Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751816AbaFFOh4 (ORCPT ); Fri, 6 Jun 2014 10:37:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29512 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751494AbaFFOhz (ORCPT ); Fri, 6 Jun 2014 10:37:55 -0400 Message-ID: <1402065449.15402.2.camel@deneb.redhat.com> Subject: Re: [PATCH] arm64: Add flush_cache_vmap call in __early_set_fixmap From: Mark Salter To: Leif Lindholm Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, steve.capper@linaro.org Date: Fri, 06 Jun 2014 10:37:29 -0400 In-Reply-To: <1402050590-23877-1-git-send-email-leif.lindholm@linaro.org> References: <1402050590-23877-1-git-send-email-leif.lindholm@linaro.org> Organization: Red Hat, Inc Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-06-06 at 11:29 +0100, Leif Lindholm wrote: > __early_set_fixmap does not do any synchronization when called to set a > fixmap entry. Add call to flush_vmap_cache(). > > Tested on hardware. > > Signed-off-by: Leif Lindholm > Tested-by: Graeme Gregory > Cc: Steve Capper > --- > arch/arm64/mm/ioremap.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c > index 7ec3283..5b8766c 100644 > --- a/arch/arm64/mm/ioremap.c > +++ b/arch/arm64/mm/ioremap.c > @@ -176,9 +176,10 @@ void __init __early_set_fixmap(enum fixed_addresses idx, > > pte = early_ioremap_pte(addr); > > - if (pgprot_val(flags)) > + if (pgprot_val(flags)) { > set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); > - else { > + flush_cache_vmap(addr, addr + PAGE_SIZE); > + } else { > pte_clear(&init_mm, addr, pte); > flush_tlb_kernel_range(addr, addr+PAGE_SIZE); > } I'm confused by the commit message mentioning synchronization but the code doing a cache flush. I see that arm64 implementation of flush_cache_vmap() is just a dsb(). If it is synchronization that we need here (and it certainly looks like we do), why not just add the dsb() directly to make that clear? -- 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/