From patchwork Tue Apr 30 16:30:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 2505651 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id 41ECF3FD85 for ; Tue, 30 Apr 2013 16:33:33 +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 1UXDTn-00078Z-24; Tue, 30 Apr 2013 16:32:35 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UXDTS-0005wB-72; Tue, 30 Apr 2013 16:32:14 +0000 Received: from mail-wg0-x234.google.com ([2a00:1450:400c:c00::234]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UXDSk-0005lD-CT for linux-arm-kernel@lists.infradead.org; Tue, 30 Apr 2013 16:31:34 +0000 Received: by mail-wg0-f52.google.com with SMTP id k13so660969wgh.19 for ; Tue, 30 Apr 2013 09:31:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references:x-gm-message-state; bh=yYjbJ7CElZbOW79k4KxQ37b/YqWFS7uc14uVXCINKak=; b=bcL2RtungkCQ7DFpi+Sa9RzMeRIQRG17xXxlsGGeQs6m+qF2ALCAlJsoTVkOWPNvfv 5e0Z/3xhvNx66/Abxk39KTFOT/N2z0ae2eBB/KiYtUmdn56c2MtiaRvoD45giZtbsy+Q XetmjE6UWut8+tD80ypTzB6ebXLt8XN9wx2hoGsO/X4Np8Pkj64I7rgI/6buvPQ4u0x3 rUsj6Lj3tKC+5FQeisGv/81+DN5Epdz4dsCuBQWDRH8ioL6N/vW6yz9ncFG7fatqVuEV ZV2frFQX+AysvbhfqyHhECt5gXWjx16B+vGjNUx0TjzF0fHqhRDpvVZXEWAY+RhD40ah pVvg== X-Received: by 10.194.93.231 with SMTP id cx7mr43448212wjb.33.1367339467634; Tue, 30 Apr 2013 09:31:07 -0700 (PDT) Received: from localhost.localdomain (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id k5sm30044708wiy.5.2013.04.30.09.31.06 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 30 Apr 2013 09:31:07 -0700 (PDT) From: Steve Capper To: linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 3/9] mm: hugetlb: Copy general hugetlb code from x86 to mm. Date: Tue, 30 Apr 2013 17:30:42 +0100 Message-Id: <1367339448-21727-4-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1367339448-21727-1-git-send-email-steve.capper@linaro.org> References: <1367339448-21727-1-git-send-email-steve.capper@linaro.org> X-Gm-Message-State: ALoCoQmqDb+SyRy7Bu6KLSRgYhENZqiSZrI6cZSrnU+bM9TuXveofBg6g6eQ0ClPMcCLqVwYeDl1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130430_123130_630766_28DC1ED5 X-CRM114-Status: GOOD ( 15.56 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Steve Capper , Catalin Marinas , Will Deacon , Michal Hocko , Ken Chen , Mel Gorman 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 The huge_pte_alloc, huge_pte_offset and follow_huge_p[mu]d functions in x86/mm/hugetlbpage.c do not rely on any architecture specific knowledge other than the fact that pmds and puds can be treated as huge ptes. To allow other architectures to use this code (and reduce the need for code duplication), this patch copies these functions into mm and provides a config flag to activate them: CONFIG_ARCH_WANT_GENERAL_HUGETLB If CONFIG_ARCH_WANT_HUGE_PMD_SHARE is also active then the huge_pmd_share code will be called by huge_pte_alloc (othewise we call pmd_alloc and skip the sharing code). Signed-off-by: Steve Capper --- mm/hugetlb.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 88 insertions(+), 9 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 41179b0..e1dc5ae 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2915,15 +2915,6 @@ out_mutex: return ret; } -/* Can be overriden by architectures */ -__attribute__((weak)) struct page * -follow_huge_pud(struct mm_struct *mm, unsigned long address, - pud_t *pud, int write) -{ - BUG(); - return NULL; -} - long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *position, unsigned long *nr_pages, @@ -3262,8 +3253,96 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; return 1; } +#define want_pmd_share() (1) +#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ +pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) +{ + return NULL; +} +#define want_pmd_share() (0) #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ +#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB +pte_t *huge_pte_alloc(struct mm_struct *mm, + unsigned long addr, unsigned long sz) +{ + pgd_t *pgd; + pud_t *pud; + pte_t *pte = NULL; + + pgd = pgd_offset(mm, addr); + pud = pud_alloc(mm, pgd, addr); + if (pud) { + if (sz == PUD_SIZE) { + pte = (pte_t *)pud; + } else { + BUG_ON(sz != PMD_SIZE); + if (want_pmd_share() && pud_none(*pud)) + pte = huge_pmd_share(mm, addr, pud); + else + pte = (pte_t *)pmd_alloc(mm, pud, addr); + } + } + BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte)); + + return pte; +} + +pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd = NULL; + + pgd = pgd_offset(mm, addr); + if (pgd_present(*pgd)) { + pud = pud_offset(pgd, addr); + if (pud_present(*pud)) { + if (pud_large(*pud)) + return (pte_t *)pud; + pmd = pmd_offset(pud, addr); + } + } + return (pte_t *) pmd; +} + +struct page * +follow_huge_pmd(struct mm_struct *mm, unsigned long address, + pmd_t *pmd, int write) +{ + struct page *page; + + page = pte_page(*(pte_t *)pmd); + if (page) + page += ((address & ~PMD_MASK) >> PAGE_SHIFT); + return page; +} + +struct page * +follow_huge_pud(struct mm_struct *mm, unsigned long address, + pud_t *pud, int write) +{ + struct page *page; + + page = pte_page(*(pte_t *)pud); + if (page) + page += ((address & ~PUD_MASK) >> PAGE_SHIFT); + return page; +} + +#else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */ + +/* Can be overriden by architectures */ +__attribute__((weak)) struct page * +follow_huge_pud(struct mm_struct *mm, unsigned long address, + pud_t *pud, int write) +{ + BUG(); + return NULL; +} + +#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ + #ifdef CONFIG_MEMORY_FAILURE /* Should be called in hugetlb_lock */