[PATCH 5/9] xen: enable swiotlb for xen domain 0.

From: Jeremy Fitzhardinge
Date: Thu May 07 2009 - 20:39:26 EST


From: Ian Campbell <ian.campbell@xxxxxxxxxx>

Impact: Xen DMA support

Enable swiotlb when running as a Xen dom0 domain.

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/Kconfig | 1 +
drivers/pci/xen-iommu.c | 5 +++++
include/xen/swiotlb.h | 9 +++++++++
4 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 861c869..2d8dd35 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -11,6 +11,8 @@
#include <asm/swiotlb.h>
#include <asm/dma.h>

+#include <xen/swiotlb.h>
+
int swiotlb __read_mostly;

static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -49,6 +51,9 @@ void __init pci_swiotlb_init(void)
if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
+ if (xen_wants_swiotlb())
+ swiotlb = 1;
+
if (swiotlb_force)
swiotlb = 1;
if (swiotlb) {
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 87c13db..2c85967 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -6,6 +6,7 @@ config XEN
bool "Xen guest support"
select PARAVIRT
select PARAVIRT_CLOCK
+ select SWIOTLB
depends on X86_64 || (X86_32 && X86_PAE && !X86_VISWS)
depends on X86_CMPXCHG && X86_TSC
help
diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
index 994671c..4625143 100644
--- a/drivers/pci/xen-iommu.c
+++ b/drivers/pci/xen-iommu.c
@@ -60,6 +60,11 @@ void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
}
}

+int xen_wants_swiotlb(void)
+{
+ return xen_initial_domain();
+}
+
dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
{
return phys_to_machine(XPADDR(paddr)).maddr;
diff --git a/include/xen/swiotlb.h b/include/xen/swiotlb.h
index 8b51ff7..75d1da1 100644
--- a/include/xen/swiotlb.h
+++ b/include/xen/swiotlb.h
@@ -6,4 +6,13 @@ 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);

+#ifdef CONFIG_PCI_XEN
+extern int xen_wants_swiotlb(void);
+#else
+static inline int xen_wants_swiotlb(void)
+{
+ return 0;
+}
+#endif
+
#endif /* _XEN_SWIOTLB_H */
--
1.6.0.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/