From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacob Pan Subject: [PATCH 2/2] powercap/rapl: reduce ipi calls Date: Fri, 11 Dec 2015 14:40:37 -0800 Message-ID: <1449873637-24300-3-git-send-email-jacob.jun.pan@linux.intel.com> References: <1449873637-24300-1-git-send-email-jacob.jun.pan@linux.intel.com> Return-path: Received: from mga14.intel.com ([192.55.52.115]:28346 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754792AbbLKWlt (ORCPT ); Fri, 11 Dec 2015 17:41:49 -0500 In-Reply-To: <1449873637-24300-1-git-send-email-jacob.jun.pan@linux.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: LKML , Linux PM , Rafael Wysocki Cc: Peter Zijlstra , X86 Kernel , Srinivas Pandruvada , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Jacob Pan Reduce remote CPU calls for MSR access by combining read modify write into one function. Suggested-by: Peter Zijlstra Signed-off-by: Jacob Pan --- drivers/powercap/intel_rapl.c | 71 ++++++++++++++++++++++--------------------- 1 file changed, 37 insertions(+), 34 deletions(-) diff --git a/drivers/powercap/intel_rapl.c b/drivers/powercap/intel_rapl.c index cc97f08..4fe1627 100644 --- a/drivers/powercap/intel_rapl.c +++ b/drivers/powercap/intel_rapl.c @@ -805,30 +805,18 @@ 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; 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; + + return rmwmsrl_safe_on_cpu(cpu, rd->msrs[rp->id], rp->mask, bits); } /* @@ -893,6 +881,21 @@ 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 +909,6 @@ 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 +922,27 @@ 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); + 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 +960,8 @@ 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) -- 1.9.1