From patchwork Tue Jul 25 13:53:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 9862047 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C0CCE602B1 for ; Tue, 25 Jul 2017 13:53:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B8C461FF82 for ; Tue, 25 Jul 2017 13:53:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AD9412237D; Tue, 25 Jul 2017 13:53:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 273E21FF82 for ; Tue, 25 Jul 2017 13:53:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=QtBsCo/0+9HPdz8cmY2jqL8EVceIJCSyxb63Wghr2E8=; b=MyZGffMzTOnBR6buz/fPs5aY8/ GE2aQUUqquO/CVzs0PG9Hr8sspBwu7cheMx3Ssr0z+XZ2oeVAOHHOK9rhy+e3OgcKNpcDr81JSDo4 zjlN1jl9O+O+aaLRiHmwtLW95Wh0OsHhFwS/5WDJuHNYmvVudXwpeQbOo6gR90Yufj/ysiJteL5xg 0ujUZg4EV6IdJCmT/O5K1ifoy5XsESfQ3qaoAzMjvtTzkk9hbvLaw1NrO75hhEDlwIsLC+cJGU8Jv YPJpQTdjRi8hnX5Qg/iuga15ZRFQG+4XBmlLU4pA3vvQV7ysj+DnKnlE5QMI9D27+pfnYNNaIkPs3 r0ENzw1Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1da0HT-0001jy-4h; Tue, 25 Jul 2017 13:53:47 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1da0HP-0001ON-8R for linux-arm-kernel@lists.infradead.org; Tue, 25 Jul 2017 13:53:45 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F211115BE; Tue, 25 Jul 2017 06:53:22 -0700 (PDT) Received: from armageddon.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BC0393F540; Tue, 25 Jul 2017 06:53:21 -0700 (PDT) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/6] kvm: arm64: Convert kvm_set_s2pte_readonly() from inline asm to cmpxchg() Date: Tue, 25 Jul 2017 14:53:05 +0100 Message-Id: <20170725135308.18173-4-catalin.marinas@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170725135308.18173-1-catalin.marinas@arm.com> References: <20170725135308.18173-1-catalin.marinas@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170725_065343_387045_DC70BEAB X-CRM114-Status: UNSURE ( 9.00 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Marc Zyngier , Will Deacon , Christoffer Dall , Steve Capper MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP To take advantage of the LSE atomic instructions and also make the code cleaner, convert the kvm_set_s2pte_readonly() function to use the more generic cmpxchg(). Cc: Marc Zyngier Cc: Christoffer Dall Cc: Will Deacon Acked-by: Mark Rutland Signed-off-by: Catalin Marinas Reviewed-by: Christoffer Dall --- arch/arm64/include/asm/kvm_mmu.h | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index a89cc22abadc..40b3ea690826 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -175,18 +175,14 @@ static inline pmd_t kvm_s2pmd_mkwrite(pmd_t pmd) static inline void kvm_set_s2pte_readonly(pte_t *pte) { - pteval_t pteval; - unsigned long tmp; - - asm volatile("// kvm_set_s2pte_readonly\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " and %0, %0, %3 // clear PTE_S2_RDWR\n" - " orr %0, %0, %4 // set PTE_S2_RDONLY\n" - " stxr %w1, %0, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*pte)) - : "L" (~PTE_S2_RDWR), "L" (PTE_S2_RDONLY)); + pteval_t old_pteval, pteval; + + do { + pteval = old_pteval = READ_ONCE(pte_val(*pte)); + pteval &= ~PTE_S2_RDWR; + pteval |= PTE_S2_RDONLY; + } while (cmpxchg_relaxed(&pte_val(*pte), old_pteval, pteval) != + old_pteval); } static inline bool kvm_s2pte_readonly(pte_t *pte)