4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Borislav Petkov <b...@suse.de>
The TOPOEXT reenablement is a workaround for broken BIOSen which didn't
enable the CPUID bit. amd_get_topology_early(), however, relies on
that bit being set so that it can read out the CPUID leaf and set
smp_num_siblings properly.
Move the reenablement up to early_init_amd(). While at it, simplify
amd_get_topology_early().
Signed-off-by: Borislav Petkov <b...@suse.de>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/kernel/cpu/amd.c | 37 +++++++++++++++++--------------------
1 file changed, 17 insertions(+), 20 deletions(-)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -318,12 +318,8 @@ static void legacy_fixup_core_id(struct
static void amd_get_topology_early(struct cpuinfo_x86 *c)
{
- if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
- u32 eax, ebx, ecx, edx;
-
- cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
- smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
- }
+ if (cpu_has(c, X86_FEATURE_TOPOEXT))
+ smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
}
/*
@@ -345,7 +341,6 @@ static void amd_get_topology(struct cpui
cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
node_id = ecx & 0xff;
- smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
if (c->x86 == 0x15)
c->cu_id = ebx & 0xff;
@@ -624,6 +619,7 @@ clear_sev:
static void early_init_amd(struct cpuinfo_x86 *c)
{
+ u64 value;
u32 dummy;
early_init_amd_mc(c);
@@ -695,6 +691,20 @@ static void early_init_amd(struct cpuinf
early_detect_mem_encrypt(c);
+ /* Re-enable TopologyExtensions if switched off by BIOS */
+ if (c->x86 == 0x15 &&
+ (c->x86_model >= 0x10 && c->x86_model <= 0x6f) &&
+ !cpu_has(c, X86_FEATURE_TOPOEXT)) {
+
+ if (msr_set_bit(0xc0011005, 54) > 0) {
+ rdmsrl(0xc0011005, value);
+ if (value & BIT_64(54)) {
+ set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+ pr_info_once(FW_INFO "CPU: Re-enabling disabled
Topology Extensions Support.\n");
+ }
+ }
+ }
+
amd_get_topology_early(c);
}
@@ -787,19 +797,6 @@ static void init_amd_bd(struct cpuinfo_x
{
u64 value;
- /* re-enable TopologyExtensions if switched off by BIOS */
- if ((c->x86_model >= 0x10) && (c->x86_model <= 0x6f) &&
- !cpu_has(c, X86_FEATURE_TOPOEXT)) {
-
- if (msr_set_bit(0xc0011005, 54) > 0) {
- rdmsrl(0xc0011005, value);
- if (value & BIT_64(54)) {
- set_cpu_cap(c, X86_FEATURE_TOPOEXT);
- pr_info_once(FW_INFO "CPU: Re-enabling disabled
Topology Extensions Support.\n");
- }
- }
- }
-
/*
* The way access filter has a performance penalty on some workloads.
* Disable it on the affected CPUs.
