On 5/1/24 13:51, Cristian Marussi wrote:
On Thu, Mar 28, 2024 at 01:11:31PM +0530, Sibi Sankar wrote:
Register for limit change notifications if supported and use the throttled
frequency from the notification to apply HW pressure.
Hi Sibi,
a bit late on this, sorry.
Just a couple of nitpicks down below.
Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
---
v4:
* Use a interim variable to show the khz calc. [Lukasz]
* Use driver_data to pass on the handle and scmi_dev instead of using
global variables. Dropped Lukasz's Rb due to adding these minor
changes.
drivers/cpufreq/scmi-cpufreq.c | 44 ++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index 3b4f6bfb2f4c..d946b7a08258 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -21,11 +21,18 @@
#include <linux/types.h>
#include <linux/units.h>
+struct scmi_cpufreq_driver_data {
+ struct scmi_device *sdev;
+ const struct scmi_handle *handle;
+};
+
struct scmi_data {
int domain_id;
int nr_opp;
struct device *cpu_dev;
+ struct cpufreq_policy *policy;
cpumask_var_t opp_shared_cpus;
+ struct notifier_block limit_notify_nb;
};
static struct scmi_protocol_handle *ph;
@@ -174,6 +181,22 @@ static struct freq_attr *scmi_cpufreq_hw_attr[] = {
NULL,
};
+static int scmi_limit_notify_cb(struct notifier_block *nb, unsigned long event, void *data)
+{
+ struct scmi_data *priv = container_of(nb, struct scmi_data, limit_notify_nb);
+ struct scmi_perf_limits_report *limit_notify = data;
+ struct cpufreq_policy *policy = priv->policy;
+ unsigned int limit_freq_khz;
+
+ limit_freq_khz = limit_notify->range_max_freq / HZ_PER_KHZ;
+
+ policy->max = clamp(limit_freq_khz, policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);
+
+ cpufreq_update_pressure(policy);
+
+ return NOTIFY_OK;
+}
+
static int scmi_cpufreq_init(struct cpufreq_policy *policy)
{
int ret, nr_opp, domain;
@@ -181,6 +204,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
struct device *cpu_dev;
struct scmi_data *priv;
struct cpufreq_frequency_table *freq_table;
+ struct scmi_cpufreq_driver_data *data = cpufreq_get_driver_data();
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
@@ -294,6 +318,17 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
}
}
+ priv->limit_notify_nb.notifier_call = scmi_limit_notify_cb;
+ ret = data->handle->notify_ops->devm_event_notifier_register(data->sdev, SCMI_PROTOCOL_PERF,
+ SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED,
+ &domain,
+ &priv->limit_notify_nb);
+ if (ret)
+ dev_warn(cpu_dev,
or &data->sdev->dev which refers to this driver ? which is more informational ? no strong opinion just a question...
Pointing to the driver is better given that we already pass on domain
info.
+ "failed to register for limits change notifier for domain %d\n", domain);
+
+ priv->policy = policy;
+
return 0;
out_free_opp:
@@ -366,12 +401,21 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev)
int ret;
struct device *dev = &sdev->dev;
const struct scmi_handle *handle;
+ struct scmi_cpufreq_driver_data *data;
handle = sdev->handle;
^^^ ....
if (!handle)
return -ENODEV;
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->sdev = sdev;
+ data->handle = handle;
^^^ ... you dont need to pass around handle AND sdev really
since you can access the handle from sdev.
+ scmi_cpufreq_driver.driver_data = data;
Ack setting sdev as driver data would suffice. Will fix it in the next
re-spin.
-Sibi
This is slightly better, but, as said, does not solve the multi-instance issue...
...the scmi cpufreq driver remains a driver that works only if instantiated (probed)
once, given how the CPUFreq core handles cpufreq_driver registration itself...
...just a note about something to work on in the future...NOT a concern for this series.
In general,
LGTM.
Thanks,
Cristian
