[PATCH 4/9] xen/swiotlb: add swiotlb_arch_range_needs_mapping hook for xen

[Jeremy Fitzhardinge]

From: Ian Campbell <ian.campbell@xxxxxxxxxx>

Impact: Xen support for DMA

Add hook so that Xen can determine whether a particular address range needs
pfn<->mfn mapping.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
 arch/x86/kernel/pci-swiotlb.c |    5 -----
 arch/x86/xen/pci-swiotlb.c    |    8 ++++++++
 drivers/pci/xen-iommu.c       |    5 +++++
 include/xen/swiotlb.h         |    1 +
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 3216674..861c869 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -13,11 +13,6 @@
 
 int swiotlb __read_mostly;
 
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
-	return 0;
-}
-
 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 					dma_addr_t *dma_handle, gfp_t flags)
 {
diff --git a/arch/x86/xen/pci-swiotlb.c b/arch/x86/xen/pci-swiotlb.c
index 1d43fde..6f248a5 100644
--- a/arch/x86/xen/pci-swiotlb.c
+++ b/arch/x86/xen/pci-swiotlb.c
@@ -43,3 +43,11 @@ phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
 
 	return baddr;
 }
+
+int swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
+{
+	if (xen_pv_domain())
+		return xen_range_needs_mapping(paddr, size);
+
+	return 0;
+}
diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
index e3d6ddb..994671c 100644
--- a/drivers/pci/xen-iommu.c
+++ b/drivers/pci/xen-iommu.c
@@ -119,6 +119,11 @@ static int range_straddles_page_boundary(phys_addr_t p, size_t size)
 	return 1;
 }
 
+int xen_range_needs_mapping(phys_addr_t paddr, size_t size)
+{
+	return range_straddles_page_boundary(paddr, size);
+}
+
 static inline void xen_dma_unmap_page(struct page *page)
 {
 	/* Xen TODO: 2.6.18 xen calls __gnttab_dma_unmap_page here
diff --git a/include/xen/swiotlb.h b/include/xen/swiotlb.h
index 4229f27..8b51ff7 100644
--- a/include/xen/swiotlb.h
+++ b/include/xen/swiotlb.h
@@ -4,5 +4,6 @@
 extern void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs);
 extern phys_addr_t xen_bus_to_phys(dma_addr_t daddr);
 extern dma_addr_t xen_phys_to_bus(phys_addr_t paddr);
+extern int xen_range_needs_mapping(phys_addr_t phys, size_t size);
 
 #endif /* _XEN_SWIOTLB_H */
-- 
1.6.0.6

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