[PATCH 1/2] dma-mapping: Add dma_release_coherent_memory to DMA API
Mark-PK Tsai
mark-pk.tsai at mediatek.com
Thu Apr 21 23:24:35 PDT 2022
Add dma_release_coherent_memory to DMA API to allow dma
user call it to release dev->dma_mem when the device is
removed.
Signed-off-by: Mark-PK Tsai <mark-pk.tsai at mediatek.com>
---
include/linux/dma-map-ops.h | 3 +++
kernel/dma/coherent.c | 10 ++++++++--
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index 0d5b06b3a4a6..53db9655efe9 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -166,6 +166,7 @@ static inline void dma_pernuma_cma_reserve(void) { }
#ifdef CONFIG_DMA_DECLARE_COHERENT
int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size);
+void dma_release_coherent_memory(struct device *dev);
int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret);
int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr);
@@ -177,6 +178,8 @@ static inline int dma_declare_coherent_memory(struct device *dev,
{
return -ENOSYS;
}
+
+#define dma_release_coherent_memory(dev) (0)
#define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0)
#define dma_release_from_dev_coherent(dev, order, vaddr) (0)
#define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0)
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index 375fb3c9538d..c21abc77c53e 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -74,7 +74,7 @@ static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr,
return ERR_PTR(-ENOMEM);
}
-static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
+static void _dma_release_coherent_memory(struct dma_coherent_mem *mem)
{
if (!mem)
return;
@@ -126,10 +126,16 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
ret = dma_assign_coherent_memory(dev, mem);
if (ret)
- dma_release_coherent_memory(mem);
+ _dma_release_coherent_memory(mem);
return ret;
}
+void dma_release_coherent_memory(struct device *dev)
+{
+ if (dev)
+ _dma_release_coherent_memory(dev->dma_mem);
+}
+
static void *__dma_alloc_from_coherent(struct device *dev,
struct dma_coherent_mem *mem,
ssize_t size, dma_addr_t *dma_handle)
--
2.18.0
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