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authorDmitry Osipenko <dmitry.osipenko@collabora.com>2022-10-17 19:22:24 +0200
committerDmitry Osipenko <dmitry.osipenko@collabora.com>2022-10-18 00:21:50 +0200
commit809d9c72c2f83ef7225379908e125eb4b662232c (patch)
treedb1899ecd7aac5b1f3c509669a2783d26c582039
parentdma-buf: Move dma_buf_vmap() to dynamic locking specification (diff)
downloadlinux-809d9c72c2f83ef7225379908e125eb4b662232c.tar.xz
linux-809d9c72c2f83ef7225379908e125eb4b662232c.zip
dma-buf: Move dma_buf_attach() to dynamic locking specification
Move dma-buf attachment API functions to the dynamic locking specification by taking the reservation lock around the mapping operations. The strict locking convention prevents deadlock situations for dma-buf importers and exporters. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-17-dmitry.osipenko@collabora.com
-rw-r--r--drivers/dma-buf/dma-buf.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 2c4381bb9478..d685a5adb122 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -859,8 +859,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
dma_buf_is_dynamic(dmabuf)) {
struct sg_table *sgt;
+ dma_resv_lock(attach->dmabuf->resv, NULL);
if (dma_buf_is_dynamic(attach->dmabuf)) {
- dma_resv_lock(attach->dmabuf->resv, NULL);
ret = dmabuf->ops->pin(attach);
if (ret)
goto err_unlock;
@@ -873,8 +873,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
ret = PTR_ERR(sgt);
goto err_unpin;
}
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
attach->sgt = sgt;
attach->dir = DMA_BIDIRECTIONAL;
}
@@ -890,8 +889,7 @@ err_unpin:
dmabuf->ops->unpin(attach);
err_unlock:
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
dma_buf_detach(dmabuf, attach);
return ERR_PTR(ret);
@@ -937,21 +935,19 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
if (WARN_ON(!dmabuf || !attach))
return;
+ dma_resv_lock(attach->dmabuf->resv, NULL);
+
if (attach->sgt) {
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_lock(attach->dmabuf->resv, NULL);
__unmap_dma_buf(attach, attach->sgt, attach->dir);
- if (dma_buf_is_dynamic(attach->dmabuf)) {
+ if (dma_buf_is_dynamic(attach->dmabuf))
dmabuf->ops->unpin(attach);
- dma_resv_unlock(attach->dmabuf->resv);
- }
}
-
- dma_resv_lock(dmabuf->resv, NULL);
list_del(&attach->node);
+
dma_resv_unlock(dmabuf->resv);
+
if (dmabuf->ops->detach)
dmabuf->ops->detach(dmabuf, attach);