[mirror_ubuntu-jammy-kernel.git] / drivers / cpufreq / amd_freq_sensitivity.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * amd_freq_sensitivity.c: AMD frequency sensitivity feedback powersave bias
 *                         for the ondemand governor.
 *
 * Copyright (C) 2013 Advanced Micro Devices, Inc.
 *
 * Author: Jacob Shin <jacob.shin@amd.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/percpu-defs.h>
#include <linux/init.h>
#include <linux/mod_devicetable.h>

#include <asm/msr.h>
#include <asm/cpufeature.h>

#include "cpufreq_ondemand.h"

#define MSR_AMD64_FREQ_SENSITIVITY_ACTUAL	0xc0010080
#define MSR_AMD64_FREQ_SENSITIVITY_REFERENCE	0xc0010081
#define CLASS_CODE_SHIFT			56
#define POWERSAVE_BIAS_MAX			1000
#define POWERSAVE_BIAS_DEF			400

struct cpu_data_t {
	u64 actual;
	u64 reference;
	unsigned int freq_prev;
};

static DEFINE_PER_CPU(struct cpu_data_t, cpu_data);

static unsigned int amd_powersave_bias_target(struct cpufreq_policy *policy,
					      unsigned int freq_next,
					      unsigned int relation)
{
	int sensitivity;
	long d_actual, d_reference;
	struct msr actual, reference;
	struct cpu_data_t *data = &per_cpu(cpu_data, policy->cpu);
	struct policy_dbs_info *policy_dbs = policy->governor_data;
	struct dbs_data *od_data = policy_dbs->dbs_data;
	struct od_dbs_tuners *od_tuners = od_data->tuners;

	if (!policy->freq_table)
		return freq_next;

	rdmsr_on_cpu(policy->cpu, MSR_AMD64_FREQ_SENSITIVITY_ACTUAL,
		&actual.l, &actual.h);
	rdmsr_on_cpu(policy->cpu, MSR_AMD64_FREQ_SENSITIVITY_REFERENCE,
		&reference.l, &reference.h);
	actual.h &= 0x00ffffff;
	reference.h &= 0x00ffffff;

	/* counter wrapped around, so stay on current frequency */
	if (actual.q < data->actual || reference.q < data->reference) {
		freq_next = policy->cur;
		goto out;
	}

	d_actual = actual.q - data->actual;
	d_reference = reference.q - data->reference;

	/* divide by 0, so stay on current frequency as well */
	if (d_reference == 0) {
		freq_next = policy->cur;
		goto out;
	}

	sensitivity = POWERSAVE_BIAS_MAX -
		(POWERSAVE_BIAS_MAX * (d_reference - d_actual) / d_reference);

	clamp(sensitivity, 0, POWERSAVE_BIAS_MAX);

	/* this workload is not CPU bound, so choose a lower freq */
	if (sensitivity < od_tuners->powersave_bias) {
		if (data->freq_prev == policy->cur)
			freq_next = policy->cur;

		if (freq_next > policy->cur)
			freq_next = policy->cur;
		else if (freq_next < policy->cur)
			freq_next = policy->min;
		else {
			unsigned int index;

			index = cpufreq_table_find_index_h(policy,
							   policy->cur - 1);
			freq_next = policy->freq_table[index].frequency;
		}

		data->freq_prev = freq_next;
	} else
		data->freq_prev = 0;

out:
	data->actual = actual.q;
	data->reference = reference.q;
	return freq_next;
}

static int __init amd_freq_sensitivity_init(void)
{
	u64 val;
	struct pci_dev *pcidev;
	unsigned int pci_vendor;

	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
		pci_vendor = PCI_VENDOR_ID_AMD;
	else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
		pci_vendor = PCI_VENDOR_ID_HYGON;
	else
		return -ENODEV;

	pcidev = pci_get_device(pci_vendor,
			PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, NULL);

	if (!pcidev) {
		if (!boot_cpu_has(X86_FEATURE_PROC_FEEDBACK))
			return -ENODEV;
	}

	if (rdmsrl_safe(MSR_AMD64_FREQ_SENSITIVITY_ACTUAL, &val))
		return -ENODEV;

	if (!(val >> CLASS_CODE_SHIFT))
		return -ENODEV;

	od_register_powersave_bias_handler(amd_powersave_bias_target,
			POWERSAVE_BIAS_DEF);
	return 0;
}
late_initcall(amd_freq_sensitivity_init);

static void __exit amd_freq_sensitivity_exit(void)
{
	od_unregister_powersave_bias_handler();
}
module_exit(amd_freq_sensitivity_exit);

static const struct x86_cpu_id amd_freq_sensitivity_ids[] = {
	X86_FEATURE_MATCH(X86_FEATURE_PROC_FEEDBACK),
	{}
};
MODULE_DEVICE_TABLE(x86cpu, amd_freq_sensitivity_ids);

MODULE_AUTHOR("Jacob Shin <jacob.shin@amd.com>");
MODULE_DESCRIPTION("AMD frequency sensitivity feedback powersave bias for "
		"the ondemand governor.");
MODULE_LICENSE("GPL");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
9c5320c8 JS	2	/*
	3	* amd_freq_sensitivity.c: AMD frequency sensitivity feedback powersave bias
	4	* for the ondemand governor.
	5	*
	6	* Copyright (C) 2013 Advanced Micro Devices, Inc.
	7	*
	8	* Author: Jacob Shin <jacob.shin@amd.com>
9c5320c8 JS	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/types.h>
59a3b3a8	14	#include <linux/pci.h>
9c5320c8 JS	15	#include <linux/percpu-defs.h>
	16	#include <linux/init.h>
	17	#include <linux/mod_devicetable.h>
	18
	19	#include <asm/msr.h>
	20	#include <asm/cpufeature.h>
	21
7d5a9956	22	#include "cpufreq_ondemand.h"
9c5320c8 JS	23
	24	#define MSR_AMD64_FREQ_SENSITIVITY_ACTUAL 0xc0010080
	25	#define MSR_AMD64_FREQ_SENSITIVITY_REFERENCE 0xc0010081
	26	#define CLASS_CODE_SHIFT 56
	27	#define POWERSAVE_BIAS_MAX 1000
	28	#define POWERSAVE_BIAS_DEF 400
	29
	30	struct cpu_data_t {
	31	u64 actual;
	32	u64 reference;
	33	unsigned int freq_prev;
	34	};
	35
	36	static DEFINE_PER_CPU(struct cpu_data_t, cpu_data);
	37
	38	static unsigned int amd_powersave_bias_target(struct cpufreq_policy *policy,
	39	unsigned int freq_next,
	40	unsigned int relation)
	41	{
	42	int sensitivity;
	43	long d_actual, d_reference;
	44	struct msr actual, reference;
	45	struct cpu_data_t *data = &per_cpu(cpu_data, policy->cpu);
bc505475 RW	46	struct policy_dbs_info *policy_dbs = policy->governor_data;
bc505475 RW	47	struct dbs_data *od_data = policy_dbs->dbs_data;
9c5320c8	48	struct od_dbs_tuners *od_tuners = od_data->tuners;
9c5320c8	49
34ac5d7a	50	if (!policy->freq_table)
9c5320c8 JS	51	return freq_next;
	52
	53	rdmsr_on_cpu(policy->cpu, MSR_AMD64_FREQ_SENSITIVITY_ACTUAL,
	54	&actual.l, &actual.h);
	55	rdmsr_on_cpu(policy->cpu, MSR_AMD64_FREQ_SENSITIVITY_REFERENCE,
	56	&reference.l, &reference.h);
	57	actual.h &= 0x00ffffff;
	58	reference.h &= 0x00ffffff;
	59
	60	/* counter wrapped around, so stay on current frequency */
	61	if (actual.q < data->actual \|\| reference.q < data->reference) {
	62	freq_next = policy->cur;
	63	goto out;
	64	}
	65
	66	d_actual = actual.q - data->actual;
	67	d_reference = reference.q - data->reference;
	68
	69	/* divide by 0, so stay on current frequency as well */
	70	if (d_reference == 0) {
	71	freq_next = policy->cur;
	72	goto out;
	73	}
	74
	75	sensitivity = POWERSAVE_BIAS_MAX -
	76	(POWERSAVE_BIAS_MAX * (d_reference - d_actual) / d_reference);
	77
	78	clamp(sensitivity, 0, POWERSAVE_BIAS_MAX);
	79
	80	/* this workload is not CPU bound, so choose a lower freq */
	81	if (sensitivity < od_tuners->powersave_bias) {
	82	if (data->freq_prev == policy->cur)
	83	freq_next = policy->cur;
	84
	85	if (freq_next > policy->cur)
	86	freq_next = policy->cur;
	87	else if (freq_next < policy->cur)
	88	freq_next = policy->min;
	89	else {
	90	unsigned int index;
	91
82577360 VK	92	index = cpufreq_table_find_index_h(policy,
82577360 VK	93	policy->cur - 1);
34ac5d7a	94	freq_next = policy->freq_table[index].frequency;
9c5320c8 JS	95	}
	96
	97	data->freq_prev = freq_next;
	98	} else
	99	data->freq_prev = 0;
	100
	101	out:
	102	data->actual = actual.q;
	103	data->reference = reference.q;
	104	return freq_next;
	105	}
	106
	107	static int __init amd_freq_sensitivity_init(void)
	108	{
	109	u64 val;
59a3b3a8	110	struct pci_dev *pcidev;
cc9690cf	111	unsigned int pci_vendor;
9c5320c8	112
cc9690cf PW	113	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
	114	pci_vendor = PCI_VENDOR_ID_AMD;
	115	else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
	116	pci_vendor = PCI_VENDOR_ID_HYGON;
	117	else
9c5320c8 JS	118	return -ENODEV;
9c5320c8 JS	119
cc9690cf	120	pcidev = pci_get_device(pci_vendor,
59a3b3a8 AA	121	PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, NULL);
	122
	123	if (!pcidev) {
108ec36b	124	if (!boot_cpu_has(X86_FEATURE_PROC_FEEDBACK))
59a3b3a8 AA	125	return -ENODEV;
59a3b3a8 AA	126	}
9c5320c8 JS	127
	128	if (rdmsrl_safe(MSR_AMD64_FREQ_SENSITIVITY_ACTUAL, &val))
	129	return -ENODEV;
	130
	131	if (!(val >> CLASS_CODE_SHIFT))
	132	return -ENODEV;
	133
	134	od_register_powersave_bias_handler(amd_powersave_bias_target,
	135	POWERSAVE_BIAS_DEF);
	136	return 0;
	137	}
	138	late_initcall(amd_freq_sensitivity_init);
	139
	140	static void __exit amd_freq_sensitivity_exit(void)
	141	{
	142	od_unregister_powersave_bias_handler();
	143	}
	144	module_exit(amd_freq_sensitivity_exit);
	145
	146	static const struct x86_cpu_id amd_freq_sensitivity_ids[] = {
	147	X86_FEATURE_MATCH(X86_FEATURE_PROC_FEEDBACK),
	148	{}
	149	};
	150	MODULE_DEVICE_TABLE(x86cpu, amd_freq_sensitivity_ids);
	151
	152	MODULE_AUTHOR("Jacob Shin <jacob.shin@amd.com>");
	153	MODULE_DESCRIPTION("AMD frequency sensitivity feedback powersave bias for "
	154	"the ondemand governor.");
	155	MODULE_LICENSE("GPL");