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Diffstat (limited to 'arch/x86_64/kernel/pci-dma.c')
-rw-r--r--arch/x86_64/kernel/pci-dma.c93
1 files changed, 56 insertions, 37 deletions
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 4dcb671..f8d8574 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -170,8 +170,20 @@ void dma_free_coherent(struct device *dev, size_t size,
}
EXPORT_SYMBOL(dma_free_coherent);
+static int forbid_dac __read_mostly;
+
int dma_supported(struct device *dev, u64 mask)
{
+#ifdef CONFIG_PCI
+ if (mask > 0xffffffff && forbid_dac > 0) {
+
+
+
+ printk(KERN_INFO "PCI: Disallowing DAC for device %s\n", dev->bus_id);
+ return 0;
+ }
+#endif
+
if (dma_ops->dma_supported)
return dma_ops->dma_supported(dev, mask);
@@ -231,57 +243,64 @@ EXPORT_SYMBOL(dma_set_mask);
allowed overwrite iommu off workarounds for specific chipsets.
soft Use software bounce buffering (default for Intel machines)
noaperture Don't touch the aperture for AGP.
+ allowdac Allow DMA >4GB
+ nodac Forbid DMA >4GB
+ panic Force panic when IOMMU overflows
*/
__init int iommu_setup(char *p)
{
- iommu_merge = 1;
+ iommu_merge = 1;
if (!p)
return -EINVAL;
- while (*p) {
- if (!strncmp(p,"off",3))
- no_iommu = 1;
- /* gart_parse_options has more force support */
- if (!strncmp(p,"force",5))
- force_iommu = 1;
- if (!strncmp(p,"noforce",7)) {
- iommu_merge = 0;
- force_iommu = 0;
- }
-
- if (!strncmp(p, "biomerge",8)) {
- iommu_bio_merge = 4096;
- iommu_merge = 1;
- force_iommu = 1;
- }
- if (!strncmp(p, "panic",5))
- panic_on_overflow = 1;
- if (!strncmp(p, "nopanic",7))
- panic_on_overflow = 0;
- if (!strncmp(p, "merge",5)) {
- iommu_merge = 1;
- force_iommu = 1;
- }
- if (!strncmp(p, "nomerge",7))
- iommu_merge = 0;
- if (!strncmp(p, "forcesac",8))
- iommu_sac_force = 1;
+ while (*p) {
+ if (!strncmp(p,"off",3))
+ no_iommu = 1;
+ /* gart_parse_options has more force support */
+ if (!strncmp(p,"force",5))
+ force_iommu = 1;
+ if (!strncmp(p,"noforce",7)) {
+ iommu_merge = 0;
+ force_iommu = 0;
+ }
+
+ if (!strncmp(p, "biomerge",8)) {
+ iommu_bio_merge = 4096;
+ iommu_merge = 1;
+ force_iommu = 1;
+ }
+ if (!strncmp(p, "panic",5))
+ panic_on_overflow = 1;
+ if (!strncmp(p, "nopanic",7))
+ panic_on_overflow = 0;
+ if (!strncmp(p, "merge",5)) {
+ iommu_merge = 1;
+ force_iommu = 1;
+ }
+ if (!strncmp(p, "nomerge",7))
+ iommu_merge = 0;
+ if (!strncmp(p, "forcesac",8))
+ iommu_sac_force = 1;
+ if (!strncmp(p, "allowdac", 8))
+ forbid_dac = 0;
+ if (!strncmp(p, "nodac", 5))
+ forbid_dac = -1;
#ifdef CONFIG_SWIOTLB
- if (!strncmp(p, "soft",4))
- swiotlb = 1;
+ if (!strncmp(p, "soft",4))
+ swiotlb = 1;
#endif
#ifdef CONFIG_IOMMU
- gart_parse_options(p);
+ gart_parse_options(p);
#endif
- p += strcspn(p, ",");
- if (*p == ',')
- ++p;
- }
- return 0;
+ p += strcspn(p, ",");
+ if (*p == ',')
+ ++p;
+ }
+ return 0;
}
early_param("iommu", iommu_setup);
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