diff mbox series

[RFC,v4,2/2] clk: Use devm_add in managed functions

Message ID e88ca46a-799d-9c86-f2d2-6284eb3c3419@free.fr (mailing list archive)
State New, archived
Headers show
Series Small devm helper for devm implementations | expand

Commit Message

Marc Gonzalez Feb. 26, 2020, 3:51 p.m. UTC 
Using the helper produces simpler code, and smaller object size.
E.g. with gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu:

    text           data     bss     dec     hex filename
-   1708             80       0    1788     6fc drivers/clk/clk-devres.o
+   1524             80       0    1604     644 drivers/clk/clk-devres.o

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
---
 drivers/clk/clk-devres.c | 101 ++++++++++++++-------------------------
 1 file changed, 37 insertions(+), 64 deletions(-)

Comments

Geert Uytterhoeven Feb. 27, 2020, 1:36 p.m. UTC | #1 
Hi Marc,

Thanks for your patch!

On Wed, Feb 26, 2020 at 4:55 PM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
> Using the helper produces simpler code, and smaller object size.
> E.g. with gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu:
>
>     text           data     bss     dec     hex filename
> -   1708             80       0    1788     6fc drivers/clk/clk-devres.o
> +   1524             80       0    1604     644 drivers/clk/clk-devres.o

And the size reduction could have been even more ;-)

> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>

> --- a/drivers/clk/clk-devres.c
> +++ b/drivers/clk/clk-devres.c

> @@ -55,25 +51,17 @@ static void devm_clk_bulk_release(struct device *dev, void *res)
>  static int __devm_clk_bulk_get(struct device *dev, int num_clks,
>                                struct clk_bulk_data *clks, bool optional)
>  {
> -       struct clk_bulk_devres *devres;
>         int ret;
>
> -       devres = devres_alloc(devm_clk_bulk_release,
> -                             sizeof(*devres), GFP_KERNEL);
> -       if (!devres)
> -               return -ENOMEM;
> -
>         if (optional)
>                 ret = clk_bulk_get_optional(dev, num_clks, clks);
>         else
>                 ret = clk_bulk_get(dev, num_clks, clks);
> -       if (!ret) {
> -               devres->clks = clks;
> -               devres->num_clks = num_clks;
> -               devres_add(dev, devres);
> -       } else {
> -               devres_free(devres);
> -       }
> +
> +       if (ret)
> +               return ret;
> +
> +       ret = devm_vadd(dev, my_clk_bulk_put, clk_bulk_args, num_clks, clks);
>
>         return ret;

return devm_vadd(...);

>  }

> @@ -128,30 +109,22 @@ static int devm_clk_match(struct device *dev, void *res, void *data)
>
>  void devm_clk_put(struct device *dev, struct clk *clk)
>  {
> -       int ret;
> -
> -       ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
> -
> -       WARN_ON(ret);
> +       WARN_ON(devres_release(dev, my_clk_put, devm_clk_match, clk));

Getting rid of "ret" is an unrelated change, which actually increases
kernel size, as the WARN_ON() parameter is stringified for the warning
message.

The rest looks good, so with the above fixed:
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert
Marc Gonzalez March 2, 2020, 10:01 a.m. UTC | #2 
On 27/02/2020 14:36, Geert Uytterhoeven wrote:

> Hi Marc,
> 
> Thanks for your patch!
> 
> On Wed, Feb 26, 2020 at 4:55 PM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
>> Using the helper produces simpler code, and smaller object size.
>> E.g. with gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu:
>>
>>     text           data     bss     dec     hex filename
>> -   1708             80       0    1788     6fc drivers/clk/clk-devres.o
>> +   1524             80       0    1604     644 drivers/clk/clk-devres.o
> 
> And the size reduction could have been even more ;-)

I'll see what I can do! ;-)

I have another patch with even smaller object code, but it requires
C11 to be well-defined (memcmp the whole struct, which requires zeros
in the padding holes).


>> --- a/drivers/clk/clk-devres.c
>> +++ b/drivers/clk/clk-devres.c
> 
>> @@ -55,25 +51,17 @@ static void devm_clk_bulk_release(struct device *dev, void *res)
>>  static int __devm_clk_bulk_get(struct device *dev, int num_clks,
>>                                struct clk_bulk_data *clks, bool optional)
>>  {
>> -       struct clk_bulk_devres *devres;
>>         int ret;
>>
>> -       devres = devres_alloc(devm_clk_bulk_release,
>> -                             sizeof(*devres), GFP_KERNEL);
>> -       if (!devres)
>> -               return -ENOMEM;
>> -
>>         if (optional)
>>                 ret = clk_bulk_get_optional(dev, num_clks, clks);
>>         else
>>                 ret = clk_bulk_get(dev, num_clks, clks);
>> -       if (!ret) {
>> -               devres->clks = clks;
>> -               devres->num_clks = num_clks;
>> -               devres_add(dev, devres);
>> -       } else {
>> -               devres_free(devres);
>> -       }
>> +
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = devm_vadd(dev, my_clk_bulk_put, clk_bulk_args, num_clks, clks);
>>
>>         return ret;
> 
> return devm_vadd(...);

If you think that makes it look better, I'll make the change!


>> @@ -128,30 +109,22 @@ static int devm_clk_match(struct device *dev, void *res, void *data)
>>
>>  void devm_clk_put(struct device *dev, struct clk *clk)
>>  {
>> -       int ret;
>> -
>> -       ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
>> -
>> -       WARN_ON(ret);
>> +       WARN_ON(devres_release(dev, my_clk_put, devm_clk_match, clk));
> 
> Getting rid of "ret" is an unrelated change, which actually increases
> kernel size, as the WARN_ON() parameter is stringified for the warning
> message.

Weird... Are you sure about that? I built the preprocessed file,
and it didn't appear to be so.

#ifndef WARN_ON
#define WARN_ON(condition) ({						\
	int __ret_warn_on = !!(condition);				\
	if (unlikely(__ret_warn_on))					\
		__WARN();						\
	unlikely(__ret_warn_on);					\
})
#endif

Maybe you were thinking of i915's WARN_ON?

#define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")

Regards.
Geert Uytterhoeven March 2, 2020, 10:14 a.m. UTC | #3 
Hi Marc,

On Mon, Mar 2, 2020 at 11:01 AM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
> On 27/02/2020 14:36, Geert Uytterhoeven wrote:
> > On Wed, Feb 26, 2020 at 4:55 PM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
> >> Using the helper produces simpler code, and smaller object size.

> >> --- a/drivers/clk/clk-devres.c
> >> +++ b/drivers/clk/clk-devres.c

> >> @@ -128,30 +109,22 @@ static int devm_clk_match(struct device *dev, void *res, void *data)
> >>
> >>  void devm_clk_put(struct device *dev, struct clk *clk)
> >>  {
> >> -       int ret;
> >> -
> >> -       ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
> >> -
> >> -       WARN_ON(ret);
> >> +       WARN_ON(devres_release(dev, my_clk_put, devm_clk_match, clk));
> >
> > Getting rid of "ret" is an unrelated change, which actually increases
> > kernel size, as the WARN_ON() parameter is stringified for the warning
> > message.
>
> Weird... Are you sure about that? I built the preprocessed file,
> and it didn't appear to be so.
>
> #ifndef WARN_ON
> #define WARN_ON(condition) ({                                           \
>         int __ret_warn_on = !!(condition);                              \
>         if (unlikely(__ret_warn_on))                                    \
>                 __WARN();                                               \
>         unlikely(__ret_warn_on);                                        \
> })
> #endif
>
> Maybe you were thinking of i915's WARN_ON?
>
> #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")

Oops, you're right.  I got trapped again by an override of a standard macro
(IMHO this should be removed).

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index be160764911b..3f4b200b5328 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -4,26 +4,22 @@ 
 #include <linux/export.h>
 #include <linux/gfp.h>
 
-static void devm_clk_release(struct device *dev, void *res)
+static void my_clk_put(struct device *dev, void *res)
 {
 	clk_put(*(struct clk **)res);
 }
 
 struct clk *devm_clk_get(struct device *dev, const char *id)
 {
-	struct clk **ptr, *clk;
-
-	ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return ERR_PTR(-ENOMEM);
-
-	clk = clk_get(dev, id);
-	if (!IS_ERR(clk)) {
-		*ptr = clk;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
-	}
+	int ret;
+	struct clk *clk = clk_get(dev, id);
+
+	if (IS_ERR(clk))
+		return clk;
+
+	ret = devm_add(dev, my_clk_put, &clk, sizeof(clk));
+	if (ret)
+		return ERR_PTR(ret);
 
 	return clk;
 }
@@ -40,14 +36,14 @@  struct clk *devm_clk_get_optional(struct device *dev, const char *id)
 }
 EXPORT_SYMBOL(devm_clk_get_optional);
 
-struct clk_bulk_devres {
-	struct clk_bulk_data *clks;
+struct clk_bulk_args {
 	int num_clks;
+	struct clk_bulk_data *clks;
 };
 
-static void devm_clk_bulk_release(struct device *dev, void *res)
+static void my_clk_bulk_put(struct device *dev, void *res)
 {
-	struct clk_bulk_devres *devres = res;
+	struct clk_bulk_args *devres = res;
 
 	clk_bulk_put(devres->num_clks, devres->clks);
 }
@@ -55,25 +51,17 @@  static void devm_clk_bulk_release(struct device *dev, void *res)
 static int __devm_clk_bulk_get(struct device *dev, int num_clks,
 			       struct clk_bulk_data *clks, bool optional)
 {
-	struct clk_bulk_devres *devres;
 	int ret;
 
-	devres = devres_alloc(devm_clk_bulk_release,
-			      sizeof(*devres), GFP_KERNEL);
-	if (!devres)
-		return -ENOMEM;
-
 	if (optional)
 		ret = clk_bulk_get_optional(dev, num_clks, clks);
 	else
 		ret = clk_bulk_get(dev, num_clks, clks);
-	if (!ret) {
-		devres->clks = clks;
-		devres->num_clks = num_clks;
-		devres_add(dev, devres);
-	} else {
-		devres_free(devres);
-	}
+
+	if (ret)
+		return ret;
+
+	ret = devm_vadd(dev, my_clk_bulk_put, clk_bulk_args, num_clks, clks);
 
 	return ret;
 }
@@ -95,24 +83,17 @@  EXPORT_SYMBOL_GPL(devm_clk_bulk_get_optional);
 int __must_check devm_clk_bulk_get_all(struct device *dev,
 				       struct clk_bulk_data **clks)
 {
-	struct clk_bulk_devres *devres;
 	int ret;
+	int num_clks = clk_bulk_get_all(dev, clks);
 
-	devres = devres_alloc(devm_clk_bulk_release,
-			      sizeof(*devres), GFP_KERNEL);
-	if (!devres)
-		return -ENOMEM;
-
-	ret = clk_bulk_get_all(dev, &devres->clks);
-	if (ret > 0) {
-		*clks = devres->clks;
-		devres->num_clks = ret;
-		devres_add(dev, devres);
-	} else {
-		devres_free(devres);
-	}
+	if (num_clks <= 0)
+		return num_clks;
 
-	return ret;
+	ret = devm_vadd(dev, my_clk_bulk_put, clk_bulk_args, num_clks, *clks);
+	if (ret)
+		return ret;
+
+	return num_clks;
 }
 EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all);
 
@@ -128,30 +109,22 @@  static int devm_clk_match(struct device *dev, void *res, void *data)
 
 void devm_clk_put(struct device *dev, struct clk *clk)
 {
-	int ret;
-
-	ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
-
-	WARN_ON(ret);
+	WARN_ON(devres_release(dev, my_clk_put, devm_clk_match, clk));
 }
 EXPORT_SYMBOL(devm_clk_put);
 
 struct clk *devm_get_clk_from_child(struct device *dev,
 				    struct device_node *np, const char *con_id)
 {
-	struct clk **ptr, *clk;
-
-	ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return ERR_PTR(-ENOMEM);
-
-	clk = of_clk_get_by_name(np, con_id);
-	if (!IS_ERR(clk)) {
-		*ptr = clk;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
-	}
+	int ret;
+	struct clk *clk = of_clk_get_by_name(np, con_id);
+
+	if (IS_ERR(clk))
+		return clk;
+
+	ret = devm_add(dev, my_clk_put, &clk, sizeof(clk));
+	if (ret)
+		return ERR_PTR(ret);
 
 	return clk;
 }