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>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8aae462f4e01..b120cffae1ee 100644
--- 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