From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH 6/7] acpi, apei, ghes: Make unmapping functionality independent from architecture. Date: Wed, 14 May 2014 13:35:42 +0100 Message-ID: <20140514123542.GG10145@arm.com> References: <1397056476-9183-1-git-send-email-tomasz.nowicki@linaro.org> <1397056476-9183-7-git-send-email-tomasz.nowicki@linaro.org> <20140513201118.GF8760@pd.tnic> <5373625B.4050401@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:46518 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbaENMfm (ORCPT ); Wed, 14 May 2014 08:35:42 -0400 Content-Disposition: inline In-Reply-To: <5373625B.4050401@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Tomasz Nowicki Cc: Borislav Petkov , Catalin Marinas , Russell King - ARM Linux , "rjw@rjwysocki.net" , "lenb@kernel.org" , "tony.luck@intel.com" , "bp@suse.de" , "m.chehab@samsung.com" , "linux-edac@vger.kernel.org" , "x86@kernel.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" On Wed, May 14, 2014 at 01:32:27PM +0100, Tomasz Nowicki wrote: > On 13.05.2014 22:11, Borislav Petkov wrote: > > On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote: > >> Till now __flush_tlb_one was used for unmapping virtual memory which > >> is x86 specific function. Replace it with more generic > >> flush_tlb_kernel_range. > >> > >> Signed-off-by: Tomasz Nowicki > >> --- > >> drivers/acpi/apei/ghes.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > >> index aaf8db3..624878b 100644 > >> --- a/drivers/acpi/apei/ghes.c > >> +++ b/drivers/acpi/apei/ghes.c > >> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr) > >> > >> BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base)); > >> unmap_kernel_range_noflush(vaddr, PAGE_SIZE); > >> - __flush_tlb_one(vaddr); > >> + flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); > >> } > >> > >> static void ghes_iounmap_irq(void __iomem *vaddr_ptr) > >> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr) > >> > >> BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base)); > >> unmap_kernel_range_noflush(vaddr, PAGE_SIZE); > >> - __flush_tlb_one(vaddr); > >> + flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); > > > > flush_tlb_kernel_range() does send an IPI to every core on x86 which is > > much more expensive than what __flush_tlb_one does. > > > > Fairer it would be if you added a __flush_tlb_one() version for arm > > which does flush_tlb_kernel_range for you. > > > > Thanks for comment. I am not sure if maintainers will allow me to add > sth like __flush_tlb_one() for arm/arm64. Let me ask them directly. > Catalin, Russell what do you think? I don't have the background for this, but if you don't need broadcasting (if this avoids IPIs on x86, I guess you don't) then why not use local_flush_tlb_kernel_range instead? Will