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Message-ID: <CAJZ5v0j8Z3dUZUuUUZPiGthN7yg03yDpWARGJLE8U2fCeUK8Qw@mail.gmail.com>
Date: Tue, 27 Jan 2026 21:17:31 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Sumit Gupta <sumitg@...dia.com>
Cc: "Rafael J. Wysocki" <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 27, 2026 at 8:01 PM Sumit Gupta <sumitg@...dia.com> wrote:
>
>
> On 27/01/26 21:54, Rafael J. Wysocki wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > 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?
>
> Yes, this patch is independent and can be applied.
Applied as 6.20 material, thanks!
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