// SPDX-License-Identifier: GPL-2.0-only /* * CPPC (Collaborative Processor Performance Control) driver for * interfacing with the CPUfreq layer and governors. See * cppc_acpi.c for CPPC specific methods. * * (C) Copyright 2014, 2015 Linaro Ltd. * Author: Ashwin Chaugule */ #define pr_fmt(fmt) "CPPC Cpufreq:" fmt #include #include #include #include #include #include #include #include #include #include /* Minimum struct length needed for the DMI processor entry we want */ #define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48 /* Offset in the DMI processor structure for the max frequency */ #define DMI_PROCESSOR_MAX_SPEED 0x14 /* * This list contains information parsed from per CPU ACPI _CPC and _PSD * structures: e.g. the highest and lowest supported performance, capabilities, * desired performance, level requested etc. Depending on the share_type, not * all CPUs will have an entry in the list. */ static LIST_HEAD(cpu_data_list); static bool boost_supported; struct cppc_workaround_oem_info { char oem_id[ACPI_OEM_ID_SIZE + 1]; char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1]; u32 oem_revision; }; static struct cppc_workaround_oem_info wa_info[] = { { .oem_id = "HISI ", .oem_table_id = "HIP07 ", .oem_revision = 0, }, { .oem_id = "HISI ", .oem_table_id = "HIP08 ", .oem_revision = 0, } }; /* Callback function used to retrieve the max frequency from DMI */ static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private) { const u8 *dmi_data = (const u8 *)dm; u16 *mhz = (u16 *)private; if (dm->type == DMI_ENTRY_PROCESSOR && dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) { u16 val = (u16)get_unaligned((const u16 *) (dmi_data + DMI_PROCESSOR_MAX_SPEED)); *mhz = val > *mhz ? val : *mhz; } } /* Look up the max frequency in DMI */ static u64 cppc_get_dmi_max_khz(void) { u16 mhz = 0; dmi_walk(cppc_find_dmi_mhz, &mhz); /* * Real stupid fallback value, just in case there is no * actual value set. */ mhz = mhz ? mhz : 1; return (1000 * mhz); } /* * If CPPC lowest_freq and nominal_freq registers are exposed then we can * use them to convert perf to freq and vice versa * * If the perf/freq point lies between Nominal and Lowest, we can treat * (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line * and extrapolate the rest * For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion */ static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu_data, unsigned int perf) { struct cppc_perf_caps *caps = &cpu_data->perf_caps; static u64 max_khz; u64 mul, div; if (caps->lowest_freq && caps->nominal_freq) { if (perf >= caps->nominal_perf) { mul = caps->nominal_freq; div = caps->nominal_perf; } else { mul = caps->nominal_freq - caps->lowest_freq; div = caps->nominal_perf - caps->lowest_perf; } } else { if (!max_khz) max_khz = cppc_get_dmi_max_khz(); mul = max_khz; div = caps->highest_perf; } return (u64)perf * mul / div; } static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu_data, unsigned int freq) { struct cppc_perf_caps *caps = &cpu_data->perf_caps; static u64 max_khz; u64 mul, div; if (caps->lowest_freq && caps->nominal_freq) { if (freq >= caps->nominal_freq) { mul = caps->nominal_perf; div = caps->nominal_freq; } else { mul = caps->lowest_perf; div = caps->lowest_freq; } } else { if (!max_khz) max_khz = cppc_get_dmi_max_khz(); mul = caps->highest_perf; div = max_khz; } return (u64)freq * mul / div; } static int cppc_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { struct cppc_cpudata *cpu_data = policy->driver_data; unsigned int cpu = policy->cpu; struct cpufreq_freqs freqs; u32 desired_perf; int ret = 0; desired_perf = cppc_cpufreq_khz_to_perf(cpu_data, target_freq); /* Return if it is exactly the same perf */ if (desired_perf == cpu_data->perf_ctrls.desired_perf) return ret; cpu_data->perf_ctrls.desired_perf = desired_perf; freqs.old = policy->cur; freqs.new = target_freq; cpufreq_freq_transition_begin(policy, &freqs); ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls); cpufreq_freq_transition_end(policy, &freqs, ret != 0); if (ret) pr_debug("Failed to set target on CPU:%d. ret:%d\n", cpu, ret); return ret; } static int cppc_verify_policy(struct cpufreq_policy_data *policy) { cpufreq_verify_within_cpu_limits(policy); return 0; } static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy) { struct cppc_cpudata *cpu_data = policy->driver_data; struct cppc_perf_caps *caps = &cpu_data->perf_caps; unsigned int cpu = policy->cpu; int ret; cpu_data->perf_ctrls.desired_perf = caps->lowest_perf; ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls); if (ret) pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", caps->lowest_perf, cpu, ret); /* Remove CPU node from list and free driver data for policy */ free_cpumask_var(cpu_data->shared_cpu_map); list_del(&cpu_data->node); kfree(policy->driver_data); policy->driver_data = NULL; } /* * The PCC subspace describes the rate at which platform can accept commands * on the shared PCC channel (including READs which do not count towards freq * transition requests), so ideally we need to use the PCC values as a fallback * if we don't have a platform specific transition_delay_us */ #ifdef CONFIG_ARM64 #include static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) { unsigned long implementor = read_cpuid_implementor(); unsigned long part_num = read_cpuid_part_number(); switch (implementor) { case ARM_CPU_IMP_QCOM: switch (part_num) { case QCOM_CPU_PART_FALKOR_V1: case QCOM_CPU_PART_FALKOR: return 10000; } } return cppc_get_transition_latency(cpu) / NSEC_PER_USEC; } #else static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu) { return cppc_get_transition_latency(cpu) / NSEC_PER_USEC; } #endif static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu) { struct cppc_cpudata *cpu_data; int ret; cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL); if (!cpu_data) goto out; if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL)) goto free_cpu; ret = acpi_get_psd_map(cpu, cpu_data); if (ret) { pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret); goto free_mask; } ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps); if (ret) { pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret); goto free_mask; } /* Convert the lowest and nominal freq from MHz to KHz */ cpu_data->perf_caps.lowest_freq *= 1000; cpu_data->perf_caps.nominal_freq *= 1000; list_add(&cpu_data->node, &cpu_data_list); return cpu_data; free_mask: free_cpumask_var(cpu_data->shared_cpu_map); free_cpu: kfree(cpu_data); out: return NULL; } static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy) { unsigned int cpu = policy->cpu; struct cppc_cpudata *cpu_data; struct cppc_perf_caps *caps; int ret; cpu_data = cppc_cpufreq_get_cpu_data(cpu); if (!cpu_data) { pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu); return -ENODEV; } caps = &cpu_data->perf_caps; policy->driver_data = cpu_data; /* * Set min to lowest nonlinear perf to avoid any efficiency penalty (see * Section 8.4.7.1.1.5 of ACPI 6.1 spec) */ policy->min = cppc_cpufreq_perf_to_khz(cpu_data, caps->lowest_nonlinear_perf); policy->max = cppc_cpufreq_perf_to_khz(cpu_data, caps->nominal_perf); /* * Set cpuinfo.min_freq to Lowest to make the full range of performance * available if userspace wants to use any perf between lowest & lowest * nonlinear perf */ policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu_data, caps->lowest_perf); policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu_data, caps->nominal_perf); policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu); policy->shared_type = cpu_data->shared_type; switch (policy->shared_type) { case CPUFREQ_SHARED_TYPE_HW: case CPUFREQ_SHARED_TYPE_NONE: /* Nothing to be done - we'll have a policy for each CPU */ break; case CPUFREQ_SHARED_TYPE_ANY: /* * All CPUs in the domain will share a policy and all cpufreq * operations will use a single cppc_cpudata structure stored * in policy->driver_data. */ cpumask_copy(policy->cpus, cpu_data->shared_cpu_map); break; default: pr_debug("Unsupported CPU co-ord type: %d\n", policy->shared_type); return -EFAULT; } /* * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost * is supported. */ if (caps->highest_perf > caps->nominal_perf) boost_supported = true; /* Set policy->cur to max now. The governors will adjust later. */ policy->cur = cppc_cpufreq_perf_to_khz(cpu_data, caps->highest_perf); cpu_data->perf_ctrls.desired_perf = caps->highest_perf; ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls); if (ret) pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", caps->highest_perf, cpu, ret); return ret; } static inline u64 get_delta(u64 t1, u64 t0) { if (t1 > t0 || t0 > ~(u32)0) return t1 - 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) { u64 delta_reference, delta_delivered; u64 reference_perf, delivered_perf; reference_perf = fb_ctrs_t0.reference_perf; delta_reference = get_delta(fb_ctrs_t1.reference, fb_ctrs_t0.reference); 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; return cppc_cpufreq_perf_to_khz(cpu_data, delivered_perf); } static unsigned int cppc_cpufreq_get_rate(unsigned int cpu) { struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0}; struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); struct cppc_cpudata *cpu_data = policy->driver_data; int ret; cpufreq_cpu_put(policy); ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0); if (ret) return ret; udelay(2); /* 2usec delay between sampling */ ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1); if (ret) return ret; return cppc_get_rate_from_fbctrs(cpu_data, fb_ctrs_t0, fb_ctrs_t1); } static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state) { struct cppc_cpudata *cpu_data = policy->driver_data; struct cppc_perf_caps *caps = &cpu_data->perf_caps; int ret; if (!boost_supported) { pr_err("BOOST not supported by CPU or firmware\n"); return -EINVAL; } if (state) policy->max = cppc_cpufreq_perf_to_khz(cpu_data, caps->highest_perf); else policy->max = cppc_cpufreq_perf_to_khz(cpu_data, caps->nominal_perf); policy->cpuinfo.max_freq = policy->max; ret = freq_qos_update_request(policy->max_freq_req, policy->max); if (ret < 0) return ret; return 0; } static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf) { struct cppc_cpudata *cpu_data = policy->driver_data; return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf); } cpufreq_freq_attr_ro(freqdomain_cpus); static struct freq_attr *cppc_cpufreq_attr[] = { &freqdomain_cpus, NULL, }; static struct cpufreq_driver cppc_cpufreq_driver = { .flags = CPUFREQ_CONST_LOOPS, .verify = cppc_verify_policy, .target = cppc_cpufreq_set_target, .get = cppc_cpufreq_get_rate, .init = cppc_cpufreq_cpu_init, .stop_cpu = cppc_cpufreq_stop_cpu, .set_boost = cppc_cpufreq_set_boost, .attr = cppc_cpufreq_attr, .name = "cppc_cpufreq", }; /* * HISI platform does not support delivered performance counter and * reference performance counter. It can calculate the performance using the * platform specific mechanism. We reuse the desired performance register to * store the real performance calculated by the platform. */ static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu) { struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); struct cppc_cpudata *cpu_data = policy->driver_data; u64 desired_perf; int ret; cpufreq_cpu_put(policy); ret = cppc_get_desired_perf(cpu, &desired_perf); if (ret < 0) return -EIO; return cppc_cpufreq_perf_to_khz(cpu_data, desired_perf); } static void cppc_check_hisi_workaround(void) { struct acpi_table_header *tbl; acpi_status status = AE_OK; int i; status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl); if (ACPI_FAILURE(status) || !tbl) return; for (i = 0; i < ARRAY_SIZE(wa_info); i++) { if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) && !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && wa_info[i].oem_revision == tbl->oem_revision) { /* Overwrite the get() callback */ cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate; break; } } acpi_put_table(tbl); } static int __init cppc_cpufreq_init(void) { if ((acpi_disabled) || !acpi_cpc_valid()) return -ENODEV; INIT_LIST_HEAD(&cpu_data_list); cppc_check_hisi_workaround(); return cpufreq_register_driver(&cppc_cpufreq_driver); } static inline void free_cpu_data(void) { struct cppc_cpudata *iter, *tmp; list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) { free_cpumask_var(iter->shared_cpu_map); list_del(&iter->node); kfree(iter); } } static void __exit cppc_cpufreq_exit(void) { cpufreq_unregister_driver(&cppc_cpufreq_driver); free_cpu_data(); } module_exit(cppc_cpufreq_exit); MODULE_AUTHOR("Ashwin Chaugule"); MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec"); MODULE_LICENSE("GPL"); late_initcall(cppc_cpufreq_init); static const struct acpi_device_id cppc_acpi_ids[] __used = { {ACPI_PROCESSOR_DEVICE_HID, }, {} }; MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);