diff mbox series

[v6,2/6] cpufreq: amd-pstate: initialize new core precision boost state

Message ID f43f48b02d42a651028f0c4690caa6e953e8bf45.1710754236.git.perry.yuan@amd.com (mailing list archive)
State Needs ACK
Headers show
Series AMD Pstate Driver Core Performance Boost | expand

Commit Message

Perry Yuan March 18, 2024, 10:11 a.m. UTC
From: Perry Yuan <Perry.Yuan@amd.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@gmx.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 39 +++++++++++++++++++++++++++---------
 include/linux/amd-pstate.h   | 13 ++++++++++++
 2 files changed, 42 insertions(+), 10 deletions(-)

Comments

Gautham R. Shenoy March 20, 2024, 11:32 a.m. UTC | #1
Hello Perry,

On Mon, Mar 18, 2024 at 06:11:09PM +0800, Perry Yuan wrote:
> From: Perry Yuan <Perry.Yuan@amd.com>
> 
> Add gloal global_params to represent current CPU Performance Boost(cpb)
      ^^^^^^
      global ? 

> 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.

Could we reword this portion along the lines of the following:

"The active, guided and passive modes of the amd-pstate driver can
support frequency boost control when the "Core Performance Boost"
(CPB) feature is enabled in the BIOS.  When enabled in BIOS, the user
has an option at runtime to allow/disallow the cores from operating in
the boost frequency range.

Add an amd_pstate_global_params object to record whether CPB is
enabled in BIOS, and if it has been activated by the user."

> 
> 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@gmx.com>
> Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 39 +++++++++++++++++++++++++++---------
>  include/linux/amd-pstate.h   | 13 ++++++++++++
>  2 files changed, 42 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 59a2db225d98..81787f83c906 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -68,6 +68,8 @@ static int cppc_state = AMD_PSTATE_UNDEFINED;
>  static bool cppc_enabled;
>  static bool amd_pstate_prefcore = true;
>  static struct quirk_entry *quirks;
> +struct amd_pstate_global_params amd_pstate_global_params;
> +EXPORT_SYMBOL_GPL(amd_pstate_global_params);
>  
>  /*
>   * AMD Energy Preference Performance (EPP)

[..snip..]

> diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h
> index 6b832153a126..c5e41de65f70 100644
> --- a/include/linux/amd-pstate.h
> +++ b/include/linux/amd-pstate.h
> @@ -134,4 +134,17 @@ struct quirk_entry {
>  	u32 lowest_freq;
>  };
>  
> +/**
> + * 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;

Will this be used in multiple files ? If no, it is better to define
this in amd-pstate.c

Otherwise, I have no other issues with the patch.

--
Thanks and Regards
gautham.
Perry Yuan March 26, 2024, 7:03 a.m. UTC | #2
[AMD Official Use Only - General]

Hi Gautham,


> -----Original Message-----
> From: Shenoy, Gautham Ranjal <gautham.shenoy@amd.com>
> Sent: Wednesday, March 20, 2024 7:32 PM
> To: Yuan, Perry <Perry.Yuan@amd.com>
> Cc: rafael.j.wysocki@intel.com; Limonciello, Mario
> <Mario.Limonciello@amd.com>; viresh.kumar@linaro.org; Huang, Ray
> <Ray.Huang@amd.com>; Petkov, Borislav <Borislav.Petkov@amd.com>; Deucher,
> Alexander <Alexander.Deucher@amd.com>; Huang, Shimmer
> <Shimmer.Huang@amd.com>; oleksandr@natalenko.name; Du, Xiaojian
> <Xiaojian.Du@amd.com>; Meng, Li (Jassmine) <Li.Meng@amd.com>; linux-
> pm@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v6 2/6] cpufreq: amd-pstate: initialize new core precision
> boost state
>
> Hello Perry,
>
> On Mon, Mar 18, 2024 at 06:11:09PM +0800, Perry Yuan wrote:
> > From: Perry Yuan <Perry.Yuan@amd.com>
> >
> > Add gloal global_params to represent current CPU Performance
> > Boost(cpb)
>       ^^^^^^
>       global ?

Typo will be fixed in v7.


>
> > 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.
>
> Could we reword this portion along the lines of the following:
>
> "The active, guided and passive modes of the amd-pstate driver can support
> frequency boost control when the "Core Performance Boost"
> (CPB) feature is enabled in the BIOS.  When enabled in BIOS, the user has an
> option at runtime to allow/disallow the cores from operating in the boost
> frequency range.
>
> Add an amd_pstate_global_params object to record whether CPB is enabled in
> BIOS, and if it has been activated by the user."

Sure, will revise the description in v7.

>
> >
> > 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@gmx.com>
> > Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
> > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
> > ---
> >  drivers/cpufreq/amd-pstate.c | 39 +++++++++++++++++++++++++++---------
> >  include/linux/amd-pstate.h   | 13 ++++++++++++
> >  2 files changed, 42 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index 59a2db225d98..81787f83c906
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -68,6 +68,8 @@ static int cppc_state = AMD_PSTATE_UNDEFINED;
> > static bool cppc_enabled;  static bool amd_pstate_prefcore = true;
> > static struct quirk_entry *quirks;
> > +struct amd_pstate_global_params amd_pstate_global_params;
> > +EXPORT_SYMBOL_GPL(amd_pstate_global_params);
> >
> >  /*
> >   * AMD Energy Preference Performance (EPP)
>
> [..snip..]
>
> > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h
> > index 6b832153a126..c5e41de65f70 100644
> > --- a/include/linux/amd-pstate.h
> > +++ b/include/linux/amd-pstate.h
> > @@ -134,4 +134,17 @@ struct quirk_entry {
> >     u32 lowest_freq;
> >  };
> >
> > +/**
> > + * 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;
>
> Will this be used in multiple files ? If no, it is better to define this in amd-pstate.c

Yes, the var will be used by amd-pstate-ut.c which can detect the CPB state for unit testing.
So we need to expose this


>
> Otherwise, I have no other issues with the patch.

Thanks for the review,

Perry.

>
> --
> Thanks and Regards
> gautham.
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 59a2db225d98..81787f83c906 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -68,6 +68,8 @@  static int cppc_state = AMD_PSTATE_UNDEFINED;
 static bool cppc_enabled;
 static bool amd_pstate_prefcore = true;
 static struct quirk_entry *quirks;
+struct amd_pstate_global_params amd_pstate_global_params;
+EXPORT_SYMBOL_GPL(amd_pstate_global_params);
 
 /*
  * AMD Energy Preference Performance (EPP)
@@ -665,18 +667,27 @@  static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
 	return 0;
 }
 
-static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
+static int amd_pstate_boost_init(struct amd_cpudata *cpudata)
 {
-	u32 highest_perf, nominal_perf;
+	u64 boost_val;
+	int ret;
 
-	highest_perf = READ_ONCE(cpudata->highest_perf);
-	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+	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;
+	}
 
-	if (highest_perf <= nominal_perf)
-		return;
+	amd_pstate_global_params.cpb_supported = !(boost_val & MSR_K7_HWCR_CPB_DIS);
+
+	if (amd_pstate_global_params.cpb_supported) {
+		cpudata->boost_supported = true;
+		current_pstate_driver->boost_enabled = true;
+	}
 
-	cpudata->boost_supported = true;
-	current_pstate_driver->boost_enabled = true;
+	amd_pstate_global_params.cpb_boost = amd_pstate_global_params.cpb_supported;
+
+	return ret;
 }
 
 static void amd_perf_ctl_reset(unsigned int cpu)
@@ -900,6 +911,11 @@  static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 
 	amd_pstate_init_prefcore(cpudata);
 
+	/* initialize cpu cores boot state */
+	ret = amd_pstate_boost_init(cpudata);
+	if (ret)
+		goto free_cpudata1;
+
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
 		goto free_cpudata1;
@@ -956,7 +972,6 @@  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;
 
@@ -1363,6 +1378,11 @@  static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 
 	amd_pstate_init_prefcore(cpudata);
 
+	/* initialize cpu cores boot state */
+	ret = amd_pstate_boost_init(cpudata);
+	if (ret)
+		goto free_cpudata1;
+
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
 		goto free_cpudata1;
@@ -1417,7 +1437,6 @@  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 6b832153a126..c5e41de65f70 100644
--- a/include/linux/amd-pstate.h
+++ b/include/linux/amd-pstate.h
@@ -134,4 +134,17 @@  struct quirk_entry {
 	u32 lowest_freq;
 };
 
+/**
+ * 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 */