x86, AMD IOMMU: more verbose Kconfig description text

This patch replaces the short description text for AMD IOMMU in Kconfig with a
more verbose one.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: robert.richter@amd.com
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8aae462f4e0152364aaf56e5075c59263e4ec2b9..b120cffae1ee3e600e75b3b80b9969cb2b71701c 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -554,7 +554,15 @@ config AMD_IOMMU
        select SWIOTLB
        depends on X86_64 && PCI && ACPI
        help
-         Select this to get support for AMD IOMMU hardware in your system.
+         With this option you can enable support for AMD IOMMU hardware in
+         your system. An IOMMU is a hardware component which provides
+         remapping of DMA memory accesses from devices. With an AMD IOMMU you
+         can isolate the the DMA memory of different devices and protect the
+         system from misbehaving device drivers or hardware.
+
+         You can find out if your system has an AMD IOMMU if you look into
+         your BIOS for an option to enable it or if you have an IVRS ACPI
+         table.
 
 # need this always selected by IOMMU for the VIA workaround
 config SWIOTLB