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Diffstat (limited to 'arch/x86/kernel/pci-swiotlb.c')
-rw-r--r--arch/x86/kernel/pci-swiotlb.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 1e23577e17cf..677077510e30 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -6,12 +6,14 @@
#include <linux/swiotlb.h>
#include <linux/bootmem.h>
#include <linux/dma-mapping.h>
+#include <linux/mem_encrypt.h>
#include <asm/iommu.h>
#include <asm/swiotlb.h>
#include <asm/dma.h>
#include <asm/xen/swiotlb-xen.h>
#include <asm/iommu_table.h>
+
int swiotlb __read_mostly;
void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -79,8 +81,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
pci_swiotlb_late_init);
/*
- * if 4GB or more detected (and iommu=off not set) return 1
- * and set swiotlb to 1.
+ * If 4GB or more detected (and iommu=off not set) or if SME is active
+ * then set swiotlb to 1 and return 1.
*/
int __init pci_swiotlb_detect_4gb(void)
{
@@ -89,6 +91,15 @@ int __init pci_swiotlb_detect_4gb(void)
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
+
+ /*
+ * If SME is active then swiotlb will be set to 1 so that bounce
+ * buffers are allocated and used for devices that do not support
+ * the addressing range required for the encryption mask.
+ */
+ if (sme_active())
+ swiotlb = 1;
+
return swiotlb;
}
IOMMU_INIT(pci_swiotlb_detect_4gb,