diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2016-12-13 13:14:17 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-12-15 11:44:29 +0100 |
| commit | 6a369583178d0b89c2c3919c4456ee22fee0f249 (patch) | |
| tree | eaaebee6ac4102b724483d19a1c6f920c5406b67 /arch/x86/kernel/tsc_sync.c | |
| parent | 31f8a651fc5784a9e6f482be5ef0dd111a535e88 (diff) | |
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/x86/kernel/tsc_sync.c')
| -rw-r--r-- | arch/x86/kernel/tsc_sync.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c index a75f696011d5..94f2ce5fb159 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; |