From 9ed0985332a6576efbc3e435459a857e50e0d72c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 9 May 2019 23:28:41 +0200 Subject: [PATCH] x86: intel_epb: Take CONFIG_PM into account Commit b9c273babce7 ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") caused kernels built with CONFIG_PM unset to crash on systems supporting the Performance and Energy Bias Hint (EPB), because it attempts to add files to sysfs directories that don't exist on those systems. Prevent that from happening by taking CONFIG_PM into account so that the code depending on it is not compiled at all when it is not set. Fixes: b9c273babce7 ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") Reported-by: Ido Schimmel Tested-by: Ido Schimmel Signed-off-by: Rafael J. Wysocki Acked-by: Ingo Molnar --- arch/x86/kernel/cpu/intel_epb.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel_epb.c b/arch/x86/kernel/cpu/intel_epb.c index f4dd73396f28..ebb14a26f117 100644 --- a/arch/x86/kernel/cpu/intel_epb.c +++ b/arch/x86/kernel/cpu/intel_epb.c @@ -97,6 +97,7 @@ static void intel_epb_restore(void) wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, (epb & ~EPB_MASK) | val); } +#ifdef CONFIG_PM static struct syscore_ops intel_epb_syscore_ops = { .suspend = intel_epb_save, .resume = intel_epb_restore, @@ -193,6 +194,25 @@ static int intel_epb_offline(unsigned int cpu) return 0; } +static inline void register_intel_ebp_syscore_ops(void) +{ + register_syscore_ops(&intel_epb_syscore_ops); +} +#else /* !CONFIG_PM */ +static int intel_epb_online(unsigned int cpu) +{ + intel_epb_restore(); + return 0; +} + +static int intel_epb_offline(unsigned int cpu) +{ + return intel_epb_save(); +} + +static inline void register_intel_ebp_syscore_ops(void) {} +#endif + static __init int intel_epb_init(void) { int ret; @@ -206,7 +226,7 @@ static __init int intel_epb_init(void) if (ret < 0) goto err_out_online; - register_syscore_ops(&intel_epb_syscore_ops); + register_intel_ebp_syscore_ops(); return 0; err_out_online: -- 2.30.2