amd64_edac: Erratum #637 workaround

F15h CPUs may report a non-DRAM address when reporting an error address
belonging to a CC6 state save area. Add a workaround to detect this
condition and compute the actual DRAM address of the error as documented
in the Revision Guide for AMD Family 15h Models 00h-0Fh Processors.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

2 files changed, 51 insertions, 2 deletions

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index e17de90ba6c6..9a8bebcf6b17 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -931,15 +931,63 @@ static int k8_early_channel_count(struct amd64_pvt *pvt)
 /* On F10h and later ErrAddr is MC4_ADDR[47:1] */
 static u64 get_error_address(struct mce *m)
 {
+        struct cpuinfo_x86 *c = &boot_cpu_data;
+        u64 addr;
         u8 start_bit = 1;
         u8 end_bit   = 47;
 
-        if (boot_cpu_data.x86 == 0xf) {
+        if (c->x86 == 0xf) {
                 start_bit = 3;
                 end_bit   = 39;
         }
 
-        return m->addr & GENMASK(start_bit, end_bit);
+        addr = m->addr & GENMASK(start_bit, end_bit);
+
+        /*
+         * Erratum 637 workaround
+         */
+        if (c->x86 == 0x15) {
+                struct amd64_pvt *pvt;
+                u64 cc6_base, tmp_addr;
+                u32 tmp;
+                u8 mce_nid, intlv_en;
+
+                if ((addr & GENMASK(24, 47)) >> 24 != 0x00fdf7)
+                        return addr;
+
+                mce_nid = amd_get_nb_id(m->extcpu);
+                pvt     = mcis[mce_nid]->pvt_info;
+
+                amd64_read_pci_cfg(pvt->F1, DRAM_LOCAL_NODE_LIM, &tmp);
+                intlv_en = tmp >> 21 & 0x7;
+
+                /* add [47:27] + 3 trailing bits */
+                cc6_base  = (tmp & GENMASK(0, 20)) << 3;
+
+                /* reverse and add DramIntlvEn */
+                cc6_base |= intlv_en ^ 0x7;
+
+                /* pin at [47:24] */
+                cc6_base <<= 24;
+
+                if (!intlv_en)
+                        return cc6_base | (addr & GENMASK(0, 23));
+
+                amd64_read_pci_cfg(pvt->F1, DRAM_LOCAL_NODE_BASE, &tmp);
+
+                                                        /* faster log2 */
+                tmp_addr  = (addr & GENMASK(12, 23)) << __fls(intlv_en + 1);
+
+                /* OR DramIntlvSel into bits [14:12] */
+                tmp_addr |= (tmp & GENMASK(21, 23)) >> 9;
+
+                /* add remaining [11:0] bits from original MC4_ADDR */
+                tmp_addr |= addr & GENMASK(0, 11);
+
+                return cc6_base | tmp_addr;
+        }
+
+        return addr;
 }
 
 static void read_dram_base_limit_regs(struct amd64_pvt *pvt, unsigned range)
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 0110930c82ed..9a666cb985b2 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -196,6 +196,7 @@
 
 #define DCT_CFG_SEL                     0x10C
 
+#define DRAM_LOCAL_NODE_BASE            0x120
 #define DRAM_LOCAL_NODE_LIM             0x124
 
 #define DRAM_BASE_HI                    0x140