During suspend or hibernation, system enters firmware. To avoid potential firmware issue that may generate #AC exception for split locked accesses, handle the #AC as fatal exception, and block suspend or hibernation, the setting of #AC for split lock is restored to firmware setting during suspend or hibernation. When resuming from suspend or hibernation, the split lock setting is restored to kernel setting.
Signed-off-by: Fenghua Yu <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> --- arch/x86/include/asm/cpu.h | 2 ++ arch/x86/kernel/cpu/test_ctl.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 45fec729c470..f2ca84deccc6 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -45,6 +45,7 @@ void detect_split_lock_ac(void); bool do_split_lock_exception(struct pt_regs *regs, unsigned long error_code); void setup_split_lock(void); void restore_split_lock_ac_firmware(void); +void restore_split_lock_ac_kernel(void); #else /* CONFIG_SPLIT_LOCK_AC */ static inline void detect_split_lock_ac(void) {} static inline bool @@ -55,5 +56,6 @@ do_split_lock_exception(struct pt_regs *regs, unsigned long error_code) static inline void setup_split_lock(void) {} static inline void restore_split_lock_ac_firmware(void) {} +static inline void restore_split_lock_ac_kernel(void) {} #endif /* CONFIG_SPLIT_LOCK_AC */ #endif /* _ASM_X86_CPU_H */ diff --git a/arch/x86/kernel/cpu/test_ctl.c b/arch/x86/kernel/cpu/test_ctl.c index 9e47f8174a47..82440740b2b9 100644 --- a/arch/x86/kernel/cpu/test_ctl.c +++ b/arch/x86/kernel/cpu/test_ctl.c @@ -16,6 +16,7 @@ #include <linux/cpu.h> #include <linux/mm.h> #include <linux/reboot.h> +#include <linux/syscore_ops.h> #include <asm/msr.h> #define DISABLE_SPLIT_LOCK_AC 0 @@ -112,6 +113,15 @@ void restore_split_lock_ac_firmware(void) restore_split_lock_ac(split_lock_ac_firmware); } +/* Restore kernel setting for #AC enable bit for split lock. */ +void restore_split_lock_ac_kernel(void) +{ + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_AC)) + return; + + restore_split_lock_ac(split_lock_ac_kernel); +} + static void split_lock_cpu_reboot(void *unused) { restore_split_lock_ac_firmware(); @@ -247,11 +257,29 @@ static int split_lock_online(unsigned int cpu) static int split_lock_offline(unsigned int cpu) { + restore_split_lock_ac_firmware(); cancel_delayed_work(&per_cpu(reenable_delayed_work, cpu)); return 0; } +static int split_lock_bsp_suspend(void) +{ + restore_split_lock_ac_firmware(); + + return 0; +} + +static void split_lock_bsp_resume(void) +{ + restore_split_lock_ac_kernel(); +} + +static struct syscore_ops split_lock_syscore_ops = { + .suspend = split_lock_bsp_suspend, + .resume = split_lock_bsp_resume, +}; + static int __init split_lock_init(void) { int ret; @@ -264,6 +292,8 @@ static int __init split_lock_init(void) if (ret < 0) return ret; + register_syscore_ops(&split_lock_syscore_ops); + register_reboot_notifier(&split_lock_reboot_nb); return 0; -- 2.5.0
