From patchwork Tue Mar 26 16:26:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 10871557 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8253513B5 for ; Tue, 26 Mar 2019 16:29:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6AD9128306 for ; Tue, 26 Mar 2019 16:29:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5F441284E8; Tue, 26 Mar 2019 16:29:19 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E2E9828306 for ; Tue, 26 Mar 2019 16:29:18 +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: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=AYWp7weqwYXUbSw2XkULYH0EHbF9J4g8P9NbCjs1PZA=; b=XplBW3qzYRbj5e w+VqXH51ByanJ37bTfBHvyKkQgkKy5JxGsVny8WqALGaVVVqKpumUkjaqTSKXuOlDBdeZHkr8Z8nm dIeceNM+nMjt9zzt9QOoGd4F5uwyFjjLqhB151ju6v+npEuBcaRiXBjgfX6VZ9452/R6R5BrZDzjk 49Ji1f/RlzCmZb0DFvSD4LHlIINouLu1ibtKCs1+OBDYnW+ZCB9gXAteizU7GPDZecw627OOcLTKM WUnPxcoqNAEYLbiZIqKEbiky4JDAodEasYRhIfAK3hx05AqKAdIj+hmd3aIuCJOb/HaE55gbzCgl4 fefn2CYTA/pvp+Qo75Vw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h8owo-0000hQ-09; Tue, 26 Mar 2019 16:29:10 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h8ov2-0007Le-KC for linux-arm-kernel@lists.infradead.org; Tue, 26 Mar 2019 16:27:45 +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 451DD1993; Tue, 26 Mar 2019 09:27:20 -0700 (PDT) Received: from e112269-lin.arm.com (e112269-lin.cambridge.arm.com [10.1.196.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 07A753F614; Tue, 26 Mar 2019 09:27:16 -0700 (PDT) From: Steven Price To: linux-mm@kvack.org Subject: [PATCH v6 12/19] mm: pagewalk: Add test_p?d callbacks Date: Tue, 26 Mar 2019 16:26:17 +0000 Message-Id: <20190326162624.20736-13-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190326162624.20736-1-steven.price@arm.com> References: <20190326162624.20736-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190326_092721_152484_7725D415 X-CRM114-Status: GOOD ( 14.98 ) 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 , x86@kernel.org, Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , Will Deacon , linux-kernel@vger.kernel.org, Steven Price , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , 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 X-Virus-Scanned: ClamAV using ClamSMTP 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. Signed-off-by: Steven Price --- include/linux/mm.h | 11 +++++++++++ mm/pagewalk.c | 24 ++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index f6de08c116e6..a4c1ed255455 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1382,6 +1382,11 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, * value means "do page table walk over the current vma," * and a negative one means "abort current page table walk * right now." 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. * @mm: mm_struct representing the target process of page table walk * @vma: vma currently walked (NULL if walking outside vmas) * @private: private data for callbacks' usage @@ -1406,6 +1411,12 @@ struct mm_walk { 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); struct mm_struct *mm; struct vm_area_struct *vma; void *private; diff --git a/mm/pagewalk.c b/mm/pagewalk.c index dac0c848b458..231655db1295 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -32,6 +32,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, unsigned long next; int err = 0; + if (walk->test_pmd) { + err = walk->test_pmd(addr, end, pmd_offset(pud, 0), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + pmd = pmd_offset(pud, addr); do { again: @@ -82,6 +90,14 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, unsigned long next; int err = 0; + if (walk->test_pud) { + err = walk->test_pud(addr, end, pud_offset(p4d, 0), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + pud = pud_offset(p4d, addr); do { again: @@ -124,6 +140,14 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, unsigned long next; int err = 0; + if (walk->test_p4d) { + err = walk->test_p4d(addr, end, p4d_offset(pgd, 0), walk); + if (err < 0) + return err; + if (err > 0) + return 0; + } + p4d = p4d_offset(pgd, addr); do { next = p4d_addr_end(addr, end);