Re: [PATCH] clk: define to_clk_regmap() as inline function

[Jerome Brunet]

On Mon 26 Oct 2020 at 17:13, Arnd Bergmann <arnd@xxxxxxxxxx> wrote:

> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Nesting container_of() causes warnings with W=2, which is
> annoying if it happens in headers and fills the build log
> like:
>
> In file included from drivers/clk/qcom/clk-alpha-pll.c:6:
> drivers/clk/qcom/clk-alpha-pll.c: In function 'clk_alpha_pll_hwfsm_enable':
> include/linux/kernel.h:852:8: warning: declaration of '__mptr' shadows a previous local [-Wshadow]
>   852 |  void *__mptr = (void *)(ptr);     \
>       |        ^~~~~~
> drivers/clk/qcom/clk-alpha-pll.c:155:31: note: in expansion of macro 'container_of'
>   155 | #define to_clk_alpha_pll(_hw) container_of(to_clk_regmap(_hw), \
>       |                               ^~~~~~~~~~~~
> drivers/clk/qcom/clk-regmap.h:27:28: note: in expansion of macro 'container_of'
>    27 | #define to_clk_regmap(_hw) container_of(_hw, struct clk_regmap, hw)
>       |                            ^~~~~~~~~~~~
> drivers/clk/qcom/clk-alpha-pll.c:155:44: note: in expansion of macro 'to_clk_regmap'
>   155 | #define to_clk_alpha_pll(_hw) container_of(to_clk_regmap(_hw), \
>       |                                            ^~~~~~~~~~~~~
> drivers/clk/qcom/clk-alpha-pll.c:254:30: note: in expansion of macro 'to_clk_alpha_pll'
>   254 |  struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>       |                              ^~~~~~~~~~~~~~~~
> include/linux/kernel.h:852:8: note: shadowed declaration is here
>   852 |  void *__mptr = (void *)(ptr);     \
>       |        ^~~~~~
>
> Redefine two copies of the to_clk_regmap() macro as inline functions
> to avoid a lot of these.
>
> Fixes: ea11dda9e091 ("clk: meson: add regmap clocks")
> Fixes: 085d7a455444 ("clk: qcom: Add a regmap type clock struct")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Acked-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>

> ---
>  drivers/clk/meson/clk-regmap.h | 5 ++++-
>  drivers/clk/qcom/clk-regmap.h  | 6 +++++-
>  2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
> index c4a39604cffd..e365312da54e 100644
> --- a/drivers/clk/meson/clk-regmap.h
> +++ b/drivers/clk/meson/clk-regmap.h
> @@ -26,7 +26,10 @@ struct clk_regmap {
>  	void		*data;
>  };
>  
> -#define to_clk_regmap(_hw) container_of(_hw, struct clk_regmap, hw)
> +static inline struct clk_regmap *to_clk_regmap(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct clk_regmap, hw);
> +}
>  
>  /**
>   * struct clk_regmap_gate_data - regmap backed gate specific data
> diff --git a/drivers/clk/qcom/clk-regmap.h b/drivers/clk/qcom/clk-regmap.h
> index 6cfc1bccb255..14ec659a3a77 100644
> --- a/drivers/clk/qcom/clk-regmap.h
> +++ b/drivers/clk/qcom/clk-regmap.h
> @@ -24,7 +24,11 @@ struct clk_regmap {
>  	unsigned int enable_mask;
>  	bool enable_is_inverted;
>  };
> -#define to_clk_regmap(_hw) container_of(_hw, struct clk_regmap, hw)
> +
> +static inline struct clk_regmap *to_clk_regmap(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct clk_regmap, hw);
> +}
>  
>  int clk_is_enabled_regmap(struct clk_hw *hw);
>  int clk_enable_regmap(struct clk_hw *hw);