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authorBorislav Petkov <bp@suse.de>2018-06-22 11:34:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-15 17:37:27 +0200
commitccd135cdd9c1839a42b3a07421023aade9dcce12 (patch)
tree7d4afe7f60efb0a219d0fa9f78c849256e7ab64b
parenteabc9764ebdcbc25b3688db9bc8eee59db34ebf7 (diff)
downloadlinux-ccd135cdd9c1839a42b3a07421023aade9dcce12.tar.gz
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(). Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/kernel/cpu/amd.c37
1 files changed, 17 insertions, 20 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ca2d8e71f020f..97e962afb9670 100644
--- 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 cpuinfo_x86 *c)
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 cpuinfo_x86 *c)
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 cpuinfo_x86 *c)
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_x86 *c)
{
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.