[Intel-xe] [PATCH v2 13/31] maple_tree: split up MA_STATE() macro

[Thomas Hellström]

On 5/2/23 02:17, Matthew Brost wrote:
> From: Danilo Krummrich <dakr at redhat.com>
>
> Split up the MA_STATE() macro such that components using the maple tree
> can easily inherit from struct ma_state and build custom tree walk
> macros to hide their internals from users.

I might misunderstand the patch, but isn't the real purpose to provide 
an MA_STATE initializer,and the way to achieve that is to split up the 
MA_STATE macro?

>
> Example:
>
> struct sample_iterator {
>          struct ma_state mas;
>          struct sample_mgr *mgr;
> };
>
> \#define SAMPLE_ITERATOR(name, __mgr, start)                    \
>          struct sample_iterator name = {                         \
>                  .mas = MA_STATE_INIT(&(__mgr)->mt, start, 0),   \
>                  .mgr = __mgr,                                   \
>          }
>
> \#define sample_iter_for_each_range(it__, entry__, end__) \
>          mas_for_each(&(it__).mas, entry__, end__)
>
> --
>
> struct sample *sample;
> SAMPLE_ITERATOR(si, min);
>
> sample_iter_for_each_range(&si, sample, max) {
>          frob(mgr, sample);
> }
>
> Signed-off-by: Danilo Krummrich <dakr at redhat.com>
> ---
>   include/linux/maple_tree.h | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
> index 1fadb5f5978b..87d55334f1c2 100644
> --- a/include/linux/maple_tree.h
> +++ b/include/linux/maple_tree.h
> @@ -423,8 +423,8 @@ struct ma_wr_state {
>   #define MA_ERROR(err) \
>   		((struct maple_enode *)(((unsigned long)err << 2) | 2UL))
>   
> -#define MA_STATE(name, mt, first, end)					\
> -	struct ma_state name = {					\
> +#define MA_STATE_INIT(mt, first, end)					\
> +	{								\

Naming: following the convention in, for example, the mutex and ww mutex 
code this should've been called

__MA_STATE_INITIALIZER(),

whereas the decapitalized name ma_state_init() would've been a (possibly 
inline) init function if it existed.

But this all should ofc be run by the maple tree maintainer(s).

FWIW, with these things addressed the change LGTM.

/Thomas


>   		.tree = mt,						\
>   		.index = first,						\
>   		.last = end,						\
> @@ -435,6 +435,9 @@ struct ma_wr_state {
>   		.mas_flags = 0,						\
>   	}
>   
> +#define MA_STATE(name, mt, first, end)					\
> +	struct ma_state name = MA_STATE_INIT(mt, first, end)
> +
>   #define MA_WR_STATE(name, ma_state, wr_entry)				\
>   	struct ma_wr_state name = {					\
>   		.mas = ma_state,					\