On Thu, May 14, 2020 at 09:16:54AM +0200, Thomas Zimmermann wrote:
Hi
Am 11.05.20 um 11:35 schrieb Daniel Vetter:
There's no direct harm, because for the shmem helpers these are noops on imported buffers. The trouble is in the locks these take - I want to change dma_buf_vmap locking, and so need to make sure that we only ever take certain locks on one side of the dma-buf interface: Either for exporters, or for importers.
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 | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 2a70159d50ef..b9cba5cc61c3 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -252,32 +252,33 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) if (shmem->vmap_use_count++ > 0) return shmem->vaddr;
- ret = drm_gem_shmem_get_pages(shmem);
- if (ret)
goto err_zero_use;- if (obj->import_attach) { shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); } else { pgprot_t prot = PAGE_KERNEL;
ret = drm_gem_shmem_get_pages(shmem);if (ret)goto err;if (!shmem->map_cached) prot = pgprot_writecombine(prot); shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, prot);
if (!shmem->vaddr)drm_gem_shmem_put_pages(shmem);}
if (!shmem->vaddr) { DRM_DEBUG_KMS("Failed to vmap pages\n"); ret = -ENOMEM;
goto err_put_pages;
goto err;}
return shmem->vaddr;
-err_put_pages:
- drm_gem_shmem_put_pages(shmem);
I found the new code to be less readable. Maybe keep the error rollback as-is and protect _put_pages() with if (!import_attach).
Hm yeah I guess I can leave this as-is mostly, makes at least the diff smaller. Imo it all looks a bit awkward, but what I've done isn't clearly better than just leaving stuff mostly where it was. -Daniel
In any case
Acked-by: Thomas Zimmermann tzimmermann@suse.de
-err_zero_use: +err: shmem->vmap_use_count = 0;
return ERR_PTR(ret);
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer