From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S936592AbdAFPwK (ORCPT <rfc822;w@1wt.eu>);
        Fri, 6 Jan 2017 10:52:10 -0500
Received: from smtp.codeaurora.org ([198.145.29.96]:57626 "EHLO
        smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S935763AbdAFPv5 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 6 Jan 2017 10:51:57 -0500
DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org 90A8F611FD
Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org
Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=cov@codeaurora.org
Subject: Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
To: Mark Rutland <mark.rutland@arm.com>
References: <20161229224335.13531-1-cov@codeaurora.org>
 <20161229224335.13531-4-cov@codeaurora.org>
 <20170103155756.GB14183@leverpostej>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Christoffer Dall <christoffer.dall@linaro.org>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>, kvm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-kernel@vger.kernel.org, shankerd@codeaurora.org,
        timur@codeaurora.org
From: Christopher Covington <cov@codeaurora.org>
Message-ID: <f5020a04-5fc7-26b5-1ded-c58e159bc722@codeaurora.org>
Date: Fri, 6 Jan 2017 10:51:53 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.2
MIME-Version: 1.0
In-Reply-To: <20170103155756.GB14183@leverpostej>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 01/03/2017 10:57 AM, Mark Rutland wrote:
> On Thu, Dec 29, 2016 at 05:43:34PM -0500, Christopher Covington wrote:
>> Refactor the KVM code to use the newly introduced __tlbi_dsb macros, which
>> will allow an errata workaround that repeats tlbi dsb sequences to only
>> change one location. This is not intended to change the generated assembly
>> and comparing before and after vmlinux objdump shows no functional changes.

@@ -32,7 +33,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
 	 * whole of Stage-1. Weep...
 	 */
 	ipa >>= 12;
-	asm volatile("tlbi ipas2e1is, %0" : : "r" (ipa));
+	__tlbi_dsb(ipas2e1is, ish, ipa);
 
 	/*
 	 * We have to ensure completion of the invalidation at Stage-2,

>> @@ -40,9 +41,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
>>  	 * complete (S1 + S2) walk based on the old Stage-2 mapping if
>>  	 * the Stage-1 invalidation happened first.
>>  	 */
>> -	dsb(ish);
> 
> Looks like this got accidentally removed. AFAICT it is still necessary.

Not removed, just hoisted above the comment block to the previous patch hunk.

>> -	asm volatile("tlbi vmalle1is" : : );
>> -	dsb(ish);
>> +	__tlbi_dsb(vmalle1is, ish);
>>  	isb();

Thanks,
Cov

-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code
Aurora Forum, a Linux Foundation Collaborative Project.