[Intel-gfx] [PATCH] drm/doc/rfc: drop the i915_gem_lmem.h header
Daniel Vetter
daniel at ffwll.ch
Tue May 11 17:28:08 UTC 2021
On Tue, May 11, 2021 at 06:03:56PM +0100, Matthew Auld wrote:
> 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 at ffwll.ch>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
I guess we need to have a note that when we land the pciid for dg1 to move
all the remaining bits over to real docs and delete the i915 lmem rfc. But
everything in due time.
-Daniel
> ---
> Documentation/gpu/rfc/i915_gem_lmem.h | 237 ------------------------
> Documentation/gpu/rfc/i915_gem_lmem.rst | 6 +-
> 2 files changed, 3 insertions(+), 240 deletions(-)
> delete mode 100644 Documentation/gpu/rfc/i915_gem_lmem.h
>
> diff --git a/Documentation/gpu/rfc/i915_gem_lmem.h b/Documentation/gpu/rfc/i915_gem_lmem.h
> deleted file mode 100644
> index d9c61bea0556..000000000000
> --- a/Documentation/gpu/rfc/i915_gem_lmem.h
> +++ /dev/null
> @@ -1,237 +0,0 @@
> -/**
> - * 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)®ion_lmem,
> - * .num_regions = 1,
> - * };
> - * struct drm_i915_gem_create_ext create_ext = {
> - * .size = 16 * PAGE_SIZE,
> - * .extensions = (uintptr_t)®ions,
> - * };
> - *
> - * 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;
> -};
> diff --git a/Documentation/gpu/rfc/i915_gem_lmem.rst b/Documentation/gpu/rfc/i915_gem_lmem.rst
> index 1d344c593018..675ba8620d66 100644
> --- a/Documentation/gpu/rfc/i915_gem_lmem.rst
> +++ b/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
> --
> 2.26.3
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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