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Message-ID: <CAJZ5v0ipgGt7tetY6p0CW0jyOh9TVeWxgXpFzveTa2CaGB8ZpA@mail.gmail.com>
Date: Tue, 27 Jan 2026 17:24:36 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Sumit Gupta <sumitg@...dia.com>
Cc: rafael@...nel.org, viresh.kumar@...aro.org, pierre.gondois@....com,
zhenglifeng1@...wei.com, ionela.voinescu@....com, lenb@...nel.org,
robert.moore@...el.com, corbet@....net, rdunlap@...radead.org,
ray.huang@....com, gautham.shenoy@....com, mario.limonciello@....com,
perry.yuan@....com, zhanjie9@...ilicon.com, linux-pm@...r.kernel.org,
linux-acpi@...r.kernel.org, linux-doc@...r.kernel.org,
acpica-devel@...ts.linux.dev, linux-kernel@...r.kernel.org,
linux-tegra@...r.kernel.org, treding@...dia.com, jonathanh@...dia.com,
vsethi@...dia.com, ksitaraman@...dia.com, sanjayc@...dia.com,
nhartman@...dia.com, bbasu@...dia.com
Subject: Re: [PATCH v6 1/9] cpufreq: CPPC: Add generic helpers for sysfs show/store
On Tue, Jan 20, 2026 at 3:57 PM Sumit Gupta <sumitg@...dia.com> wrote:
>
> Add generic helper functions for u64 sysfs attributes that follow the
> common pattern of calling CPPC get/set APIs:
> - cppc_cpufreq_sysfs_show_u64(): reads value and handles -EOPNOTSUPP
> - cppc_cpufreq_sysfs_store_u64(): parses input and calls set function
>
> Add CPPC_CPUFREQ_ATTR_RW_U64() macro to generate show/store functions
> using these helpers, reducing boilerplate for simple attributes.
>
> Convert auto_act_window and energy_performance_preference_val to use
> the new macro.
>
> No functional changes.
>
> Signed-off-by: Sumit Gupta <sumitg@...dia.com>
> ---
> drivers/cpufreq/cppc_cpufreq.c | 69 ++++++++++++----------------------
> 1 file changed, 25 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 36e8a75a37f1..c95dcd7719c3 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -863,73 +863,54 @@ static ssize_t store_auto_select(struct cpufreq_policy *policy,
> return count;
> }
>
> -static ssize_t show_auto_act_window(struct cpufreq_policy *policy, char *buf)
> +static ssize_t cppc_cpufreq_sysfs_show_u64(unsigned int cpu,
> + int (*get_func)(int, u64 *),
> + char *buf)
> {
> u64 val;
> - int ret;
> -
> - ret = cppc_get_auto_act_window(policy->cpu, &val);
> + int ret = get_func((int)cpu, &val);
>
> - /* show "<unsupported>" when this register is not supported by cpc */
> if (ret == -EOPNOTSUPP)
> return sysfs_emit(buf, "<unsupported>\n");
> -
> if (ret)
> return ret;
>
> return sysfs_emit(buf, "%llu\n", val);
> }
>
> -static ssize_t store_auto_act_window(struct cpufreq_policy *policy,
> - const char *buf, size_t count)
> +static ssize_t cppc_cpufreq_sysfs_store_u64(unsigned int cpu,
> + int (*set_func)(int, u64),
> + const char *buf, size_t count)
> {
> - u64 usec;
> + u64 val;
> int ret;
>
> - ret = kstrtou64(buf, 0, &usec);
> + ret = kstrtou64(buf, 0, &val);
> if (ret)
> return ret;
>
> - ret = cppc_set_auto_act_window(policy->cpu, usec);
> - if (ret)
> - return ret;
> + ret = set_func((int)cpu, val);
>
> - return count;
> + return ret ? ret : count;
> }
>
> -static ssize_t show_energy_performance_preference_val(struct cpufreq_policy *policy, char *buf)
> -{
> - u64 val;
> - int ret;
> -
> - ret = cppc_get_epp_perf(policy->cpu, &val);
> -
> - /* show "<unsupported>" when this register is not supported by cpc */
> - if (ret == -EOPNOTSUPP)
> - return sysfs_emit(buf, "<unsupported>\n");
> -
> - if (ret)
> - return ret;
> -
> - return sysfs_emit(buf, "%llu\n", val);
> +#define CPPC_CPUFREQ_ATTR_RW_U64(_name, _get_func, _set_func) \
> +static ssize_t show_##_name(struct cpufreq_policy *policy, char *buf) \
> +{ \
> + return cppc_cpufreq_sysfs_show_u64(policy->cpu, _get_func, buf);\
> +} \
> +static ssize_t store_##_name(struct cpufreq_policy *policy, \
> + const char *buf, size_t count) \
> +{ \
> + return cppc_cpufreq_sysfs_store_u64(policy->cpu, _set_func, \
> + buf, count); \
> }
>
> -static ssize_t store_energy_performance_preference_val(struct cpufreq_policy *policy,
> - const char *buf, size_t count)
> -{
> - u64 val;
> - int ret;
> +CPPC_CPUFREQ_ATTR_RW_U64(auto_act_window, cppc_get_auto_act_window,
> + cppc_set_auto_act_window)
>
> - ret = kstrtou64(buf, 0, &val);
> - if (ret)
> - return ret;
> -
> - ret = cppc_set_epp(policy->cpu, val);
> - if (ret)
> - return ret;
> -
> - return count;
> -}
> +CPPC_CPUFREQ_ATTR_RW_U64(energy_performance_preference_val,
> + cppc_get_epp_perf, cppc_set_epp)
>
> cpufreq_freq_attr_ro(freqdomain_cpus);
> cpufreq_freq_attr_rw(auto_select);
> --
It looks like this patch could be applied independently of the other
patches in the series.
Do you want me to do so?
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