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