x86/CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings
commit 7ce2f0393ea2396142b7faf6ee9b1f3676d08a5f upstream
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().
[dwmw2: Backport to 4.9]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index fa2bdf5..6de5964 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -300,12 +300,8 @@
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;
}
/*
@@ -326,7 +322,6 @@
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;
@@ -578,6 +573,8 @@
static void early_init_amd(struct cpuinfo_x86 *c)
{
+ u64 value;
+
early_init_amd_mc(c);
/*
@@ -645,6 +642,21 @@
if (cpu_has_amd_erratum(c, amd_erratum_400))
set_cpu_bug(c, X86_BUG_AMD_E400);
+
+ /* 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);
}
@@ -737,19 +749,6 @@
{
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.