// 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 <ashwin.chaugule@linaro.org> */ #define pr_fmt(fmt)	"CPPC Cpufreq:"	fmt #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/time.h>#include <linux/vmalloc.h> #include <asm/unaligned.h> #include <acpi/cppc_acpi.h> /* Minimum struct length needed for the DMI processor entry we want */#define DMI_ENTRY_PROCESSOR_MIN_LENGTH	48 /* Offest in the DMI processor structure for the max frequency */#define DMI_PROCESSOR_MAX_SPEED  0x14 /* * These structs contain information parsed from per CPU * ACPI _CPC structures. * e.g. For each CPU the highest, lowest supported * performance capabilities, desired performance level * requested etc. */static struct cppc_cpudata **all_cpu_data; 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 bool apply_hisi_workaround; 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,	}}; static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu,					unsigned int perf); /* * 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 cpunum){	struct cppc_cpudata *cpudata = all_cpu_data[cpunum];	u64 desired_perf;	int ret; 	ret = cppc_get_desired_perf(cpunum, &desired_perf);	if (ret < 0)		return -EIO; 	return cppc_cpufreq_perf_to_khz(cpudata, 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)			apply_hisi_workaround = true;	}} /* 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,					unsigned int perf){	static u64 max_khz;	struct cppc_perf_caps *caps = &cpu->perf_caps;	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 = cpu->perf_caps.highest_perf;	}	return (u64)perf * mul / div;} static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu,					unsigned int freq){	static u64 max_khz;	struct cppc_perf_caps *caps = &cpu->perf_caps;	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 = cpu->perf_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;	struct cpufreq_freqs freqs;	u32 desired_perf;	int ret = 0; 	cpu = all_cpu_data[policy->cpu]; 	desired_perf = cppc_cpufreq_khz_to_perf(cpu, target_freq);	/* Return if it is exactly the same perf */	if (desired_perf == cpu->perf_ctrls.desired_perf)		return ret; 	cpu->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, &cpu->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->cpu, ret); 	return ret;} static int cppc_verify_policy(struct cpufreq_policy *policy){	cpufreq_verify_within_cpu_limits(policy);	return 0;} static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy){	int cpu_num = policy->cpu;	struct cppc_cpudata *cpu = all_cpu_data[cpu_num];	int ret; 	cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf; 	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);	if (ret)		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",				cpu->perf_caps.lowest_perf, cpu_num, ret);} /* * 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 * trasition 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 <asm/cputype.h> static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu){	unsigned long implementor = read_cpuid_implementor();	unsigned long part_num = read_cpuid_part_number();	unsigned int delay_us = 0; 	switch (implementor) {	case ARM_CPU_IMP_QCOM:		switch (part_num) {		case QCOM_CPU_PART_FALKOR_V1:		case QCOM_CPU_PART_FALKOR:			delay_us = 10000;			break;		default:			delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;			break;		}		break;	default:		delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;		break;	} 	return delay_us;} #else static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu){	return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;}#endif static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy){	struct cppc_cpudata *cpu;	unsigned int cpu_num = policy->cpu;	int ret = 0; 	cpu = all_cpu_data[policy->cpu]; 	cpu->cpu = cpu_num;	ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps); 	if (ret) {		pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",				cpu_num, ret);		return ret;	} 	/* Convert the lowest and nominal freq from MHz to KHz */	cpu->perf_caps.lowest_freq *= 1000;	cpu->perf_caps.nominal_freq *= 1000; 	/*	 * 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, cpu->perf_caps.lowest_nonlinear_perf);	policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_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, cpu->perf_caps.lowest_perf);	policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_perf); 	policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu_num);	policy->shared_type = cpu->shared_type; 	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {		int i; 		cpumask_copy(policy->cpus, cpu->shared_cpu_map); 		for_each_cpu(i, policy->cpus) {			if (unlikely(i == policy->cpu))				continue; 			memcpy(&all_cpu_data[i]->perf_caps, &cpu->perf_caps,			       sizeof(cpu->perf_caps));		}	} else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {		/* Support only SW_ANY for now. */		pr_debug("Unsupported CPU co-ord type\n");		return -EFAULT;	} 	cpu->cur_policy = policy; 	/* Set policy->cur to max now. The governors will adjust later. */	policy->cur = cppc_cpufreq_perf_to_khz(cpu,					cpu->perf_caps.highest_perf);	cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf; 	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);	if (ret)		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",				cpu->perf_caps.highest_perf, cpu_num, 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,				     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->perf_ctrls.desired_perf; 	return cppc_cpufreq_perf_to_khz(cpu, delivered_perf);} static unsigned int cppc_cpufreq_get_rate(unsigned int cpunum){	struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};	struct cppc_cpudata *cpu = all_cpu_data[cpunum];	int ret; 	if (apply_hisi_workaround)		return hisi_cppc_cpufreq_get_rate(cpunum); 	ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t0);	if (ret)		return ret; 	udelay(2); /* 2usec delay between sampling */ 	ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t1);	if (ret)		return ret; 	return cppc_get_rate_from_fbctrs(cpu, fb_ctrs_t0, fb_ctrs_t1);} 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,	.name = "cppc_cpufreq",}; static int __init cppc_cpufreq_init(void){	int i, ret = 0;	struct cppc_cpudata *cpu; 	if (acpi_disabled)		return -ENODEV; 	all_cpu_data = kcalloc(num_possible_cpus(), sizeof(void *),			       GFP_KERNEL);	if (!all_cpu_data)		return -ENOMEM; 	for_each_possible_cpu(i) {		all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);		if (!all_cpu_data[i])			goto out; 		cpu = all_cpu_data[i];		if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))			goto out;	} 	ret = acpi_get_psd_map(all_cpu_data);	if (ret) {		pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");		goto out;	} 	cppc_check_hisi_workaround(); 	ret = cpufreq_register_driver(&cppc_cpufreq_driver);	if (ret)		goto out; 	return ret; out:	for_each_possible_cpu(i) {		cpu = all_cpu_data[i];		if (!cpu)			break;		free_cpumask_var(cpu->shared_cpu_map);		kfree(cpu);	} 	kfree(all_cpu_data);	return -ENODEV;} static void __exit cppc_cpufreq_exit(void){	struct cppc_cpudata *cpu;	int i; 	cpufreq_unregister_driver(&cppc_cpufreq_driver); 	for_each_possible_cpu(i) {		cpu = all_cpu_data[i];		free_cpumask_var(cpu->shared_cpu_map);		kfree(cpu);	} 	kfree(all_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);