This fixes a FIXME in src/cpu/amd/mtrr/amd_mtrr.c and shuts up the

Linux kernel, which was previously complaining that the MTRR setup
is wrong, if the cpu supports more than CONFIG_CPU_ADDR_BITS bits of
address space.

Shamelessly copied from Linux arch/x86/kernel/cpu/mtrr/main.c

Signed-off-by: Tobias Diedrich <ranma+coreboot@tdiedrich.de>
Acked-by: Scott Duplichan <scott@notabs.org>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6052 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

diff --git a/src/cpu/amd/mtrr/amd_mtrr.c b/src/cpu/amd/mtrr/amd_mtrr.c
index c113f3f8fa831e7ce0a7aa62f6c8d7860831d954..26f4cbe80a886c368dd7b62ae897061129362d00 100644 (file)
--- a/src/cpu/amd/mtrr/amd_mtrr.c
+++ b/src/cpu/amd/mtrr/amd_mtrr.c
@@ -1,5 +1,6 @@
 #include <console/console.h>
 #include <device/device.h>
+#include <arch/cpu.h>
 #include <cpu/x86/mtrr.h>
 #include <cpu/amd/mtrr.h>
 #include <cpu/x86/cache.h>
@@ -175,11 +176,13 @@ void amd_setup_mtrrs(void)
 
        enable_cache();
 
-       /* FIXME we should probably query the cpu for this
-        * but so far this is all any recent AMD cpu has supported.
-        */
        address_bits = CONFIG_CPU_ADDR_BITS; //K8 could be 40, and GH could be 48
 
+       /* AMD specific cpuid function to query number of address bits */
+       if (cpuid_eax(0x80000000) >= 0x80000008) {
+               address_bits = cpuid_eax(0x80000008) & 0xff;
+       }
+
        /* Now that I have mapped what is memory and what is not
         * Setup the mtrrs so we can cache the memory.
         */