Re: [PATCH V2 04/10] cpufreq: powerpc_cbe: Switch to QoS requests instead of cpufreq notifier

From: Rafael J. Wysocki
Date: Fri Aug 09 2019 - 05:02:10 EST


On Fri, Aug 9, 2019 at 4:34 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
>
> On 23-07-19, 11:44, Viresh Kumar wrote:
> > 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(-)
>
> -------------------------8<-------------------------

If you do it this way, Patchwork will not pick up the patch.

Please send afresh with "[Update]" or bumped up version number in the
subject (or both).

> From b84e1c119d63ab842c9e4f3acbc3aec22efa866d Mon Sep 17 00:00:00 2001
> Message-Id: <b84e1c119d63ab842c9e4f3acbc3aec22efa866d.1565318034.git.viresh.kumar@xxxxxxxxxx>
> From: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Date: Fri, 5 Jul 2019 15:49:48 +0530
> Subject: [PATCH] cpufreq: powerpc_cbe: Switch to QoS requests instead of
> cpufreq notifier
>
> 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>

And here you can say that it replaces an earlier patch.

> ---
> - dev_pm_qos_update_request() can return 1 on success
> 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..bc9dd30395c4 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 < 0)
> + 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);