Re: [PATCH 1/2] linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>
From: Paul Cercueil
Date: Fri Apr 09 2021 - 05:38:55 EST
Le ven. 9 avril 2021 à 17:30, Masahiro Yamada <masahiroy@xxxxxxxxxx> a
écrit :
On Fri, Apr 9, 2021 at 5:15 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx>
wrote:
Hi Masahiro,
Le ven. 9 avril 2021 à 5:58, Masahiro Yamada
<masahiroy@xxxxxxxxxx> a
écrit :
> <linux/kconfig.h> is included from all the kernel-space source
files,
> including C, assembly, linker scripts. It is intended to contain
> minimal
> set of macros to evaluate CONFIG options.
>
> IF_ENABLED() is an intruder here because (x ? y : z) is C code,
which
> should not be included from assembly files or linker scripts.
>
> Also, <linux/kconfig.h> is no longer self-contained because NULL
is
> defined in <linux/stddef.h>.
>
> Move IF_ENABLED() out to <linux/kernel.h> as PTR_IF().
>
> PTR_IF(IS_ENABLED(CONFIG_FOO), ...) is slightly longer than
> IF_ENABLED(CONFIG_FOO, ...), but it is not a big deal because
> sub-systems often define dedicated macros such as of_match_ptr(),
> pm_ptr() etc. for common use-cases.
What's the idea behind changing IF_ENABLED() to PTR_IF()? You didn't
explain that. What's wrong with IF_ENABLED()?
PTR_IF() is a more generalized variant, which I believe is
a better fit in <linux/kernel.h>
The first parameter does not need to be a CONFIG option,
but any expression.
Fair enough, but we could still have IF_ENABLED as a specialized
variant of PTR_IF:
#define IF_ENABLED(cfg, ptr) PTR_IF(IS_ENABLED(cfg), (ptr))
-Paul
Cheers,
-Paul
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> drivers/pinctrl/pinctrl-ingenic.c | 20 ++++++++++----------
> include/linux/kconfig.h | 6 ------
> include/linux/kernel.h | 2 ++
> 3 files changed, 12 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-ingenic.c
> b/drivers/pinctrl/pinctrl-ingenic.c
> index f2746125b077..b21e2ae4528d 100644
> --- a/drivers/pinctrl/pinctrl-ingenic.c
> +++ b/drivers/pinctrl/pinctrl-ingenic.c
> @@ -2496,43 +2496,43 @@ static int __init
> ingenic_pinctrl_probe(struct platform_device *pdev)
> static const struct of_device_id ingenic_pinctrl_of_match[] = {
> {
> .compatible = "ingenic,jz4740-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4740,
&jz4740_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4740),
&jz4740_chip_info)
> },
> {
> .compatible = "ingenic,jz4725b-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4725B,
&jz4725b_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4725B),
&jz4725b_chip_info)
> },
> {
> .compatible = "ingenic,jz4760-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4760,
&jz4760_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4760),
&jz4760_chip_info)
> },
> {
> .compatible = "ingenic,jz4760b-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4760,
&jz4760_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4760),
&jz4760_chip_info)
> },
> {
> .compatible = "ingenic,jz4770-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4770,
&jz4770_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4770),
&jz4770_chip_info)
> },
> {
> .compatible = "ingenic,jz4780-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_JZ4780,
&jz4780_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_JZ4780),
&jz4780_chip_info)
> },
> {
> .compatible = "ingenic,x1000-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_X1000,
&x1000_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_X1000),
&x1000_chip_info)
> },
> {
> .compatible = "ingenic,x1000e-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_X1000,
&x1000_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_X1000),
&x1000_chip_info)
> },
> {
> .compatible = "ingenic,x1500-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_X1500,
&x1500_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_X1500),
&x1500_chip_info)
> },
> {
> .compatible = "ingenic,x1830-pinctrl",
> - .data = IF_ENABLED(CONFIG_MACH_X1830,
&x1830_chip_info)
> + .data = PTR_IF(IS_ENABLED(CONFIG_MACH_X1830),
&x1830_chip_info)
> },
> { /* sentinel */ },
> };
> diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
> index 24a59cb06963..cc8fa109cfa3 100644
> --- a/include/linux/kconfig.h
> +++ b/include/linux/kconfig.h
> @@ -70,10 +70,4 @@
> */
> #define IS_ENABLED(option) __or(IS_BUILTIN(option),
> IS_MODULE(option))
>
> -/*
> - * IF_ENABLED(CONFIG_FOO, ptr) evaluates to (ptr) if CONFIG_FOO
is
> set to 'y'
> - * or 'm', NULL otherwise.
> - */
> -#define IF_ENABLED(option, ptr) (IS_ENABLED(option) ? (ptr) :
NULL)
> -
> #endif /* __LINUX_KCONFIG_H */
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 5b7ed6dc99ac..8685ca4cf287 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -38,6 +38,8 @@
> #define PTR_ALIGN_DOWN(p, a) ((typeof(p))ALIGN_DOWN((unsigned
> long)(p), (a)))
> #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) -
1)) == 0)
>
> +#define PTR_IF(cond, ptr) ((cond) ? (ptr) : NULL)
> +
> /* generic data direction definitions */
> #define READ 0
> #define WRITE 1
> --
> 2.27.0
>
--
Best Regards
Masahiro Yamada