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author | Thomas Gleixner <tglx@linutronix.de> | 2016-12-13 13:14:17 +0000 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2016-12-15 11:44:29 +0100 |
commit | 6a369583178d0b89c2c3919c4456ee22fee0f249 (patch) | |
tree | eaaebee6ac4102b724483d19a1c6f920c5406b67 /arch | |
parent | 31f8a651fc5784a9e6f482be5ef0dd111a535e88 (diff) | |
download | op-kernel-dev-6a369583178d0b89c2c3919c4456ee22fee0f249.zip op-kernel-dev-6a369583178d0b89c2c3919c4456ee22fee0f249.tar.gz |
x86/tsc: Validate TSC_ADJUST after resume
Some 'feature' BIOSes fiddle with the TSC_ADJUST register during
suspend/resume which renders the TSC unusable.
Add sanity checks into the resume path and restore the
original value if it was adjusted.
Reported-and-tested-by: Roland Scheidegger <rscheidegger_lists@hispeed.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bruce Schlobohm <bruce.schlobohm@intel.com>
Cc: Kevin Stanton <kevin.b.stanton@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Allen Hung <allen_hung@dell.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20161213131211.317654500@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/tsc.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/process.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/tsc.c | 6 | ||||
-rw-r--r-- | arch/x86/kernel/tsc_sync.c | 6 | ||||
-rw-r--r-- | arch/x86/power/cpu.c | 1 |
5 files changed, 13 insertions, 6 deletions
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index c054eaa..372ad0c 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -47,12 +47,12 @@ extern int tsc_clocksource_reliable; */ #ifdef CONFIG_X86_TSC extern bool tsc_store_and_check_tsc_adjust(void); -extern void tsc_verify_tsc_adjust(void); +extern void tsc_verify_tsc_adjust(bool resume); extern void check_tsc_sync_source(int cpu); extern void check_tsc_sync_target(void); #else static inline bool tsc_store_and_check_tsc_adjust(void) { return false; } -static inline void tsc_verify_tsc_adjust(void) { } +static inline void tsc_verify_tsc_adjust(bool resume) { } static inline void check_tsc_sync_source(int cpu) { } static inline void check_tsc_sync_target(void) { } #endif diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 4fe5dc8..a67e0f0 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -277,7 +277,7 @@ void exit_idle(void) void arch_cpu_idle_enter(void) { - tsc_verify_tsc_adjust(); + tsc_verify_tsc_adjust(false); local_touch_nmi(); enter_idle(); } diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 2bb8de4..bfb541a 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1080,6 +1080,11 @@ static void detect_art(void) static struct clocksource clocksource_tsc; +static void tsc_resume(struct clocksource *cs) +{ + tsc_verify_tsc_adjust(true); +} + /* * We used to compare the TSC to the cycle_last value in the clocksource * structure to avoid a nasty time-warp. This can be observed in a @@ -1112,6 +1117,7 @@ static struct clocksource clocksource_tsc = { .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, .archdata = { .vclock_mode = VCLOCK_TSC }, + .resume = tsc_resume, }; void mark_tsc_unstable(char *reason) diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c index a75f696..94f2ce5 100644 --- a/arch/x86/kernel/tsc_sync.c +++ b/arch/x86/kernel/tsc_sync.c @@ -30,7 +30,7 @@ struct tsc_adjust { static DEFINE_PER_CPU(struct tsc_adjust, tsc_adjust); -void tsc_verify_tsc_adjust(void) +void tsc_verify_tsc_adjust(bool resume) { struct tsc_adjust *adj = this_cpu_ptr(&tsc_adjust); s64 curval; @@ -39,7 +39,7 @@ void tsc_verify_tsc_adjust(void) return; /* Rate limit the MSR check */ - if (time_before(jiffies, adj->nextcheck)) + if (!resume && time_before(jiffies, adj->nextcheck)) return; adj->nextcheck = jiffies + HZ; @@ -51,7 +51,7 @@ void tsc_verify_tsc_adjust(void) /* Restore the original value */ wrmsrl(MSR_IA32_TSC_ADJUST, adj->adjusted); - if (!adj->warned) { + if (!adj->warned || resume) { pr_warn(FW_BUG "TSC ADJUST differs: CPU%u %lld --> %lld. Restoring\n", smp_processor_id(), adj->adjusted, curval); adj->warned = true; diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 53cace2..66ade16 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -252,6 +252,7 @@ static void notrace __restore_processor_state(struct saved_context *ctxt) fix_processor_context(); do_fpu_end(); + tsc_verify_tsc_adjust(true); x86_platform.restore_sched_clock_state(); mtrr_bp_restore(); perf_restore_debug_store(); |