Hi
Am 03.06.20 um 15:12 schrieb Daniel Vetter:
On Thu, May 14, 2020 at 09:30:04AM +0200, Thomas Zimmermann wrote:
Hi
Am 11.05.20 um 11:35 schrieb Daniel Vetter:
Just a bit of light paranoia. Also sprinkle this check over drm_gem_shmem_get_sg_table, which should only be called when exporting, same for the pin/unpin functions, on which it relies to work correctly.
Cc: Gerd Hoffmann kraxel@redhat.com Cc: Rob Herring robh@kernel.org Cc: Noralf Trønnes noralf@tronnes.org Signed-off-by: Daniel Vetter daniel.vetter@intel.com
drivers/gpu/drm/drm_gem_shmem_helper.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 117a7841e284..f7011338813e 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -170,6 +170,8 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) { int ret;
- WARN_ON(shmem->base.import_attach);
- ret = mutex_lock_interruptible(&shmem->pages_lock); if (ret) return ret;
@@ -225,6 +227,8 @@ int drm_gem_shmem_pin(struct drm_gem_object *obj) { struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
- WARN_ON(shmem->base.import_attach);
I don't understand this change. If a driver pins pages it now has to check that the pages are not imported?
Nope. There's two classes of functions in the helpers, and I'm trying to unconfuse them:
stuff used to implement gem_funcs. These are obviously only ever used on native objects, never on imported ones (on imported ones we try to forward through the dma-buf layer to the exporter). drm_gem_shmem_pin is only used in that role to implement gem_funcs->pin. Calling it on an imported buffer is indeed a bug.
the other set of functions are for drivers to do their stuff. The interface which (implicitly) pins stuff into places is various set of get_pages, which do have different paths for native and imported objects.
Thanks for explaining. Patch is
Acked-by: Thomas Zimmermann tzimmermann@suse.de
Apologies that I missed your question here, I merged all the patches leading up to this one for now.
Thanks, Daniel
return drm_gem_shmem_get_pages(shmem); } EXPORT_SYMBOL(drm_gem_shmem_pin); @@ -240,6 +244,8 @@ void drm_gem_shmem_unpin(struct drm_gem_object *obj) { struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
- WARN_ON(shmem->base.import_attach);
- drm_gem_shmem_put_pages(shmem);
} EXPORT_SYMBOL(drm_gem_shmem_unpin); @@ -510,6 +516,8 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma) struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); int ret;
- WARN_ON(shmem->base.import_attach);
- ret = drm_gem_shmem_get_pages(shmem); WARN_ON_ONCE(ret != 0);
@@ -611,6 +619,8 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj) { struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
- WARN_ON(shmem->base.import_attach);
- return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT);
} EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer