x86: Geode Multi-Function General Purpose Timers support

This adds support for Multi-Function General Purpose Timers.  It detects the
available timers during southbridge init, and provides an API for allocating
and setting the timers.  They're higher resolution than the standard PIT, so
the MFGPTs come in handy for quite a few things.

Note that we never clobber the timers that the BIOS might have opted to use;
we just check for unused timers.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a57c1f216b21..2128de6d80ea 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1160,6 +1160,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
         nomce           [X86-32] Machine Check Exception
 
+        nomfgpt         [X86-32] Disable Multi-Function General Purpose
+                        Timer usage (for AMD Geode machines).
+
         noreplace-paravirt      [X86-32,PV_OPS] Don't patch paravirt_ops
 
         noreplace-smp   [X86-32,SMP] Don't replace SMP instructions