diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 15 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/arm,smmu.txt | 28 |
2 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index e4c9e0e46b95..130e7ecaf9a6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1578,6 +1578,15 @@ extended tables themselves, and also PASID support. With this option set, extended tables will not be used even on hardware which claims to support them. + tboot_noforce [Default Off] + Do not force the Intel IOMMU enabled under tboot. + By default, tboot will force Intel IOMMU on, which + could harm performance of some high-throughput + devices like 40GBit network cards, even if identity + mapping is enabled. + Note that using this option lowers the security + provided by tboot because it makes the system + vulnerable to DMA attacks. intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. @@ -1644,6 +1653,12 @@ nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. + iommu.passthrough= + [ARM64] Configure DMA to bypass the IOMMU by default. + Format: { "0" | "1" } + 0 - Use IOMMU translation for DMA. + 1 - Bypass the IOMMU for DMA. + unset - Use IOMMU translation for DMA. io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt index 6cdf32d037fc..8a6ffce12af5 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt @@ -60,6 +60,17 @@ conditions. aliases of secure registers have to be used during SMMU configuration. +- stream-match-mask : For SMMUs supporting stream matching and using + #iommu-cells = <1>, specifies a mask of bits to ignore + when matching stream IDs (e.g. this may be programmed + into the SMRn.MASK field of every stream match register + used). For cases where it is desirable to ignore some + portion of every Stream ID (e.g. for certain MMU-500 + configurations given globally unique input IDs). This + property is not valid for SMMUs using stream indexing, + or using stream matching with #iommu-cells = <2>, and + may be ignored if present in such cases. + ** Deprecated properties: - mmu-masters (deprecated in favour of the generic "iommus" binding) : @@ -109,3 +120,20 @@ conditions. master3 { iommus = <&smmu2 1 0x30>; }; + + + /* ARM MMU-500 with 10-bit stream ID input configuration */ + smmu3: iommu { + compatible = "arm,mmu-500", "arm,smmu-v2"; + ... + #iommu-cells = <1>; + /* always ignore appended 5-bit TBU number */ + stream-match-mask = 0x7c00; + }; + + bus { + /* bus whose child devices emit one unique 10-bit stream + ID each, but may master through multiple SMMU TBUs */ + iommu-map = <0 &smmu3 0 0x400>; + ... + }; |