From patchwork Fri Nov 1 14:09:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 11223265 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 26B7C1515 for ; Fri, 1 Nov 2019 14:13:36 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C3B9B2085B for ; Fri, 1 Nov 2019 14:13:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aCpTwl8c" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3B9B2085B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version: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=noKaBm4cp0UtJiykwZ+L+rHXIk2fvoYk4S5NkVNxAHg=; b=aCpTwl8cClUlQH C+xl/2TZfoBs1XKgSrViSCHl8EnoSDARwzCH1hb4KRQ1vplq0tmOkRZpuE7Z30OeANZpiokAoibzI BPDlaFY2aUDjmcpuBFWHsGYjXOsFf7Gb1sZtPplRgy12E7dBLE0TvXuhhaAJuA8QP03AqMsYYbPQi VANicjKXTGemfRV87l0S0SX1bSFKIxfs3rv3FGvUidvb0a5nD/w5U7l/YoYcSHcxbIXjy17mzlTpC DdHDzn+b4R+MPWioMAywVEDsD6vTwzf7+4OUEkfdvH9a6+ZCn4sq8gq4gP/u194eHH2C4ua59etb7 VT0vsX1X9U6f499SVTYw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQXgB-0003TP-A1; Fri, 01 Nov 2019 14:13:31 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQXdI-0000dZ-P1 for linux-arm-kernel@lists.infradead.org; Fri, 01 Nov 2019 14:10:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 49F66337; Fri, 1 Nov 2019 07:10:32 -0700 (PDT) Received: from e112269-lin.cambridge.arm.com (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 98E773F718; Fri, 1 Nov 2019 07:10:29 -0700 (PDT) From: Steven Price To: Andrew Morton , linux-mm@kvack.org Subject: [PATCH v15 13/23] mm: pagewalk: Add test_p?d callbacks Date: Fri, 1 Nov 2019 14:09:32 +0000 Message-Id: <20191101140942.51554-14-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191101140942.51554-1-steven.price@arm.com> References: <20191101140942.51554-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191101_071032_903241_92A7867D X-CRM114-Status: GOOD ( 15.00 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Zong Li , Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, Steven Price , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , linux-arm-kernel@lists.infradead.org, "Liang, Kan" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org It is useful to be able to skip parts of the page table tree even when walking without VMAs. Add test_p?d callbacks similar to test_walk but which are called just before a table at that level is walked. If the callback returns non-zero then the entire table is skipped. Tested-by: Zong Li Signed-off-by: Steven Price --- include/linux/pagewalk.h | 11 +++++++++++ mm/pagewalk.c | 24 ++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index ed2bb399fac2..fe61448c5900 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -24,6 +24,11 @@ struct mm_walk; * "do page table walk over the current vma", returning * a negative value means "abort current page table walk * right now" and returning 1 means "skip the current vma" + * @test_pmd: similar to test_walk(), but called for every pmd. + * @test_pud: similar to test_walk(), but called for every pud. + * @test_p4d: similar to test_walk(), but called for every p4d. + * Returning 0 means walk this part of the page tables, + * returning 1 means to skip this range. * * p?d_entry callbacks are called even if those levels are folded on a * particular architecture/configuration. @@ -46,6 +51,12 @@ struct mm_walk_ops { struct mm_walk *walk); int (*test_walk)(unsigned long addr, unsigned long next, struct mm_walk *walk); + int (*test_pmd)(unsigned long addr, unsigned long next, + pmd_t *pmd_start, struct mm_walk *walk); + int (*test_pud)(unsigned long addr, unsigned long next, + pud_t *pud_start, struct mm_walk *walk); + int (*test_p4d)(unsigned long addr, unsigned long next, + p4d_t *p4d_start, struct mm_walk *walk); }; /** diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 626e7fdb0508..4616281f5b69 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -34,6 +34,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, const struct mm_walk_ops *ops = walk->ops; int err = 0; + if (ops->test_pmd) { + err = ops->test_pmd(addr, end, pmd_offset(pud, 0UL), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + pmd = pmd_offset(pud, addr); do { again: @@ -85,6 +93,14 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, const struct mm_walk_ops *ops = walk->ops; int err = 0; + if (ops->test_pud) { + err = ops->test_pud(addr, end, pud_offset(p4d, 0UL), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + pud = pud_offset(p4d, addr); do { again: @@ -128,6 +144,14 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, const struct mm_walk_ops *ops = walk->ops; int err = 0; + if (ops->test_p4d) { + err = ops->test_p4d(addr, end, p4d_offset(pgd, 0UL), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + p4d = p4d_offset(pgd, addr); do { next = p4d_addr_end(addr, end);