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Diffstat (limited to 'arch/x86/kernel/pci-dma.c')
-rw-r--r--arch/x86/kernel/pci-dma.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index b49d00da2ae..1c4d769e21e 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -1,6 +1,7 @@
#include <linux/dma-mapping.h>
#include <linux/dma-debug.h>
#include <linux/dmar.h>
+#include <linux/export.h>
#include <linux/bootmem.h>
#include <linux/gfp.h>
#include <linux/pci.h>
@@ -44,6 +45,15 @@ int iommu_detected __read_mostly = 0;
*/
int iommu_pass_through __read_mostly;
+/*
+ * Group multi-function PCI devices into a single device-group for the
+ * iommu_device_group interface. This tells the iommu driver to pretend
+ * it cannot distinguish between functions of a device, exposing only one
+ * group for the device. Useful for disallowing use of individual PCI
+ * functions from userspace drivers.
+ */
+int iommu_group_mf __read_mostly;
+
extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
/* Dummy device used for NULL arguments (normally ISA). */
@@ -117,8 +127,8 @@ again:
}
/*
- * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
- * documentation.
+ * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel
+ * parameter documentation.
*/
static __init int iommu_setup(char *p)
{
@@ -168,6 +178,8 @@ static __init int iommu_setup(char *p)
#endif
if (!strncmp(p, "pt", 2))
iommu_pass_through = 1;
+ if (!strncmp(p, "group_mf", 8))
+ iommu_group_mf = 1;
gart_parse_options(p);