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authorAlexander Duyck <alexander.h.duyck@intel.com>2016-11-02 14:12:47 +0300
committerKonrad Rzeszutek Wilk <konrad@kernel.org>2016-11-07 23:06:32 +0300
commit7641842164c34b672ef3e70e881e8a72735305c1 (patch)
tree3cc9ce655ba49870ff070225b231f1d2074566b3
parentebcf6f979d55f35dfe36956364f0dce8c738220b (diff)
downloadlinux-7641842164c34b672ef3e70e881e8a72735305c1.tar.xz
swiotlb-xen: Enforce return of DMA_ERROR_CODE in mapping function
The mapping function should always return DMA_ERROR_CODE when a mapping has failed as this is what the DMA API expects when a DMA error has occurred. The current function for mapping a page in Xen was returning either DMA_ERROR_CODE or 0 depending on where it failed. On x86 DMA_ERROR_CODE is 0, but on other architectures such as ARM it is ~0. We need to make sure we return the same error value if either the mapping failed or the device is not capable of accessing the mapping. If we are returning DMA_ERROR_CODE as our error value we can drop the function for checking the error code as the default is to compare the return value against DMA_ERROR_CODE if no function is defined. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
-rw-r--r--arch/arm/xen/mm.c1
-rw-r--r--arch/x86/xen/pci-swiotlb-xen.c1
-rw-r--r--drivers/xen/swiotlb-xen.c18
-rw-r--r--include/xen/swiotlb-xen.h3
4 files changed, 6 insertions, 17 deletions
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index d062f08f5020..bd62d94f8ac5 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -186,7 +186,6 @@ struct dma_map_ops *xen_dma_ops;
EXPORT_SYMBOL(xen_dma_ops);
static struct dma_map_ops xen_swiotlb_dma_ops = {
- .mapping_error = xen_swiotlb_dma_mapping_error,
.alloc = xen_swiotlb_alloc_coherent,
.free = xen_swiotlb_free_coherent,
.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index 0e98e5d241d0..a9fafb5c8738 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -19,7 +19,6 @@
int xen_swiotlb __read_mostly;
static struct dma_map_ops xen_swiotlb_dma_ops = {
- .mapping_error = xen_swiotlb_dma_mapping_error,
.alloc = xen_swiotlb_alloc_coherent,
.free = xen_swiotlb_free_coherent,
.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 87e6035c9e81..b8014bf2b2ed 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -416,11 +416,12 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
/*
* Ensure that the address returned is DMA'ble
*/
- if (!dma_capable(dev, dev_addr, size)) {
- swiotlb_tbl_unmap_single(dev, map, size, dir);
- dev_addr = 0;
- }
- return dev_addr;
+ if (dma_capable(dev, dev_addr, size))
+ return dev_addr;
+
+ swiotlb_tbl_unmap_single(dev, map, size, dir);
+
+ return DMA_ERROR_CODE;
}
EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
@@ -648,13 +649,6 @@ xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
}
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device);
-int
-xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
-{
- return !dma_addr;
-}
-EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error);
-
/*
* Return whether the given device DMA address mask can be supported
* properly. For example, if your device can only drive the low 24-bits
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index 7c35e279d1e3..a0083be5d529 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -51,9 +51,6 @@ xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
int nelems, enum dma_data_direction dir);
extern int
-xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
-
-extern int
xen_swiotlb_dma_supported(struct device *hwdev, u64 mask);
extern int