From 17669006adf64d35a74cb21e3c8dfb6fb8be689f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 22 Nov 2016 12:24:00 -0800 Subject: [PATCH] cpufreq/intel_pstate: Use CPPC to get max performance Use the acpi cppc_lib interface to get CPPC performance limits and update the per cpu priority for the ITMT scheduler. If the highest performance of CPUs differs the ITMT feature is enabled. Co-developed-by: Srinivas Pandruvada Signed-off-by: Rafael J. Wysocki Signed-off-by: Tim Chen Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada Cc: bp@suse.de Link: http://lkml.kernel.org/r/0998b98943bcdec7d1ddd4ff27358da555ea8e92.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner --- drivers/cpufreq/Kconfig.x86 | 1 + drivers/cpufreq/intel_pstate.c | 56 +++++++++++++++++++++++++++++++++- 2 files changed, 56 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index adbd1de1cea5..c6d273b43ff9 100644 --- a/drivers/cpufreq/Kconfig.x86 +++ b/drivers/cpufreq/Kconfig.x86 @@ -6,6 +6,7 @@ config X86_INTEL_PSTATE bool "Intel P state control" depends on X86 select ACPI_PROCESSOR if ACPI + select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_ITMT help This driver provides a P state for Intel core processors. The driver implements an internal governor and will become diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 4737520ec823..e8dc42fc0915 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -44,6 +44,7 @@ #ifdef CONFIG_ACPI #include +#include #endif #define FRAC_BITS 8 @@ -379,14 +380,67 @@ static bool intel_pstate_get_ppc_enable_status(void) return acpi_ppc; } +#ifdef CONFIG_ACPI_CPPC_LIB + +/* The work item is needed to avoid CPU hotplug locking issues */ +static void intel_pstste_sched_itmt_work_fn(struct work_struct *work) +{ + sched_set_itmt_support(); +} + +static DECLARE_WORK(sched_itmt_work, intel_pstste_sched_itmt_work_fn); + +static void intel_pstate_set_itmt_prio(int cpu) +{ + struct cppc_perf_caps cppc_perf; + static u32 max_highest_perf = 0, min_highest_perf = U32_MAX; + int ret; + + ret = cppc_get_perf_caps(cpu, &cppc_perf); + if (ret) + return; + + /* + * The priorities can be set regardless of whether or not + * sched_set_itmt_support(true) has been called and it is valid to + * update them at any time after it has been called. + */ + sched_set_itmt_core_prio(cppc_perf.highest_perf, cpu); + + if (max_highest_perf <= min_highest_perf) { + if (cppc_perf.highest_perf > max_highest_perf) + max_highest_perf = cppc_perf.highest_perf; + + if (cppc_perf.highest_perf < min_highest_perf) + min_highest_perf = cppc_perf.highest_perf; + + if (max_highest_perf > min_highest_perf) { + /* + * This code can be run during CPU online under the + * CPU hotplug locks, so sched_set_itmt_support() + * cannot be called from here. Queue up a work item + * to invoke it. + */ + schedule_work(&sched_itmt_work); + } + } +} +#else +static void intel_pstate_set_itmt_prio(int cpu) +{ +} +#endif + static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy) { struct cpudata *cpu; int ret; int i; - if (hwp_active) + if (hwp_active) { + intel_pstate_set_itmt_prio(policy->cpu); return; + } if (!intel_pstate_get_ppc_enable_status()) return;