From b67d2d039f645f266af8ec87e9af112ed6ef9140 Mon Sep 17 00:00:00 2001 From: Mukul Joshi Date: Wed, 28 Jan 2026 14:31:18 -0500 Subject: [PATCH] drm/gem: Add callback for when handle count goes to 0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add an optional callback for driver-specific cleanup when the GEM handle of an object is freed. This will be used by AMDGPU to enable freeing of memory exported to other nodes in a UALink pod once all user mode references are gone. The callback is called outside the object_name_lock and before releasing the reference count on the GEM object Suggested-by: Christian König Signed-off-by: Mukul Joshi Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 9 +++++++++ drivers/gpu/drm/drm_gem.c | 5 ++++- include/drm/drm_gem.h | 11 +++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index f754a4a3a1c2..0d579517c03c 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -386,6 +386,14 @@ static int amdgpu_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_str return drm_gem_ttm_mmap(obj, vma); } +static void amdgpu_gem_object_handle_free(struct drm_gem_object *gobj) +{ + struct amdgpu_bo *aobj = gem_to_amdgpu_bo(gobj); + + amdgpu_ualink_revoke_exported_memory(aobj); + +} + const struct drm_gem_object_funcs amdgpu_gem_object_funcs = { .free = amdgpu_gem_object_free, .open = amdgpu_gem_object_open, @@ -395,6 +403,7 @@ const struct drm_gem_object_funcs amdgpu_gem_object_funcs = { .vunmap = drm_gem_ttm_vunmap, .mmap = amdgpu_gem_object_mmap, .vm_ops = &amdgpu_gem_vm_ops, + .handle_free = amdgpu_gem_object_handle_free }; static bool amdgpu_gem_are_domains_valid(u32 domains) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 018df97d590d..4dfd08f48a0e 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -353,8 +353,11 @@ void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) } mutex_unlock(&dev->object_name_lock); - if (final) + if (final) { + if (obj->funcs->handle_free) + obj->funcs->handle_free(obj); drm_gem_object_put(obj); + } } /* diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 885244e375d3..708ee0edb2c9 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -227,6 +227,17 @@ struct drm_gem_object_funcs { */ size_t (*rss)(struct drm_gem_object *obj); + /** + * @handle_free: + * + * This callback is called when the GEM handle count goes down to 0. + * It is currently used by AMDGPU driver to release their exported BO + * handles. + * + * This callback is optional. + */ + void (*handle_free)(struct drm_gem_object *obj); + /** * @vm_ops: *