[PATCH 07/10] cpufreq: powerpc_cbe: Switch to QoS requests instead of cpufreq notifier

From: Viresh Kumar
Date: Tue Jul 16 2019 - 05:55:20 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 ppc_cbe_cpufreq driver.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/ppc_cbe_cpufreq.c | 19 +++++-
drivers/cpufreq/ppc_cbe_cpufreq.h | 8 +++
drivers/cpufreq/ppc_cbe_cpufreq_pmi.c | 96 +++++++++++++++++----------
3 files changed, 86 insertions(+), 37 deletions(-)

diff --git a/drivers/cpufreq/ppc_cbe_cpufreq.c b/drivers/cpufreq/ppc_cbe_cpufreq.c
index b83f36febf03..c58abb4cca3a 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq.c
+++ b/drivers/cpufreq/ppc_cbe_cpufreq.c
@@ -110,6 +110,13 @@ static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
#endif

policy->freq_table = cbe_freqs;
+ cbe_cpufreq_pmi_policy_init(policy);
+ return 0;
+}
+
+static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cbe_cpufreq_pmi_policy_exit(policy);
return 0;
}

@@ -129,6 +136,7 @@ static struct cpufreq_driver cbe_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = cbe_cpufreq_target,
.init = cbe_cpufreq_cpu_init,
+ .exit = cbe_cpufreq_cpu_exit,
.name = "cbe-cpufreq",
.flags = CPUFREQ_CONST_LOOPS,
};
@@ -139,15 +147,24 @@ static struct cpufreq_driver cbe_cpufreq_driver = {

static int __init cbe_cpufreq_init(void)
{
+ int ret;
+
if (!machine_is(cell))
return -ENODEV;

- return cpufreq_register_driver(&cbe_cpufreq_driver);
+ cbe_cpufreq_pmi_init();
+
+ ret = cpufreq_register_driver(&cbe_cpufreq_driver);
+ if (ret)
+ cbe_cpufreq_pmi_exit();
+
+ return ret;
}

static void __exit cbe_cpufreq_exit(void)
{
cpufreq_unregister_driver(&cbe_cpufreq_driver);
+ cbe_cpufreq_pmi_exit();
}

module_init(cbe_cpufreq_init);
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq.h b/drivers/cpufreq/ppc_cbe_cpufreq.h
index 9d973519d669..00cd8633b0d9 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq.h
+++ b/drivers/cpufreq/ppc_cbe_cpufreq.h
@@ -20,6 +20,14 @@ int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode);

#if IS_ENABLED(CONFIG_CPU_FREQ_CBE_PMI)
extern bool cbe_cpufreq_has_pmi;
+void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy);
+void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy);
+void cbe_cpufreq_pmi_init(void);
+void cbe_cpufreq_pmi_exit(void);
#else
#define cbe_cpufreq_has_pmi (0)
+static inline void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy) {}
+static inline void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy) {}
+static inline void cbe_cpufreq_pmi_init(void) {}
+static inline void cbe_cpufreq_pmi_exit(void) {}
#endif
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
index 97c8ee4614b7..0babb27c1c72 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
@@ -12,6 +12,7 @@
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/of_platform.h>
+#include <linux/pm_qos.h>

#include <asm/processor.h>
#include <asm/prom.h>
@@ -24,8 +25,6 @@

#include "ppc_cbe_cpufreq.h"

-static u8 pmi_slow_mode_limit[MAX_CBE];
-
bool cbe_cpufreq_has_pmi = false;
EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);

@@ -65,64 +64,89 @@ EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);

static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
{
+ struct cpufreq_policy *policy;
+ struct dev_pm_qos_request *req;
u8 node, slow_mode;
+ int cpu, ret;

BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);

node = pmi_msg.data1;
slow_mode = pmi_msg.data2;

- pmi_slow_mode_limit[node] = slow_mode;
+ cpu = cbe_node_to_cpu(node);

pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
-}
-
-static int pmi_notifier(struct notifier_block *nb,
- unsigned long event, void *data)
-{
- struct cpufreq_policy *policy = data;
- struct cpufreq_frequency_table *cbe_freqs = policy->freq_table;
- u8 node;
-
- /* Should this really be called for CPUFREQ_ADJUST and CPUFREQ_NOTIFY
- * policy events?)
- */
- node = cbe_cpu_to_node(policy->cpu);
-
- pr_debug("got notified, event=%lu, node=%u\n", event, node);

- if (pmi_slow_mode_limit[node] != 0) {
- pr_debug("limiting node %d to slow mode %d\n",
- node, pmi_slow_mode_limit[node]);
+ policy = cpufreq_cpu_get(cpu);
+ if (!policy) {
+ pr_warn("cpufreq policy not found cpu%d\n", cpu);
+ return;
+ }

- cpufreq_verify_within_limits(policy, 0,
+ req = policy->driver_data;

- cbe_freqs[pmi_slow_mode_limit[node]].frequency);
- }
+ ret = dev_pm_qos_update_request(req,
+ policy->freq_table[slow_mode].frequency);
+ if (ret)
+ pr_warn("Failed to update freq constraint: %d\n", ret);
+ else
+ pr_debug("limiting node %d to slow mode %d\n", node, slow_mode);

- return 0;
+ cpufreq_cpu_put(policy);
}

-static struct notifier_block pmi_notifier_block = {
- .notifier_call = pmi_notifier,
-};
-
static struct pmi_handler cbe_pmi_handler = {
.type = PMI_TYPE_FREQ_CHANGE,
.handle_pmi_message = cbe_cpufreq_handle_pmi,
};

+void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy)
+{
+ struct dev_pm_qos_request *req;
+ int ret;
+
+ if (!cbe_cpufreq_has_pmi)
+ return;
+
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return;
+
+ ret = dev_pm_qos_add_request(get_cpu_device(policy->cpu), req,
+ DEV_PM_QOS_MAX_FREQUENCY,
+ policy->freq_table[0].frequency);
+ if (ret < 0) {
+ pr_err("Failed to add freq constraint (%d)\n", ret);
+ kfree(req);
+ return;
+ }

+ policy->driver_data = req;
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_init);

-static int __init cbe_cpufreq_pmi_init(void)
+void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy)
{
- cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;
+ struct dev_pm_qos_request *req = policy->driver_data;

- if (!cbe_cpufreq_has_pmi)
- return -ENODEV;
+ if (cbe_cpufreq_has_pmi) {
+ dev_pm_qos_remove_request(req);
+ kfree(req);
+ }
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_exit);

- cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
+void cbe_cpufreq_pmi_init(void)
+{
+ if (!pmi_register_handler(&cbe_pmi_handler))
+ cbe_cpufreq_has_pmi = true;
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_init);

- return 0;
+void cbe_cpufreq_pmi_exit(void)
+{
+ pmi_unregister_handler(&cbe_pmi_handler);
+ cbe_cpufreq_has_pmi = false;
}
-device_initcall(cbe_cpufreq_pmi_init);
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_exit);
--
2.21.0.rc0.269.g1a574e7a288b