[PATCH 5.15 226/279] drm/cma-helper: Release non-coherent memory with dma_free_noncoherent()

Greg Kroah-Hartman
2021-11-24T14:03:43Z

From: Thomas Zimmermann <tzimmermann@suse.de>

commit 995f54ea962e03ec08b8bc6a4fe11a32b420edd3 upstream.

The GEM CMA helpers allocate non-coherent (i.e., cached) backing storage
with dma_alloc_noncoherent(), but release it with dma_free_wc(). Fix this
with a call to dma_free_noncoherent(). Writecombining storage is still
released with dma_free_wc().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: cf8ccbc72d61 ("drm: Add support for GEM buffers backed by non-coherent memory")
Acked-by: Paul Cercueil <paul@crapouillou.net>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20210708175146.10618-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/drm_gem_cma_helper.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -210,8 +210,13 @@ void drm_gem_cma_free_object(struct drm_
dma_buf_vunmap(gem_obj->import_attach->dmabuf, &map);
drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
} else if (cma_obj->vaddr) {
- dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
- cma_obj->vaddr, cma_obj->paddr);
+ if (cma_obj->map_noncoherent)
+ dma_free_noncoherent(gem_obj->dev->dev, cma_obj->base.size,
+ cma_obj->vaddr, cma_obj->paddr,
+ DMA_TO_DEVICE);
+ else
+ dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
+ cma_obj->vaddr, cma_obj->paddr);
}

drm_gem_object_release(gem_obj);