diff options
Diffstat (limited to 'Documentation')
4 files changed, 111 insertions, 39 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 13f13fdd4731..0081d83457e8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -301,6 +301,9 @@ allowed anymore to lift isolation requirements as needed. This option does not override iommu=pt + force_enable - Force enable the IOMMU on platforms known + to be buggy with IOMMU enabled. Use this + option with care. amd_iommu_dump= [HW,X86-64] Enable AMD IOMMU driver option to dump the ACPI table @@ -2031,7 +2034,7 @@ forcing Dual Address Cycle for PCI cards supporting greater than 32-bit addressing. - iommu.strict= [ARM64] Configure TLB invalidation behaviour + iommu.strict= [ARM64, X86] Configure TLB invalidation behaviour Format: { "0" | "1" } 0 - Lazy mode. Request that DMA unmap operations use deferred @@ -2042,6 +2045,10 @@ 1 - Strict mode (default). DMA unmap operations invalidate IOMMU hardware TLBs synchronously. + Note: on x86, the default behaviour depends on the + equivalent driver-specific parameters, but a strict + mode explicitly specified by either method takes + precedence. iommu.passthrough= [ARM64, X86] Configure DMA to bypass the IOMMU by default. diff --git a/Documentation/devicetree/bindings/iommu/iommu.txt b/Documentation/devicetree/bindings/iommu/iommu.txt index 3c36334e4f94..26ba9e530f13 100644 --- a/Documentation/devicetree/bindings/iommu/iommu.txt +++ b/Documentation/devicetree/bindings/iommu/iommu.txt @@ -92,6 +92,24 @@ Optional properties: tagging DMA transactions with an address space identifier. By default, this is 0, which means that the device only has one address space. +- dma-can-stall: When present, the master can wait for a transaction to + complete for an indefinite amount of time. Upon translation fault some + IOMMUs, instead of aborting the translation immediately, may first + notify the driver and keep the transaction in flight. This allows the OS + to inspect the fault and, for example, make physical pages resident + before updating the mappings and completing the transaction. Such IOMMU + accepts a limited number of simultaneous stalled transactions before + having to either put back-pressure on the master, or abort new faulting + transactions. + + Firmware has to opt-in stalling, because most buses and masters don't + support it. In particular it isn't compatible with PCI, where + transactions have to complete before a time limit. More generally it + won't work in systems and masters that haven't been designed for + stalling. For example the OS, in order to handle a stalled transaction, + may attempt to retrieve pages from secondary storage in a stalled + domain, leading to a deadlock. + Notes: ====== diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt b/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt deleted file mode 100644 index 6ecefea1c6f9..000000000000 --- a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt +++ /dev/null @@ -1,38 +0,0 @@ -Rockchip IOMMU -============== - -A Rockchip DRM iommu translates io virtual addresses to physical addresses for -its master device. Each slave device is bound to a single master device, and -shares its clocks, power domain and irq. - -Required properties: -- compatible : Should be "rockchip,iommu" -- reg : Address space for the configuration registers -- interrupts : Interrupt specifier for the IOMMU instance -- interrupt-names : Interrupt name for the IOMMU instance -- #iommu-cells : Should be <0>. This indicates the iommu is a - "single-master" device, and needs no additional information - to associate with its master device. See: - Documentation/devicetree/bindings/iommu/iommu.txt -- clocks : A list of clocks required for the IOMMU to be accessible by - the host CPU. -- clock-names : Should contain the following: - "iface" - Main peripheral bus clock (PCLK/HCL) (required) - "aclk" - AXI bus clock (required) - -Optional properties: -- rockchip,disable-mmu-reset : Don't use the mmu reset operation. - Some mmu instances may produce unexpected results - when the reset operation is used. - -Example: - - vopl_mmu: iommu@ff940300 { - compatible = "rockchip,iommu"; - reg = <0xff940300 0x100>; - interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>; - interrupt-names = "vopl_mmu"; - clocks = <&cru ACLK_VOP1>, <&cru HCLK_VOP1>; - clock-names = "aclk", "iface"; - #iommu-cells = <0>; - }; diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml new file mode 100644 index 000000000000..d2e28a9e3545 --- /dev/null +++ b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml @@ -0,0 +1,85 @@ +# SPDX-License-Identifier: GPL-2.0-only +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iommu/rockchip,iommu.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Rockchip IOMMU + +maintainers: + - Heiko Stuebner <heiko@sntech.de> + +description: |+ + A Rockchip DRM iommu translates io virtual addresses to physical addresses for + its master device. Each slave device is bound to a single master device and + shares its clocks, power domain and irq. + + For information on assigning IOMMU controller to its peripheral devices, + see generic IOMMU bindings. + +properties: + compatible: + enum: + - rockchip,iommu + - rockchip,rk3568-iommu + + reg: + items: + - description: configuration registers for MMU instance 0 + - description: configuration registers for MMU instance 1 + minItems: 1 + maxItems: 2 + + interrupts: + items: + - description: interruption for MMU instance 0 + - description: interruption for MMU instance 1 + minItems: 1 + maxItems: 2 + + clocks: + items: + - description: Core clock + - description: Interface clock + + clock-names: + items: + - const: aclk + - const: iface + + "#iommu-cells": + const: 0 + + power-domains: + maxItems: 1 + + rockchip,disable-mmu-reset: + $ref: /schemas/types.yaml#/definitions/flag + description: | + Do not use the mmu reset operation. + Some mmu instances may produce unexpected results + when the reset operation is used. + +required: + - compatible + - reg + - interrupts + - clocks + - clock-names + - "#iommu-cells" + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/rk3399-cru.h> + #include <dt-bindings/interrupt-controller/arm-gic.h> + + vopl_mmu: iommu@ff940300 { + compatible = "rockchip,iommu"; + reg = <0xff940300 0x100>; + interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&cru ACLK_VOP1>, <&cru HCLK_VOP1>; + clock-names = "aclk", "iface"; + #iommu-cells = <0>; + }; |