drm/doc/rfc: drop the i915_gem_lmem.h header

The proper headers have now landed in include/uapi/drm/i915_drm.h, so we
can drop i915_gem_lmem.h and instead just reference the real headers for
pulling in the kernel doc.
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210511170356.430284-1-matthew.auld@intel.com

Documentation/gpu/rfc/i915_gem_lmem.h

-/**
- * enum drm_i915_gem_memory_class - Supported memory classes
- */
-enum drm_i915_gem_memory_class {
-	/** @I915_MEMORY_CLASS_SYSTEM: System memory */
-	I915_MEMORY_CLASS_SYSTEM = 0,
-	/** @I915_MEMORY_CLASS_DEVICE: Device local-memory */
-	I915_MEMORY_CLASS_DEVICE,
-};
-
-/**
- * struct drm_i915_gem_memory_class_instance - Identify particular memory region
- */
-struct drm_i915_gem_memory_class_instance {
-	/** @memory_class: See enum drm_i915_gem_memory_class */
-	__u16 memory_class;
-
-	/** @memory_instance: Which instance */
-	__u16 memory_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.
- */
-struct drm_i915_memory_region_info {
-	/** @region: The class:instance pair encoding */
-	struct drm_i915_gem_memory_class_instance region;
-
-	/** @rsvd0: MBZ */
-	__u32 rsvd0;
-
-	/** @probed_size: Memory probed by the driver (-1 = unknown) */
-	__u64 probed_size;
-
-	/** @unallocated_size: Estimate of memory remaining (-1 = unknown) */
-	__u64 unallocated_size;
-
-	/** @rsvd1: MBZ */
-	__u64 rsvd1[8];
-};
-
-/**
- * struct drm_i915_query_memory_regions
- *
- * The region info query enumerates all regions known to the driver by filling
- * in an array of struct drm_i915_memory_region_info structures.
- *
- * Example for getting the list of supported regions:
- *
- * .. code-block:: C
- *
- *	struct drm_i915_query_memory_regions *info;
- *	struct drm_i915_query_item item = {
- *		.query_id = DRM_I915_QUERY_MEMORY_REGIONS;
- *	};
- *	struct drm_i915_query query = {
- *		.num_items = 1,
- *		.items_ptr = (uintptr_t)&item,
- *	};
- *	int err, i;
- *
- *	// First query the size of the blob we need, this needs to be large
- *	// enough to hold our array of regions. The kernel will fill out the
- *	// item.length for us, which is the number of bytes we need.
- *	err = ioctl(fd, DRM_IOCTL_I915_QUERY, &query);
- *	if (err) ...
- *
- *	info = calloc(1, item.length);
- *	// Now that we allocated the required number of bytes, we call the ioctl
- *	// again, this time with the data_ptr pointing to our newly allocated
- *	// blob, which the kernel can then populate with the all the region info.
- *	item.data_ptr = (uintptr_t)&info,
- *
- *	err = ioctl(fd, DRM_IOCTL_I915_QUERY, &query);
- *	if (err) ...
- *
- *	// We can now access each region in the array
- *	for (i = 0; i < info->num_regions; i++) {
- *		struct drm_i915_memory_region_info mr = info->regions[i];
- *		u16 class = mr.region.class;
- *		u16 instance = mr.region.instance;
- *
- *		....
- *	}
- *
- *	free(info);
- */
-struct drm_i915_query_memory_regions {
-	/** @num_regions: Number of supported regions */
-	__u32 num_regions;
-
-	/** @rsvd: MBZ */
-	__u32 rsvd[3];
-
-	/** @regions: Info about each supported region */
-	struct drm_i915_memory_region_info regions[];
-};
-
-#define DRM_I915_GEM_CREATE_EXT		0xdeadbeaf
-#define DRM_IOCTL_I915_GEM_CREATE_EXT	DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_CREATE_EXT, struct drm_i915_gem_create_ext)
-
-/**
- * struct drm_i915_gem_create_ext - Existing gem_create behaviour, with added
- * extension support using struct i915_user_extension.
- *
- * Note that in the future we want to have our buffer flags here, at least for
- * the stuff that is immutable. Previously we would have two ioctls, one to
- * create the object with gem_create, and another to apply various parameters,
- * however this creates some ambiguity for the params which are considered
- * immutable. Also in general we're phasing out the various SET/GET ioctls.
- */
-struct drm_i915_gem_create_ext {
-	/**
-	 * @size: Requested size for the object.
-	 *
-	 * The (page-aligned) allocated size for the object will be returned.
-	 *
-	 * Note that for some devices we have might have further minimum
-	 * page-size restrictions(larger than 4K), like for device local-memory.
-	 * However in general the final size here should always reflect any
-	 * rounding up, if for example using the I915_GEM_CREATE_EXT_MEMORY_REGIONS
-	 * extension to place the object in device local-memory.
-	 */
-	__u64 size;
-	/**
-	 * @handle: Returned handle for the object.
-	 *
-	 * Object handles are nonzero.
-	 */
-	__u32 handle;
-	/** @flags: MBZ */
-	__u32 flags;
-	/**
-	 * @extensions: The chain of extensions to apply to this object.
-	 *
-	 * This will be useful in the future when we need to support several
-	 * different extensions, and we need to apply more than one when
-	 * creating the object. See struct i915_user_extension.
-	 *
-	 * If we don't supply any extensions then we get the same old gem_create
-	 * behaviour.
-	 *
-	 * For I915_GEM_CREATE_EXT_MEMORY_REGIONS usage see
-	 * struct drm_i915_gem_create_ext_memory_regions.
-	 */
-#define I915_GEM_CREATE_EXT_MEMORY_REGIONS 0
-	__u64 extensions;
-};
-
-/**
- * struct drm_i915_gem_create_ext_memory_regions - The
- * I915_GEM_CREATE_EXT_MEMORY_REGIONS extension.
- *
- * Set the object with the desired set of placements/regions in priority
- * order. Each entry must be unique and supported by the device.
- *
- * This is provided as an array of struct drm_i915_gem_memory_class_instance, or
- * an equivalent layout of class:instance pair encodings. See struct
- * drm_i915_query_memory_regions and DRM_I915_QUERY_MEMORY_REGIONS for how to
- * query the supported regions for a device.
- *
- * As an example, on discrete devices, if we wish to set the placement as
- * device local-memory we can do something like:
- *
- * .. code-block:: C
- *
- *	struct drm_i915_gem_memory_class_instance region_lmem = {
- *              .memory_class = I915_MEMORY_CLASS_DEVICE,
- *              .memory_instance = 0,
- *      };
- *      struct drm_i915_gem_create_ext_memory_regions regions = {
- *              .base = { .name = I915_GEM_CREATE_EXT_MEMORY_REGIONS },
- *              .regions = (uintptr_t)&region_lmem,
- *              .num_regions = 1,
- *      };
- *      struct drm_i915_gem_create_ext create_ext = {
- *              .size = 16 * PAGE_SIZE,
- *              .extensions = (uintptr_t)&regions,
- *      };
- *
- *      int err = ioctl(fd, DRM_IOCTL_I915_GEM_CREATE_EXT, &create_ext);
- *      if (err) ...
- *
- * At which point we get the object handle in &drm_i915_gem_create_ext.handle,
- * along with the final object size in &drm_i915_gem_create_ext.size, which
- * should account for any rounding up, if required.
- */
-struct drm_i915_gem_create_ext_memory_regions {
-	/** @base: Extension link. See struct i915_user_extension. */
-	struct i915_user_extension base;
-
-	/** @pad: MBZ */
-	__u32 pad;
-	/** @num_regions: Number of elements in the @regions array. */
-	__u32 num_regions;
-	/**
-	 * @regions: The regions/placements array.
-	 *
-	 * An array of struct drm_i915_gem_memory_class_instance.
-	 */
-	__u64 regions;
-};

Documentation/gpu/rfc/i915_gem_lmem.rst

@@ -48,7 +48,7 @@ particular instance, since we can have more than one per class.
 In the future we also want to expose more information which can further
 describe the capabilities of a region.
 
-.. kernel-doc:: Documentation/gpu/rfc/i915_gem_lmem.h
+.. kernel-doc:: include/uapi/drm/i915_drm.h
         :functions: drm_i915_gem_memory_class drm_i915_gem_memory_class_instance drm_i915_memory_region_info drm_i915_query_memory_regions
 
 GEM_CREATE_EXT
@@ -61,7 +61,7 @@ Side note: We also need to support PXP[1] in the near future, which is also
 applicable to integrated platforms, and adds its own gem_create_ext extension,
 which basically lets userspace mark a buffer as "protected".
 
-.. kernel-doc:: Documentation/gpu/rfc/i915_gem_lmem.h
+.. kernel-doc:: include/uapi/drm/i915_drm.h
         :functions: drm_i915_gem_create_ext
 
 I915_GEM_CREATE_EXT_MEMORY_REGIONS
@@ -73,7 +73,7 @@ them each to use the class/instance encoding, as per the output of the regions
 query. Having the list in priority order will be useful in the future when
 placing an object, say during eviction.
 
-.. kernel-doc:: Documentation/gpu/rfc/i915_gem_lmem.h
+.. kernel-doc:: include/uapi/drm/i915_drm.h
         :functions: drm_i915_gem_create_ext_memory_regions
 
 One fair criticism here is that this seems a little over-engineered[2]. If we