Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-23 Thread kajoljain 



On 3/23/22 21:02, Dan Williams wrote:
> On Wed, Mar 23, 2022 at 3:05 AM Michael Ellerman  wrote:
>>
>> Dan Williams  writes:
>>> On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:
 On 3/22/22 03:09, Dan Williams wrote:
> On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>>
>> The following build failure occures when CONFIG_PERF_EVENTS is not set
>> as generic pmu functions are not visible in that scenario.
>>
>> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
>> perf_event’ has no member named ‘attr’
>>  p->nvdimm_events_map[event->attr.config],
>>^~
>> In file included from ./include/linux/list.h:5,
>>  from ./include/linux/kobject.h:19,
>>  from ./include/linux/of.h:17,
>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> arch/powerpc/platforms/pseries/papr_scm.c: In function 
>> ‘papr_scm_pmu_event_init’:
>> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
>> perf_event’ has no member named ‘pmu’
>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>  ^~
>> ./include/linux/container_of.h:18:26: note: in definition of macro 
>> ‘container_of’
>>   void *__mptr = (void *)(ptr); \
>>   ^~~
>> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
>> macro ‘to_nvdimm_pmu’
>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>   ^
>> In file included from ./include/linux/bits.h:22,
>>  from ./include/linux/bitops.h:6,
>>  from ./include/linux/of.h:15,
>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>>
>> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
>> and disabling the papr_scm perf interface support incase this config
>> is not set
>>
>> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
>> (Commit id
>> based on linux-next tree)
>> Signed-off-by: Kajol Jain 
>> ---
>>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
>
> This is a bit messier than I would have liked mainly because it dumps
> a bunch of ifdefery into a C file contrary to coding style, "Wherever
> possible, don't use preprocessor conditionals (#if, #ifdef) in .c
> files". I would expect this all to move to an organization like:

 Hi Dan,
   Thanks for reviewing the patches. Inorder to avoid the multiple
 ifdefs checks, we can also add stub function for papr_scm_pmu_register.
 With that change we will just have one ifdef check for
 CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
 avoid adding new files specific for papr_scm perf interface.

 Below is the code snippet for that change, let me know if looks fine to
 you. I tested it
 with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
 value combinations.

 diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
 b/arch/powerpc/platforms/pseries/papr_scm.c
 index 4dd513d7c029..38fabb44d3c3 100644
 --- a/arch/powerpc/platforms/pseries/papr_scm.c
 +++ b/arch/powerpc/platforms/pseries/papr_scm.c
 @@ -69,8 +69,6 @@
  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
  #define PAPR_SCM_PERF_STATS_VERSION 0x1

 -#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
 -
  /* Struct holding a single performance metric */
  struct papr_scm_perf_stat {
 u8 stat_id[8];
 @@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
 papr_scm_priv *p,
 return 0;
  }

 +#ifdef CONFIG_PERF_EVENTS
 +#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
 +
  static int papr_scm_pmu_get_value(struct perf_event *event, struct
 device *dev, u64 *count)
  {
 struct papr_scm_perf_stat *stat;
 @@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
 papr_scm_priv *p)
 dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
  }

 +#else
 +static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }
>>>
>>> Since this isn't in a header file, it does not need to be marked
>>> "inline" the compiler will figure it out.
>>>
 +#endif
>>>
>>> It might be time to create:
>>>
>>> arch/powerpc/platforms/pseries/papr_scm.h
>>>
>>> ...there is quite a bit of header material accrued in papr_scm.c and
>>> once the ifdefs start landing in it then it becomes a nominal coding
>>> style issue. That said, this is certainly more palatable than the
>>> previous version. So if you don't want to create papr_scm.h yet for
>>>

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-23 Thread Dan Williams 
On Wed, Mar 23, 2022 at 3:05 AM Michael Ellerman  wrote:
>
> Dan Williams  writes:
> > On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:
> >> On 3/22/22 03:09, Dan Williams wrote:
> >> > On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
> >> >>
> >> >> The following build failure occures when CONFIG_PERF_EVENTS is not set
> >> >> as generic pmu functions are not visible in that scenario.
> >> >>
> >> >> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
> >> >> perf_event’ has no member named ‘attr’
> >> >>  p->nvdimm_events_map[event->attr.config],
> >> >>^~
> >> >> In file included from ./include/linux/list.h:5,
> >> >>  from ./include/linux/kobject.h:19,
> >> >>  from ./include/linux/of.h:17,
> >> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> >> >> arch/powerpc/platforms/pseries/papr_scm.c: In function 
> >> >> ‘papr_scm_pmu_event_init’:
> >> >> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
> >> >> perf_event’ has no member named ‘pmu’
> >> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >> >>  ^~
> >> >> ./include/linux/container_of.h:18:26: note: in definition of macro 
> >> >> ‘container_of’
> >> >>   void *__mptr = (void *)(ptr); \
> >> >>   ^~~
> >> >> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
> >> >> macro ‘to_nvdimm_pmu’
> >> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >> >>   ^
> >> >> In file included from ./include/linux/bits.h:22,
> >> >>  from ./include/linux/bitops.h:6,
> >> >>  from ./include/linux/of.h:15,
> >> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> >> >>
> >> >> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
> >> >> and disabling the papr_scm perf interface support incase this config
> >> >> is not set
> >> >>
> >> >> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
> >> >> (Commit id
> >> >> based on linux-next tree)
> >> >> Signed-off-by: Kajol Jain 
> >> >> ---
> >> >>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
> >> >
> >> > This is a bit messier than I would have liked mainly because it dumps
> >> > a bunch of ifdefery into a C file contrary to coding style, "Wherever
> >> > possible, don't use preprocessor conditionals (#if, #ifdef) in .c
> >> > files". I would expect this all to move to an organization like:
> >>
> >> Hi Dan,
> >>   Thanks for reviewing the patches. Inorder to avoid the multiple
> >> ifdefs checks, we can also add stub function for papr_scm_pmu_register.
> >> With that change we will just have one ifdef check for
> >> CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
> >> avoid adding new files specific for papr_scm perf interface.
> >>
> >> Below is the code snippet for that change, let me know if looks fine to
> >> you. I tested it
> >> with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
> >> value combinations.
> >>
> >> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
> >> b/arch/powerpc/platforms/pseries/papr_scm.c
> >> index 4dd513d7c029..38fabb44d3c3 100644
> >> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> >> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> >> @@ -69,8 +69,6 @@
> >>  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
> >>  #define PAPR_SCM_PERF_STATS_VERSION 0x1
> >>
> >> -#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
> >> -
> >>  /* Struct holding a single performance metric */
> >>  struct papr_scm_perf_stat {
> >> u8 stat_id[8];
> >> @@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
> >> papr_scm_priv *p,
> >> return 0;
> >>  }
> >>
> >> +#ifdef CONFIG_PERF_EVENTS
> >> +#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
> >> +
> >>  static int papr_scm_pmu_get_value(struct perf_event *event, struct
> >> device *dev, u64 *count)
> >>  {
> >> struct papr_scm_perf_stat *stat;
> >> @@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
> >> papr_scm_priv *p)
> >> dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
> >>  }
> >>
> >> +#else
> >> +static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }
> >
> > Since this isn't in a header file, it does not need to be marked
> > "inline" the compiler will figure it out.
> >
> >> +#endif
> >
> > It might be time to create:
> >
> > arch/powerpc/platforms/pseries/papr_scm.h
> >
> > ...there is quite a bit of header material accrued in papr_scm.c and
> > once the ifdefs start landing in it then it becomes a nominal coding
> > style issue. That said, this is certainly more palatable than the
> > previous version. So if you don't want to create papr_scm.h yet for
> >

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-23 Thread Michael Ellerman 
Dan Williams  writes:
> On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:
>> On 3/22/22 03:09, Dan Williams wrote:
>> > On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>> >>
>> >> The following build failure occures when CONFIG_PERF_EVENTS is not set
>> >> as generic pmu functions are not visible in that scenario.
>> >>
>> >> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
>> >> perf_event’ has no member named ‘attr’
>> >>  p->nvdimm_events_map[event->attr.config],
>> >>^~
>> >> In file included from ./include/linux/list.h:5,
>> >>  from ./include/linux/kobject.h:19,
>> >>  from ./include/linux/of.h:17,
>> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> >> arch/powerpc/platforms/pseries/papr_scm.c: In function 
>> >> ‘papr_scm_pmu_event_init’:
>> >> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
>> >> perf_event’ has no member named ‘pmu’
>> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>> >>  ^~
>> >> ./include/linux/container_of.h:18:26: note: in definition of macro 
>> >> ‘container_of’
>> >>   void *__mptr = (void *)(ptr); \
>> >>   ^~~
>> >> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
>> >> macro ‘to_nvdimm_pmu’
>> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>> >>   ^
>> >> In file included from ./include/linux/bits.h:22,
>> >>  from ./include/linux/bitops.h:6,
>> >>  from ./include/linux/of.h:15,
>> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> >>
>> >> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
>> >> and disabling the papr_scm perf interface support incase this config
>> >> is not set
>> >>
>> >> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
>> >> (Commit id
>> >> based on linux-next tree)
>> >> Signed-off-by: Kajol Jain 
>> >> ---
>> >>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
>> >
>> > This is a bit messier than I would have liked mainly because it dumps
>> > a bunch of ifdefery into a C file contrary to coding style, "Wherever
>> > possible, don't use preprocessor conditionals (#if, #ifdef) in .c
>> > files". I would expect this all to move to an organization like:
>>
>> Hi Dan,
>>   Thanks for reviewing the patches. Inorder to avoid the multiple
>> ifdefs checks, we can also add stub function for papr_scm_pmu_register.
>> With that change we will just have one ifdef check for
>> CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
>> avoid adding new files specific for papr_scm perf interface.
>>
>> Below is the code snippet for that change, let me know if looks fine to
>> you. I tested it
>> with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
>> value combinations.
>>
>> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
>> b/arch/powerpc/platforms/pseries/papr_scm.c
>> index 4dd513d7c029..38fabb44d3c3 100644
>> --- a/arch/powerpc/platforms/pseries/papr_scm.c
>> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
>> @@ -69,8 +69,6 @@
>>  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
>>  #define PAPR_SCM_PERF_STATS_VERSION 0x1
>>
>> -#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
>> -
>>  /* Struct holding a single performance metric */
>>  struct papr_scm_perf_stat {
>> u8 stat_id[8];
>> @@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
>> papr_scm_priv *p,
>> return 0;
>>  }
>>
>> +#ifdef CONFIG_PERF_EVENTS
>> +#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
>> +
>>  static int papr_scm_pmu_get_value(struct perf_event *event, struct
>> device *dev, u64 *count)
>>  {
>> struct papr_scm_perf_stat *stat;
>> @@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
>> papr_scm_priv *p)
>> dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
>>  }
>>
>> +#else
>> +static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }
>
> Since this isn't in a header file, it does not need to be marked
> "inline" the compiler will figure it out.
>
>> +#endif
>
> It might be time to create:
>
> arch/powerpc/platforms/pseries/papr_scm.h
>
> ...there is quite a bit of header material accrued in papr_scm.c and
> once the ifdefs start landing in it then it becomes a nominal coding
> style issue. That said, this is certainly more palatable than the
> previous version. So if you don't want to create papr_scm.h yet for
> this, at least make a note in the changelog that the first portion of
> arch/powerpc/platforms/pseries/papr_scm.c is effectively papr_scm.h
> content and may move there in the future, or something like that.

IMHO the only thing that belongs in a header is content that's needed by

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-23 Thread Vaibhav Jain 
Dan Williams  writes:

> On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:
>>
>>
>>
>> On 3/22/22 03:09, Dan Williams wrote:
>> > On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>> >>
>> >> The following build failure occures when CONFIG_PERF_EVENTS is not set
>> >> as generic pmu functions are not visible in that scenario.
>> >>
>> >> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
>> >> perf_event’ has no member named ‘attr’
>> >>  p->nvdimm_events_map[event->attr.config],
>> >>^~
>> >> In file included from ./include/linux/list.h:5,
>> >>  from ./include/linux/kobject.h:19,
>> >>  from ./include/linux/of.h:17,
>> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> >> arch/powerpc/platforms/pseries/papr_scm.c: In function 
>> >> ‘papr_scm_pmu_event_init’:
>> >> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
>> >> perf_event’ has no member named ‘pmu’
>> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>> >>  ^~
>> >> ./include/linux/container_of.h:18:26: note: in definition of macro 
>> >> ‘container_of’
>> >>   void *__mptr = (void *)(ptr); \
>> >>   ^~~
>> >> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
>> >> macro ‘to_nvdimm_pmu’
>> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>> >>   ^
>> >> In file included from ./include/linux/bits.h:22,
>> >>  from ./include/linux/bitops.h:6,
>> >>  from ./include/linux/of.h:15,
>> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> >>
>> >> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
>> >> and disabling the papr_scm perf interface support incase this config
>> >> is not set
>> >>
>> >> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
>> >> (Commit id
>> >> based on linux-next tree)
>> >> Signed-off-by: Kajol Jain 
>> >> ---
>> >>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
>> >
>> > This is a bit messier than I would have liked mainly because it dumps
>> > a bunch of ifdefery into a C file contrary to coding style, "Wherever
>> > possible, don't use preprocessor conditionals (#if, #ifdef) in .c
>> > files". I would expect this all to move to an organization like:
>>
>> Hi Dan,
>>   Thanks for reviewing the patches. Inorder to avoid the multiple
>> ifdefs checks, we can also add stub function for papr_scm_pmu_register.
>> With that change we will just have one ifdef check for
>> CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
>> avoid adding new files specific for papr_scm perf interface.
>>
>> Below is the code snippet for that change, let me know if looks fine to
>> you. I tested it
>> with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
>> value combinations.
>>
>> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
>> b/arch/powerpc/platforms/pseries/papr_scm.c
>> index 4dd513d7c029..38fabb44d3c3 100644
>> --- a/arch/powerpc/platforms/pseries/papr_scm.c
>> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
>> @@ -69,8 +69,6 @@
>>  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
>>  #define PAPR_SCM_PERF_STATS_VERSION 0x1
>>
>> -#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
>> -
>>  /* Struct holding a single performance metric */
>>  struct papr_scm_perf_stat {
>> u8 stat_id[8];
>> @@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
>> papr_scm_priv *p,
>> return 0;
>>  }
>>
>> +#ifdef CONFIG_PERF_EVENTS
>> +#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
>> +
>>  static int papr_scm_pmu_get_value(struct perf_event *event, struct
>> device *dev, u64 *count)
>>  {
>> struct papr_scm_perf_stat *stat;
>> @@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
>> papr_scm_priv *p)
>> dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
>>  }
>>
>> +#else
>> +static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }
>
> Since this isn't in a header file, it does not need to be marked
> "inline" the compiler will figure it out.
>
>> +#endif
>
> It might be time to create:
>
> arch/powerpc/platforms/pseries/papr_scm.h
>
> ...there is quite a bit of header material accrued in papr_scm.c and
> once the ifdefs start landing in it then it becomes a nominal coding
> style issue. That said, this is certainly more palatable than the
> previous version. So if you don't want to create papr_scm.h yet for
> this, at least make a note in the changelog that the first portion of
> arch/powerpc/platforms/pseries/papr_scm.c is effectively papr_scm.h
> content and may move there in the future, or something like that.

Great suggestion Dan and incidently we are already working on

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-23 Thread Aneesh Kumar K V 

On 3/22/22 10:02 PM, Dan Williams wrote:

On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:




On 3/22/22 03:09, Dan Williams wrote:

On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:


The following build failure occures when CONFIG_PERF_EVENTS is not set
as generic pmu functions are not visible in that scenario.

arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ 
has no member named ‘attr’
  p->nvdimm_events_map[event->attr.config],
^~
In file included from ./include/linux/list.h:5,
  from ./include/linux/kobject.h:19,
  from ./include/linux/of.h:17,
  from arch/powerpc/platforms/pseries/papr_scm.c:5:
arch/powerpc/platforms/pseries/papr_scm.c: In function 
‘papr_scm_pmu_event_init’:
arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ 
has no member named ‘pmu’
   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
  ^~
./include/linux/container_of.h:18:26: note: in definition of macro 
‘container_of’
   void *__mptr = (void *)(ptr); \
   ^~~
arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of macro 
‘to_nvdimm_pmu’
   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
   ^
In file included from ./include/linux/bits.h:22,
  from ./include/linux/bitops.h:6,
  from ./include/linux/of.h:15,
  from arch/powerpc/platforms/pseries/papr_scm.c:5:

Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
and disabling the papr_scm perf interface support incase this config
is not set

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit id
based on linux-next tree)
Signed-off-by: Kajol Jain 
---
  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++


This is a bit messier than I would have liked mainly because it dumps
a bunch of ifdefery into a C file contrary to coding style, "Wherever
possible, don't use preprocessor conditionals (#if, #ifdef) in .c
files". I would expect this all to move to an organization like:


Hi Dan,
   Thanks for reviewing the patches. Inorder to avoid the multiple
ifdefs checks, we can also add stub function for papr_scm_pmu_register.
With that change we will just have one ifdef check for
CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
avoid adding new files specific for papr_scm perf interface.

Below is the code snippet for that change, let me know if looks fine to
you. I tested it
with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
value combinations.

diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
b/arch/powerpc/platforms/pseries/papr_scm.c
index 4dd513d7c029..38fabb44d3c3 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -69,8 +69,6 @@
  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
  #define PAPR_SCM_PERF_STATS_VERSION 0x1

-#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
-
  /* Struct holding a single performance metric */
  struct papr_scm_perf_stat {
 u8 stat_id[8];
@@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
papr_scm_priv *p,
 return 0;
  }

+#ifdef CONFIG_PERF_EVENTS
+#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
+
  static int papr_scm_pmu_get_value(struct perf_event *event, struct
device *dev, u64 *count)
  {
 struct papr_scm_perf_stat *stat;
@@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
papr_scm_priv *p)
 dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
  }

+#else
+static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }


Since this isn't in a header file, it does not need to be marked
"inline" the compiler will figure it out.


+#endif


It might be time to create:

arch/powerpc/platforms/pseries/papr_scm.h

...there is quite a bit of header material accrued in papr_scm.c and
once the ifdefs start landing in it then it becomes a nominal coding
style issue. That said, this is certainly more palatable than the
previous version. So if you don't want to create papr_scm.h yet for
this, at least make a note in the changelog that the first portion of
arch/powerpc/platforms/pseries/papr_scm.c is effectively papr_scm.h
content and may move there in the future, or something like that.


There was an attempt to do that earlier. We should get that reposted 
with further changes move more details to header.


https://lore.kernel.org/nvdimm/163454440296.431294.2368481747380790011.st...@lep8c.aus.stglabs.ibm.com

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-22 Thread Dan Williams 
On Tue, Mar 22, 2022 at 7:30 AM kajoljain  wrote:
>
>
>
> On 3/22/22 03:09, Dan Williams wrote:
> > On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
> >>
> >> The following build failure occures when CONFIG_PERF_EVENTS is not set
> >> as generic pmu functions are not visible in that scenario.
> >>
> >> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
> >> perf_event’ has no member named ‘attr’
> >>  p->nvdimm_events_map[event->attr.config],
> >>^~
> >> In file included from ./include/linux/list.h:5,
> >>  from ./include/linux/kobject.h:19,
> >>  from ./include/linux/of.h:17,
> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> >> arch/powerpc/platforms/pseries/papr_scm.c: In function 
> >> ‘papr_scm_pmu_event_init’:
> >> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
> >> perf_event’ has no member named ‘pmu’
> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >>  ^~
> >> ./include/linux/container_of.h:18:26: note: in definition of macro 
> >> ‘container_of’
> >>   void *__mptr = (void *)(ptr); \
> >>   ^~~
> >> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
> >> macro ‘to_nvdimm_pmu’
> >>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >>   ^
> >> In file included from ./include/linux/bits.h:22,
> >>  from ./include/linux/bitops.h:6,
> >>  from ./include/linux/of.h:15,
> >>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> >>
> >> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
> >> and disabling the papr_scm perf interface support incase this config
> >> is not set
> >>
> >> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
> >> (Commit id
> >> based on linux-next tree)
> >> Signed-off-by: Kajol Jain 
> >> ---
> >>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
> >
> > This is a bit messier than I would have liked mainly because it dumps
> > a bunch of ifdefery into a C file contrary to coding style, "Wherever
> > possible, don't use preprocessor conditionals (#if, #ifdef) in .c
> > files". I would expect this all to move to an organization like:
>
> Hi Dan,
>   Thanks for reviewing the patches. Inorder to avoid the multiple
> ifdefs checks, we can also add stub function for papr_scm_pmu_register.
> With that change we will just have one ifdef check for
> CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
> avoid adding new files specific for papr_scm perf interface.
>
> Below is the code snippet for that change, let me know if looks fine to
> you. I tested it
> with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
> value combinations.
>
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
> b/arch/powerpc/platforms/pseries/papr_scm.c
> index 4dd513d7c029..38fabb44d3c3 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -69,8 +69,6 @@
>  #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
>  #define PAPR_SCM_PERF_STATS_VERSION 0x1
>
> -#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
> -
>  /* Struct holding a single performance metric */
>  struct papr_scm_perf_stat {
> u8 stat_id[8];
> @@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
> papr_scm_priv *p,
> return 0;
>  }
>
> +#ifdef CONFIG_PERF_EVENTS
> +#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
> +
>  static int papr_scm_pmu_get_value(struct perf_event *event, struct
> device *dev, u64 *count)
>  {
> struct papr_scm_perf_stat *stat;
> @@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
> papr_scm_priv *p)
> dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
>  }
>
> +#else
> +static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }

Since this isn't in a header file, it does not need to be marked
"inline" the compiler will figure it out.

> +#endif

It might be time to create:

arch/powerpc/platforms/pseries/papr_scm.h

...there is quite a bit of header material accrued in papr_scm.c and
once the ifdefs start landing in it then it becomes a nominal coding
style issue. That said, this is certainly more palatable than the
previous version. So if you don't want to create papr_scm.h yet for
this, at least make a note in the changelog that the first portion of
arch/powerpc/platforms/pseries/papr_scm.c is effectively papr_scm.h
content and may move there in the future, or something like that.

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-22 Thread kajoljain 



On 3/22/22 07:15, Dan Williams wrote:
> On Mon, Mar 21, 2022 at 2:39 PM Dan Williams  wrote:
>>
>> On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>>>
>>> The following build failure occures when CONFIG_PERF_EVENTS is not set
>>> as generic pmu functions are not visible in that scenario.
>>>
>>> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
>>> perf_event’ has no member named ‘attr’
>>>  p->nvdimm_events_map[event->attr.config],
>>>^~
>>> In file included from ./include/linux/list.h:5,
>>>  from ./include/linux/kobject.h:19,
>>>  from ./include/linux/of.h:17,
>>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>>> arch/powerpc/platforms/pseries/papr_scm.c: In function 
>>> ‘papr_scm_pmu_event_init’:
>>> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
>>> perf_event’ has no member named ‘pmu’
>>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>>  ^~
>>> ./include/linux/container_of.h:18:26: note: in definition of macro 
>>> ‘container_of’
>>>   void *__mptr = (void *)(ptr); \
>>>   ^~~
>>> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
>>> macro ‘to_nvdimm_pmu’
>>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>>   ^
>>> In file included from ./include/linux/bits.h:22,
>>>  from ./include/linux/bitops.h:6,
>>>  from ./include/linux/of.h:15,
>>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>>>
>>> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
>>> and disabling the papr_scm perf interface support incase this config
>>> is not set
>>>
>>> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
>>> (Commit id
>>> based on linux-next tree)
>>> Signed-off-by: Kajol Jain 
>>> ---
>>>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
>>
>> This is a bit messier than I would have liked mainly because it dumps
>> a bunch of ifdefery into a C file contrary to coding style, "Wherever
>> possible, don't use preprocessor conditionals (#if, #ifdef) in .c
>> files". I would expect this all to move to an organization like:
>>
>> arch/powerpc/platforms/pseries/papr_scm/main.c
>> arch/powerpc/platforms/pseries/papr_scm/perf.c
>>
>> ...and a new config symbol like:
>>
>> config PAPR_SCM_PERF
>>depends on PAPR_SCM && PERF_EVENTS
>>def_bool y
>>
>> ...with wrappers in header files to make everything compile away
>> without any need for main.c to carry an ifdef.
>>
>> Can you turn a patch like that in the next couple days? Otherwise, I
>> think if Linus saw me sending a late breaking compile fix that threw
>> coding style out the window he'd have cause to just drop the pull
>> request entirely.
> 
> Also, please base it on the current state of the libnvdimm-for-next
> branch as -next includes some of the SMART health changes leading to
> at least one conflict.

Ok Dan, I will rebase my changes on top of libnvdimm-for-next branch.

Thanks,
Kajol Jain

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-22 Thread kajoljain 



On 3/22/22 03:09, Dan Williams wrote:
> On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>>
>> The following build failure occures when CONFIG_PERF_EVENTS is not set
>> as generic pmu functions are not visible in that scenario.
>>
>> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ 
>> has no member named ‘attr’
>>  p->nvdimm_events_map[event->attr.config],
>>^~
>> In file included from ./include/linux/list.h:5,
>>  from ./include/linux/kobject.h:19,
>>  from ./include/linux/of.h:17,
>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>> arch/powerpc/platforms/pseries/papr_scm.c: In function 
>> ‘papr_scm_pmu_event_init’:
>> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ 
>> has no member named ‘pmu’
>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>  ^~
>> ./include/linux/container_of.h:18:26: note: in definition of macro 
>> ‘container_of’
>>   void *__mptr = (void *)(ptr); \
>>   ^~~
>> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
>> macro ‘to_nvdimm_pmu’
>>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>>   ^
>> In file included from ./include/linux/bits.h:22,
>>  from ./include/linux/bitops.h:6,
>>  from ./include/linux/of.h:15,
>>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>>
>> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
>> and disabling the papr_scm perf interface support incase this config
>> is not set
>>
>> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit 
>> id
>> based on linux-next tree)
>> Signed-off-by: Kajol Jain 
>> ---
>>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
> 
> This is a bit messier than I would have liked mainly because it dumps
> a bunch of ifdefery into a C file contrary to coding style, "Wherever
> possible, don't use preprocessor conditionals (#if, #ifdef) in .c
> files". I would expect this all to move to an organization like:

Hi Dan,
  Thanks for reviewing the patches. Inorder to avoid the multiple
ifdefs checks, we can also add stub function for papr_scm_pmu_register.
With that change we will just have one ifdef check for
CONFIG_PERF_EVENTS config in both papr_scm.c and nd.h file. Hence we can
avoid adding new files specific for papr_scm perf interface.

Below is the code snippet for that change, let me know if looks fine to
you. I tested it
with set/unset PAPR_SCM config value and set/unset PERF_EVENTS config
value combinations.

diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
b/arch/powerpc/platforms/pseries/papr_scm.c
index 4dd513d7c029..38fabb44d3c3 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -69,8 +69,6 @@
 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
 #define PAPR_SCM_PERF_STATS_VERSION 0x1

-#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
-
 /* Struct holding a single performance metric */
 struct papr_scm_perf_stat {
u8 stat_id[8];
@@ -346,6 +344,9 @@ static ssize_t drc_pmem_query_stats(struct
papr_scm_priv *p,
return 0;
 }

+#ifdef CONFIG_PERF_EVENTS
+#define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
+
 static int papr_scm_pmu_get_value(struct perf_event *event, struct
device *dev, u64 *count)
 {
struct papr_scm_perf_stat *stat;
@@ -558,6 +559,10 @@ static void papr_scm_pmu_register(struct
papr_scm_priv *p)
dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
 }

+#else
+static inline void papr_scm_pmu_register(struct papr_scm_priv *p) { }
+#endif
+
 /*
  * Issue hcall to retrieve dimm health info and populate papr_scm_priv
with the
  * health information.
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 3fb806748716..ba0296dca9db 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -15,7 +15,7 @@ nd_e820-y := e820.o
 libnvdimm-y := core.o
 libnvdimm-y += bus.o
 libnvdimm-y += dimm_devs.o
-libnvdimm-y += nd_perf.o
+libnvdimm-$(CONFIG_PERF_EVENTS) += nd_perf.o
 libnvdimm-y += dimm.o
 libnvdimm-y += region_devs.o
 libnvdimm-y += region.o
diff --git a/include/linux/nd.h b/include/linux/nd.h
index 7b2ccbdc1cbc..a387e2b630ad 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -57,15 +57,22 @@ struct nvdimm_pmu {
struct cpumask arch_cpumask;
 };

+#ifdef CONFIG_PERF_EVENTS
 extern ssize_t nvdimm_events_sysfs_show(struct device *dev,
struct device_attribute *attr,
char *page);

 int register_nvdimm_pmu(struct nvdimm_pmu *nvdimm, struct
platform_device *pdev);
 void unregister_nvdimm_pmu(struct nvdimm_pmu

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-21 Thread Dan Williams 
On Mon, Mar 21, 2022 at 2:39 PM Dan Williams  wrote:
>
> On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
> >
> > The following build failure occures when CONFIG_PERF_EVENTS is not set
> > as generic pmu functions are not visible in that scenario.
> >
> > arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct 
> > perf_event’ has no member named ‘attr’
> >  p->nvdimm_events_map[event->attr.config],
> >^~
> > In file included from ./include/linux/list.h:5,
> >  from ./include/linux/kobject.h:19,
> >  from ./include/linux/of.h:17,
> >  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> > arch/powerpc/platforms/pseries/papr_scm.c: In function 
> > ‘papr_scm_pmu_event_init’:
> > arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct 
> > perf_event’ has no member named ‘pmu’
> >   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >  ^~
> > ./include/linux/container_of.h:18:26: note: in definition of macro 
> > ‘container_of’
> >   void *__mptr = (void *)(ptr); \
> >   ^~~
> > arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of 
> > macro ‘to_nvdimm_pmu’
> >   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
> >   ^
> > In file included from ./include/linux/bits.h:22,
> >  from ./include/linux/bitops.h:6,
> >  from ./include/linux/of.h:15,
> >  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> >
> > Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
> > and disabling the papr_scm perf interface support incase this config
> > is not set
> >
> > Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") 
> > (Commit id
> > based on linux-next tree)
> > Signed-off-by: Kajol Jain 
> > ---
> >  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
>
> This is a bit messier than I would have liked mainly because it dumps
> a bunch of ifdefery into a C file contrary to coding style, "Wherever
> possible, don't use preprocessor conditionals (#if, #ifdef) in .c
> files". I would expect this all to move to an organization like:
>
> arch/powerpc/platforms/pseries/papr_scm/main.c
> arch/powerpc/platforms/pseries/papr_scm/perf.c
>
> ...and a new config symbol like:
>
> config PAPR_SCM_PERF
>depends on PAPR_SCM && PERF_EVENTS
>def_bool y
>
> ...with wrappers in header files to make everything compile away
> without any need for main.c to carry an ifdef.
>
> Can you turn a patch like that in the next couple days? Otherwise, I
> think if Linus saw me sending a late breaking compile fix that threw
> coding style out the window he'd have cause to just drop the pull
> request entirely.

Also, please base it on the current state of the libnvdimm-for-next
branch as -next includes some of the SMART health changes leading to
at least one conflict.

Re: [PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-21 Thread Dan Williams 
On Fri, Mar 18, 2022 at 4:42 AM Kajol Jain  wrote:
>
> The following build failure occures when CONFIG_PERF_EVENTS is not set
> as generic pmu functions are not visible in that scenario.
>
> arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ 
> has no member named ‘attr’
>  p->nvdimm_events_map[event->attr.config],
>^~
> In file included from ./include/linux/list.h:5,
>  from ./include/linux/kobject.h:19,
>  from ./include/linux/of.h:17,
>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
> arch/powerpc/platforms/pseries/papr_scm.c: In function 
> ‘papr_scm_pmu_event_init’:
> arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ 
> has no member named ‘pmu’
>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>  ^~
> ./include/linux/container_of.h:18:26: note: in definition of macro 
> ‘container_of’
>   void *__mptr = (void *)(ptr); \
>   ^~~
> arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of macro 
> ‘to_nvdimm_pmu’
>   struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
>   ^
> In file included from ./include/linux/bits.h:22,
>  from ./include/linux/bitops.h:6,
>  from ./include/linux/of.h:15,
>  from arch/powerpc/platforms/pseries/papr_scm.c:5:
>
> Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
> and disabling the papr_scm perf interface support incase this config
> is not set
>
> Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit 
> id
> based on linux-next tree)
> Signed-off-by: Kajol Jain 
> ---
>  arch/powerpc/platforms/pseries/papr_scm.c | 15 +++

This is a bit messier than I would have liked mainly because it dumps
a bunch of ifdefery into a C file contrary to coding style, "Wherever
possible, don't use preprocessor conditionals (#if, #ifdef) in .c
files". I would expect this all to move to an organization like:

arch/powerpc/platforms/pseries/papr_scm/main.c
arch/powerpc/platforms/pseries/papr_scm/perf.c

...and a new config symbol like:

config PAPR_SCM_PERF
   depends on PAPR_SCM && PERF_EVENTS
   def_bool y

...with wrappers in header files to make everything compile away
without any need for main.c to carry an ifdef.

Can you turn a patch like that in the next couple days? Otherwise, I
think if Linus saw me sending a late breaking compile fix that threw
coding style out the window he'd have cause to just drop the pull
request entirely.

[PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

2022-03-18 Thread Kajol Jain 
The following build failure occures when CONFIG_PERF_EVENTS is not set
as generic pmu functions are not visible in that scenario.

arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ 
has no member named ‘attr’
 p->nvdimm_events_map[event->attr.config],
   ^~
In file included from ./include/linux/list.h:5,
 from ./include/linux/kobject.h:19,
 from ./include/linux/of.h:17,
 from arch/powerpc/platforms/pseries/papr_scm.c:5:
arch/powerpc/platforms/pseries/papr_scm.c: In function 
‘papr_scm_pmu_event_init’:
arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ 
has no member named ‘pmu’
  struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
 ^~
./include/linux/container_of.h:18:26: note: in definition of macro 
‘container_of’
  void *__mptr = (void *)(ptr); \
  ^~~
arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of macro 
‘to_nvdimm_pmu’
  struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
  ^
In file included from ./include/linux/bits.h:22,
 from ./include/linux/bitops.h:6,
 from ./include/linux/of.h:15,
 from arch/powerpc/platforms/pseries/papr_scm.c:5:

Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
and disabling the papr_scm perf interface support incase this config
is not set

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit id
based on linux-next tree)
Signed-off-by: Kajol Jain 
---
 arch/powerpc/platforms/pseries/papr_scm.c | 15 +++
 1 file changed, 15 insertions(+)

---
- This fix patch changes are added and tested on top of linux-next tree
  on the 'next-20220315' branch.
---
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c 
b/arch/powerpc/platforms/pseries/papr_scm.c
index 4f65bc0fb861..ffe85aeb4127 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -19,7 +19,10 @@
 #include 
 #include 
 #include 
+
+#ifdef CONFIG_PERF_EVENTS
 #include 
+#endif
 
 #define BIND_ANY_ADDR (~0ul)
 
@@ -69,7 +72,9 @@
 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
 #define PAPR_SCM_PERF_STATS_VERSION 0x1
 
+#ifdef CONFIG_PERF_EVENTS
 #define to_nvdimm_pmu(_pmu)container_of(_pmu, struct nvdimm_pmu, pmu)
+#endif
 
 /* Struct holding a single performance metric */
 struct papr_scm_perf_stat {
@@ -127,8 +132,10 @@ struct papr_scm_priv {
/* The bits which needs to be overridden */
u64 health_bitmap_inject_mask;
 
+#ifdef CONFIG_PERF_EVENTS
 /* array to have event_code and stat_id mappings */
char **nvdimm_events_map;
+#endif
 };
 
 static int papr_scm_pmem_flush(struct nd_region *nd_region,
@@ -349,6 +356,7 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
return 0;
 }
 
+#ifdef CONFIG_PERF_EVENTS
 static int papr_scm_pmu_get_value(struct perf_event *event, struct device 
*dev, u64 *count)
 {
struct papr_scm_perf_stat *stat;
@@ -560,6 +568,7 @@ static void papr_scm_pmu_register(struct papr_scm_priv *p)
 pmu_err_print:
dev_info(>pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
 }
+#endif
 
 /*
  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
@@ -1537,7 +1546,10 @@ static int papr_scm_probe(struct platform_device *pdev)
goto err2;
 
platform_set_drvdata(pdev, p);
+
+#ifdef CONFIG_PERF_EVENTS
papr_scm_pmu_register(p);
+#endif
 
return 0;
 
@@ -1557,11 +1569,14 @@ static int papr_scm_remove(struct platform_device *pdev)
nvdimm_bus_unregister(p->bus);
drc_pmem_unbind(p);
 
+#ifdef CONFIG_PERF_EVENTS
if (pdev->archdata.priv)
unregister_nvdimm_pmu(pdev->archdata.priv);
 
pdev->archdata.priv = NULL;
kfree(p->nvdimm_events_map);
+#endif
+
kfree(p->bus_desc.provider_name);
kfree(p);
 
-- 
2.31.1