2021-05-04 07:16:55

by Guo Ren

Subject: [PATCH] csky: syscache: Fixup duplicate cache flush

From: Guo Ren <[email protected]>

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 <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Arnd Bergmann <[email protected]>
---
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;
+ case ICACHE:
+ flush_icache_mm_range(current->mm,
+ (unsigned long)addr,
+ (unsigned long)addr + bytes);
break;
default:
return -EINVAL;
--
2.7.4

2021-05-04 17:22:57

by Randy Dunlap

Subject: Re: [PATCH] csky: syscache: Fixup duplicate cache flush

On 5/4/21 12:14 AM, [email protected] wrote:
> From: Guo Ren <[email protected]>
>
> 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 <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Arnd Bergmann <[email protected]>

Acked-by: Randy Dunlap <[email protected]>

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