Am 18.03.25 um 20:22 schrieb Daniel Almeida:

From: Asahi Lina lina@asahilina.net

Drivers may want to support driver-private objects, which cannot be shared. This allows them to share a single lock and enables other optimizations.

Add an `exportable` field to drm_gem_object, which blocks PRIME export if set to false. It is initialized to true in drm_gem_private_object_init.

We already have a method for doing that which is used by almost all drivers (except for lsdc).

Basically you just create a function which checks the per-requisites if a buffer can be exported before calling drm_gem_prime_export() and installs that as .export callback into the drm_gem_object_funcs.

See amdgpu_gem_prime_export() for a simpler example.

Regards, Christian.

Signed-off-by: Asahi Lina lina@asahilina.net Signed-off-by: Daniel Almeida daniel.almeida@collabora.com

---

drivers/gpu/drm/drm_gem.c | 1 + drivers/gpu/drm/drm_prime.c | 5 +++++ include/drm/drm_gem.h | 8 ++++++++ 3 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index ee811764c3df4b4e9c377a66afd4967512ba2001..8f998fe6beecd285ce3e2d5badfa95eb7d7bd548 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -195,6 +195,7 @@ void drm_gem_private_object_init(struct drm_device *dev, drm_vma_node_reset(&obj->vma_node); INIT_LIST_HEAD(&obj->lru_node);

• obj->exportable = true;

} EXPORT_SYMBOL(drm_gem_private_object_init); diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 32a8781cfd67b82ece7b7b94625715171bb41917..20aa350280abe9a6ed6742e131ff50c65bc9dfa9 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -387,6 +387,11 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev, return dmabuf; }

• if (!obj->exportable) {

• dmabuf = ERR_PTR(-EINVAL);
  

• return dmabuf;
  

• }
• if (obj->funcs && obj->funcs->export) dmabuf = obj->funcs->export(obj, flags); else

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index fdae947682cd0b7b06db5e35e120f049a0f30179..f700e4996eccb92597cca6b8c3df8e35b864c1e1 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -432,6 +432,14 @@ struct drm_gem_object { * The current LRU list that the GEM object is on. */ struct drm_gem_lru *lru;

• /**

• * @exportable:
  

• *
  

• * Whether this GEM object can be exported via the drm_gem_object_funcs->export
  

• * callback. Defaults to true.
  

• */
  

• bool exportable;

}; /**