From c263b4471dd42895b409652b3f3567fcb5cdaae1 Mon Sep 17 00:00:00 2001 From: Marco Schmidt Date: Sat, 6 Jun 2009 11:21:52 +0000 Subject: Fix for Erratum 343 for AMD Fam10h CPUs. Signed-off-by: Marco Schmidt Acked-by: Patrick Georgi Acked-by: Stefan Reinauer git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4345 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- src/cpu/amd/car/cache_as_ram.inc | 18 ++++++++++++++++++ src/cpu/amd/car/post_cache_as_ram.c | 14 ++++++++++++++ 2 files changed, 32 insertions(+) (limited to 'src/cpu/amd') diff --git a/src/cpu/amd/car/cache_as_ram.inc b/src/cpu/amd/car/cache_as_ram.inc index 162680db73..94990a66f7 100644 --- a/src/cpu/amd/car/cache_as_ram.inc +++ b/src/cpu/amd/car/cache_as_ram.inc @@ -27,6 +27,8 @@ /* for CAR_FAM10 */ #define CacheSizeAPStack 0x400 /* 1K */ +#define MSR_FAM10 0xC001102A + #define jmp_if_k8(x) comisd %xmm2, %xmm1; jb x #define CPUID_MASK 0x0ff00f00 @@ -122,6 +124,22 @@ CAR_FAM10_out: bts $15, %eax wrmsr + /* Erratum 343, RevGuide for Fam10h, Pub#41322 Rev. 3.33 */ + + /* read-address has to be stored in the ecx register */ + movl $MSR_FAM10, %ecx + + /* execute special read command for msr-register. Result is then in the EDX:EAX-registers (MSBs in EDX) */ + rdmsr + + /* Set bit 35 to 1 in EAX */ + bts $35, %eax + + /* write back the modified register EDX:EAX to the MSR specified in ECX */ + wrmsr + + /* Erratum 343 end */ + CAR_FAM10_out_post_errata: /* Set MtrrFixDramModEn for clear fixed mtrr */ diff --git a/src/cpu/amd/car/post_cache_as_ram.c b/src/cpu/amd/car/post_cache_as_ram.c index ce8ef19647..89366e0e33 100644 --- a/src/cpu/amd/car/post_cache_as_ram.c +++ b/src/cpu/amd/car/post_cache_as_ram.c @@ -23,7 +23,19 @@ static void inline __attribute__((always_inline)) memcopy(void *dest, const voi : "S" (src), "D" (dest), "c" ((bytes)>>2) ); } +/* Disable Erratum 343 Workaround, see RevGuide for Fam10h, Pub#41322 Rev 3.33 */ +static void vErrata343(void) +{ + msr_t msr; + unsigned int uiMask = 0xFFFFFFF7; + +#ifdef BU_CFG2_MSR + msr = rdmsr(BU_CFG2_MSR); + msr.hi &= uiMask; // set bit 35 to 0 + wrmsr(BU_CFG2_MSR, msr); +#endif +} static void post_cache_as_ram(void) { @@ -56,6 +68,8 @@ static void post_cache_as_ram(void) print_debug("Copying data from cache to RAM -- switching to use RAM as stack... "); /* from here don't store more data in CAR */ + vErrata343(); + #if 0 __asm__ volatile ( "pushl %eax\n\t" -- cgit v1.2.3