4.17-stable review patch. If anyone has any objections, please let me know.
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From: Borislav Petkov bp@suse.de
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 --- 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; }
/* @@ -344,7 +340,6 @@ 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; @@ -635,6 +630,7 @@ clear_sev:
static void early_init_amd(struct cpuinfo_x86 *c) { + u64 value; u32 dummy;
early_init_amd_mc(c); @@ -706,6 +702,20 @@ 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); }
@@ -798,19 +808,6 @@ 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.