Merge tag 'iommu-updates-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / Documentation / admin-guide / kernel-parameters.txt

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 84dc579..828d114 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -301,10 +301,7 @@
        amd_iommu=      [HW,X86-64]
                        Pass parameters to the AMD IOMMU driver in the system.
                        Possible values are:
-                       fullflush - enable flushing of IO/TLB entries when
-                                   they are unmapped. Otherwise they are
-                                   flushed before they will be reused, which
-                                   is a lot of faster
+                       fullflush - Deprecated, equivalent to iommu.strict=1
                        off       - do not initialize any AMD IOMMU found in
                                    the system
                        force_isolation - Force device isolation for all
@@ -1958,18 +1955,17 @@
                        this case, gfx device will use physical address for
                        DMA.
                strict [Default Off]
-                       With this option on every unmap_single operation will
-                       result in a hardware IOTLB flush operation as opposed
-                       to batching them for performance.
+                       Deprecated, equivalent to iommu.strict=1.
                sp_off [Default Off]
                        By default, super page will be supported if Intel IOMMU
                        has the capability. With this option, super page will
                        not be supported.
-               sm_on [Default Off]
-                       By default, scalable mode will be disabled even if the
-                       hardware advertises that it has support for the scalable
-                       mode translation. With this option set, scalable mode
-                       will be used on hardware which claims to support it.
+               sm_on
+                       Enable the Intel IOMMU scalable mode if the hardware
+                       advertises that it has support for the scalable mode
+                       translation.
+               sm_off
+                       Disallow use of the Intel IOMMU scalable mode.
                tboot_noforce [Default Off]
                        Do not force the Intel IOMMU enabled under tboot.
                        By default, tboot will force Intel IOMMU on, which
@@ -2061,13 +2057,12 @@
                          throughput at the cost of reduced device isolation.
                          Will fall back to strict mode if not supported by
                          the relevant IOMMU driver.
-                       1 - Strict mode (default).
+                       1 - Strict mode.
                          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.
+                       unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
+                       Note: on x86, strict mode specified via one of the
+                       legacy driver-specific options takes precedence.
 
        iommu.passthrough=
                        [ARM64, X86] Configure DMA to bypass the IOMMU by default.