forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
156 lines
4.0 KiB
156 lines
4.0 KiB
// 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 <[email protected]> |
|
*/ |
|
|
|
#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 <asm/cpu_device_id.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 __maybe_unused amd_freq_sensitivity_ids[] = { |
|
X86_MATCH_FEATURE(X86_FEATURE_PROC_FEEDBACK, NULL), |
|
{} |
|
}; |
|
MODULE_DEVICE_TABLE(x86cpu, amd_freq_sensitivity_ids); |
|
|
|
MODULE_AUTHOR("Jacob Shin <[email protected]>"); |
|
MODULE_DESCRIPTION("AMD frequency sensitivity feedback powersave bias for " |
|
"the ondemand governor."); |
|
MODULE_LICENSE("GPL");
|
|
|