From f14a1396d8f19b6c53593045eba86d10360a0cee Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Wed, 24 Feb 2016 13:31:36 -0800 Subject: [PATCH] powercap/rapl: reduce ipi calls Reduce remote CPU calls for MSR access by combining read modify write into one function. Suggested-by: Peter Zijlstra Signed-off-by: Jacob Pan Signed-off-by: Rafael J. Wysocki --- drivers/powercap/intel_rapl.c | 119 ++++++++++++++++++++++++---------- 1 file changed, 85 insertions(+), 34 deletions(-) diff --git a/drivers/powercap/intel_rapl.c b/drivers/powercap/intel_rapl.c index 6c592dc71aee..a50e644ae07a 100644 --- a/drivers/powercap/intel_rapl.c +++ b/drivers/powercap/intel_rapl.c @@ -133,6 +133,12 @@ struct rapl_domain_data { unsigned long timestamp; }; +struct msrl_action { + u32 msr_no; + u64 clear_mask; + u64 set_mask; + int err; +}; #define DOMAIN_STATE_INACTIVE BIT(0) #define DOMAIN_STATE_POWER_LIMIT_SET BIT(1) @@ -800,35 +806,62 @@ static int rapl_read_data_raw(struct rapl_domain *rd, return 0; } + +static int msrl_update_safe(u32 msr_no, u64 clear_mask, u64 set_mask) +{ + int err; + u64 val; + + err = rdmsrl_safe(msr_no, &val); + if (err) + goto out; + + val &= ~clear_mask; + val |= set_mask; + + err = wrmsrl_safe(msr_no, val); + +out: + return err; +} + +static void msrl_update_func(void *info) +{ + struct msrl_action *ma = info; + + ma->err = msrl_update_safe(ma->msr_no, ma->clear_mask, ma->set_mask); +} + /* Similar use of primitive info in the read counterpart */ static int rapl_write_data_raw(struct rapl_domain *rd, enum rapl_primitives prim, unsigned long long value) { - u64 msr_val; - u32 msr; struct rapl_primitive_info *rp = &rpi[prim]; int cpu; + u64 bits; + struct msrl_action ma; + int ret; cpu = find_active_cpu_on_package(rd->package_id); if (cpu < 0) return cpu; - msr = rd->msrs[rp->id]; - if (rdmsrl_safe_on_cpu(cpu, msr, &msr_val)) { - dev_dbg(&rd->power_zone.dev, - "failed to read msr 0x%x on cpu %d\n", msr, cpu); - return -EIO; - } - value = rapl_unit_xlate(rd, rd->package_id, rp->unit, value, 1); - msr_val &= ~rp->mask; - msr_val |= value << rp->shift; - if (wrmsrl_safe_on_cpu(cpu, msr, msr_val)) { - dev_dbg(&rd->power_zone.dev, - "failed to write msr 0x%x on cpu %d\n", msr, cpu); - return -EIO; - } - return 0; + bits = rapl_unit_xlate(rd, rd->package_id, rp->unit, value, 1); + bits |= bits << rp->shift; + memset(&ma, 0, sizeof(ma)); + + ma.msr_no = rd->msrs[rp->id]; + ma.clear_mask = rp->mask; + ma.set_mask = bits; + + ret = smp_call_function_single(cpu, msrl_update_func, &ma, 1); + if (ret) + WARN_ON_ONCE(ret); + else + ret = ma.err; + + return ret; } /* @@ -893,6 +926,21 @@ static int rapl_check_unit_atom(struct rapl_package *rp, int cpu) return 0; } +static void power_limit_irq_save_cpu(void *info) +{ + u32 l, h = 0; + struct rapl_package *rp = (struct rapl_package *)info; + + /* save the state of PLN irq mask bit before disabling it */ + rdmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h); + if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) { + rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE; + rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED; + } + l &= ~PACKAGE_THERM_INT_PLN_ENABLE; + wrmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); +} + /* REVISIT: * When package power limit is set artificially low by RAPL, LVT @@ -906,7 +954,6 @@ static int rapl_check_unit_atom(struct rapl_package *rp, int cpu) static void package_power_limit_irq_save(int package_id) { - u32 l, h = 0; int cpu; struct rapl_package *rp; @@ -920,20 +967,30 @@ static void package_power_limit_irq_save(int package_id) cpu = find_active_cpu_on_package(package_id); if (cpu < 0) return; - /* save the state of PLN irq mask bit before disabling it */ - rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h); - if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) { - rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE; - rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED; - } - l &= ~PACKAGE_THERM_INT_PLN_ENABLE; - wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); + if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN)) + return; + + smp_call_function_single(cpu, power_limit_irq_save_cpu, rp, 1); +} + +static void power_limit_irq_restore_cpu(void *info) +{ + u32 l, h = 0; + struct rapl_package *rp = (struct rapl_package *)info; + + rdmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h); + + if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE) + l |= PACKAGE_THERM_INT_PLN_ENABLE; + else + l &= ~PACKAGE_THERM_INT_PLN_ENABLE; + + wrmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); } /* restore per package power limit interrupt enable state */ static void package_power_limit_irq_restore(int package_id) { - u32 l, h; int cpu; struct rapl_package *rp; @@ -951,14 +1008,8 @@ static void package_power_limit_irq_restore(int package_id) /* irq enable state not saved, nothing to restore */ if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) return; - rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h); - if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE) - l |= PACKAGE_THERM_INT_PLN_ENABLE; - else - l &= ~PACKAGE_THERM_INT_PLN_ENABLE; - - wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); + smp_call_function_single(cpu, power_limit_irq_restore_cpu, rp, 1); } static void set_floor_freq_default(struct rapl_domain *rd, bool mode)