amdk8: This patch fixes ram init problems when using the 9W Sempron part.

Trying to read the FIDVID register when the processor does not support FIDVID
control causes a GP Fault. This patch reads the startup FID from a different
MSR. I have verified this patch to work on the dbm690t platform.

Signed-off-by: Dan Lykowski <lykowdk@gmail.com>
Acked-by: Peter Stuge <peter@stuge.se>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3863 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

2 files changed, 37 insertions, 10 deletions

diff --git a/src/northbridge/amd/amdk8/raminit_f.c b/src/northbridge/amd/amdk8/raminit_f.c
index a883fa401d..0dcb0f6821 100644
--- a/src/northbridge/amd/amdk8/raminit_f.c
+++ b/src/northbridge/amd/amdk8/raminit_f.c
@@ -1656,14 +1656,28 @@ static uint8_t get_exact_divisor(int i, uint8_t divisor)
 	  /*15*/   200, 160, 120, 100,
 	};
 
-	unsigned fid_cur;
+	
 	int index;
-
 	msr_t msr;
-	msr = rdmsr(0xc0010042);
-	fid_cur = msr.lo & 0x3f;
 
-	index = fid_cur>>1;
+	/* Check for FID control support */
+	struct cpuid_result cpuid1;
+	cpuid1 = cpuid(0x8000007);
+	if( cpuid1.edx & 0x02 ) {
+		/* Use current FID */
+		unsigned fid_cur;
+		msr = rdmsr(0xc0010042);
+		fid_cur = msr.lo & 0x3f;
+
+		index = fid_cur>>1;
+	} else {
+		/* Use startup FID */
+		unsigned fid_start;
+		msr = rdmsr(0xc0010015);
+		fid_start = (msr.lo & (0x3f << 24));
+		
+		index = fid_start>>25;
+	}
 
 	if (index>12) return divisor;
 
diff --git a/src/northbridge/amd/amdk8/raminit_f_dqs.c b/src/northbridge/amd/amdk8/raminit_f_dqs.c
index e8add87a7e..dc49d4e893 100644
--- a/src/northbridge/amd/amdk8/raminit_f_dqs.c
+++ b/src/northbridge/amd/amdk8/raminit_f_dqs.c
@@ -432,14 +432,27 @@ static uint16_t get_exact_T1000(unsigned i)
 	 /*15*/   5000, 4000, 3000, 2500,
 	};
 
-	unsigned fid_cur;
 	int index;
-
 	msr_t msr;
-	msr = rdmsr(0xc0010042);
-	fid_cur = msr.lo & 0x3f;
 
-	index = fid_cur>>1;
+	/* Check for FID control support */
+	struct cpuid_result cpuid1;
+	cpuid1 = cpuid(0x8000007);
+	if( cpuid1.edx & 0x02 ) {
+		/* Use current FID */
+		unsigned fid_cur;
+		msr = rdmsr(0xc0010042);
+		fid_cur = msr.lo & 0x3f;
+
+		index = fid_cur>>1;
+	} else {
+		/* Use startup FID */
+		unsigned fid_start;
+		msr = rdmsr(0xc0010015);
+		fid_start = (msr.lo & (0x3f << 24));
+		
+		index = fid_start>>25;
+	}
 
 	if(index>12) return T1000_a[i];