Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753008Ab2BCCgB (ORCPT ); Thu, 2 Feb 2012 21:36:01 -0500 Received: from relais.videotron.ca ([24.201.245.36]:15018 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751066Ab2BCCgA (ORCPT ); Thu, 2 Feb 2012 21:36:00 -0500 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN; CHARSET=US-ASCII Date: Thu, 02 Feb 2012 21:35:59 -0500 (EST) From: Nicolas Pitre To: Stephen Boyd Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas Subject: Re: [PATCH] ARM: cache-v7: Disable preemption when reading CCSIDR In-reply-to: <1328234629-32735-1-git-send-email-sboyd@codeaurora.org> Message-id: References: <1328234629-32735-1-git-send-email-sboyd@codeaurora.org> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1644 Lines: 44 On Thu, 2 Feb 2012, Stephen Boyd wrote: > On 02/02/12 17:18, 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. Withthat change: Reviewed-by: Nicolas Pitre Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/