In case of loadable modules using dma-iommu helpers, it makes sense to
drop the reference to the iova cache on module exit. Add a helper called
iommu_dma_cleanup() that undoes the effects of iommu_dma_init(), so that
modules can be unloaded cleanly.
Signed-off-by: Tomasz Figa <tf...@chromium.org>
---
drivers/iommu/dma-iommu.c | 6 ++++++
include/linux/dma-iommu.h | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7cdeaf930106..51afa18a5de1 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -82,6 +82,12 @@ int iommu_dma_init(void)
}
EXPORT_SYMBOL(iommu_dma_init);
+void iommu_dma_cleanup(void)
+{
+ iova_cache_put();
+}
+EXPORT_SYMBOL(iommu_dma_cleanup);
+
/**
* iommu_get_dma_cookie - Acquire DMA-API resources for a domain
* @domain: IOMMU domain to prepare for DMA-API usage
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 92f20832fd28..b12d9207a87a 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -24,7 +24,9 @@
#include <linux/iommu.h>
#include <linux/msi.h>
+/* Framework initialization - reference counted */
int iommu_dma_init(void);
+void iommu_dma_cleanup(void);
/* Domain management interface for IOMMU drivers */
int iommu_get_dma_cookie(struct iommu_domain *domain);
@@ -85,6 +87,10 @@ static inline int iommu_dma_init(void)
return 0;
}
+static inline void iommu_dma_cleanup(void)
+{
+}
+
static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
{
return -ENODEV;
--
2.13.2.725.g09c95d1e9-goog
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