Commit 8838eb6c authored by Ashok Raj's avatar Ashok Raj Committed by Ingo Molnar

x86/mce: Clear Local MCE opt-in before kexec

kexec could boot a kernel that could be legacy with no knowledge
of LMCE. Hence we should make sure we clear LMCE optin before
kexec reboot.
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1439396985-12812-9-git-send-email-bp@alien8.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4d1d5cdc
......@@ -151,10 +151,12 @@ extern int mce_p5_enabled;
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);
void mcheck_cpu_clear(struct cpuinfo_x86 *c);
void mcheck_vendor_init_severity(void);
#else
static inline int mcheck_init(void) { return 0; }
static inline void mcheck_cpu_init(struct cpuinfo_x86 *c) {}
static inline void mcheck_cpu_clear(struct cpuinfo_x86 *c) {}
static inline void mcheck_vendor_init_severity(void) {}
#endif
......@@ -181,12 +183,14 @@ DECLARE_PER_CPU(struct device *, mce_device);
#ifdef CONFIG_X86_MCE_INTEL
void mce_intel_feature_init(struct cpuinfo_x86 *c);
void mce_intel_feature_clear(struct cpuinfo_x86 *c);
void cmci_clear(void);
void cmci_reenable(void);
void cmci_rediscover(void);
void cmci_recheck(void);
#else
static inline void mce_intel_feature_init(struct cpuinfo_x86 *c) { }
static inline void mce_intel_feature_clear(struct cpuinfo_x86 *c) { }
static inline void cmci_clear(void) {}
static inline void cmci_reenable(void) {}
static inline void cmci_rediscover(void) {}
......
......@@ -1606,6 +1606,17 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
}
}
static void __mcheck_cpu_clear_vendor(struct cpuinfo_x86 *c)
{
switch (c->x86_vendor) {
case X86_VENDOR_INTEL:
mce_intel_feature_clear(c);
break;
default:
break;
}
}
static void mce_start_timer(unsigned int cpu, struct timer_list *t)
{
unsigned long iv = check_interval * HZ;
......@@ -1672,6 +1683,25 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
__mcheck_cpu_init_timer();
}
/*
* Called for each booted CPU to clear some machine checks opt-ins
*/
void mcheck_cpu_clear(struct cpuinfo_x86 *c)
{
if (mca_cfg.disabled)
return;
if (!mce_available(c))
return;
/*
* Possibly to clear general settings generic to x86
* __mcheck_cpu_clear_generic(c);
*/
__mcheck_cpu_clear_vendor(c);
}
/*
* mce_chrdev: Character device /dev/mcelog to read and clear the MCE log.
*/
......
......@@ -434,7 +434,7 @@ static void intel_init_cmci(void)
cmci_recheck();
}
void intel_init_lmce(void)
static void intel_init_lmce(void)
{
u64 val;
......@@ -447,9 +447,26 @@ void intel_init_lmce(void)
wrmsrl(MSR_IA32_MCG_EXT_CTL, val | MCG_EXT_CTL_LMCE_EN);
}
static void intel_clear_lmce(void)
{
u64 val;
if (!lmce_supported())
return;
rdmsrl(MSR_IA32_MCG_EXT_CTL, val);
val &= ~MCG_EXT_CTL_LMCE_EN;
wrmsrl(MSR_IA32_MCG_EXT_CTL, val);
}
void mce_intel_feature_init(struct cpuinfo_x86 *c)
{
intel_init_thermal(c);
intel_init_cmci();
intel_init_lmce();
}
void mce_intel_feature_clear(struct cpuinfo_x86 *c)
{
intel_clear_lmce();
}
......@@ -29,6 +29,7 @@
#include <asm/debugreg.h>
#include <asm/nmi.h>
#include <asm/tlbflush.h>
#include <asm/mce.h>
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
......@@ -319,6 +320,7 @@ void stop_this_cpu(void *dummy)
*/
set_cpu_online(smp_processor_id(), false);
disable_local_APIC();
mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
for (;;)
halt();
......
......@@ -30,6 +30,7 @@
#include <asm/proto.h>
#include <asm/apic.h>
#include <asm/nmi.h>
#include <asm/mce.h>
#include <asm/trace/irq_vectors.h>
/*
* Some notes on x86 processor bugs affecting SMP operation:
......@@ -243,6 +244,7 @@ static void native_stop_other_cpus(int wait)
finish:
local_irq_save(flags);
disable_local_APIC();
mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
local_irq_restore(flags);
}
......
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