diff options
Diffstat (limited to 'drivers/cpufreq/cppc_cpufreq.c')
-rw-r--r-- | drivers/cpufreq/cppc_cpufreq.c | 245 |
1 files changed, 233 insertions, 12 deletions
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 8a482c434ea6..b8e1b8ea628c 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -10,14 +10,18 @@ #define pr_fmt(fmt) "CPPC Cpufreq:" fmt +#include <linux/arch_topology.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/cpu.h> #include <linux/cpufreq.h> #include <linux/dmi.h> +#include <linux/irq_work.h> +#include <linux/kthread.h> #include <linux/time.h> #include <linux/vmalloc.h> +#include <uapi/linux/sched/types.h> #include <asm/unaligned.h> @@ -57,6 +61,204 @@ static struct cppc_workaround_oem_info wa_info[] = { } }; +#ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE + +/* Frequency invariance support */ +struct cppc_freq_invariance { + int cpu; + struct irq_work irq_work; + struct kthread_work work; + struct cppc_perf_fb_ctrs prev_perf_fb_ctrs; + struct cppc_cpudata *cpu_data; +}; + +static DEFINE_PER_CPU(struct cppc_freq_invariance, cppc_freq_inv); +static struct kthread_worker *kworker_fie; +static bool fie_disabled; + +static struct cpufreq_driver cppc_cpufreq_driver; +static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu); +static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data, + struct cppc_perf_fb_ctrs fb_ctrs_t0, + struct cppc_perf_fb_ctrs fb_ctrs_t1); + +/** + * cppc_scale_freq_workfn - CPPC arch_freq_scale updater for frequency invariance + * @work: The work item. + * + * The CPPC driver register itself with the topology core to provide its own + * implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which + * gets called by the scheduler on every tick. + * + * Note that the arch specific counters have higher priority than CPPC counters, + * if available, though the CPPC driver doesn't need to have any special + * handling for that. + * + * On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we + * reach here from hard-irq context), which then schedules a normal work item + * and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable + * based on the counter updates since the last tick. + */ +static void cppc_scale_freq_workfn(struct kthread_work *work) +{ + struct cppc_freq_invariance *cppc_fi; + struct cppc_perf_fb_ctrs fb_ctrs = {0}; + struct cppc_cpudata *cpu_data; + unsigned long local_freq_scale; + u64 perf; + + cppc_fi = container_of(work, struct cppc_freq_invariance, work); + cpu_data = cppc_fi->cpu_data; + + if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) { + pr_warn("%s: failed to read perf counters\n", __func__); + return; + } + + cppc_fi->prev_perf_fb_ctrs = fb_ctrs; + perf = cppc_perf_from_fbctrs(cpu_data, cppc_fi->prev_perf_fb_ctrs, + fb_ctrs); + + perf <<= SCHED_CAPACITY_SHIFT; + local_freq_scale = div64_u64(perf, cpu_data->perf_caps.highest_perf); + if (WARN_ON(local_freq_scale > 1024)) + local_freq_scale = 1024; + + per_cpu(arch_freq_scale, cppc_fi->cpu) = local_freq_scale; +} + +static void cppc_irq_work(struct irq_work *irq_work) +{ + struct cppc_freq_invariance *cppc_fi; + + cppc_fi = container_of(irq_work, struct cppc_freq_invariance, irq_work); + kthread_queue_work(kworker_fie, &cppc_fi->work); +} + +static void cppc_scale_freq_tick(void) +{ + struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id()); + + /* + * cppc_get_perf_ctrs() can potentially sleep, call that from the right + * context. + */ + irq_work_queue(&cppc_fi->irq_work); +} + +static struct scale_freq_data cppc_sftd = { + .source = SCALE_FREQ_SOURCE_CPPC, + .set_freq_scale = cppc_scale_freq_tick, +}; + +static void cppc_freq_invariance_policy_init(struct cpufreq_policy *policy, + struct cppc_cpudata *cpu_data) +{ + struct cppc_perf_fb_ctrs fb_ctrs = {0}; + struct cppc_freq_invariance *cppc_fi; + int i, ret; + + if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + return; + + if (fie_disabled) + return; + + for_each_cpu(i, policy->cpus) { + cppc_fi = &per_cpu(cppc_freq_inv, i); + cppc_fi->cpu = i; + cppc_fi->cpu_data = cpu_data; + kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn); + init_irq_work(&cppc_fi->irq_work, cppc_irq_work); + + ret = cppc_get_perf_ctrs(i, &fb_ctrs); + if (ret) { + pr_warn("%s: failed to read perf counters: %d\n", + __func__, ret); + fie_disabled = true; + } else { + cppc_fi->prev_perf_fb_ctrs = fb_ctrs; + } + } +} + +static void __init cppc_freq_invariance_init(void) +{ + struct sched_attr attr = { + .size = sizeof(struct sched_attr), + .sched_policy = SCHED_DEADLINE, + .sched_nice = 0, + .sched_priority = 0, + /* + * Fake (unused) bandwidth; workaround to "fix" + * priority inheritance. + */ + .sched_runtime = 1000000, + .sched_deadline = 10000000, + .sched_period = 10000000, + }; + int ret; + + if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + return; + + if (fie_disabled) + return; + + kworker_fie = kthread_create_worker(0, "cppc_fie"); + if (IS_ERR(kworker_fie)) + return; + + ret = sched_setattr_nocheck(kworker_fie->task, &attr); + if (ret) { + pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__, + ret); + kthread_destroy_worker(kworker_fie); + return; + } + + /* Register for freq-invariance */ + topology_set_scale_freq_source(&cppc_sftd, cpu_present_mask); +} + +static void cppc_freq_invariance_exit(void) +{ + struct cppc_freq_invariance *cppc_fi; + int i; + + if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate) + return; + + if (fie_disabled) + return; + + topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, cpu_present_mask); + + for_each_possible_cpu(i) { + cppc_fi = &per_cpu(cppc_freq_inv, i); + irq_work_sync(&cppc_fi->irq_work); + } + + kthread_destroy_worker(kworker_fie); + kworker_fie = NULL; +} + +#else +static inline void +cppc_freq_invariance_policy_init(struct cpufreq_policy *policy, + struct cppc_cpudata *cpu_data) +{ +} + +static inline void cppc_freq_invariance_init(void) +{ +} + +static inline void cppc_freq_invariance_exit(void) +{ +} +#endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */ + /* Callback function used to retrieve the max frequency from DMI */ static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private) { @@ -355,9 +557,12 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy) cpu_data->perf_ctrls.desired_perf = caps->highest_perf; ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls); - if (ret) + if (ret) { pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", caps->highest_perf, cpu, ret); + } else { + cppc_freq_invariance_policy_init(policy, cpu_data); + } return ret; } @@ -370,12 +575,12 @@ static inline u64 get_delta(u64 t1, u64 t0) return (u32)t1 - (u32)t0; } -static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu_data, - struct cppc_perf_fb_ctrs fb_ctrs_t0, - struct cppc_perf_fb_ctrs fb_ctrs_t1) +static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data, + struct cppc_perf_fb_ctrs fb_ctrs_t0, + struct cppc_perf_fb_ctrs fb_ctrs_t1) { u64 delta_reference, delta_delivered; - u64 reference_perf, delivered_perf; + u64 reference_perf; reference_perf = fb_ctrs_t0.reference_perf; @@ -384,12 +589,21 @@ static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu_data, delta_delivered = get_delta(fb_ctrs_t1.delivered, fb_ctrs_t0.delivered); - /* Check to avoid divide-by zero */ - if (delta_reference || delta_delivered) - delivered_perf = (reference_perf * delta_delivered) / - delta_reference; - else - delivered_perf = cpu_data->perf_ctrls.desired_perf; + /* Check to avoid divide-by zero and invalid delivered_perf */ + if (!delta_reference || !delta_delivered) + return cpu_data->perf_ctrls.desired_perf; + + return (reference_perf * delta_delivered) / delta_reference; +} + +static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu_data, + struct cppc_perf_fb_ctrs fb_ctrs_t0, + struct cppc_perf_fb_ctrs fb_ctrs_t1) +{ + u64 delivered_perf; + + delivered_perf = cppc_perf_from_fbctrs(cpu_data, fb_ctrs_t0, + fb_ctrs_t1); return cppc_cpufreq_perf_to_khz(cpu_data, delivered_perf); } @@ -514,6 +728,8 @@ static void cppc_check_hisi_workaround(void) static int __init cppc_cpufreq_init(void) { + int ret; + if ((acpi_disabled) || !acpi_cpc_valid()) return -ENODEV; @@ -521,7 +737,11 @@ static int __init cppc_cpufreq_init(void) cppc_check_hisi_workaround(); - return cpufreq_register_driver(&cppc_cpufreq_driver); + ret = cpufreq_register_driver(&cppc_cpufreq_driver); + if (!ret) + cppc_freq_invariance_init(); + + return ret; } static inline void free_cpu_data(void) @@ -538,6 +758,7 @@ static inline void free_cpu_data(void) static void __exit cppc_cpufreq_exit(void) { + cppc_freq_invariance_exit(); cpufreq_unregister_driver(&cppc_cpufreq_driver); free_cpu_data(); |