Architectural MSRs associated with microcode are for P6 or higher.
Add a check to early microcode to detect < P6.
Without a check for < P6 - we end up reading from unimplemented MSRs
on Pentium.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue.l...@nexus-software.ie>
---
arch/x86/kernel/microcode_intel_early.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/microcode_intel_early.c
b/arch/x86/kernel/microcode_intel_early.c
index d893e8e..e1ff9bf 100644
--- a/arch/x86/kernel/microcode_intel_early.c
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -396,6 +396,9 @@ static int __cpuinit collect_cpu_info_early(struct
ucode_cpu_info *uci)
x86 = get_x86_family(csig.sig);
x86_model = get_x86_model(csig.sig);
+ if (x86 < 6)
+ return UCODE_ERROR;
+
if ((x86_model >= 5) || (x86 > 6)) {
/* get processor flags from MSR 0x17 */
native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
@@ -428,9 +431,13 @@ static void __ref show_saved_mc(void)
pr_debug("no micorcode data saved.\n");
return;
}
- pr_debug("Total microcode saved: %d\n", mc_saved_data.mc_saved_count);
- collect_cpu_info_early(&uci);
+ if (collect_cpu_info_early(&uci) == UCODE_ERROR) {
+ pr_debug("microcode unavailable on this architecture\n");
+ return;
+ }
+
+ pr_debug("Total microcode saved: %d\n", mc_saved_data.mc_saved_count);
sig = uci.cpu_sig.sig;
pf = uci.cpu_sig.pf;
@@ -609,7 +616,8 @@ void __cpuinit show_ucode_info_early(void)
struct ucode_cpu_info uci;
if (delay_ucode_info) {
- collect_cpu_info_early(&uci);
+ if (collect_cpu_info_early(&uci) == UCODE_ERROR)
+ return;
print_ucode_info(&uci, current_mc_date);
delay_ucode_info = 0;
}
@@ -724,7 +732,8 @@ _load_ucode_intel_bsp(struct mc_saved_data *mc_saved_data,
unsigned long initrd_end_early,
struct ucode_cpu_info *uci)
{
- collect_cpu_info_early(uci);
+ if (collect_cpu_info_early(uci) == UCODE_ERROR)
+ return;
scan_microcode(initrd_start_early, initrd_end_early, mc_saved_data,
mc_saved_in_initrd, uci);
load_microcode(mc_saved_data, mc_saved_in_initrd,
@@ -789,7 +798,9 @@ void __cpuinit load_ucode_intel_ap(void)
if (mc_saved_data_p->mc_saved_count == 0)
return;
- collect_cpu_info_early(&uci);
+ if (collect_cpu_info_early(&uci) == UCODE_ERROR)
+ return;
+
load_microcode(mc_saved_data_p, mc_saved_in_initrd_p,
initrd_start_addr, &uci);
apply_microcode_early(mc_saved_data_p, &uci);
--
1.7.10.4
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