When allocating the swiotlb buffer under Xen, make sure the memory is
physically contiguous so that its really suitable for DMA.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/kernel/pci-swiotlb.c | 17 +++++++++++++++--
drivers/pci/xen-iommu.c | 16 ++++++++++++++++
include/xen/swiotlb.h | 12 ++++++++++++
3 files changed, 43 insertions(+), 2 deletions(-)
create mode 100644 include/xen/swiotlb.h
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 34f12e9..a7b9410 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -11,16 +11,29 @@
#include <asm/swiotlb.h>
#include <asm/dma.h>
+#include <xen/swiotlb.h>
+#include <asm/xen/hypervisor.h>
+
int swiotlb __read_mostly;
void * __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
{
- return alloc_bootmem_low_pages(size);
+ void *ret = alloc_bootmem_low_pages(size);
+
+ if (ret && xen_pv_domain())
+ xen_swiotlb_fixup(ret, size, nslabs);
+
+ return ret;
}
void *swiotlb_alloc(unsigned order, unsigned long nslabs)
{
- return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
+ void *ret = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
+
+ if (ret && xen_pv_domain())
+ xen_swiotlb_fixup(ret, 1u << order, nslabs);
+
+ return ret;
}
dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
index 5b701e8..dc0da76 100644
--- a/drivers/pci/xen-iommu.c
+++ b/drivers/pci/xen-iommu.c
@@ -12,6 +12,7 @@
#include <xen/grant_table.h>
#include <xen/page.h>
#include <xen/xen-ops.h>
+#include <xen/swiotlb.h>
#include <asm/iommu.h>
#include <asm/swiotlb.h>
@@ -42,6 +43,21 @@ struct dma_coherent_mem {
unsigned long *bitmap;
};
+void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
+{
+ unsigned order = get_order(size);
+
+ printk(KERN_DEBUG "xen_swiotlb_fixup: buf=%p size=%zu order=%u\n",
+ buf, size, order);
+
+ if (WARN_ON(size != (PAGE_SIZE << order)))
+ return;
+
+ if (xen_create_contiguous_region((unsigned long)buf,
+ order, 0xffffffff))
+ printk(KERN_ERR "xen_create_contiguous_region failed\n");
+}
+
static inline int address_needs_mapping(struct device *hwdev,
dma_addr_t addr)
{
diff --git a/include/xen/swiotlb.h b/include/xen/swiotlb.h
new file mode 100644
index 0000000..8d59439
--- /dev/null
+++ b/include/xen/swiotlb.h
@@ -0,0 +1,12 @@
+#ifndef _XEN_SWIOTLB_H
+#define _XEN_SWIOTLB_H
+
+#ifdef CONFIG_PCI_XEN
+extern void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs);
+#else
+static inline void xen_swiotlb_fixup(void *buf, size_t size, unsigned long
nslabs)
+{
+}
+#endif
+
+#endif /* _XEN_SWIOTLB_H */
--
1.6.0.6
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