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x86/microcode/intel: Add a helper which gives the microcode revision 

Since on Intel we're required to do CPUID(1) first, before reading
the microcode revision MSR, let's add a special helper which does the
required steps so that we don't forget to do them next time, when we
want to read the microcode revision.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hifive-unleashed-5.1
Borislav Petkov 2017-01-09 12:41:45 +01:00 committed by Thomas Gleixner
parent f3e2a51f56
commit 4167709bbf
3 changed files with 31 additions and 38 deletions
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15
arch/x86/include/asm/microcode_intel.h
View File

@ -52,6 +52,21 @@ struct extended_sigtable {
#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
static inline u32 intel_get_microcode_revision(void)
{
u32 rev, dummy;
native_wrmsrl(MSR_IA32_UCODE_REV, 0);
/* As documented in the SDM: Do a CPUID 1 here */
native_cpuid_eax(1);
/* get the current revision from MSR 0x8B */
native_rdmsr(MSR_IA32_UCODE_REV, dummy, rev);
return rev;
}
#ifdef CONFIG_MICROCODE_INTEL
extern void __init load_ucode_intel_bsp(void);
extern void load_ucode_intel_ap(void);

11
arch/x86/kernel/cpu/intel.c
View File

@ -14,6 +14,7 @@
#include <asm/bugs.h>
#include <asm/cpu.h>
#include <asm/intel-family.h>
#include <asm/microcode_intel.h>
#ifdef CONFIG_X86_64
#include <linux/topology.h>
@ -78,14 +79,8 @@ static void early_init_intel(struct cpuinfo_x86 *c)
(c->x86 == 0x6 && c->x86_model >= 0x0e))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) {
unsigned lower_word;
wrmsr(MSR_IA32_UCODE_REV, 0, 0);
/* Required by the SDM */
native_cpuid_eax(1);
rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode);
}
if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
c->microcode = intel_get_microcode_revision();
/*
* Atom erratum AAE44/AAF40/AAG38/AAH41:

43
arch/x86/kernel/cpu/microcode/intel.c
View File

@ -390,15 +390,8 @@ static int collect_cpu_info_early(struct ucode_cpu_info *uci)
native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
csig.pf = 1 << ((val[1] >> 18) & 7);
}
native_wrmsrl(MSR_IA32_UCODE_REV, 0);
/* As documented in the SDM: Do a CPUID 1 here */
native_cpuid_eax(1);
/* get the current revision from MSR 0x8B */
native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
csig.rev = val[1];
csig.rev = intel_get_microcode_revision();
uci->cpu_sig = csig;
uci->valid = 1;
@ -582,7 +575,7 @@ static inline void print_ucode(struct ucode_cpu_info *uci)
static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
{
struct microcode_intel *mc;
unsigned int val[2];
u32 rev;
mc = uci->mc;
if (!mc)
@ -590,21 +583,16 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
/* write microcode via MSR 0x79 */
native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
native_wrmsrl(MSR_IA32_UCODE_REV, 0);
/* As documented in the SDM: Do a CPUID 1 here */
native_cpuid_eax(1);
/* get the current revision from MSR 0x8B */
native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
if (val[1] != mc->hdr.rev)
rev = intel_get_microcode_revision();
if (rev != mc->hdr.rev)
return -1;
#ifdef CONFIG_X86_64
/* Flush global tlb. This is precaution. */
flush_tlb_early();
#endif
uci->cpu_sig.rev = val[1];
uci->cpu_sig.rev = rev;
if (early)
print_ucode(uci);
@ -784,8 +772,8 @@ static int apply_microcode_intel(int cpu)
struct microcode_intel *mc;
struct ucode_cpu_info *uci;
struct cpuinfo_x86 *c;
unsigned int val[2];
static int prev_rev;
u32 rev;
/* We should bind the task to the CPU */
if (WARN_ON(raw_smp_processor_id() != cpu))
@ -802,33 +790,28 @@ static int apply_microcode_intel(int cpu)
/* write microcode via MSR 0x79 */
wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
wrmsrl(MSR_IA32_UCODE_REV, 0);
/* As documented in the SDM: Do a CPUID 1 here */
native_cpuid_eax(1);
rev = intel_get_microcode_revision();
/* get the current revision from MSR 0x8B */
rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
if (val[1] != mc->hdr.rev) {
if (rev != mc->hdr.rev) {
pr_err("CPU%d update to revision 0x%x failed\n",
cpu, mc->hdr.rev);
return -1;
}
if (val[1] != prev_rev) {
if (rev != prev_rev) {
pr_info("updated to revision 0x%x, date = %04x-%02x-%02x\n",
val[1],
rev,
mc->hdr.date & 0xffff,
mc->hdr.date >> 24,
(mc->hdr.date >> 16) & 0xff);
prev_rev = val[1];
prev_rev = rev;
}
c = &cpu_data(cpu);
uci->cpu_sig.rev = val[1];
c->microcode = val[1];
uci->cpu_sig.rev = rev;
c->microcode = rev;
return 0;
}