Re: [PATCH 32/34] m68k: rework get_mmu_context()

From: Greg Ungerer <gerg@kernel.org>
To: Yury Norov <yury.norov@gmail.com>,
	linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Hugh Dickins <hughd@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-m68k@lists.linux-m68k.org
Cc: Jan Kara <jack@suse.cz>,
	Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>,
	Matthew Wilcox <willy@infradead.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>,
	Alexey Klimov <klimov.linux@gmail.com>
Subject: Re: [PATCH 32/34] m68k: rework get_mmu_context()
Date: Wed, 22 Nov 2023 00:39:05 +1000	[thread overview]
Message-ID: <1f38c998-93e9-4dbb-abc8-401d8175dad4@kernel.org> (raw)
In-Reply-To: <20231118155105.25678-33-yury.norov@gmail.com>

Hi Yury,

On 19/11/23 01:51, Yury Norov wrote:
> ALSA code opencodes atomic find_and_set_bit_wrap(). Switch it to
   ^^^^
m68k?

> dedicated function.
> 
> Signed-off-by: Yury Norov <yury.norov@gmail.com>

Looks ok to me:

Acked-by: Greg Ungerer <gerg@linux-m68k.org>

Regards
Greg

> ---
>   arch/m68k/include/asm/mmu_context.h | 11 +++++------
>   1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/m68k/include/asm/mmu_context.h b/arch/m68k/include/asm/mmu_context.h
> index 141bbdfad960..0419ad87a1c1 100644
> --- a/arch/m68k/include/asm/mmu_context.h
> +++ b/arch/m68k/include/asm/mmu_context.h
> @@ -35,12 +35,11 @@ static inline void get_mmu_context(struct mm_struct *mm)
>   		atomic_inc(&nr_free_contexts);
>   		steal_context();
>   	}
> -	ctx = next_mmu_context;
> -	while (test_and_set_bit(ctx, context_map)) {
> -		ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx);
> -		if (ctx > LAST_CONTEXT)
> -			ctx = 0;
> -	}
> +
> +	do {
> +		ctx = find_and_set_bit_wrap(context_map, LAST_CONTEXT + 1, next_mmu_context);
> +	} while (ctx > LAST_CONTEXT);
> +
>   	next_mmu_context = (ctx + 1) & LAST_CONTEXT;
>   	mm->context = ctx;
>   	context_mm[ctx] = mm;