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Message-ID:
<CYYPR12MB8655BD01782AC71FF60E94549C292@CYYPR12MB8655.namprd12.prod.outlook.com>
Date: Thu, 14 Mar 2024 09:11:14 +0000
From: "Yuan, Perry" <Perry.Yuan@....com>
To: "Shenoy, Gautham Ranjal" <gautham.shenoy@....com>
CC: "rafael.j.wysocki@...el.com" <rafael.j.wysocki@...el.com>, "Limonciello,
Mario" <Mario.Limonciello@....com>, "viresh.kumar@...aro.org"
<viresh.kumar@...aro.org>, "Huang, Ray" <Ray.Huang@....com>, "Petkov,
Borislav" <Borislav.Petkov@....com>, "Deucher, Alexander"
<Alexander.Deucher@....com>, "Huang, Shimmer" <Shimmer.Huang@....com>, "Du,
Xiaojian" <Xiaojian.Du@....com>, "Meng, Li (Jassmine)" <Li.Meng@....com>,
"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v4 1/7] cpufreq: amd-pstate: initialize new core precision
boost state
[AMD Official Use Only - General]
> -----Original Message-----
> From: Shenoy, Gautham Ranjal <gautham.shenoy@....com>
> Sent: Thursday, March 14, 2024 5:05 PM
> To: Yuan, Perry <Perry.Yuan@....com>
> Cc: rafael.j.wysocki@...el.com; Limonciello, Mario
> <Mario.Limonciello@....com>; viresh.kumar@...aro.org; Huang, Ray
> <Ray.Huang@....com>; Petkov, Borislav <Borislav.Petkov@....com>;
> Deucher, Alexander <Alexander.Deucher@....com>; Huang, Shimmer
> <Shimmer.Huang@....com>; Du, Xiaojian <Xiaojian.Du@....com>; Meng,
> Li (Jassmine) <Li.Meng@....com>; linux-pm@...r.kernel.org; linux-
> kernel@...r.kernel.org
> Subject: Re: [PATCH v4 1/7] cpufreq: amd-pstate: initialize new core precision
> boost state
>
> On Wed, Mar 13, 2024 at 06:04:38PM +0800, Perry Yuan wrote:
> > From: Perry Yuan <Perry.Yuan@....com>
> >
> > Add gloal global_params to represent current CPU Performance
> > Boost(cpb) state for cpu frequency scaling, both active and passive
> > modes all can support CPU cores frequency boosting control which is
> > based on the BIOS setting, while BIOS turn on the "Core Performance
> > Boost", it will allow OS control each core highest perf limitation from OS side.
> >
> > If core performance boost is disabled while a core is in a boosted
> > P-state, the core transitions to the highest performance non-boosted
> > P-state, that is the same as the nominal frequency limit.
> >
> > Reported-by: Artem S. Tashkinov" <aros@....com>
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
> > Signed-off-by: Perry Yuan <Perry.Yuan@....com>
> > ---
> > drivers/cpufreq/amd-pstate.c | 50 ++++++++++++------------------------
> > include/linux/amd-pstate.h | 14 ++++++++++
> > 2 files changed, 31 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index 2015c9fcc3c9..ef6381b48e76
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -67,6 +67,8 @@ static struct cpufreq_driver amd_pstate_epp_driver;
> > static int cppc_state = AMD_PSTATE_UNDEFINED; static bool
> > cppc_enabled; static bool amd_pstate_prefcore = true;
> > +struct amd_pstate_global_params amd_pstate_global_params;
> > +EXPORT_SYMBOL_GPL(amd_pstate_global_params);
> >
> > /*
> > * AMD Energy Preference Performance (EPP) @@ -676,43 +678,21 @@
> > static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
> > return lowest_nonlinear_freq * 1000; }
> >
> > -static int amd_pstate_set_boost(struct cpufreq_policy *policy, int
> > state)
> > +static int amd_pstate_boost_init(struct amd_cpudata *cpudata)
> > {
> > - struct amd_cpudata *cpudata = policy->driver_data;
> > + u64 boost_val;
> > int ret;
> >
> > - if (!cpudata->boost_supported) {
> > - pr_err("Boost mode is not supported by this processor or
> SBIOS\n");
> > - return -EINVAL;
> > - }
> > -
> > - if (state)
> > - policy->cpuinfo.max_freq = cpudata->max_freq;
> > - else
> > - policy->cpuinfo.max_freq = cpudata->nominal_freq;
> > -
> > - policy->max = policy->cpuinfo.max_freq;
> > -
> > - ret = freq_qos_update_request(&cpudata->req[1],
> > - policy->cpuinfo.max_freq);
> > - if (ret < 0)
> > + ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
> > + if (ret) {
> > + pr_err_once("failed to read initial CPU boost state!\n");
> > return ret;
> > + }
> >
> > - return 0;
> > -}
> > -
> > -static void amd_pstate_boost_init(struct amd_cpudata *cpudata) -{
> > - u32 highest_perf, nominal_perf;
> > -
> > - highest_perf = READ_ONCE(cpudata->highest_perf);
> > - nominal_perf = READ_ONCE(cpudata->nominal_perf);
> > -
> > - if (highest_perf <= nominal_perf)
> > - return;
> > + amd_pstate_global_params.cpb_supported = !((boost_val >> 25) &
> 0x1);
>
> Can we move the definition of MSR_K7_HWCR_CPB_DIS from
> drivers/cpufreq/acpi-cpufreq.h to msr-index.h and use it here ?
> something like the following:
That's a brilliant idea!
Let me add a new patch to move it in next version.
Perry.
>
> ----------- x8---------------------------------------------------------------------
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-
> index.h
> index f1bd7b91b3c6..e5380cad903c 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -736,6 +736,8 @@
> #define MSR_K7_HWCR_IRPERF_EN
> BIT_ULL(MSR_K7_HWCR_IRPERF_EN_BIT)
> #define MSR_K7_FID_VID_CTL 0xc0010041
> #define MSR_K7_FID_VID_STATUS 0xc0010042
> +#define MSR_K7_HWCR_CPB_DIS_BIT 25
> +#define MSR_K7_HWCR_CPB_DIS
> BIT_ULL(MSR_K7_HWCR_CPB_DIS_BIT)
>
> /* K6 MSRs */
> #define MSR_K6_WHCR 0xc0000082
> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> index 37f1cdf46d29..7089aca6cc0d 100644
> --- a/drivers/cpufreq/acpi-cpufreq.c
> +++ b/drivers/cpufreq/acpi-cpufreq.c
> @@ -31,6 +31,7 @@
> #include <acpi/cppc_acpi.h>
>
> #include <asm/msr.h>
> +#include <asm/msr-index.h>
> #include <asm/processor.h>
> #include <asm/cpufeature.h>
> #include <asm/cpu_device_id.h>
> @@ -50,8 +51,6 @@ enum {
> #define AMD_MSR_RANGE (0x7)
> #define HYGON_MSR_RANGE (0x7)
>
> -#define MSR_K7_HWCR_CPB_DIS (1ULL << 25)
> -
> struct acpi_cpufreq_data {
> unsigned int resume;
> unsigned int cpu_feature;
>
>
>
> The rest of the patch looks good to me.
Thank you for the review!
>
>
> --
> Thanks and Regards
> gautham.
>
>
> > + amd_pstate_global_params.cpb_boost =
> > +amd_pstate_global_params.cpb_supported;
> >
> > - cpudata->boost_supported = true;
> > - current_pstate_driver->boost_enabled = true;
> > + return ret;
> > }
> >
> > static void amd_perf_ctl_reset(unsigned int cpu) @@ -855,6 +835,9 @@
> > static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
> > if (ret)
> > goto free_cpudata1;
> >
> > + /* initialize cpu cores boot state */
> > + amd_pstate_boost_init(cpudata);
> > +
> > min_freq = amd_get_min_freq(cpudata);
> > max_freq = amd_get_max_freq(cpudata);
> > nominal_freq = amd_get_nominal_freq(cpudata); @@ -906,7 +889,6
> @@
> > static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
> >
> > policy->driver_data = cpudata;
> >
> > - amd_pstate_boost_init(cpudata);
> > if (!current_pstate_driver->adjust_perf)
> > current_pstate_driver->adjust_perf =
> amd_pstate_adjust_perf;
> >
> > @@ -1317,6 +1299,9 @@ static int amd_pstate_epp_cpu_init(struct
> cpufreq_policy *policy)
> > if (ret)
> > goto free_cpudata1;
> >
> > + /* initialize cpu cores boot state */
> > + amd_pstate_boost_init(cpudata);
> > +
> > min_freq = amd_get_min_freq(cpudata);
> > max_freq = amd_get_max_freq(cpudata);
> > nominal_freq = amd_get_nominal_freq(cpudata); @@ -1367,7
> +1352,6 @@
> > static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> > return ret;
> > WRITE_ONCE(cpudata->cppc_cap1_cached, value);
> > }
> > - amd_pstate_boost_init(cpudata);
> >
> > return 0;
> >
> > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h
> > index d21838835abd..c6e2a97913de 100644
> > --- a/include/linux/amd-pstate.h
> > +++ b/include/linux/amd-pstate.h
> > @@ -124,4 +124,18 @@ static const char * const
> amd_pstate_mode_string[] = {
> > [AMD_PSTATE_GUIDED] = "guided",
> > NULL,
> > };
> > +
> > +/**
> > + * struct amd_pstate_global_params - Global parameters, mostly tunable
> via sysfs.
> > + * @cpb_boost: Whether or not to use boost CPU P-states.
> > + * @cpb_supported: Whether or not CPU boost P-states are available
> > + * based on the MSR_K7_HWCR bit[25] state
> > + */
> > +struct amd_pstate_global_params {
> > + bool cpb_boost;
> > + bool cpb_supported;
> > +};
> > +
> > +extern struct amd_pstate_global_params amd_pstate_global_params;
> > +
> > #endif /* _LINUX_AMD_PSTATE_H */
> > --
> > 2.34.1
> >
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