From 11f38236f7bb51c04164e0f5a9630cc6b2f9e099 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 30 May 2023 01:39:33 +0300 Subject: [PATCH] drm: Don't assert held reservation lock for dma-buf mmapping MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Don't assert held dma-buf reservation lock on memory mapping of exported buffer. We're going to change dma-buf mmap() locking policy such that exporters will have to handle the lock. The previous locking policy caused deadlock problem for DRM drivers in a case of self-imported dma-bufs once these drivers are moved to use reservation lock universally. The problem is solved by moving the lock down to exporters. This patch prepares DRM drivers for the locking policy update. Reviewed-by: Emil Velikov Acked-by: Christian König Signed-off-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-2-dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-3-dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-4-dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-2-dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-3-dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-4-dmitry.osipenko@collabora.com --- drivers/gpu/drm/drm_prime.c | 2 -- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 2 -- drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 2 -- drivers/gpu/drm/tegra/gem.c | 2 -- 4 files changed, 8 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 6bcf324ef81c96..f9d4e228b09ea0 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -778,8 +778,6 @@ int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) { struct drm_gem_object *obj = dma_buf->priv; - dma_resv_assert_held(dma_buf->resv); - return drm_gem_prime_mmap(obj, vma); } EXPORT_SYMBOL(drm_gem_dmabuf_mmap); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c index fd556a076d0516..1df74f7aa3dcbd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c @@ -97,8 +97,6 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct * struct drm_i915_private *i915 = to_i915(obj->base.dev); int ret; - dma_resv_assert_held(dma_buf->resv); - if (obj->base.size < vma->vm_end - vma->vm_start) return -EINVAL; diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c index 3abc47521b2c97..8e194dbc95066e 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c +++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c @@ -66,8 +66,6 @@ static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, struct drm_gem_object *obj = buffer->priv; int ret = 0; - dma_resv_assert_held(buffer->resv); - ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma); if (ret < 0) return ret; diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index dea38892d6e66e..a4023163493dca 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -694,8 +694,6 @@ static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma) struct drm_gem_object *gem = buf->priv; int err; - dma_resv_assert_held(buf->resv); - err = drm_gem_mmap_obj(gem, gem->size, vma); if (err < 0) return err;