uAPI support (including

			 * I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS), but on

			 * such systems we should never actually end up with a

			 * small BAR configuration, assuming we are able to load

			 * the kernel module. Hence it should be safe to treat

			 * this the same as when @probed_cpu_visible_size ==

			 * @probed_size.

			 */

			__u64 probed_cpu_visible_size;

		};

	};

};



/**