[PATCH] ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier

From: Viresh Kumar
Date: Mon Jul 15 2019 - 05:36:02 EST

The cpufreq core now takes the min/max frequency constraints via QoS
requests and the CPUFREQ_ADJUST notifier shall get removed later on.

Switch over to using the QoS request for maximum frequency constraint
for acpi driver.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/acpi/processor_driver.c | 37 ++++++++++--
drivers/acpi/processor_perflib.c | 96 +++++++++++---------------------
drivers/acpi/processor_thermal.c | 81 +++++++++++++--------------
include/acpi/processor.h | 21 ++++---
4 files changed, 118 insertions(+), 117 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index aea8d674a33d..2c911fcaa4b4 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -284,6 +284,29 @@ static int acpi_processor_stop(struct device *dev)
return 0;
}

+bool acpi_processor_cpufreq_init;
+
+static int acpi_processor_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct cpufreq_policy *policy = data;
+ int cpu = policy->cpu;
+
+ if (event == CPUFREQ_CREATE_POLICY) {
+ acpi_thermal_cpufreq_init(cpu);
+ acpi_processor_ppc_init(cpu);
+ } else if (event == CPUFREQ_REMOVE_POLICY) {
+ acpi_processor_ppc_exit(cpu);
+ acpi_thermal_cpufreq_exit(cpu);
+ }
+
+ return 0;
+}
+
+static struct notifier_block acpi_processor_notifier_block = {
+ .notifier_call = acpi_processor_notifier,
+};
+
/*
* We keep the driver loaded even when ACPI is not running.
* This is needed for the powernow-k8 driver, that works even without
@@ -310,8 +333,10 @@ static int __init acpi_processor_driver_init(void)
cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
NULL, acpi_soft_cpu_dead);

- acpi_thermal_cpufreq_init();
- acpi_processor_ppc_init();
+ if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
+ CPUFREQ_POLICY_NOTIFIER))
+ acpi_processor_cpufreq_init = true;
+
acpi_processor_throttling_init();
return 0;
err:
@@ -324,8 +349,12 @@ static void __exit acpi_processor_driver_exit(void)
if (acpi_disabled)
return;

- acpi_processor_ppc_exit();
- acpi_thermal_cpufreq_exit();
+ if (acpi_processor_cpufreq_init) {
+ cpufreq_unregister_notifier(&acpi_processor_notifier_block,
+ CPUFREQ_POLICY_NOTIFIER);
+ acpi_processor_cpufreq_init = false;
+ }
+
cpuhp_remove_state_nocalls(hp_online);
cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
driver_unregister(&acpi_processor_driver);
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index ee87cb6f6e59..fc74b8075c36 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -50,57 +50,13 @@ module_param(ignore_ppc, int, 0644);
MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
"limited by BIOS, this should help");

-#define PPC_REGISTERED 1
-#define PPC_IN_USE 2
-
-static int acpi_processor_ppc_status;
-
-static int acpi_processor_ppc_notifier(struct notifier_block *nb,
- unsigned long event, void *data)
-{
- struct cpufreq_policy *policy = data;
- struct acpi_processor *pr;
- unsigned int ppc = 0;
-
- if (ignore_ppc < 0)
- ignore_ppc = 0;
-
- if (ignore_ppc)
- return 0;
-
- if (event != CPUFREQ_ADJUST)
- return 0;
-
- mutex_lock(&performance_mutex);
-
- pr = per_cpu(processors, policy->cpu);
- if (!pr || !pr->performance)
- goto out;
-
- ppc = (unsigned int)pr->performance_platform_limit;
-
- if (ppc >= pr->performance->state_count)
- goto out;
-
- cpufreq_verify_within_limits(policy, 0,
- pr->performance->states[ppc].
- core_frequency * 1000);
-
- out:
- mutex_unlock(&performance_mutex);
-
- return 0;
-}
-
-static struct notifier_block acpi_ppc_notifier_block = {
- .notifier_call = acpi_processor_ppc_notifier,
-};
+static bool acpi_processor_ppc_in_use;

static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
acpi_status status = 0;
unsigned long long ppc = 0;
-
+ int ret;

if (!pr)
return -EINVAL;
@@ -112,7 +68,7 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);

if (status != AE_NOT_FOUND)
- acpi_processor_ppc_status |= PPC_IN_USE;
+ acpi_processor_ppc_in_use = true;

if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
@@ -124,6 +80,16 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)

pr->performance_platform_limit = (int)ppc;

+ if (ignore_ppc || ppc >= pr->performance->state_count)
+ return 0;
+
+ ret = dev_pm_qos_update_request(&pr->perflib_req,
+ pr->performance->states[ppc].core_frequency * 1000);
+ if (ret) {
+ pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
+ pr->id, ret);
+ }
+
return 0;
}

@@ -184,23 +150,29 @@ int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
}
EXPORT_SYMBOL(acpi_processor_get_bios_limit);

-void acpi_processor_ppc_init(void)
+void acpi_processor_ppc_init(int cpu)
{
- if (!cpufreq_register_notifier
- (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
- acpi_processor_ppc_status |= PPC_REGISTERED;
- else
- printk(KERN_DEBUG
- "Warning: Processor Platform Limit not supported.\n");
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+ int ret;
+
+ ret = dev_pm_qos_add_request(get_cpu_device(cpu),
+ &pr->perflib_req, DEV_PM_QOS_MAX_FREQUENCY,
+ INT_MAX);
+ if (ret < 0) {
+ pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
+ ret);
+ return;
+ }
+
+ if (ignore_ppc < 0)
+ ignore_ppc = 0;
}

-void acpi_processor_ppc_exit(void)
+void acpi_processor_ppc_exit(int cpu)
{
- if (acpi_processor_ppc_status & PPC_REGISTERED)
- cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
- CPUFREQ_POLICY_NOTIFIER);
+ struct acpi_processor *pr = per_cpu(processors, cpu);

- acpi_processor_ppc_status &= ~PPC_REGISTERED;
+ dev_pm_qos_remove_request(&pr->perflib_req);
}

static int acpi_processor_get_performance_control(struct acpi_processor *pr)
@@ -477,7 +449,7 @@ int acpi_processor_notify_smm(struct module *calling_module)
static int is_done = 0;
int result;

- if (!(acpi_processor_ppc_status & PPC_REGISTERED))
+ if (!acpi_processor_cpufreq_init)
return -EBUSY;

if (!try_module_get(calling_module))
@@ -513,7 +485,7 @@ int acpi_processor_notify_smm(struct module *calling_module)
* we can allow the cpufreq driver to be rmmod'ed. */
is_done = 1;

- if (!(acpi_processor_ppc_status & PPC_IN_USE))
+ if (!acpi_processor_ppc_in_use)
module_put(calling_module);

return 0;
@@ -742,7 +714,7 @@ acpi_processor_register_performance(struct acpi_processor_performance
{
struct acpi_processor *pr;

- if (!(acpi_processor_ppc_status & PPC_REGISTERED))
+ if (!acpi_processor_cpufreq_init)
return -EINVAL;

mutex_lock(&performance_mutex);
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index 50fb0107375e..1483e24fdea9 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -35,7 +35,6 @@ ACPI_MODULE_NAME("processor_thermal");
#define CPUFREQ_THERMAL_MAX_STEP 3

static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
-static unsigned int acpi_thermal_cpufreq_is_init = 0;

#define reduction_pctg(cpu) \
per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
@@ -61,35 +60,11 @@ static int phys_package_first_cpu(int cpu)
static int cpu_has_cpufreq(unsigned int cpu)
{
struct cpufreq_policy policy;
- if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
+ if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
return 0;
return 1;
}

-static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
- unsigned long event, void *data)
-{
- struct cpufreq_policy *policy = data;
- unsigned long max_freq = 0;
-
- if (event != CPUFREQ_ADJUST)
- goto out;
-
- max_freq = (
- policy->cpuinfo.max_freq *
- (100 - reduction_pctg(policy->cpu) * 20)
- ) / 100;
-
- cpufreq_verify_within_limits(policy, 0, max_freq);
-
- out:
- return 0;
-}
-
-static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
- .notifier_call = acpi_thermal_cpufreq_notifier,
-};
-
static int cpufreq_get_max_state(unsigned int cpu)
{
if (!cpu_has_cpufreq(cpu))
@@ -108,7 +83,10 @@ static int cpufreq_get_cur_state(unsigned int cpu)

static int cpufreq_set_cur_state(unsigned int cpu, int state)
{
- int i;
+ struct cpufreq_policy *policy;
+ struct acpi_processor *pr;
+ unsigned long max_freq;
+ int i, ret;

if (!cpu_has_cpufreq(cpu))
return 0;
@@ -121,33 +99,50 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
* frequency.
*/
for_each_online_cpu(i) {
- if (topology_physical_package_id(i) ==
+ if (topology_physical_package_id(i) !=
topology_physical_package_id(cpu))
- cpufreq_update_policy(i);
+ continue;
+
+ pr = per_cpu(processors, i);
+
+ policy = cpufreq_cpu_get(i);
+ if (!policy)
+ return -EINVAL;
+
+ max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
+
+ cpufreq_cpu_put(policy);
+
+ ret = dev_pm_qos_update_request(&pr->thermal_req, max_freq);
+ if (ret) {
+ pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
+ pr->id, ret);
+ }
}
return 0;
}

-void acpi_thermal_cpufreq_init(void)
+void acpi_thermal_cpufreq_init(int cpu)
{
- int i;
-
- i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
- CPUFREQ_POLICY_NOTIFIER);
- if (!i)
- acpi_thermal_cpufreq_is_init = 1;
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+ int ret;
+
+ ret = dev_pm_qos_add_request(get_cpu_device(cpu),
+ &pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
+ INT_MAX);
+ if (ret < 0) {
+ pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
+ ret);
+ return;
+ }
}

-void acpi_thermal_cpufreq_exit(void)
+void acpi_thermal_cpufreq_exit(int cpu)
{
- if (acpi_thermal_cpufreq_is_init)
- cpufreq_unregister_notifier
- (&acpi_thermal_cpufreq_notifier_block,
- CPUFREQ_POLICY_NOTIFIER);
+ struct acpi_processor *pr = per_cpu(processors, cpu);

- acpi_thermal_cpufreq_is_init = 0;
+ dev_pm_qos_remove_request(&pr->thermal_req);
}
-
#else /* ! CONFIG_CPU_FREQ */
static int cpufreq_get_max_state(unsigned int cpu)
{
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 1194a4c78d55..ea21a6d20da7 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -4,6 +4,8 @@

#include <linux/kernel.h>
#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/pm_qos.h>
#include <linux/thermal.h>
#include <asm/acpi.h>

@@ -230,6 +232,8 @@ struct acpi_processor {
struct acpi_processor_limit limit;
struct thermal_cooling_device *cdev;
struct device *dev; /* Processor device. */
+ struct dev_pm_qos_request perflib_req;
+ struct dev_pm_qos_request thermal_req;
};

struct acpi_processor_errata {
@@ -296,16 +300,17 @@ static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx
/* in processor_perflib.c */

#ifdef CONFIG_CPU_FREQ
-void acpi_processor_ppc_init(void);
-void acpi_processor_ppc_exit(void);
+extern bool acpi_processor_cpufreq_init;
+void acpi_processor_ppc_init(int cpu);
+void acpi_processor_ppc_exit(int cpu);
void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag);
extern int acpi_processor_get_bios_limit(int cpu, unsigned int *limit);
#else
-static inline void acpi_processor_ppc_init(void)
+static inline void acpi_processor_ppc_init(int cpu)
{
return;
}
-static inline void acpi_processor_ppc_exit(void)
+static inline void acpi_processor_ppc_exit(int cpu)
{
return;
}
@@ -421,14 +426,14 @@ static inline int acpi_processor_hotplug(struct acpi_processor *pr)
int acpi_processor_get_limit_info(struct acpi_processor *pr);
extern const struct thermal_cooling_device_ops processor_cooling_ops;
#if defined(CONFIG_ACPI_CPU_FREQ_PSS) & defined(CONFIG_CPU_FREQ)
-void acpi_thermal_cpufreq_init(void);
-void acpi_thermal_cpufreq_exit(void);
+void acpi_thermal_cpufreq_init(int cpu);
+void acpi_thermal_cpufreq_exit(int cpu);
#else
-static inline void acpi_thermal_cpufreq_init(void)
+static inline void acpi_thermal_cpufreq_init(int cpu)
{
return;
}
-static inline void acpi_thermal_cpufreq_exit(void)
+static inline void acpi_thermal_cpufreq_exit(int cpu)
{
return;
}