lkml.org 
[lkml]   [2012]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ARM: cache-v7: Disable preemption when reading CCSIDR
Hello.

On 03-02-2012 7:04, Nicolas Pitre wrote:

>>>>> If you simply disable/restore IRQs around the critical region then you
>>>>> don't have to worry about __v7_setup. Plus this will allow for
>>>>> v7_flush_dcache_all to still be callable from atomic context.
>>>> Ok. Here's a patch. I still need to test it. I'll send another patch
>>>> series to cleanup the get_thread_info stuff (there's two of them?).
>>>>
>>>> arch/arm/mm/cache-v7.S | 6 ++++++
>>>> 1 files changed, 6 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
>>>> index 07c4bc8..654a5fc 100644
>>>> --- a/arch/arm/mm/cache-v7.S
>>>> +++ b/arch/arm/mm/cache-v7.S
>>>> @@ -54,9 +54,15 @@ loop1:
>>>> and r1, r1, #7 @ mask of the bits for current cache only
>>>> cmp r1, #2 @ see what cache we have at this level
>>>> blt skip @ skip if no cache, or just i-cache
>>>> +#ifdef CONFIG_PREEMPT
>>>> + save_and_disable_irqs r9 @ make cssr&csidr read atomic
>>>> +#endif
>>>> mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
>>>> isb @ isb to sych the new cssr&csidr
>>>> mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
>>>> +#ifdef CONFIG_PREEMPT
>>>> + restore_irqs r9
>>>> +#endif

>>> I'd suggest using restore_irqs_notrace instead. The IRQ-off period is
>>> so small that there is no point tracing it.

>> Thanks. I'll make sure to do that before uploading to the patch tracker.

> Might be worth flagging this for the stable kernels as well
> (CC: stable@kernel.org).

The new address is stable@vger.kernel.org as Greg KH wrote.

WBR, Sergei


\
 
 \ /
  Last update: 2012-02-03 12:19    [W:2.123 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site