Merge branches 'arm/omap', 'arm/exynos', 'arm/smmu', 'arm/mediatek', 'arm/qcom',...

[sfrench/cifs-2.6.git] / Documentation / admin-guide / kernel-parameters.txt

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4c1971960afa30484cfe0d2533e9cf28d003662c..d31ffa110461156a8abdf2703514e57e3f42beb9 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1732,6 +1732,11 @@
                        Note that using this option lowers the security
                        provided by tboot because it makes the system
                        vulnerable to DMA attacks.
+               nobounce [Default off]
+                       Disable bounce buffer for unstrusted devices such as
+                       the Thunderbolt devices. This will treat the untrusted
+                       devices as the trusted ones, hence might expose security
+                       risks of DMA attacks.
 
        intel_idle.max_cstate=  [KNL,HW,ACPI,X86]
                        0       disables intel_idle and fall back on acpi_idle.
@@ -1811,7 +1816,7 @@
                          synchronously.
 
        iommu.passthrough=
-                       [ARM64] Configure DMA to bypass the IOMMU by default.
+                       [ARM64, X86] Configure DMA to bypass the IOMMU by default.
                        Format: { "0" | "1" }
                        0 - Use IOMMU translation for DMA.
                        1 - Bypass the IOMMU for DMA.