amd64_edac: Fix syndrome calculation on K8

commit 41c310447fe06bcedc22b75752c18b60e0b9521b upstream.

When calculating the DCT channel from the syndrome we need to know the
syndrome type (x4 vs x8). On F10h, this is read out from extended PCI
cfg space register F3x180 while on K8 we only support x4 syndromes and
don't have extended PCI config space anyway.

Make the code accessing F3x180 F10h only and fall back to x4 syndromes
on everything else.

Reported-by: Jeffrey Merkey <jeffmerkey@gmail.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 3391e6739d06ef32fdfcf56a7dcfc7c9d2347f3b..72904c8736cdf92bd90221809fe7665b72fb0f48 100644 (file)
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1958,20 +1958,20 @@ static int get_channel_from_ecc_syndrome(struct mem_ctl_info *mci, u16 syndrome)
        u32 value = 0;
        int err_sym = 0;
 
-       amd64_read_pci_cfg(pvt->misc_f3_ctl, 0x180, &value);
+       if (boot_cpu_data.x86 == 0x10) {
 
-       /* F3x180[EccSymbolSize]=1, x8 symbols */
-       if (boot_cpu_data.x86 == 0x10 &&
-           boot_cpu_data.x86_model > 7 &&
-           value & BIT(25)) {
-               err_sym = decode_syndrome(syndrome, x8_vectors,
-                                         ARRAY_SIZE(x8_vectors), 8);
-               return map_err_sym_to_channel(err_sym, 8);
-       } else {
-               err_sym = decode_syndrome(syndrome, x4_vectors,
-                                         ARRAY_SIZE(x4_vectors), 4);
-               return map_err_sym_to_channel(err_sym, 4);
+               amd64_read_pci_cfg(pvt->misc_f3_ctl, 0x180, &value);
+
+               /* F3x180[EccSymbolSize]=1 => x8 symbols */
+               if (boot_cpu_data.x86_model > 7 &&
+                   value & BIT(25)) {
+                       err_sym = decode_syndrome(syndrome, x8_vectors,
+                                                 ARRAY_SIZE(x8_vectors), 8);
+                       return map_err_sym_to_channel(err_sym, 8);
+               }
        }
+       err_sym = decode_syndrome(syndrome, x4_vectors, ARRAY_SIZE(x4_vectors), 4);
+       return map_err_sym_to_channel(err_sym, 4);
 }
 
 /*