Am 07.01.22 um 16:49 schrieb Matthew Auld:
On 26/12/2021 22:24, Arunpravin wrote:
Move the base i915 buddy allocator code into drm
- Move i915_buddy.h to include/drm
- Move i915_buddy.c to drm root folder
- Rename "i915" string with "drm" string wherever applicable
- Rename "I915" string with "DRM" string wherever applicable
- Fix header file dependencies
- Fix alignment issues
- add Makefile support for drm buddy
- export functions and write kerneldoc description
- Remove i915 selftest config check condition as buddy selftest
will be moved to drm selftest folder
cleanup i915 buddy references in i915 driver module
and replace with drm buddy
v2:
- include header file in alphabetical order(Thomas)
- merged changes listed in the body section into a single patch
to keep the build intact(Christian, Jani)
v3:
- make drm buddy a separate module(Thomas, Christian)
v4:
- Fix build error reported by kernel test robot <lkp@xxxxxxxxx>
- removed i915 buddy selftest from i915_mock_selftests.h to
avoid build error
- removed selftests/i915_buddy.c file as we create a new set of
buddy test cases in drm/selftests folder
v5:
- Fix merge conflict issue
Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx>
<snip>
+int drm_buddy_init(struct drm_buddy_mm *mm, u64 size, u64 chunk_size)
+{
+ unsigned int i;
+ u64 offset;
+
+ if (size < chunk_size)
+ return -EINVAL;
+
+ if (chunk_size < PAGE_SIZE)
+ return -EINVAL;
+
+ if (!is_power_of_2(chunk_size))
+ return -EINVAL;
+
+ size = round_down(size, chunk_size);
+
+ mm->size = size;
+ mm->avail = size;
+ mm->chunk_size = chunk_size;
+ mm->max_order = ilog2(size) - ilog2(chunk_size);
+
+ BUG_ON(mm->max_order > DRM_BUDDY_MAX_ORDER);
+
+ mm->slab_blocks = KMEM_CACHE(drm_buddy_block, 0);
+ if (!mm->slab_blocks)
+ return -ENOMEM;
It looks like every KMEM_CACHE() also creates a debugfs entry? See the
error here[1]. I guess because we end with multiple instances in i915.
If so, is it possible to have a single KMEM_CACHE() as part of the
buddy module, similar to what i915 was doing previously?
Oh, that is a really good point, this code here doesn't make to much sense.
The value of a KMEM_CACHE() is to allow speeding up allocation of the
same structure size between different drm_buddy object. If you allocate
one cache per drm_buddy that makes the whole functionality useless.
Please fix, this is actually a bug.
Christian.
[1]
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fintel-gfx-ci.01.org%2Ftree%2Fdrm-tip%2FTrybot_8217%2Fshard-skl4%2Figt%40i915_selftest%40mock%40memory_region.html&data=04%7C01%7Cchristian.koenig%40amd.com%7C56202fbe886f415c3b8308d9d1f5409c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637771673545453215%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ZnRmAQo%2BjX414hbqHigL4R18oBDKLIugUQIVcwhFI%2BY%3D&reserved=0
