From patchwork Fri Mar 28 15:01:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 3903931 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4CAFB9F2B6 for ; Fri, 28 Mar 2014 15:02:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 679A2202FE for ; Fri, 28 Mar 2014 15:02:53 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5A66F20256 for ; Fri, 28 Mar 2014 15:02:52 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WTYIk-00058F-Oh; Fri, 28 Mar 2014 15:02:34 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WTYId-0008Dd-Bj; Fri, 28 Mar 2014 15:02:27 +0000 Received: from mail-wg0-f45.google.com ([74.125.82.45]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WTYIH-00085i-7E for linux-arm-kernel@lists.infradead.org; Fri, 28 Mar 2014 15:02:16 +0000 Received: by mail-wg0-f45.google.com with SMTP id l18so3760312wgh.16 for ; Fri, 28 Mar 2014 08:01:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=XNVK0vbQQ9JnU3xbUvjvgJurklkWmtxwvzvyhcsmRNQ=; b=ESu5jAxptfizf6tBsjdYR8fVfeJM3eNOqOI5SytZ4wX2gMqh9WBOVeSzLvCEsbdXj6 dOvaDV+uPIwelgJl3E+aBcNP+nLRjTZvqr/sKSeoFkKVy/g6fGyUXYmzkPmNrcNVGciN ooIsUwOrtYZTOgJB0P+MNU1bJLl/p25eD7ZXH8usnsIxro/Zu69sgNu2hUV+LfwLIdT9 oo0Nkx7F+HiHHSe49WjtxOV8F0bJXwTFwExuSBJZAln5MMZJ0PudjdzdM+I0GzQoN+Dj 8xkJRGuv6pAWUz98C3jDigbQbDhDAS9ZR9KDVpGdAyTP1Ro5UFis/mGFHhxYNqYchwuN 1MiQ== X-Gm-Message-State: ALoCoQln4ezQrvZ9jq3LTjdMI3drJ3t3CSPJ0KVcl5+ZeESF71YKK9koVsYG6Dtmlk0sDCLR0pCT X-Received: by 10.180.91.114 with SMTP id cd18mr13220286wib.28.1396018903041; Fri, 28 Mar 2014 08:01:43 -0700 (PDT) Received: from marmot.wormnet.eu (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id fo6sm8038670wib.7.2014.03.28.08.01.41 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Mar 2014 08:01:42 -0700 (PDT) From: Steve Capper To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: [RFC PATCH V4 2/7] arm: mm: Introduce special ptes for LPAE Date: Fri, 28 Mar 2014 15:01:27 +0000 Message-Id: <1396018892-6773-3-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1396018892-6773-1-git-send-email-steve.capper@linaro.org> References: <1396018892-6773-1-git-send-email-steve.capper@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140328_110205_526207_D33BC560 X-CRM114-Status: GOOD ( 13.57 ) X-Spam-Score: -2.6 (--) Cc: peterz@infradead.org, gary.robertson@linaro.org, akpm@linux-foundation.org, anders.roxell@linaro.org, Steve Capper X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We need a mechanism to tag ptes as being special, this indicates that no attempt should be made to access the underlying struct page * associated with the pte. This is used by the fast_gup when operating on ptes as it has no means to access VMAs (that also contain this information) locklessly. The L_PTE_SPECIAL bit is already allocated for LPAE, this patch modifies pte_special and pte_mkspecial to make use of it, and defines __HAVE_ARCH_PTE_SPECIAL. This patch also excludes special ptes from the icache/dcache sync logic. Signed-off-by: Steve Capper --- Changed in V4: set_pte_at will not perform an icache sync for special ptes. --- arch/arm/include/asm/pgtable-2level.h | 2 ++ arch/arm/include/asm/pgtable-3level.h | 8 ++++++++ arch/arm/include/asm/pgtable.h | 6 ++---- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h index dfff709..26d1742 100644 --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -181,6 +181,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) #define pmd_addr_end(addr,end) (end) #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext) +#define pte_special(pte) (0) +static inline pte_t pte_mkspecial(pte_t pte) { return pte; } /* * We don't have huge page support for short descriptors, for the moment diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 85c60ad..b286ba9 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -207,6 +207,14 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) #define pte_huge(pte) (pte_val(pte) && !(pte_val(pte) & PTE_TABLE_BIT)) #define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT)) +#define pte_special(pte) (!!(pte_val(pte) & L_PTE_SPECIAL)) +static inline pte_t pte_mkspecial(pte_t pte) +{ + pte_val(pte) |= L_PTE_SPECIAL; + return pte; +} +#define __HAVE_ARCH_PTE_SPECIAL + #define pmd_young(pmd) (pmd_val(pmd) & PMD_SECT_AF) #define __HAVE_ARCH_PMD_WRITE diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 7d59b52..e6139e3 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -220,7 +220,6 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY) #define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG) #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN)) -#define pte_special(pte) (0) #define pte_present_user(pte) (pte_present(pte) && (pte_val(pte) & L_PTE_USER)) @@ -238,7 +237,8 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, unsigned long ext = 0; if (addr < TASK_SIZE && pte_present_user(pteval)) { - __sync_icache_dcache(pteval); + if (!pte_special(pteval)) + __sync_icache_dcache(pteval); ext |= PTE_EXT_NG; } @@ -257,8 +257,6 @@ PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG); PTE_BIT_FUNC(mkexec, &= ~L_PTE_XN); PTE_BIT_FUNC(mknexec, |= L_PTE_XN); -static inline pte_t pte_mkspecial(pte_t pte) { return pte; } - static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |