PM: Add EXPORT macros for exporting PM functions

Message ID 20230213132048.2612961-1-rf@opensource.cirrus.com
State New
Headers
Series PM: Add EXPORT macros for exporting PM functions |

Commit Message

Richard Fitzgerald Feb. 13, 2023, 1:20 p.m. UTC
  Add a set of macros for exporting functions only if CONFIG_PM
is enabled.

The naming follows the style of the standard EXPORT_SYMBOL_*()
macros that they replace.

Sometimes a module wants to export PM functions directly to other
drivers, not a complete struct dev_pm_ops. A typical example is
where a core library exports the generic (shared) implementation
and calling code wraps one or more of these in custom code.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 include/linux/pm.h | 8 ++++++++
 1 file changed, 8 insertions(+)
  

Comments

Rafael J. Wysocki Feb. 13, 2023, 3:43 p.m. UTC | #1
On Mon, Feb 13, 2023 at 2:20 PM Richard Fitzgerald
<rf@opensource.cirrus.com> wrote:
>
> Add a set of macros for exporting functions only if CONFIG_PM
> is enabled.
>
> The naming follows the style of the standard EXPORT_SYMBOL_*()
> macros that they replace.
>
> Sometimes a module wants to export PM functions directly to other
> drivers, not a complete struct dev_pm_ops. A typical example is
> where a core library exports the generic (shared) implementation
> and calling code wraps one or more of these in custom code.
>
> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
> ---
>  include/linux/pm.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/pm.h b/include/linux/pm.h
> index 93cd34f00822..21618f7087f8 100644
> --- a/include/linux/pm.h
> +++ b/include/linux/pm.h
> @@ -379,9 +379,17 @@ const struct dev_pm_ops name = { \
>         const struct dev_pm_ops name;                                   \
>         __EXPORT_SYMBOL(name, sec, ns);                                 \
>         const struct dev_pm_ops name
> +#define EXPORT_PM_FN(name)             EXPORT_SYMBOL(name)
> +#define EXPORT_PM_FN_GPL(name)         EXPORT_SYMBOL_GPL(name)
> +#define EXPORT_PM_FN_NS(name, ns)      EXPORT_SYMBOL_NS(name, ns)
> +#define EXPORT_PM_FN_NS_GPL(name, ns)  EXPORT_SYMBOL_NS_GPL(name, ns)

Why are the non-GPL variants needed?

>  #else
>  #define _EXPORT_DEV_PM_OPS(name, sec, ns)                              \
>         static __maybe_unused const struct dev_pm_ops __static_##name
> +#define EXPORT_PM_FN(name)
> +#define EXPORT_PM_FN_GPL(name)
> +#define EXPORT_PM_FN_NS(name, ns)
> +#define EXPORT_PM_FN_NS_GPL(name, ns)
>  #endif
>
>  #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")
> --
> 2.30.2
>
  
Richard Fitzgerald Feb. 13, 2023, 3:50 p.m. UTC | #2
On 13/02/2023 15:43, Rafael J. Wysocki wrote:
> On Mon, Feb 13, 2023 at 2:20 PM Richard Fitzgerald
> <rf@opensource.cirrus.com> wrote:
>>
>> Add a set of macros for exporting functions only if CONFIG_PM
>> is enabled.
>>
>> The naming follows the style of the standard EXPORT_SYMBOL_*()
>> macros that they replace.
>>
>> Sometimes a module wants to export PM functions directly to other
>> drivers, not a complete struct dev_pm_ops. A typical example is
>> where a core library exports the generic (shared) implementation
>> and calling code wraps one or more of these in custom code.
>>
>> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
>> ---
>>   include/linux/pm.h | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/include/linux/pm.h b/include/linux/pm.h
>> index 93cd34f00822..21618f7087f8 100644
>> --- a/include/linux/pm.h
>> +++ b/include/linux/pm.h
>> @@ -379,9 +379,17 @@ const struct dev_pm_ops name = { \
>>          const struct dev_pm_ops name;                                   \
>>          __EXPORT_SYMBOL(name, sec, ns);                                 \
>>          const struct dev_pm_ops name
>> +#define EXPORT_PM_FN(name)             EXPORT_SYMBOL(name)
>> +#define EXPORT_PM_FN_GPL(name)         EXPORT_SYMBOL_GPL(name)
>> +#define EXPORT_PM_FN_NS(name, ns)      EXPORT_SYMBOL_NS(name, ns)
>> +#define EXPORT_PM_FN_NS_GPL(name, ns)  EXPORT_SYMBOL_NS_GPL(name, ns)
> 
> Why are the non-GPL variants needed?
>

I did all four because there are all four variants of EXPORT_DEV_PM_OPS.
Why are the non-GPL variants of EXPORT_DEV_PM_OPS needed?

I can remove the non-GPL variants of my macros.

>>   #else
>>   #define _EXPORT_DEV_PM_OPS(name, sec, ns)                              \
>>          static __maybe_unused const struct dev_pm_ops __static_##name
>> +#define EXPORT_PM_FN(name)
>> +#define EXPORT_PM_FN_GPL(name)
>> +#define EXPORT_PM_FN_NS(name, ns)
>> +#define EXPORT_PM_FN_NS_GPL(name, ns)
>>   #endif
>>
>>   #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")
>> --
>> 2.30.2
>>
  
Rafael J. Wysocki Feb. 13, 2023, 3:57 p.m. UTC | #3
On Mon, Feb 13, 2023 at 4:50 PM Richard Fitzgerald
<rf@opensource.cirrus.com> wrote:
>
> On 13/02/2023 15:43, Rafael J. Wysocki wrote:
> > On Mon, Feb 13, 2023 at 2:20 PM Richard Fitzgerald
> > <rf@opensource.cirrus.com> wrote:
> >>
> >> Add a set of macros for exporting functions only if CONFIG_PM
> >> is enabled.
> >>
> >> The naming follows the style of the standard EXPORT_SYMBOL_*()
> >> macros that they replace.
> >>
> >> Sometimes a module wants to export PM functions directly to other
> >> drivers, not a complete struct dev_pm_ops. A typical example is
> >> where a core library exports the generic (shared) implementation
> >> and calling code wraps one or more of these in custom code.
> >>
> >> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
> >> ---
> >>   include/linux/pm.h | 8 ++++++++
> >>   1 file changed, 8 insertions(+)
> >>
> >> diff --git a/include/linux/pm.h b/include/linux/pm.h
> >> index 93cd34f00822..21618f7087f8 100644
> >> --- a/include/linux/pm.h
> >> +++ b/include/linux/pm.h
> >> @@ -379,9 +379,17 @@ const struct dev_pm_ops name = { \
> >>          const struct dev_pm_ops name;                                   \
> >>          __EXPORT_SYMBOL(name, sec, ns);                                 \
> >>          const struct dev_pm_ops name
> >> +#define EXPORT_PM_FN(name)             EXPORT_SYMBOL(name)
> >> +#define EXPORT_PM_FN_GPL(name)         EXPORT_SYMBOL_GPL(name)
> >> +#define EXPORT_PM_FN_NS(name, ns)      EXPORT_SYMBOL_NS(name, ns)
> >> +#define EXPORT_PM_FN_NS_GPL(name, ns)  EXPORT_SYMBOL_NS_GPL(name, ns)
> >
> > Why are the non-GPL variants needed?
> >
>
> I did all four because there are all four variants of EXPORT_DEV_PM_OPS.
> Why are the non-GPL variants of EXPORT_DEV_PM_OPS needed?

They aren't or at least they should not be needed in the mainline.

> I can remove the non-GPL variants of my macros.

Yes, please!

> >>   #else
> >>   #define _EXPORT_DEV_PM_OPS(name, sec, ns)                              \
> >>          static __maybe_unused const struct dev_pm_ops __static_##name
> >> +#define EXPORT_PM_FN(name)
> >> +#define EXPORT_PM_FN_GPL(name)
> >> +#define EXPORT_PM_FN_NS(name, ns)
> >> +#define EXPORT_PM_FN_NS_GPL(name, ns)
> >>   #endif
> >>
> >>   #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")
> >> --
> >> 2.30.2
> >>
  

Patch

diff --git a/include/linux/pm.h b/include/linux/pm.h
index 93cd34f00822..21618f7087f8 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -379,9 +379,17 @@  const struct dev_pm_ops name = { \
 	const struct dev_pm_ops name;					\
 	__EXPORT_SYMBOL(name, sec, ns);					\
 	const struct dev_pm_ops name
+#define EXPORT_PM_FN(name)		EXPORT_SYMBOL(name)
+#define EXPORT_PM_FN_GPL(name)		EXPORT_SYMBOL_GPL(name)
+#define EXPORT_PM_FN_NS(name, ns)	EXPORT_SYMBOL_NS(name, ns)
+#define EXPORT_PM_FN_NS_GPL(name, ns)	EXPORT_SYMBOL_NS_GPL(name, ns)
 #else
 #define _EXPORT_DEV_PM_OPS(name, sec, ns)				\
 	static __maybe_unused const struct dev_pm_ops __static_##name
+#define EXPORT_PM_FN(name)
+#define EXPORT_PM_FN_GPL(name)
+#define EXPORT_PM_FN_NS(name, ns)
+#define EXPORT_PM_FN_NS_GPL(name, ns)
 #endif
 
 #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")