[PATCH V2 0/2] additional sysfs entries for CPPC

[PATCH V2 0/2] additional sysfs entries for CPPC

[Prashanth Prakash]

This patch-set adds few additional sysfs entries to expose the
performance capabilities of each CPU. The performance capabilities
include highest perf, lowest perf, nominal perf and lowest
non-linear perf. See 8.4.7.1 for ACPI 6.1 spec for details on
these capabilities.

cppc_cpufreq driver operates in KHz scale whereas the delivered
performance computed in userspace will be in abstract CPPC scale, so
exposing perf capabilities should allow userspace to figure out the
conversion factor from CPPC scale to KHz.

Changes in V2:
 - Removed caching of perf caps based on Rafael's inputs

Prashanth Prakash (2):
  ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps
  ACPI / CPPC: add sysfs entries for CPPC perf capabilities

 drivers/acpi/cppc_acpi.c | 80 ++++++++++++++++++++++++++----------------------
 include/acpi/cppc_acpi.h |  3 +-
 2 files changed, 46 insertions(+), 37 deletions(-)

-- 
Qualcomm Datacenter Technologies on behalf of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V2 1/2] ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps

[Prashanth Prakash]

Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed
via sysfs to the usespace. Lowest non linear perf is the lowest performance
level at which nonlinear power savings are achieved.

Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
---
 drivers/acpi/cppc_acpi.c | 19 +++++++++++--------
 include/acpi/cppc_acpi.h |  1 +
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 3ca0729..f5f3c29 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -972,9 +972,9 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 {
 	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
-	struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
-								 *nom_perf;
-	u64 high, low, nom;
+	struct cpc_register_resource *highest_reg, *lowest_reg,
+		*lowest_non_linear_reg, *nominal_reg;
+	u64 high, low, nom, low_non_linear;
 	int ret = 0, regs_in_pcc = 0;
 
 	if (!cpc_desc) {
@@ -984,12 +984,12 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 
 	highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
 	lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
-	ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
-	nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
+	lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
+	nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
 
 	/* Are any of the regs PCC ?*/
 	if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
-		CPC_IN_PCC(ref_perf) || CPC_IN_PCC(nom_perf)) {
+		CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg)) {
 		regs_in_pcc = 1;
 		down_write(&pcc_data.pcc_lock);
 		/* Ring doorbell once to update PCC subspace */
@@ -1005,10 +1005,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	cpc_read(cpunum, lowest_reg, &low);
 	perf_caps->lowest_perf = low;
 
-	cpc_read(cpunum, nom_perf, &nom);
+	cpc_read(cpunum, nominal_reg, &nom);
 	perf_caps->nominal_perf = nom;
 
-	if (!high || !low || !nom)
+	cpc_read(cpunum, lowest_non_linear_reg, &low_non_linear);
+	perf_caps->lowest_non_linear_perf = low_non_linear;
+
+	if (!high || !low || !nom || !low_non_linear)
 		ret = -EFAULT;
 
 out_err:
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 427a7c3..3f64660 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -103,6 +103,7 @@ struct cppc_perf_caps {
 	u32 highest_perf;
 	u32 nominal_perf;
 	u32 lowest_perf;
+	u32 lowest_non_linear_perf;
 };
 
 struct cppc_perf_ctrls {
-- 
Qualcomm Datacenter Technologies on behalf of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V2 1/2] ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps

[Rafael J. Wysocki]

On Wednesday, March 29, 2017 01:49:59 PM Prashanth Prakash wrote:
> Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed
> via sysfs to the usespace. Lowest non linear perf is the lowest performance
> level at which nonlinear power savings are achieved.
> 
> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>

Except that I would spell "nonlinear" as one word which appears to be a common
practice, it looks OK to me.

> ---
>  drivers/acpi/cppc_acpi.c | 19 +++++++++++--------
>  include/acpi/cppc_acpi.h |  1 +
>  2 files changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 3ca0729..f5f3c29 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -972,9 +972,9 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
>  int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>  {
>  	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
> -	struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
> -								 *nom_perf;
> -	u64 high, low, nom;
> +	struct cpc_register_resource *highest_reg, *lowest_reg,
> +		*lowest_non_linear_reg, *nominal_reg;
> +	u64 high, low, nom, low_non_linear;

min_nonlinear here?

>  	int ret = 0, regs_in_pcc = 0;
>  
>  	if (!cpc_desc) {
> @@ -984,12 +984,12 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>  
>  	highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
>  	lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
> -	ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
> -	nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
> +	lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
> +	nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
>  
>  	/* Are any of the regs PCC ?*/
>  	if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
> -		CPC_IN_PCC(ref_perf) || CPC_IN_PCC(nom_perf)) {
> +		CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg)) {
>  		regs_in_pcc = 1;
>  		down_write(&pcc_data.pcc_lock);
>  		/* Ring doorbell once to update PCC subspace */
> @@ -1005,10 +1005,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>  	cpc_read(cpunum, lowest_reg, &low);
>  	perf_caps->lowest_perf = low;
>  
> -	cpc_read(cpunum, nom_perf, &nom);
> +	cpc_read(cpunum, nominal_reg, &nom);
>  	perf_caps->nominal_perf = nom;
>  
> -	if (!high || !low || !nom)
> +	cpc_read(cpunum, lowest_non_linear_reg, &low_non_linear);
> +	perf_caps->lowest_non_linear_perf = low_non_linear;
> +
> +	if (!high || !low || !nom || !low_non_linear)
>  		ret = -EFAULT;
>  
>  out_err:
> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
> index 427a7c3..3f64660 100644
> --- a/include/acpi/cppc_acpi.h
> +++ b/include/acpi/cppc_acpi.h
> @@ -103,6 +103,7 @@ struct cppc_perf_caps {
>  	u32 highest_perf;
>  	u32 nominal_perf;
>  	u32 lowest_perf;
> +	u32 lowest_non_linear_perf;
>  };
>  
>  struct cppc_perf_ctrls {
> 

I can make the above changes for you if you agree. :-)

Thanks,
Rafael

Re: [PATCH V2 1/2] ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps

[Prakash, Prashanth]

Hi Rafael,

On 4/18/2017 8:28 AM, Rafael J. Wysocki wrote:
> On Wednesday, March 29, 2017 01:49:59 PM Prashanth Prakash wrote:
>> Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed
>> via sysfs to the usespace. Lowest non linear perf is the lowest performance
>> level at which nonlinear power savings are achieved.
>>
>> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
> Except that I would spell "nonlinear" as one word which appears to be a common
> practice, it looks OK to me.
>
>> ---
>>  drivers/acpi/cppc_acpi.c | 19 +++++++++++--------
>>  include/acpi/cppc_acpi.h |  1 +
>>  2 files changed, 12 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
>> index 3ca0729..f5f3c29 100644
>> --- a/drivers/acpi/cppc_acpi.c
>> +++ b/drivers/acpi/cppc_acpi.c
>> @@ -972,9 +972,9 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
>>  int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>>  {
>>  	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
>> -	struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
>> -								 *nom_perf;
>> -	u64 high, low, nom;
>> +	struct cpc_register_resource *highest_reg, *lowest_reg,
>> +		*lowest_non_linear_reg, *nominal_reg;
>> +	u64 high, low, nom, low_non_linear;
> min_nonlinear here?
>
>>  	int ret = 0, regs_in_pcc = 0;
>>  
>>  	if (!cpc_desc) {
>> @@ -984,12 +984,12 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>>  
>>  	highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
>>  	lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
>> -	ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
>> -	nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
>> +	lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
>> +	nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
>>  
>>  	/* Are any of the regs PCC ?*/
>>  	if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
>> -		CPC_IN_PCC(ref_perf) || CPC_IN_PCC(nom_perf)) {
>> +		CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg)) {
>>  		regs_in_pcc = 1;
>>  		down_write(&pcc_data.pcc_lock);
>>  		/* Ring doorbell once to update PCC subspace */
>> @@ -1005,10 +1005,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
>>  	cpc_read(cpunum, lowest_reg, &low);
>>  	perf_caps->lowest_perf = low;
>>  
>> -	cpc_read(cpunum, nom_perf, &nom);
>> +	cpc_read(cpunum, nominal_reg, &nom);
>>  	perf_caps->nominal_perf = nom;
>>  
>> -	if (!high || !low || !nom)
>> +	cpc_read(cpunum, lowest_non_linear_reg, &low_non_linear);
>> +	perf_caps->lowest_non_linear_perf = low_non_linear;
>> +
>> +	if (!high || !low || !nom || !low_non_linear)
>>  		ret = -EFAULT;
>>  
>>  out_err:
>> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
>> index 427a7c3..3f64660 100644
>> --- a/include/acpi/cppc_acpi.h
>> +++ b/include/acpi/cppc_acpi.h
>> @@ -103,6 +103,7 @@ struct cppc_perf_caps {
>>  	u32 highest_perf;
>>  	u32 nominal_perf;
>>  	u32 lowest_perf;
>> +	u32 lowest_non_linear_perf;
>>  };
>>  
>>  struct cppc_perf_ctrls {
>>
> I can make the above changes for you if you agree. :-)

Thanks! Yes, you can make those correction :-)

--
Thanks,
Prashanth

[PATCH V2 2/2] ACPI / CPPC: add sysfs entries for CPPC perf capabilities

[Prashanth Prakash]

Computed delivered performance using CPPC feedback counters are in the
CPPC abstract scale, whereas cppc_cpufreq driver operates in KHz scale.
Exposing the CPPC performance capabilities (highest,lowest, nominal,
lowest non-linear) will allow userspace to figure out the conversion
factor from CPPC abstract scale to KHz.

Also rename ctr_wrap_time to wraparound_time so that show_cppc_data()
macro will work with it.

Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
---
 drivers/acpi/cppc_acpi.c | 61 ++++++++++++++++++++++++++----------------------
 include/acpi/cppc_acpi.h |  2 +-
 2 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f5f3c29..90ac2f2 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -132,49 +132,54 @@ struct cppc_attr {
 
 #define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj)
 
+#define show_cppc_data(access_fn, struct_name, member_name)		\
+	static ssize_t show_##member_name(struct kobject *kobj,		\
+					struct attribute *attr,	char *buf) \
+	{								\
+		struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);		\
+		struct struct_name st_name = {0};			\
+		int ret;						\
+									\
+		ret = access_fn(cpc_ptr->cpu_id, &st_name);		\
+		if (ret)						\
+			return ret;					\
+									\
+		return scnprintf(buf, PAGE_SIZE, "%llu\n",		\
+				(u64)st_name.member_name);		\
+	}								\
+	define_one_cppc_ro(member_name)
+
+show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf);
+show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf);
+show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf);
+show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_non_linear_perf);
+show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf);
+show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
+
 static ssize_t show_feedback_ctrs(struct kobject *kobj,
 		struct attribute *attr, char *buf)
 {
 	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
 	struct cppc_perf_fb_ctrs fb_ctrs = {0};
+	int ret;
 
-	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+	ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+	if (ret)
+		return ret;
 
 	return scnprintf(buf, PAGE_SIZE, "ref:%llu del:%llu\n",
 			fb_ctrs.reference, fb_ctrs.delivered);
 }
 define_one_cppc_ro(feedback_ctrs);
 
-static ssize_t show_reference_perf(struct kobject *kobj,
-		struct attribute *attr, char *buf)
-{
-	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
-	struct cppc_perf_fb_ctrs fb_ctrs = {0};
-
-	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
-
-	return scnprintf(buf, PAGE_SIZE, "%llu\n",
-			fb_ctrs.reference_perf);
-}
-define_one_cppc_ro(reference_perf);
-
-static ssize_t show_wraparound_time(struct kobject *kobj,
-				struct attribute *attr, char *buf)
-{
-	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
-	struct cppc_perf_fb_ctrs fb_ctrs = {0};
-
-	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
-
-	return scnprintf(buf, PAGE_SIZE, "%llu\n", fb_ctrs.ctr_wrap_time);
-
-}
-define_one_cppc_ro(wraparound_time);
-
 static struct attribute *cppc_attrs[] = {
 	&feedback_ctrs.attr,
 	&reference_perf.attr,
 	&wraparound_time.attr,
+	&highest_perf.attr,
+	&lowest_perf.attr,
+	&lowest_non_linear_perf.attr,
+	&nominal_perf.attr,
 	NULL
 };
 
@@ -1086,7 +1091,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 	perf_fb_ctrs->delivered = delivered;
 	perf_fb_ctrs->reference = reference;
 	perf_fb_ctrs->reference_perf = ref_perf;
-	perf_fb_ctrs->ctr_wrap_time = ctr_wrap_time;
+	perf_fb_ctrs->wraparound_time = ctr_wrap_time;
 out_err:
 	if (regs_in_pcc)
 		up_write(&pcc_data.pcc_lock);
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 3f64660..08c2c78 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -116,7 +116,7 @@ struct cppc_perf_fb_ctrs {
 	u64 reference;
 	u64 delivered;
 	u64 reference_perf;
-	u64 ctr_wrap_time;
+	u64 wraparound_time;
 };
 
 /* Per CPU container for runtime CPPC management. */
-- 
Qualcomm Datacenter Technologies on behalf of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V2 0/2] additional sysfs entries for CPPC

[Prakash, Prashanth]

Cc++

Any feedback on this?

On 3/29/2017 1:49 PM, Prashanth Prakash wrote:
> This patch-set adds few additional sysfs entries to expose the
> performance capabilities of each CPU. The performance capabilities
> include highest perf, lowest perf, nominal perf and lowest
> non-linear perf. See 8.4.7.1 for ACPI 6.1 spec for details on
> these capabilities.
>
> cppc_cpufreq driver operates in KHz scale whereas the delivered
> performance computed in userspace will be in abstract CPPC scale, so
> exposing perf capabilities should allow userspace to figure out the
> conversion factor from CPPC scale to KHz.
>
> Changes in V2:
>  - Removed caching of perf caps based on Rafael's inputs
>
> Prashanth Prakash (2):
>   ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps
>   ACPI / CPPC: add sysfs entries for CPPC perf capabilities
>
>  drivers/acpi/cppc_acpi.c | 80 ++++++++++++++++++++++++++----------------------
>  include/acpi/cppc_acpi.h |  3 +-
>  2 files changed, 46 insertions(+), 37 deletions(-)
>
--
Thanks,
Prashanth

Re: [PATCH V2 0/2] additional sysfs entries for CPPC

[Rafael J. Wysocki]

On Monday, April 17, 2017 09:42:15 AM Prakash, Prashanth wrote:
> Cc++
> 
> Any feedback on this?
> 
> On 3/29/2017 1:49 PM, Prashanth Prakash wrote:
> > This patch-set adds few additional sysfs entries to expose the
> > performance capabilities of each CPU. The performance capabilities
> > include highest perf, lowest perf, nominal perf and lowest
> > non-linear perf. See 8.4.7.1 for ACPI 6.1 spec for details on
> > these capabilities.
> >
> > cppc_cpufreq driver operates in KHz scale whereas the delivered
> > performance computed in userspace will be in abstract CPPC scale, so
> > exposing perf capabilities should allow userspace to figure out the
> > conversion factor from CPPC scale to KHz.
> >
> > Changes in V2:
> >  - Removed caching of perf caps based on Rafael's inputs
> >
> > Prashanth Prakash (2):
> >   ACPI / CPPC: Read lowest non linear perf in cppc_get_perf_caps
> >   ACPI / CPPC: add sysfs entries for CPPC perf capabilities
> >
> >  drivers/acpi/cppc_acpi.c | 80 ++++++++++++++++++++++++++----------------------
> >  include/acpi/cppc_acpi.h |  3 +-
> >  2 files changed, 46 insertions(+), 37 deletions(-)

I am about to get to this.

Thanks,
Rafael