linux/drivers/cpufreq/acpi-cpufreq.c
Mario Limonciello 6c09e3b445 x86/amd: Rename amd_get_highest_perf() to amd_get_boost_ratio_numerator()
The function name is ambiguous because it returns an intermediate value
for calculating maximum frequency rather than the CPPC 'Highest Perf'
register.

Rename the function to clarify its use and allow the function to return
errors. Adjust the consumer in acpi-cpufreq to catch errors.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
2024-09-11 10:23:22 -05:00

1053 lines
26 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* acpi-cpufreq.c - ACPI Processor P-States Driver
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/cpufreq.h>
#include <linux/compiler.h>
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/string_helpers.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <acpi/processor.h>
#include <acpi/cppc_acpi.h>
#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/cpu_device_id.h>
MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");
enum {
UNDEFINED_CAPABLE = 0,
SYSTEM_INTEL_MSR_CAPABLE,
SYSTEM_AMD_MSR_CAPABLE,
SYSTEM_IO_CAPABLE,
};
#define INTEL_MSR_RANGE (0xffff)
#define AMD_MSR_RANGE (0x7)
#define HYGON_MSR_RANGE (0x7)
struct acpi_cpufreq_data {
unsigned int resume;
unsigned int cpu_feature;
unsigned int acpi_perf_cpu;
cpumask_var_t freqdomain_cpus;
void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
};
/* acpi_perf_data is a pointer to percpu data. */
static struct acpi_processor_performance __percpu *acpi_perf_data;
static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
{
return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
}
static struct cpufreq_driver acpi_cpufreq_driver;
static unsigned int acpi_pstate_strict;
static bool boost_state(unsigned int cpu)
{
u32 lo, hi;
u64 msr;
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_INTEL:
case X86_VENDOR_CENTAUR:
case X86_VENDOR_ZHAOXIN:
rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
msr = lo | ((u64)hi << 32);
return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
msr = lo | ((u64)hi << 32);
return !(msr & MSR_K7_HWCR_CPB_DIS);
}
return false;
}
static int boost_set_msr(bool enable)
{
u32 msr_addr;
u64 msr_mask, val;
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_INTEL:
case X86_VENDOR_CENTAUR:
case X86_VENDOR_ZHAOXIN:
msr_addr = MSR_IA32_MISC_ENABLE;
msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
break;
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
msr_addr = MSR_K7_HWCR;
msr_mask = MSR_K7_HWCR_CPB_DIS;
break;
default:
return -EINVAL;
}
rdmsrl(msr_addr, val);
if (enable)
val &= ~msr_mask;
else
val |= msr_mask;
wrmsrl(msr_addr, val);
return 0;
}
static void boost_set_msr_each(void *p_en)
{
bool enable = (bool) p_en;
boost_set_msr(enable);
}
static int set_boost(struct cpufreq_policy *policy, int val)
{
on_each_cpu_mask(policy->cpus, boost_set_msr_each,
(void *)(long)val, 1);
pr_debug("CPU %*pbl: Core Boosting %s.\n",
cpumask_pr_args(policy->cpus), str_enabled_disabled(val));
return 0;
}
static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
{
struct acpi_cpufreq_data *data = policy->driver_data;
if (unlikely(!data))
return -ENODEV;
return cpufreq_show_cpus(data->freqdomain_cpus, buf);
}
cpufreq_freq_attr_ro(freqdomain_cpus);
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
size_t count)
{
int ret;
unsigned int val = 0;
if (!acpi_cpufreq_driver.set_boost)
return -EINVAL;
ret = kstrtouint(buf, 10, &val);
if (ret || val > 1)
return -EINVAL;
cpus_read_lock();
set_boost(policy, val);
cpus_read_unlock();
return count;
}
static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
{
return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
}
cpufreq_freq_attr_rw(cpb);
#endif
static int check_est_cpu(unsigned int cpuid)
{
struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
return cpu_has(cpu, X86_FEATURE_EST);
}
static int check_amd_hwpstate_cpu(unsigned int cpuid)
{
struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
}
static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
{
struct acpi_cpufreq_data *data = policy->driver_data;
struct acpi_processor_performance *perf;
int i;
perf = to_perf_data(data);
for (i = 0; i < perf->state_count; i++) {
if (value == perf->states[i].status)
return policy->freq_table[i].frequency;
}
return 0;
}
static unsigned extract_msr(struct cpufreq_policy *policy, u32 msr)
{
struct acpi_cpufreq_data *data = policy->driver_data;
struct cpufreq_frequency_table *pos;
struct acpi_processor_performance *perf;
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
msr &= AMD_MSR_RANGE;
else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
msr &= HYGON_MSR_RANGE;
else
msr &= INTEL_MSR_RANGE;
perf = to_perf_data(data);
cpufreq_for_each_entry(pos, policy->freq_table)
if (msr == perf->states[pos->driver_data].status)
return pos->frequency;
return policy->freq_table[0].frequency;
}
static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
{
struct acpi_cpufreq_data *data = policy->driver_data;
switch (data->cpu_feature) {
case SYSTEM_INTEL_MSR_CAPABLE:
case SYSTEM_AMD_MSR_CAPABLE:
return extract_msr(policy, val);
case SYSTEM_IO_CAPABLE:
return extract_io(policy, val);
default:
return 0;
}
}
static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
{
u32 val, dummy __always_unused;
rdmsr(MSR_IA32_PERF_CTL, val, dummy);
return val;
}
static void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
{
u32 lo, hi;
rdmsr(MSR_IA32_PERF_CTL, lo, hi);
lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
wrmsr(MSR_IA32_PERF_CTL, lo, hi);
}
static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
{
u32 val, dummy __always_unused;
rdmsr(MSR_AMD_PERF_CTL, val, dummy);
return val;
}
static void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
{
wrmsr(MSR_AMD_PERF_CTL, val, 0);
}
static u32 cpu_freq_read_io(struct acpi_pct_register *reg)
{
u32 val;
acpi_os_read_port(reg->address, &val, reg->bit_width);
return val;
}
static void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
{
acpi_os_write_port(reg->address, val, reg->bit_width);
}
struct drv_cmd {
struct acpi_pct_register *reg;
u32 val;
union {
void (*write)(struct acpi_pct_register *reg, u32 val);
u32 (*read)(struct acpi_pct_register *reg);
} func;
};
/* Called via smp_call_function_single(), on the target CPU */
static void do_drv_read(void *_cmd)
{
struct drv_cmd *cmd = _cmd;
cmd->val = cmd->func.read(cmd->reg);
}
static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
{
struct acpi_processor_performance *perf = to_perf_data(data);
struct drv_cmd cmd = {
.reg = &perf->control_register,
.func.read = data->cpu_freq_read,
};
int err;
err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */
return cmd.val;
}
/* Called via smp_call_function_many(), on the target CPUs */
static void do_drv_write(void *_cmd)
{
struct drv_cmd *cmd = _cmd;
cmd->func.write(cmd->reg, cmd->val);
}
static void drv_write(struct acpi_cpufreq_data *data,
const struct cpumask *mask, u32 val)
{
struct acpi_processor_performance *perf = to_perf_data(data);
struct drv_cmd cmd = {
.reg = &perf->control_register,
.val = val,
.func.write = data->cpu_freq_write,
};
int this_cpu;
this_cpu = get_cpu();
if (cpumask_test_cpu(this_cpu, mask))
do_drv_write(&cmd);
smp_call_function_many(mask, do_drv_write, &cmd, 1);
put_cpu();
}
static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
{
u32 val;
if (unlikely(cpumask_empty(mask)))
return 0;
val = drv_read(data, mask);
pr_debug("%s = %u\n", __func__, val);
return val;
}
static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
{
struct acpi_cpufreq_data *data;
struct cpufreq_policy *policy;
unsigned int freq;
unsigned int cached_freq;
pr_debug("%s (%d)\n", __func__, cpu);
policy = cpufreq_cpu_get_raw(cpu);
if (unlikely(!policy))
return 0;
data = policy->driver_data;
if (unlikely(!data || !policy->freq_table))
return 0;
cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
if (freq != cached_freq) {
/*
* The dreaded BIOS frequency change behind our back.
* Force set the frequency on next target call.
*/
data->resume = 1;
}
pr_debug("cur freq = %u\n", freq);
return freq;
}
static unsigned int check_freqs(struct cpufreq_policy *policy,
const struct cpumask *mask, unsigned int freq)
{
struct acpi_cpufreq_data *data = policy->driver_data;
unsigned int cur_freq;
unsigned int i;
for (i = 0; i < 100; i++) {
cur_freq = extract_freq(policy, get_cur_val(mask, data));
if (cur_freq == freq)
return 1;
udelay(10);
}
return 0;
}
static int acpi_cpufreq_target(struct cpufreq_policy *policy,
unsigned int index)
{
struct acpi_cpufreq_data *data = policy->driver_data;
struct acpi_processor_performance *perf;
const struct cpumask *mask;
unsigned int next_perf_state = 0; /* Index into perf table */
int result = 0;
if (unlikely(!data)) {
return -ENODEV;
}
perf = to_perf_data(data);
next_perf_state = policy->freq_table[index].driver_data;
if (perf->state == next_perf_state) {
if (unlikely(data->resume)) {
pr_debug("Called after resume, resetting to P%d\n",
next_perf_state);
data->resume = 0;
} else {
pr_debug("Already at target state (P%d)\n",
next_perf_state);
return 0;
}
}
/*
* The core won't allow CPUs to go away until the governor has been
* stopped, so we can rely on the stability of policy->cpus.
*/
mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
cpumask_of(policy->cpu) : policy->cpus;
drv_write(data, mask, perf->states[next_perf_state].control);
if (acpi_pstate_strict) {
if (!check_freqs(policy, mask,
policy->freq_table[index].frequency)) {
pr_debug("%s (%d)\n", __func__, policy->cpu);
result = -EAGAIN;
}
}
if (!result)
perf->state = next_perf_state;
return result;
}
static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
unsigned int target_freq)
{
struct acpi_cpufreq_data *data = policy->driver_data;
struct acpi_processor_performance *perf;
struct cpufreq_frequency_table *entry;
unsigned int next_perf_state, next_freq, index;
/*
* Find the closest frequency above target_freq.
*/
if (policy->cached_target_freq == target_freq)
index = policy->cached_resolved_idx;
else
index = cpufreq_table_find_index_dl(policy, target_freq,
false);
entry = &policy->freq_table[index];
next_freq = entry->frequency;
next_perf_state = entry->driver_data;
perf = to_perf_data(data);
if (perf->state == next_perf_state) {
if (unlikely(data->resume))
data->resume = 0;
else
return next_freq;
}
data->cpu_freq_write(&perf->control_register,
perf->states[next_perf_state].control);
perf->state = next_perf_state;
return next_freq;
}
static unsigned long
acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
{
struct acpi_processor_performance *perf;
perf = to_perf_data(data);
if (cpu_khz) {
/* search the closest match to cpu_khz */
unsigned int i;
unsigned long freq;
unsigned long freqn = perf->states[0].core_frequency * 1000;
for (i = 0; i < (perf->state_count-1); i++) {
freq = freqn;
freqn = perf->states[i+1].core_frequency * 1000;
if ((2 * cpu_khz) > (freqn + freq)) {
perf->state = i;
return freq;
}
}
perf->state = perf->state_count-1;
return freqn;
} else {
/* assume CPU is at P0... */
perf->state = 0;
return perf->states[0].core_frequency * 1000;
}
}
static void free_acpi_perf_data(void)
{
unsigned int i;
/* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
for_each_possible_cpu(i)
free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
->shared_cpu_map);
free_percpu(acpi_perf_data);
}
static int cpufreq_boost_down_prep(unsigned int cpu)
{
/*
* Clear the boost-disable bit on the CPU_DOWN path so that
* this cpu cannot block the remaining ones from boosting.
*/
return boost_set_msr(1);
}
/*
* acpi_cpufreq_early_init - initialize ACPI P-States library
*
* Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
* in order to determine correct frequency and voltage pairings. We can
* do _PDC and _PSD and find out the processor dependency for the
* actual init that will happen later...
*/
static int __init acpi_cpufreq_early_init(void)
{
unsigned int i;
pr_debug("%s\n", __func__);
acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
if (!acpi_perf_data) {
pr_debug("Memory allocation error for acpi_perf_data.\n");
return -ENOMEM;
}
for_each_possible_cpu(i) {
if (!zalloc_cpumask_var_node(
&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
GFP_KERNEL, cpu_to_node(i))) {
/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
free_acpi_perf_data();
return -ENOMEM;
}
}
/* Do initialization in ACPI core */
acpi_processor_preregister_performance(acpi_perf_data);
return 0;
}
#ifdef CONFIG_SMP
/*
* Some BIOSes do SW_ANY coordination internally, either set it up in hw
* or do it in BIOS firmware and won't inform about it to OS. If not
* detected, this has a side effect of making CPU run at a different speed
* than OS intended it to run at. Detect it and handle it cleanly.
*/
static int bios_with_sw_any_bug;
static int sw_any_bug_found(const struct dmi_system_id *d)
{
bios_with_sw_any_bug = 1;
return 0;
}
static const struct dmi_system_id sw_any_bug_dmi_table[] = {
{
.callback = sw_any_bug_found,
.ident = "Supermicro Server X6DLP",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
DMI_MATCH(DMI_BIOS_VERSION, "080010"),
DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
},
},
{ }
};
static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
{
/* Intel Xeon Processor 7100 Series Specification Update
* https://www.intel.com/Assets/PDF/specupdate/314554.pdf
* AL30: A Machine Check Exception (MCE) Occurring during an
* Enhanced Intel SpeedStep Technology Ratio Change May Cause
* Both Processor Cores to Lock Up. */
if (c->x86_vendor == X86_VENDOR_INTEL) {
if ((c->x86 == 15) &&
(c->x86_model == 6) &&
(c->x86_stepping == 8)) {
pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
return -ENODEV;
}
}
return 0;
}
#endif
#ifdef CONFIG_ACPI_CPPC_LIB
static u64 get_max_boost_ratio(unsigned int cpu)
{
struct cppc_perf_caps perf_caps;
u64 highest_perf, nominal_perf;
int ret;
if (acpi_pstate_strict)
return 0;
ret = cppc_get_perf_caps(cpu, &perf_caps);
if (ret) {
pr_debug("CPU%d: Unable to get performance capabilities (%d)\n",
cpu, ret);
return 0;
}
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
ret = amd_get_boost_ratio_numerator(cpu, &highest_perf);
if (ret) {
pr_debug("CPU%d: Unable to get boost ratio numerator (%d)\n",
cpu, ret);
return 0;
}
} else {
highest_perf = perf_caps.highest_perf;
}
nominal_perf = perf_caps.nominal_perf;
if (!highest_perf || !nominal_perf) {
pr_debug("CPU%d: highest or nominal performance missing\n", cpu);
return 0;
}
if (highest_perf < nominal_perf) {
pr_debug("CPU%d: nominal performance above highest\n", cpu);
return 0;
}
return div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
}
#else
static inline u64 get_max_boost_ratio(unsigned int cpu) { return 0; }
#endif
static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *freq_table;
struct acpi_processor_performance *perf;
struct acpi_cpufreq_data *data;
unsigned int cpu = policy->cpu;
struct cpuinfo_x86 *c = &cpu_data(cpu);
unsigned int valid_states = 0;
unsigned int result = 0;
u64 max_boost_ratio;
unsigned int i;
#ifdef CONFIG_SMP
static int blacklisted;
#endif
pr_debug("%s\n", __func__);
#ifdef CONFIG_SMP
if (blacklisted)
return blacklisted;
blacklisted = acpi_cpufreq_blacklist(c);
if (blacklisted)
return blacklisted;
#endif
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
result = -ENOMEM;
goto err_free;
}
perf = per_cpu_ptr(acpi_perf_data, cpu);
data->acpi_perf_cpu = cpu;
policy->driver_data = data;
if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
result = acpi_processor_register_performance(perf, cpu);
if (result)
goto err_free_mask;
policy->shared_type = perf->shared_type;
/*
* Will let policy->cpus know about dependency only when software
* coordination is required.
*/
if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
cpumask_copy(policy->cpus, perf->shared_cpu_map);
}
cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
#ifdef CONFIG_SMP
dmi_check_system(sw_any_bug_dmi_table);
if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
}
if (check_amd_hwpstate_cpu(cpu) && boot_cpu_data.x86 < 0x19 &&
!acpi_pstate_strict) {
cpumask_clear(policy->cpus);
cpumask_set_cpu(cpu, policy->cpus);
cpumask_copy(data->freqdomain_cpus,
topology_sibling_cpumask(cpu));
policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
pr_info_once("overriding BIOS provided _PSD data\n");
}
#endif
/* capability check */
if (perf->state_count <= 1) {
pr_debug("No P-States\n");
result = -ENODEV;
goto err_unreg;
}
if (perf->control_register.space_id != perf->status_register.space_id) {
result = -ENODEV;
goto err_unreg;
}
switch (perf->control_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
boot_cpu_data.x86 == 0xf) {
pr_debug("AMD K8 systems must use native drivers.\n");
result = -ENODEV;
goto err_unreg;
}
pr_debug("SYSTEM IO addr space\n");
data->cpu_feature = SYSTEM_IO_CAPABLE;
data->cpu_freq_read = cpu_freq_read_io;
data->cpu_freq_write = cpu_freq_write_io;
break;
case ACPI_ADR_SPACE_FIXED_HARDWARE:
pr_debug("HARDWARE addr space\n");
if (check_est_cpu(cpu)) {
data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
data->cpu_freq_read = cpu_freq_read_intel;
data->cpu_freq_write = cpu_freq_write_intel;
break;
}
if (check_amd_hwpstate_cpu(cpu)) {
data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
data->cpu_freq_read = cpu_freq_read_amd;
data->cpu_freq_write = cpu_freq_write_amd;
break;
}
result = -ENODEV;
goto err_unreg;
default:
pr_debug("Unknown addr space %d\n",
(u32) (perf->control_register.space_id));
result = -ENODEV;
goto err_unreg;
}
freq_table = kcalloc(perf->state_count + 1, sizeof(*freq_table),
GFP_KERNEL);
if (!freq_table) {
result = -ENOMEM;
goto err_unreg;
}
/* detect transition latency */
policy->cpuinfo.transition_latency = 0;
for (i = 0; i < perf->state_count; i++) {
if ((perf->states[i].transition_latency * 1000) >
policy->cpuinfo.transition_latency)
policy->cpuinfo.transition_latency =
perf->states[i].transition_latency * 1000;
}
/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
policy->cpuinfo.transition_latency > 20 * 1000) {
policy->cpuinfo.transition_latency = 20 * 1000;
pr_info_once("P-state transition latency capped at 20 uS\n");
}
/* table init */
for (i = 0; i < perf->state_count; i++) {
if (i > 0 && perf->states[i].core_frequency >=
freq_table[valid_states-1].frequency / 1000)
continue;
freq_table[valid_states].driver_data = i;
freq_table[valid_states].frequency =
perf->states[i].core_frequency * 1000;
valid_states++;
}
freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
max_boost_ratio = get_max_boost_ratio(cpu);
if (max_boost_ratio) {
unsigned int freq = freq_table[0].frequency;
/*
* Because the loop above sorts the freq_table entries in the
* descending order, freq is the maximum frequency in the table.
* Assume that it corresponds to the CPPC nominal frequency and
* use it to set cpuinfo.max_freq.
*/
policy->cpuinfo.max_freq = freq * max_boost_ratio >> SCHED_CAPACITY_SHIFT;
} else {
/*
* If the maximum "boost" frequency is unknown, ask the arch
* scale-invariance code to use the "nominal" performance for
* CPU utilization scaling so as to prevent the schedutil
* governor from selecting inadequate CPU frequencies.
*/
arch_set_max_freq_ratio(true);
}
policy->freq_table = freq_table;
perf->state = 0;
switch (perf->control_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
/*
* The core will not set policy->cur, because
* cpufreq_driver->get is NULL, so we need to set it here.
* However, we have to guess it, because the current speed is
* unknown and not detectable via IO ports.
*/
policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
break;
case ACPI_ADR_SPACE_FIXED_HARDWARE:
acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
break;
default:
break;
}
/* notify BIOS that we exist */
acpi_processor_notify_smm(THIS_MODULE);
pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
for (i = 0; i < perf->state_count; i++)
pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
(i == perf->state ? '*' : ' '), i,
(u32) perf->states[i].core_frequency,
(u32) perf->states[i].power,
(u32) perf->states[i].transition_latency);
/*
* the first call to ->target() should result in us actually
* writing something to the appropriate registers.
*/
data->resume = 1;
policy->fast_switch_possible = !acpi_pstate_strict &&
!(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
if (perf->states[0].core_frequency * 1000 != freq_table[0].frequency)
pr_warn(FW_WARN "P-state 0 is not max freq\n");
if (acpi_cpufreq_driver.set_boost) {
set_boost(policy, acpi_cpufreq_driver.boost_enabled);
policy->boost_enabled = acpi_cpufreq_driver.boost_enabled;
}
return result;
err_unreg:
acpi_processor_unregister_performance(cpu);
err_free_mask:
free_cpumask_var(data->freqdomain_cpus);
err_free:
kfree(data);
policy->driver_data = NULL;
return result;
}
static void acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
struct acpi_cpufreq_data *data = policy->driver_data;
pr_debug("%s\n", __func__);
cpufreq_boost_down_prep(policy->cpu);
policy->fast_switch_possible = false;
policy->driver_data = NULL;
acpi_processor_unregister_performance(data->acpi_perf_cpu);
free_cpumask_var(data->freqdomain_cpus);
kfree(policy->freq_table);
kfree(data);
}
static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
{
struct acpi_cpufreq_data *data = policy->driver_data;
pr_debug("%s\n", __func__);
data->resume = 1;
return 0;
}
static struct freq_attr *acpi_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&freqdomain_cpus,
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
&cpb,
#endif
NULL,
};
static struct cpufreq_driver acpi_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = acpi_cpufreq_target,
.fast_switch = acpi_cpufreq_fast_switch,
.bios_limit = acpi_processor_get_bios_limit,
.init = acpi_cpufreq_cpu_init,
.exit = acpi_cpufreq_cpu_exit,
.resume = acpi_cpufreq_resume,
.name = "acpi-cpufreq",
.attr = acpi_cpufreq_attr,
};
static void __init acpi_cpufreq_boost_init(void)
{
if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) {
pr_debug("Boost capabilities not present in the processor\n");
return;
}
acpi_cpufreq_driver.set_boost = set_boost;
acpi_cpufreq_driver.boost_enabled = boost_state(0);
}
static int __init acpi_cpufreq_probe(struct platform_device *pdev)
{
int ret;
if (acpi_disabled)
return -ENODEV;
/* don't keep reloading if cpufreq_driver exists */
if (cpufreq_get_current_driver())
return -ENODEV;
pr_debug("%s\n", __func__);
ret = acpi_cpufreq_early_init();
if (ret)
return ret;
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
/* this is a sysfs file with a strange name and an even stranger
* semantic - per CPU instantiation, but system global effect.
* Lets enable it only on AMD CPUs for compatibility reasons and
* only if configured. This is considered legacy code, which
* will probably be removed at some point in the future.
*/
if (!check_amd_hwpstate_cpu(0)) {
struct freq_attr **attr;
pr_debug("CPB unsupported, do not expose it\n");
for (attr = acpi_cpufreq_attr; *attr; attr++)
if (*attr == &cpb) {
*attr = NULL;
break;
}
}
#endif
acpi_cpufreq_boost_init();
ret = cpufreq_register_driver(&acpi_cpufreq_driver);
if (ret) {
free_acpi_perf_data();
}
return ret;
}
static void acpi_cpufreq_remove(struct platform_device *pdev)
{
pr_debug("%s\n", __func__);
cpufreq_unregister_driver(&acpi_cpufreq_driver);
free_acpi_perf_data();
}
static struct platform_driver acpi_cpufreq_platdrv = {
.driver = {
.name = "acpi-cpufreq",
},
.remove_new = acpi_cpufreq_remove,
};
static int __init acpi_cpufreq_init(void)
{
return platform_driver_probe(&acpi_cpufreq_platdrv, acpi_cpufreq_probe);
}
static void __exit acpi_cpufreq_exit(void)
{
platform_driver_unregister(&acpi_cpufreq_platdrv);
}
module_param(acpi_pstate_strict, uint, 0644);
MODULE_PARM_DESC(acpi_pstate_strict,
"value 0 or non-zero. non-zero -> strict ACPI checks are "
"performed during frequency changes.");
late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);
MODULE_ALIAS("platform:acpi-cpufreq");