[linux-2.6-block.git] / drivers / cpufreq / cppc_cpufreq.c

/*
 * 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>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#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;

/* 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;

	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;
	}

	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);
Commit	Line	Data
5477fb3b AC	1	/*
	2	* CPPC (Collaborative Processor Performance Control) driver for
	3	* interfacing with the CPUfreq layer and governors. See
	4	* cppc_acpi.c for CPPC specific methods.
	5	*
	6	* (C) Copyright 2014, 2015 Linaro Ltd.
	7	* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; version 2
	12	* of the License.
	13	*/
	14
	15	#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/delay.h>
	20	#include <linux/cpu.h>
	21	#include <linux/cpufreq.h>
ad38677d	22	#include <linux/dmi.h>
3d41386d	23	#include <linux/time.h>
5477fb3b AC	24	#include <linux/vmalloc.h>
5477fb3b AC	25
ad38677d AS	26	#include <asm/unaligned.h>
ad38677d AS	27
5477fb3b AC	28	#include <acpi/cppc_acpi.h>
5477fb3b AC	29
ad38677d AS	30	/* Minimum struct length needed for the DMI processor entry we want */
	31	#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
	32
	33	/* Offest in the DMI processor structure for the max frequency */
	34	#define DMI_PROCESSOR_MAX_SPEED 0x14
	35
5477fb3b AC	36	/*
	37	* These structs contain information parsed from per CPU
	38	* ACPI _CPC structures.
	39	* e.g. For each CPU the highest, lowest supported
	40	* performance capabilities, desired performance level
	41	* requested etc.
	42	*/
41dd6403	43	static struct cppc_cpudata **all_cpu_data;
5477fb3b	44
ad38677d AS	45	/* Callback function used to retrieve the max frequency from DMI */
	46	static void cppc_find_dmi_mhz(const struct dmi_header dm, void private)
	47	{
	48	const u8 dmi_data = (const u8 )dm;
	49	u16 mhz = (u16 )private;
	50
	51	if (dm->type == DMI_ENTRY_PROCESSOR &&
	52	dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
	53	u16 val = (u16)get_unaligned((const u16 *)
	54	(dmi_data + DMI_PROCESSOR_MAX_SPEED));
	55	mhz = val > mhz ? val : *mhz;
	56	}
	57	}
	58
	59	/* Look up the max frequency in DMI */
	60	static u64 cppc_get_dmi_max_khz(void)
	61	{
	62	u16 mhz = 0;
	63
	64	dmi_walk(cppc_find_dmi_mhz, &mhz);
	65
	66	/*
	67	* Real stupid fallback value, just in case there is no
	68	* actual value set.
	69	*/
	70	mhz = mhz ? mhz : 1;
	71
	72	return (1000 * mhz);
	73	}
	74
256f19d2 PP	75	/*
	76	* If CPPC lowest_freq and nominal_freq registers are exposed then we can
	77	* use them to convert perf to freq and vice versa
	78	*
	79	* If the perf/freq point lies between Nominal and Lowest, we can treat
	80	* (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line
	81	* and extrapolate the rest
	82	* For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion
	83	*/
	84	static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu,
	85	unsigned int perf)
	86	{
	87	static u64 max_khz;
	88	struct cppc_perf_caps *caps = &cpu->perf_caps;
	89	u64 mul, div;
	90
	91	if (caps->lowest_freq && caps->nominal_freq) {
	92	if (perf >= caps->nominal_perf) {
	93	mul = caps->nominal_freq;
	94	div = caps->nominal_perf;
	95	} else {
	96	mul = caps->nominal_freq - caps->lowest_freq;
	97	div = caps->nominal_perf - caps->lowest_perf;
	98	}
	99	} else {
	100	if (!max_khz)
	101	max_khz = cppc_get_dmi_max_khz();
	102	mul = max_khz;
	103	div = cpu->perf_caps.highest_perf;
	104	}
	105	return (u64)perf * mul / div;
	106	}
	107
	108	static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu,
	109	unsigned int freq)
	110	{
	111	static u64 max_khz;
	112	struct cppc_perf_caps *caps = &cpu->perf_caps;
	113	u64 mul, div;
	114
	115	if (caps->lowest_freq && caps->nominal_freq) {
	116	if (freq >= caps->nominal_freq) {
	117	mul = caps->nominal_perf;
	118	div = caps->nominal_freq;
	119	} else {
	120	mul = caps->lowest_perf;
	121	div = caps->lowest_freq;
	122	}
	123	} else {
	124	if (!max_khz)
	125	max_khz = cppc_get_dmi_max_khz();
	126	mul = cpu->perf_caps.highest_perf;
	127	div = max_khz;
	128	}
	129
	130	return (u64)freq * mul / div;
	131	}
	132
5477fb3b AC	133	static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
	134	unsigned int target_freq,
	135	unsigned int relation)
	136	{
41dd6403	137	struct cppc_cpudata *cpu;
5477fb3b	138	struct cpufreq_freqs freqs;
c197d758	139	u32 desired_perf;
5477fb3b AC	140	int ret = 0;
	141
	142	cpu = all_cpu_data[policy->cpu];
	143
256f19d2	144	desired_perf = cppc_cpufreq_khz_to_perf(cpu, target_freq);
c197d758 HT	145	/* Return if it is exactly the same perf */
	146	if (desired_perf == cpu->perf_ctrls.desired_perf)
	147	return ret;
	148
	149	cpu->perf_ctrls.desired_perf = desired_perf;
5477fb3b AC	150	freqs.old = policy->cur;
	151	freqs.new = target_freq;
	152
	153	cpufreq_freq_transition_begin(policy, &freqs);
	154	ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
	155	cpufreq_freq_transition_end(policy, &freqs, ret != 0);
	156
	157	if (ret)
	158	pr_debug("Failed to set target on CPU:%d. ret:%d\n",
	159	cpu->cpu, ret);
	160
	161	return ret;
	162	}
	163
	164	static int cppc_verify_policy(struct cpufreq_policy *policy)
	165	{
	166	cpufreq_verify_within_cpu_limits(policy);
	167	return 0;
	168	}
	169
	170	static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
	171	{
	172	int cpu_num = policy->cpu;
41dd6403	173	struct cppc_cpudata *cpu = all_cpu_data[cpu_num];
5477fb3b AC	174	int ret;
	175
	176	cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
	177
	178	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
	179	if (ret)
	180	pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
	181	cpu->perf_caps.lowest_perf, cpu_num, ret);
	182	}
	183
d4f3388a PP	184	/*
	185	* The PCC subspace describes the rate at which platform can accept commands
	186	* on the shared PCC channel (including READs which do not count towards freq
	187	* trasition requests), so ideally we need to use the PCC values as a fallback
	188	* if we don't have a platform specific transition_delay_us
	189	*/
	190	#ifdef CONFIG_ARM64
	191	#include <asm/cputype.h>
	192
	193	static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu)
	194	{
	195	unsigned long implementor = read_cpuid_implementor();
	196	unsigned long part_num = read_cpuid_part_number();
	197	unsigned int delay_us = 0;
	198
	199	switch (implementor) {
	200	case ARM_CPU_IMP_QCOM:
	201	switch (part_num) {
	202	case QCOM_CPU_PART_FALKOR_V1:
	203	case QCOM_CPU_PART_FALKOR:
	204	delay_us = 10000;
	205	break;
	206	default:
	207	delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
	208	break;
	209	}
	210	break;
	211	default:
	212	delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
	213	break;
	214	}
	215
	216	return delay_us;
	217	}
	218
	219	#else
	220
	221	static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu)
	222	{
	223	return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
	224	}
	225	#endif
	226
5477fb3b AC	227	static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
5477fb3b AC	228	{
41dd6403	229	struct cppc_cpudata *cpu;
5477fb3b AC	230	unsigned int cpu_num = policy->cpu;
	231	int ret = 0;
	232
	233	cpu = all_cpu_data[policy->cpu];
	234
	235	cpu->cpu = cpu_num;
	236	ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);
	237
	238	if (ret) {
	239	pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
	240	cpu_num, ret);
	241	return ret;
	242	}
	243
256f19d2 PP	244	/* Convert the lowest and nominal freq from MHz to KHz */
	245	cpu->perf_caps.lowest_freq *= 1000;
	246	cpu->perf_caps.nominal_freq *= 1000;
ad38677d	247
73808d0f PP	248	/*
	249	* Set min to lowest nonlinear perf to avoid any efficiency penalty (see
	250	* Section 8.4.7.1.1.5 of ACPI 6.1 spec)
	251	*/
256f19d2 PP	252	policy->min = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_nonlinear_perf);
256f19d2 PP	253	policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_perf);
73808d0f PP	254
	255	/*
	256	* Set cpuinfo.min_freq to Lowest to make the full range of performance
	257	* available if userspace wants to use any perf between lowest & lowest
	258	* nonlinear perf
	259	*/
256f19d2 PP	260	policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_perf);
256f19d2 PP	261	policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_perf);
73808d0f	262
d4f3388a	263	policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu_num);
9dc17917	264	policy->shared_type = cpu->shared_type;
5477fb3b	265
8913315e SY	266	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
	267	int i;
	268
5477fb3b	269	cpumask_copy(policy->cpus, cpu->shared_cpu_map);
8913315e SY	270
	271	for_each_cpu(i, policy->cpus) {
	272	if (unlikely(i == policy->cpu))
	273	continue;
	274
	275	memcpy(&all_cpu_data[i]->perf_caps, &cpu->perf_caps,
	276	sizeof(cpu->perf_caps));
	277	}
	278	} else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) {
5477fb3b AC	279	/* Support only SW_ANY for now. */
	280	pr_debug("Unsupported CPU co-ord type\n");
	281	return -EFAULT;
	282	}
	283
5477fb3b AC	284	cpu->cur_policy = policy;
	285
	286	/* Set policy->cur to max now. The governors will adjust later. */
256f19d2 PP	287	policy->cur = cppc_cpufreq_perf_to_khz(cpu,
256f19d2 PP	288	cpu->perf_caps.highest_perf);
ad38677d	289	cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
5477fb3b AC	290
	291	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
	292	if (ret)
	293	pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
	294	cpu->perf_caps.highest_perf, cpu_num, ret);
	295
	296	return ret;
	297	}
	298
33477d84 GC	299	static inline u64 get_delta(u64 t1, u64 t0)
	300	{
	301	if (t1 > t0 \|\| t0 > ~(u32)0)
	302	return t1 - t0;
	303
	304	return (u32)t1 - (u32)t0;
	305	}
	306
	307	static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu,
	308	struct cppc_perf_fb_ctrs fb_ctrs_t0,
	309	struct cppc_perf_fb_ctrs fb_ctrs_t1)
	310	{
	311	u64 delta_reference, delta_delivered;
	312	u64 reference_perf, delivered_perf;
	313
	314	reference_perf = fb_ctrs_t0.reference_perf;
	315
	316	delta_reference = get_delta(fb_ctrs_t1.reference,
	317	fb_ctrs_t0.reference);
	318	delta_delivered = get_delta(fb_ctrs_t1.delivered,
	319	fb_ctrs_t0.delivered);
	320
	321	/* Check to avoid divide-by zero */
	322	if (delta_reference \|\| delta_delivered)
	323	delivered_perf = (reference_perf * delta_delivered) /
	324	delta_reference;
	325	else
	326	delivered_perf = cpu->perf_ctrls.desired_perf;
	327
	328	return cppc_cpufreq_perf_to_khz(cpu, delivered_perf);
	329	}
	330
	331	static unsigned int cppc_cpufreq_get_rate(unsigned int cpunum)
	332	{
	333	struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
	334	struct cppc_cpudata *cpu = all_cpu_data[cpunum];
	335	int ret;
	336
	337	ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t0);
	338	if (ret)
	339	return ret;
	340
	341	udelay(2); /* 2usec delay between sampling */
	342
	343	ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t1);
	344	if (ret)
	345	return ret;
	346
	347	return cppc_get_rate_from_fbctrs(cpu, fb_ctrs_t0, fb_ctrs_t1);
	348	}
	349
5477fb3b AC	350	static struct cpufreq_driver cppc_cpufreq_driver = {
	351	.flags = CPUFREQ_CONST_LOOPS,
	352	.verify = cppc_verify_policy,
	353	.target = cppc_cpufreq_set_target,
33477d84	354	.get = cppc_cpufreq_get_rate,
5477fb3b AC	355	.init = cppc_cpufreq_cpu_init,
	356	.stop_cpu = cppc_cpufreq_stop_cpu,
	357	.name = "cppc_cpufreq",
	358	};
	359
	360	static int __init cppc_cpufreq_init(void)
	361	{
	362	int i, ret = 0;
41dd6403	363	struct cppc_cpudata *cpu;
5477fb3b AC	364
	365	if (acpi_disabled)
	366	return -ENODEV;
	367
6396bb22 KC	368	all_cpu_data = kcalloc(num_possible_cpus(), sizeof(void *),
6396bb22 KC	369	GFP_KERNEL);
5477fb3b AC	370	if (!all_cpu_data)
	371	return -ENOMEM;
	372
	373	for_each_possible_cpu(i) {
41dd6403	374	all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
5477fb3b AC	375	if (!all_cpu_data[i])
	376	goto out;
	377
	378	cpu = all_cpu_data[i];
	379	if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
	380	goto out;
	381	}
	382
	383	ret = acpi_get_psd_map(all_cpu_data);
	384	if (ret) {
	385	pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
	386	goto out;
	387	}
	388
	389	ret = cpufreq_register_driver(&cppc_cpufreq_driver);
	390	if (ret)
	391	goto out;
	392
	393	return ret;
	394
	395	out:
55b55abc CH	396	for_each_possible_cpu(i) {
	397	cpu = all_cpu_data[i];
	398	if (!cpu)
	399	break;
	400	free_cpumask_var(cpu->shared_cpu_map);
	401	kfree(cpu);
	402	}
5477fb3b AC	403
	404	kfree(all_cpu_data);
	405	return -ENODEV;
	406	}
	407
a29a1e76 AC	408	static void __exit cppc_cpufreq_exit(void)
a29a1e76 AC	409	{
41dd6403	410	struct cppc_cpudata *cpu;
a29a1e76 AC	411	int i;
	412
	413	cpufreq_unregister_driver(&cppc_cpufreq_driver);
	414
	415	for_each_possible_cpu(i) {
	416	cpu = all_cpu_data[i];
	417	free_cpumask_var(cpu->shared_cpu_map);
	418	kfree(cpu);
	419	}
	420
	421	kfree(all_cpu_data);
	422	}
	423
	424	module_exit(cppc_cpufreq_exit);
	425	MODULE_AUTHOR("Ashwin Chaugule");
	426	MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
	427	MODULE_LICENSE("GPL");
	428
5477fb3b	429	late_initcall(cppc_cpufreq_init);
974f8649	430
8ff3c226	431	static const struct acpi_device_id cppc_acpi_ids[] __used = {
974f8649 PP	432	{ACPI_PROCESSOR_DEVICE_HID, },
	433	{}
	434	};
	435
	436	MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);