[PATCH v2 0/5] PM / devfreq: make module code usage consistent.

[PATCH v2 0/5] PM / devfreq: make module code usage consistent.

[Paul Gortmaker]

For anyone new to the underlying goal of this cleanup, we are trying to
not use module support for code that can never be built as a module since:

 (1) it is easy to accidentally write unused module_exit and remove code
 (2) it can be misleading when reading the source, thinking it can be
     modular when the Makefile and/or Kconfig prohibit it
 (3) it requires the include of the module.h header file which in turn
     includes nearly everything else, thus adding to CPP overhead.
 (4) it gets copied/replicated into other code and spreads like weeds.

We have already merged lots of these for mainline to date, so there
is really nothing new to see here, in terms of the type of change.

That said, devfreq changes seen here cover the following categories:

  -just replacement of modular macros with their non-modular
   equivalents that CPP would have inserted anyway

  -the removal of including module.h ; replaced with init.h
   and export.h as required based on whether the file used it.

  -the removal of the unused __exit functions that would never
   be called.

  -the conversion of 3 bool Kconfig to tristate to reflect the
   module author's intended or re-evaluated choice. (new in v2).

There are no initcall level changes here; everything stays at the level
of initcall it was previously; simply by the fact that it was not
using modular versions to begin with.

Build tested for arm and arm64 allmodconfig (for which all the drivers
touched here get coverage) on the linux-next tree from Fri. to ensure
no silly typos crept in.

The three drivers converted from bool to trisate are done as per
Chanwoo's request.  I have confirmed they build and modpost to a
.ko file but I don't have the hardware to test module loading
and/or any other runtime behaviour.

Paul.
---

[v2: convert patch #3,4,5 from demodule cleanup to one line conversion
     from bool to tristate; confirm =m after "allmodconfig"; retest.]

[v1: https://lkml.kernel.org/r/20160621051501.18396-1-paul.gortmaker@windriver.com ]

Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org

Paul Gortmaker (5):
  PM / devfreq: make devfreq explicitly non-modular
  PM / devfreq: make devfreq-event explicitly non-modular
  PM / devfreq: make exynos-bus ARM_EXYNOS_BUS_DEVFREQ tristate
  PM / devfreq: make event/exynos-nocp DEVFREQ_EVENT_EXYNOS_NOCP
    tristate
  PM / devfreq: make event/exynos-ppmu DEVFREQ_EVENT_EXYNOS_PPMU
    tristate

 drivers/devfreq/Kconfig         |  2 +-
 drivers/devfreq/devfreq-event.c | 12 +-----------
 drivers/devfreq/devfreq.c       | 13 +------------
 drivers/devfreq/event/Kconfig   |  4 ++--
 4 files changed, 5 insertions(+), 26 deletions(-)

-- 
2.8.4

[PATCH 1/5] PM / devfreq: make devfreq explicitly non-modular

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

menuconfig PM_DEVFREQ
      bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

This code wasn't using module_init, so we don't need to be concerned
with altering the initcall level here.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

We don't replace module.h with init.h since the file already has that.
But we do add export.h since this file does export some symbols.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/devfreq/devfreq.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index e92418facc92..3cc558df8295 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -15,7 +15,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/pm_opp.h>
@@ -1199,13 +1199,6 @@ static int __init devfreq_init(void)
 }
 subsys_initcall(devfreq_init);
 
-static void __exit devfreq_exit(void)
-{
-	class_destroy(devfreq_class);
-	destroy_workqueue(devfreq_wq);
-}
-module_exit(devfreq_exit);
-
 /*
  * The followings are helper functions for devfreq user device drivers with
  * OPP framework.
@@ -1471,7 +1464,3 @@ void devm_devfreq_unregister_notifier(struct device *dev,
 			       devm_devfreq_dev_match, devfreq));
 }
 EXPORT_SYMBOL(devm_devfreq_unregister_notifier);
-
-MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
-MODULE_DESCRIPTION("devfreq class support");
-MODULE_LICENSE("GPL");
-- 
2.8.4

Re: [PATCH 1/5] PM / devfreq: make devfreq explicitly non-modular

[Chanwoo Choi]

Hi Paul,

On 2016년 06월 26일 03:43, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> menuconfig PM_DEVFREQ
>       bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
> 
> This code wasn't using module_init, so we don't need to be concerned
> with altering the initcall level here.
> 
> We also delete the MODULE_LICENSE tag etc. since all that information
> is already contained at the top of the file in the comments.
> 
> We don't replace module.h with init.h since the file already has that.
> But we do add export.h since this file does export some symbols.
> 
> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/devfreq/devfreq.c | 13 +------------
>  1 file changed, 1 insertion(+), 12 deletions(-)

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

Regards,
Chanwoo Choi

[PATCH 2/5] PM / devfreq: make devfreq-event explicitly non-modular

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

menuconfig PM_DEVFREQ_EVENT
	bool "DEVFREQ-Event device Support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

This code wasn't using module_init, so we don't need to be concerned
with altering the initcall level here.

We don't replace module.h with init.h since the file already has that.
But we do add export.h since this file does export some symbols.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/devfreq/devfreq-event.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 39b048eda2ce..9aea2c7ecbe6 100644
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -15,7 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/err.h>
 #include <linux/init.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/of.h>
@@ -481,13 +481,3 @@ static int __init devfreq_event_init(void)
 	return 0;
 }
 subsys_initcall(devfreq_event_init);
-
-static void __exit devfreq_event_exit(void)
-{
-	class_destroy(devfreq_event_class);
-}
-module_exit(devfreq_event_exit);
-
-MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
-MODULE_DESCRIPTION("DEVFREQ-Event class support");
-MODULE_LICENSE("GPL");
-- 
2.8.4

Re: [PATCH 2/5] PM / devfreq: make devfreq-event explicitly non-modular

[Chanwoo Choi]

Hi Paul,

On 2016년 06월 26일 03:43, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> menuconfig PM_DEVFREQ_EVENT
> 	bool "DEVFREQ-Event device Support"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
> 
> This code wasn't using module_init, so we don't need to be concerned
> with altering the initcall level here.
> 
> We don't replace module.h with init.h since the file already has that.
> But we do add export.h since this file does export some symbols.
> 
> We also delete the MODULE_LICENSE tag etc. since all that information
> is already contained at the top of the file in the comments.
> 
> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Chanwoo Choi <cw00.choi@samsung.com>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/devfreq/devfreq-event.c | 12 +-----------
>  1 file changed, 1 insertion(+), 11 deletions(-)

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Regards,
Chanwoo Choi

[PATCH 3/5] PM / devfreq: make exynos-bus ARM_EXYNOS_BUS_DEVFREQ tristate

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

devfreq/Kconfig:config ARM_EXYNOS_BUS_DEVFREQ
devfreq/Kconfig:        bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"

...meaning that it currently is not being built as a module by anyone.

Rather than rip out the existing modular code, Chanwoo indicated
that he'd rather see the driver offered as tristate.

I don't have the hardware for runtime validation, so this change
is only validated for compile and modpost.

Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/devfreq/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 78dac0e9da11..a5be56ec57f2 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -75,7 +75,7 @@ config DEVFREQ_GOV_PASSIVE
 comment "DEVFREQ Drivers"
 
 config ARM_EXYNOS_BUS_DEVFREQ
-	bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
+	tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
 	depends on ARCH_EXYNOS
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	select DEVFREQ_GOV_PASSIVE
-- 
2.8.4

Re: [PATCH 3/5] PM / devfreq: make exynos-bus ARM_EXYNOS_BUS_DEVFREQ tristate

[Chanwoo Choi]

Hi Paul,

On 2016년 06월 26일 03:43, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> devfreq/Kconfig:config ARM_EXYNOS_BUS_DEVFREQ
> devfreq/Kconfig:        bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Rather than rip out the existing modular code, Chanwoo indicated
> that he'd rather see the driver offered as tristate.
> 
> I don't have the hardware for runtime validation, so this change
> is only validated for compile and modpost.
> 
> Cc: Chanwoo Choi <cw00.choi@samsung.com>
> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Kukjin Kim <kgene@kernel.org>
> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Cc: linux-pm@vger.kernel.org
> Cc: linux-samsung-soc@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/devfreq/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
> index 78dac0e9da11..a5be56ec57f2 100644
> --- a/drivers/devfreq/Kconfig
> +++ b/drivers/devfreq/Kconfig
> @@ -75,7 +75,7 @@ config DEVFREQ_GOV_PASSIVE
>  comment "DEVFREQ Drivers"
>  
>  config ARM_EXYNOS_BUS_DEVFREQ
> -	bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
> +	tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
>  	depends on ARCH_EXYNOS
>  	select DEVFREQ_GOV_SIMPLE_ONDEMAND
>  	select DEVFREQ_GOV_PASSIVE
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Regards,
Chanwoo Choi

[PATCH 4/5] PM / devfreq: make event/exynos-nocp DEVFREQ_EVENT_EXYNOS_NOCP tristate

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

event/Kconfig:config DEVFREQ_EVENT_EXYNOS_NOCP
event/Kconfig:  bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"

...meaning that it currently is not being built as a module by anyone.

Rather than rip out the existing modular code, Chanwoo indicated
that he'd rather see the driver offered as tristate.

I don't have the hardware for runtime validation, so this change
is only validated for compile and modpost.

Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/devfreq/event/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
index 1e8b4f469f38..96ea29d1ede5 100644
--- a/drivers/devfreq/event/Kconfig
+++ b/drivers/devfreq/event/Kconfig
@@ -14,7 +14,7 @@ menuconfig PM_DEVFREQ_EVENT
 if PM_DEVFREQ_EVENT
 
 config DEVFREQ_EVENT_EXYNOS_NOCP
-	bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
+	tristate "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
 	depends on ARCH_EXYNOS
 	select PM_OPP
 	help
-- 
2.8.4

Re: [PATCH 4/5] PM / devfreq: make event/exynos-nocp DEVFREQ_EVENT_EXYNOS_NOCP tristate

[Chanwoo Choi]

Hi Paul,

On 2016년 06월 26일 03:43, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> event/Kconfig:config DEVFREQ_EVENT_EXYNOS_NOCP
> event/Kconfig:  bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Rather than rip out the existing modular code, Chanwoo indicated
> that he'd rather see the driver offered as tristate.
> 
> I don't have the hardware for runtime validation, so this change
> is only validated for compile and modpost.
> 
> Cc: Chanwoo Choi <cw00.choi@samsung.com>
> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Kukjin Kim <kgene@kernel.org>
> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Cc: linux-pm@vger.kernel.org
> Cc: linux-samsung-soc@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/devfreq/event/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
> index 1e8b4f469f38..96ea29d1ede5 100644
> --- a/drivers/devfreq/event/Kconfig
> +++ b/drivers/devfreq/event/Kconfig
> @@ -14,7 +14,7 @@ menuconfig PM_DEVFREQ_EVENT
>  if PM_DEVFREQ_EVENT
>  
>  config DEVFREQ_EVENT_EXYNOS_NOCP
> -	bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
> +	tristate "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
>  	depends on ARCH_EXYNOS
>  	select PM_OPP
>  	help
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Regards,
Chanwoo Choi

[PATCH 5/5] PM / devfreq: make event/exynos-ppmu DEVFREQ_EVENT_EXYNOS_PPMU tristate

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

config DEVFREQ_EVENT_EXYNOS_PPMU
  bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"

...meaning that it currently is not being built as a module by anyone.

Rather than rip out the existing modular code, Chanwoo indicated
that he'd rather see the driver offered as tristate.

I don't have the hardware for runtime validation, so this change
is only validated for compile and modpost.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/devfreq/event/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
index 96ea29d1ede5..eb6f74a2b6b9 100644
--- a/drivers/devfreq/event/Kconfig
+++ b/drivers/devfreq/event/Kconfig
@@ -22,7 +22,7 @@ config DEVFREQ_EVENT_EXYNOS_NOCP
 	  (Network on Chip) Probe counters to measure the bandwidth of AXI bus.
 
 config DEVFREQ_EVENT_EXYNOS_PPMU
-	bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
+	tristate "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
 	depends on ARCH_EXYNOS
 	select PM_OPP
 	help
-- 
2.8.4

Re: [PATCH 5/5] PM / devfreq: make event/exynos-ppmu DEVFREQ_EVENT_EXYNOS_PPMU tristate

[Chanwoo Choi]

Hi Paul,

On 2016년 06월 26일 03:43, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> config DEVFREQ_EVENT_EXYNOS_PPMU
>   bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Rather than rip out the existing modular code, Chanwoo indicated
> that he'd rather see the driver offered as tristate.
> 
> I don't have the hardware for runtime validation, so this change
> is only validated for compile and modpost.
> 
> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Kukjin Kim <kgene@kernel.org>
> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Cc: Chanwoo Choi <cw00.choi@samsung.com>
> Cc: linux-pm@vger.kernel.org
> Cc: linux-samsung-soc@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/devfreq/event/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
> index 96ea29d1ede5..eb6f74a2b6b9 100644
> --- a/drivers/devfreq/event/Kconfig
> +++ b/drivers/devfreq/event/Kconfig
> @@ -22,7 +22,7 @@ config DEVFREQ_EVENT_EXYNOS_NOCP
>  	  (Network on Chip) Probe counters to measure the bandwidth of AXI bus.
>  
>  config DEVFREQ_EVENT_EXYNOS_PPMU
> -	bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
> +	tristate "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
>  	depends on ARCH_EXYNOS
>  	select PM_OPP
>  	help
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Regards,
Chanwoo Choi