[Intel-gfx] [PATCH] drm/doc/rfc: drop the i915_gem_lmem.h header
Matthew Auld
matthew.auld at intel.com
Wed May 12 07:38:55 UTC 2021
On 11/05/2021 18:29, Daniel Vetter wrote:
> On Tue, May 11, 2021 at 07:28:08PM +0200, Daniel Vetter wrote:
>> 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.
>
> One thing I forgot: The include stanza will I think result in the
> explicitly included functions not showing up in the normal driver uapi
> docs. Which I think is fine while we settle all this. Or do I get this
> wrong?
It all looks ok in the rendered html, but yeah the explicitly inlcuded
functions/structs don't seem to link back to driver-uapi, and instead
just link to the "local version" in i915_gem_lmem.
> -Daniel
>
>> -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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