diff options
| -rw-r--r-- | Documentation/Intel-IOMMU.txt | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/Documentation/Intel-IOMMU.txt b/Documentation/Intel-IOMMU.txt index 49585b6e1ea2..9dae6b47e398 100644 --- a/Documentation/Intel-IOMMU.txt +++ b/Documentation/Intel-IOMMU.txt @@ -1,3 +1,4 @@ +=================== Linux IOMMU Support =================== @@ -9,11 +10,11 @@ This guide gives a quick cheat sheet for some basic understanding. Some Keywords -DMAR - DMA remapping -DRHD - DMA Remapping Hardware Unit Definition -RMRR - Reserved memory Region Reporting Structure -ZLR - Zero length reads from PCI devices -IOVA - IO Virtual address. +- DMAR - DMA remapping +- DRHD - DMA Remapping Hardware Unit Definition +- RMRR - Reserved memory Region Reporting Structure +- ZLR - Zero length reads from PCI devices +- IOVA - IO Virtual address. Basic stuff ----------- @@ -33,7 +34,7 @@ devices that need to access these regions. OS is expected to setup unity mappings for these regions for these devices to access these regions. How is IOVA generated? ---------------------- +---------------------- Well behaved drivers call pci_map_*() calls before sending command to device that needs to perform DMA. Once DMA is completed and mapping is no longer @@ -82,14 +83,14 @@ in ACPI. ACPI: DMAR (v001 A M I OEMDMAR 0x00000001 MSFT 0x00000097) @ 0x000000007f5b5ef0 When DMAR is being processed and initialized by ACPI, prints DMAR locations -and any RMRR's processed. +and any RMRR's processed:: -ACPI DMAR:Host address width 36 -ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000 -ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000 -ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000 -ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff -ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff + ACPI DMAR:Host address width 36 + ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000 + ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000 + ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000 + ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff + ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff When DMAR is enabled for use, you will notice.. @@ -98,10 +99,12 @@ PCI-DMA: Using DMAR IOMMU Fault reporting --------------- -DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 -DMAR:[fault reason 05] PTE Write access is not set -DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 -DMAR:[fault reason 05] PTE Write access is not set +:: + + DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 + DMAR:[fault reason 05] PTE Write access is not set + DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 + DMAR:[fault reason 05] PTE Write access is not set TBD ---- |