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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-15 12:58:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-15 12:58:58 -0700
commit486088bc4689f826b80aa317b45ac9e42e8b25ee (patch)
treeadf5847a6119d24da990d9e336f005c4a316e6be /Documentation/Intel-IOMMU.txt
parent52f6c588c77b76d548201470c2a28263a41b462b (diff)
parent43e5f7e1fa66531777c49791014c3124ea9208d8 (diff)
Merge tag 'standardize-docs' of git://git.lwn.net/linux
Pull documentation format standardization from Jonathan Corbet: "This series converts a number of top-level documents to the RST format without incorporating them into the Sphinx tree. The hope is to bring some uniformity to kernel documentation and, perhaps more importantly, have our existing docs serve as an example of the desired formatting for those that will be added later. Mauro has gone through and fixed up a lot of top-level documentation files to make them conform to the RST format, but without moving or renaming them in any way. This will help when we incorporate the ones we want to keep into the Sphinx doctree, but the real purpose is to bring a bit of uniformity to our documentation and let the top-level docs serve as examples for those writing new ones" * tag 'standardize-docs' of git://git.lwn.net/linux: (84 commits) docs: kprobes.txt: Fix whitespacing tee.txt: standardize document format cgroup-v2.txt: standardize document format dell_rbu.txt: standardize document format zorro.txt: standardize document format xz.txt: standardize document format xillybus.txt: standardize document format vfio.txt: standardize document format vfio-mediated-device.txt: standardize document format unaligned-memory-access.txt: standardize document format this_cpu_ops.txt: standardize document format svga.txt: standardize document format static-keys.txt: standardize document format smsc_ece1099.txt: standardize document format SM501.txt: standardize document format siphash.txt: standardize document format sgi-ioc4.txt: standardize document format SAK.txt: standardize document format rpmsg.txt: standardize document format robust-futexes.txt: standardize document format ...
Diffstat (limited to 'Documentation/Intel-IOMMU.txt')
-rw-r--r--Documentation/Intel-IOMMU.txt37
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
----