[PATCH] ARM: cache-v7: Disable preemption when reading CCSIDR
From: nico@fluxnic.net (Nicolas Pitre)
Date: 2012-02-03 02:36:01
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On Thu, 2 Feb 2012, Stephen Boyd wrote:
quoted hunk ↗ jump to hunk
On 02/02/12 17:18, Nicolas Pitre wrote:quoted
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. Withthat change: Reviewed-by: Nicolas Pitre <redacted> Nicolas