[PATCH v4 4/6] drm: Don't assert held reservation lock for dma-buf mmapping
From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Date: 2023-05-29 22:46:36
Also in:
intel-gfx, linux-media, linux-tegra, lkml
Subsystem:
drm drivers, drm drivers and misc gpu patches, drm drivers for nvidia tegra, drm drivers for ti omap, intel drm i915 driver (meteor lake, dg2 and older excluding poulsbo, moorestown and derivative), the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Thierry Reding, Mikko Perttunen, Tomi Valkeinen, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi, Tvrtko Ursulin, Linus Torvalds
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 <redacted> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <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 149cd4ff6a3b..cea85e84666f 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c@@ -781,8 +781,6 @@ int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) struct drm_gem_object *obj = dma_buf->priv; struct drm_device *dev = obj->dev; - dma_resv_assert_held(dma_buf->resv); - if (!dev->driver->gem_prime_mmap) return -ENOSYS;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index fd556a076d05..1df74f7aa3dc 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 3abc47521b2c..8e194dbc9506 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 bce991a2ccc0..871ef5d26523 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c@@ -693,8 +693,6 @@ 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;
--
2.40.1