Re: [PATCH] csky: syscache: Fixup duplicate cache flush
From: Randy Dunlap
Date: Tue May 04 2021 - 13:22:06 EST
On 5/4/21 12:14 AM, guoren@xxxxxxxxxx wrote:
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> The current csky logic of sys_cacheflush is wrong, it'll cause
> icache flush call dcache flush again. Now fixup it with a
> conditional "break & fallthrough".
>
> Fixes: 997153b9a75c ("csky: Add flush_icache_mm to defer flush icache all")
> Fixes: 0679d29d3e23 ("csky: fix syscache.c fallthrough warning")
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
more below:
> ---
> arch/csky/mm/syscache.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/arch/csky/mm/syscache.c b/arch/csky/mm/syscache.c
> index 4e51d63..a7b53b0 100644
> --- a/arch/csky/mm/syscache.c
> +++ b/arch/csky/mm/syscache.c
> @@ -12,15 +12,18 @@ SYSCALL_DEFINE3(cacheflush,
> int, cache)
> {
> switch (cache) {
> - case ICACHE:
> case BCACHE:
> - flush_icache_mm_range(current->mm,
> - (unsigned long)addr,
> - (unsigned long)addr + bytes);
> - fallthrough;
> case DCACHE:
> dcache_wb_range((unsigned long)addr,
> (unsigned long)addr + bytes);
> + if (cache == BCACHE)
> + fallthrough;
> + else
> + break;
I think the above would be more readable as:
if (cache != BCACHE)
break;
fallthrough;
fwiw.
> + case ICACHE:
> + flush_icache_mm_range(current->mm,
> + (unsigned long)addr,
> + (unsigned long)addr + bytes);
> break;
> default:
> return -EINVAL;
>
thanks.
--
~Randy