[net-next PATCH 02/27] swiotlb-xen: Enforce return of DMA_ERROR_CODE in mapping function
From: Alexander Duyck <hidden>
Date: 2016-10-25 21:38:17
Also in:
intel-wired-lan, linux-mm, lkml
Subsystem:
arm port, the rest, x86 architecture (32-bit and 64-bit), xen hypervisor arm, xen hypervisor interface, xen hypervisor x86, xen swiotlb subsystem · Maintainers:
Russell King, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Stefano Stabellini, Juergen Gross
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 <redacted> Signed-off-by: Alexander Duyck <redacted> --- arch/arm/xen/mm.c | 1 - arch/x86/xen/pci-swiotlb-xen.c | 1 - drivers/xen/swiotlb-xen.c | 18 ++++++------------ include/xen/swiotlb-xen.h | 3 --- 4 files changed, 6 insertions(+), 17 deletions(-)
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index d062f08..bd62d94 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c@@ -186,7 +186,6 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) 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 0e98e5d..a9fafb5 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 87e6035..b8014bf 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 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, } 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 7c35e27..a0083be 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h@@ -51,9 +51,6 @@ extern void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 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 --
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