Messages in this thread Patch in this message | | | Date | Thu, 14 Jan 2021 16:54:27 +0000 | From | Cristian Marussi <> | Subject | Re: [PATCH v6 2/4] scmi-cpufreq: Move CPU initialisation to probe |
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Hi Nicola,
a few remarks down below.
On Mon, Jan 11, 2021 at 03:45:22PM +0000, Nicola Mazzucato wrote: > Some of the cpu related initialisation can be done at probe stage. > This patch moves those initialisations from the ->init callback to the > probe stage. > > This is done in preparation for adding support to retrieve additional > information from DT (CPUs sharing v/f lines). > > Signed-off-by: Nicola Mazzucato <nicola.mazzucato@arm.com> > --- > drivers/cpufreq/scmi-cpufreq.c | 180 ++++++++++++++++++++++++--------- > 1 file changed, 135 insertions(+), 45 deletions(-) > > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > index 15b213ed78fa..4aa97cdc5997 100644 > --- a/drivers/cpufreq/scmi-cpufreq.c > +++ b/drivers/cpufreq/scmi-cpufreq.c > @@ -25,6 +25,14 @@ struct scmi_data { > struct device *cpu_dev; > }; > > +/* Per-CPU storage for runtime management */ > +struct scmi_cpudata { > + cpumask_var_t scmi_shared_cpus; > + struct cpufreq_frequency_table *freq_table; > +}; > + > +static struct scmi_cpudata *cpudata_table; > + > static const struct scmi_handle *handle; > > static unsigned int scmi_cpufreq_get_rate(unsigned int cpu) > @@ -120,13 +128,10 @@ scmi_get_cpu_power(unsigned long *power, unsigned long *KHz, > > static int scmi_cpufreq_init(struct cpufreq_policy *policy) > { > - int ret, nr_opp; > + int ret; > unsigned int latency; > struct device *cpu_dev; > struct scmi_data *priv; > - struct cpufreq_frequency_table *freq_table; > - struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power); > - bool power_scale_mw; > > cpu_dev = get_cpu_device(policy->cpu); > if (!cpu_dev) { > @@ -134,42 +139,19 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) > return -ENODEV; > } > > - ret = handle->perf_ops->device_opps_add(handle, cpu_dev); > - if (ret) { > - dev_warn(cpu_dev, "failed to add opps to the device\n"); > - return ret; > - } > - > - ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus); > - if (ret) { > - dev_warn(cpu_dev, "failed to get sharing cpumask\n"); > - return ret; > - } > - > - ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); > - if (ret) { > - dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", > - __func__, ret); > - return ret; > - } > - > priv = kzalloc(sizeof(*priv), GFP_KERNEL); > if (!priv) { > ret = -ENOMEM; > goto out_free_opp; > } > > - ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); > - if (ret) { > - dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); > - goto out_free_priv; > - } > + cpumask_copy(policy->cpus, cpudata_table[policy->cpu].scmi_shared_cpus); > > priv->cpu_dev = cpu_dev; > priv->domain_id = handle->perf_ops->device_domain_id(cpu_dev); > > policy->driver_data = priv; > - policy->freq_table = freq_table; > + policy->freq_table = cpudata_table[policy->cpu].freq_table; > > /* SCMI allows DVFS request for any domain from any CPU */ > policy->dvfs_possible_from_any_cpu = true; > @@ -183,23 +165,8 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) > policy->fast_switch_possible = > handle->perf_ops->fast_switch_possible(handle, cpu_dev); > > - nr_opp = dev_pm_opp_get_opp_count(cpu_dev); > - if (nr_opp <= 0) { > - dev_err(cpu_dev, "%s: No OPPs for this device: %d\n", > - __func__, ret); > - > - ret = -ENODEV; > - goto out_free_priv; > - } > - > - power_scale_mw = handle->perf_ops->power_scale_mw_get(handle); > - em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus, > - power_scale_mw); > - > return 0; > > -out_free_priv: > - kfree(priv); > out_free_opp: > dev_pm_opp_remove_all_dynamic(cpu_dev); >
My understanding (but I could be wrong given my limited familiarity with CPUFREQ ... so bear with me) is that dev_pm_opp_remove_all_dynamic() is meant to clean dynamic OPPs added by dev_pm_opp_add() which in turn in this driver is folded inside the handle->perf_ops->device_opps_add() call, so is not that this call should be added also on the error path inside the new scmi_init_device() ? (this was already faulty this way in the original code to be honest...if faulty at all :D)
I added a few such invocations down below as rough untested example of what I mean.
> @@ -210,7 +177,6 @@ static int scmi_cpufreq_exit(struct cpufreq_policy *policy) > { > struct scmi_data *priv = policy->driver_data; > > - dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); > dev_pm_opp_remove_all_dynamic(priv->cpu_dev); > kfree(priv); > > @@ -231,10 +197,102 @@ static struct cpufreq_driver scmi_cpufreq_driver = { > .exit = scmi_cpufreq_exit, > }; > > +static int scmi_init_cpudata(void) > +{ > + int cpu; > + unsigned int ncpus = num_possible_cpus(); > + > + cpudata_table = kzalloc(sizeof(*cpudata_table) * ncpus, GFP_KERNEL); Shouldn/t this be a kcalloc() given it's an array allocation, checkpatch complains too.
> + if (!cpudata_table) > + return -ENOMEM; > + > + for_each_possible_cpu(cpu) { > + if (!zalloc_cpumask_var(&cpudata_table[cpu].scmi_shared_cpus, > + GFP_KERNEL)) > + goto out; > + } > + > + return 0; > + > +out: > + kfree(cpudata_table); > + return -ENOMEM; > +} > + > +static int scmi_init_device(const struct scmi_handle *handle, int cpu) > +{ > + struct device *cpu_dev; > + int ret, nr_opp; > + struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power); > + bool power_scale_mw; > + cpumask_var_t scmi_cpus; > + > + if (!zalloc_cpumask_var(&scmi_cpus, GFP_KERNEL)) > + return -ENOMEM; > + > + cpumask_set_cpu(cpu, scmi_cpus); > + > + cpu_dev = get_cpu_device(cpu); > + > + ret = scmi_get_sharing_cpus(cpu_dev, scmi_cpus); > + if (ret) { > + dev_warn(cpu_dev, "failed to get sharing cpumask\n"); > + goto free_cpumask; > + } > + > + /* > + * We get here for each CPU. Add OPPs only on those CPUs for which we > + * haven't already done so, or set their OPPs as shared. > + */ > + nr_opp = dev_pm_opp_get_opp_count(cpu_dev); > + if (nr_opp <= 0) { > + ret = handle->perf_ops->device_opps_add(handle, cpu_dev); > + if (ret) { > + dev_warn(cpu_dev, "failed to add opps to the device\n"); > + goto free_cpumask; > + } > + > + ret = dev_pm_opp_set_sharing_cpus(cpu_dev, scmi_cpus); > + if (ret) { > + dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", > + __func__, ret); goto free_dynamic_opps; > + } > + > + nr_opp = dev_pm_opp_get_opp_count(cpu_dev); > + if (nr_opp <= 0) { > + dev_err(cpu_dev, "%s: No OPPs for this device: %d\n", > + __func__, ret); > + > + ret = -ENODEV; goto free_dynamic_opps; > + } > + > + power_scale_mw = handle->perf_ops->power_scale_mw_get(handle); > + em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, scmi_cpus, > + power_scale_mw); > + } > + > + ret = dev_pm_opp_init_cpufreq_table(cpu_dev, > + &cpudata_table[cpu].freq_table); > + if (ret) { > + dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); goto free_dynamic_opps; > + } > + > + cpumask_copy(cpudata_table[cpu].scmi_shared_cpus, scmi_cpus); > + free_dynamic_opps: dev_pm_opp_remove_all_dynamic(cpu_dev); > +free_cpumask: > + free_cpumask_var(scmi_cpus); > + return ret; > +} > + > static int scmi_cpufreq_probe(struct scmi_device *sdev) > { > int ret; > struct device *dev = &sdev->dev; > + int cpu; > + struct device *cpu_dev; > > handle = sdev->handle; > > @@ -247,6 +305,24 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev) > devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL); > #endif > > + ret = scmi_init_cpudata(); > + if (ret) { > + pr_err("%s: init cpu data failed\n", __func__); > + return ret; > + } > + > + for_each_possible_cpu(cpu) { > + cpu_dev = get_cpu_device(cpu); > + > + ret = scmi_init_device(handle, cpu); > + if (ret) { > + dev_err(cpu_dev, "%s: init device failed\n", > + __func__); > + goto clean; > + } > + } > + > ret = cpufreq_register_driver(&scmi_cpufreq_driver); > if (ret) { > dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
/* clean any dynamic OPPs already set */ clean: for_each_possible_cpu(cpu) { cpu_dev = get_cpu_device(cpu);
dev_pm_opp_remove_all_dynamic(cpu_dev); }
return ret; }
Thanks
Cristian > @@ -258,6 +334,20 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev) > > static void scmi_cpufreq_remove(struct scmi_device *sdev) > { > + int cpu; > + struct device *cpu_dev; > + > + for_each_possible_cpu(cpu) { > + cpu_dev = get_cpu_device(cpu); > + > + dev_pm_opp_free_cpufreq_table(cpu_dev, > + &cpudata_table[cpu].freq_table); > + > + free_cpumask_var(cpudata_table[cpu].scmi_shared_cpus); > + } > + > + kfree(cpudata_table); > + > cpufreq_unregister_driver(&scmi_cpufreq_driver); > } > > -- > 2.27.0 >
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