From patchwork Tue Mar 19 02:23:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Souptick Joarder X-Patchwork-Id: 10858709 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 8FF4013B5 for ; Tue, 19 Mar 2019 02:19:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7456328F93 for ; Tue, 19 Mar 2019 02:19:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 67D23290B7; Tue, 19 Mar 2019 02:19:24 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9F5AA28F93 for ; Tue, 19 Mar 2019 02:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727404AbfCSCTW (ORCPT ); Mon, 18 Mar 2019 22:19:22 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:38058 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726832AbfCSCTW (ORCPT ); Mon, 18 Mar 2019 22:19:22 -0400 Received: by mail-pg1-f195.google.com with SMTP id v1so8026216pgi.5; Mon, 18 Mar 2019 19:19:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=jm1r7D/rts2BI9YcnuOGIHlHQpyxSGz4aZOvJE/yi+Xo4uNlBnfqja0VcY+FpX9fSD 28+KDFT/SwkBAZZ1o4TLSIUGewjtegnrMoy3LszzvJ2CwtfqOtcuC7wJMFFFvVyHlntf uVBrnde4SmEejwST8D2NZ4eGXPi4DunUxkLIHtZ751AARCv/ODl5lir046VNuABgvsGw ZJyDyGnygvc719vLtey2Vx/RTxTJZUmAHCZjnD1cfEDxhYMw8LC/WDb1WQdzBkzOb/W1 DSw3Z0nbuStKECnh1LO8ozlsCAfA6F5QmcQvncr/iEYxCA4scPRMbXzNynH1JZmbcdsw XsMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=H9KMYd2wM2iVe7DFzDWsrZ2UKj2zb7T35qjkQcsAQN9sCdGvapLlwMwmVuhVACgX7O jXg+UVP8iw0DhEpBUe7jCnLNZwKNYlAJxplQa5ni4sUCMZc+JMEOkrd7c+Y+cSRRDPpl fpeohYFbEtlc2uXvC/nIR0A5NsitXyPhqOS5WDtNjHogBN6aPnw+2hDLO5YWRISeAVqe ST0YgQN8H/JuMW00cd3sZ22FvWwUddi+3r+fQVGKn5XN3jMEBd7WtTljnGQH25DqL4q1 jwnAkcTcsC796tfkOB+Yp7IXOomxUzMDsyrvwGJuv+SJmtvnQ8iMJOxrhyq2o7Lyc7em ggBQ== X-Gm-Message-State: APjAAAVsJ8DPrl54K3r0zoJm/ViAPP/0cTw9h16bCLoTLmlycHh3k69w uh4u3wy6pY+F3QnfQU5s3O+RRpDp X-Google-Smtp-Source: APXvYqz9KjQMMuck4sjrn6Sq3LDJfmEoJ+bGuZkApQa2UhKviptEqmVda9dABsOdlmGAuvojp7es6Q== X-Received: by 2002:a17:902:20e8:: with SMTP id v37mr2843228plg.168.1552961960808; Mon, 18 Mar 2019 19:19:20 -0700 (PDT) Received: from jordon-HP-15-Notebook-PC ([106.51.22.39]) by smtp.gmail.com with ESMTPSA id q18sm14908138pgv.9.2019.03.18.19.19.19 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 18 Mar 2019 19:19:20 -0700 (PDT) Date: Tue, 19 Mar 2019 07:53:54 +0530 From: Souptick Joarder To: akpm@linux-foundation.org, willy@infradead.org, mhocko@suse.com, kirill.shutemov@linux.intel.com, vbabka@suse.cz, riel@surriel.com, sfr@canb.auug.org.au, rppt@linux.vnet.ibm.com, peterz@infradead.org, linux@armlinux.org.uk, robin.murphy@arm.com, iamjoonsoo.kim@lge.com, treding@nvidia.com, keescook@chromium.org, m.szyprowski@samsung.com, stefanr@s5r6.in-berlin.de, hjc@rock-chips.com, heiko@sntech.de, airlied@linux.ie, oleksandr_andrushchenko@epam.com, joro@8bytes.org, pawel@osciak.com, kyungmin.park@samsung.com, mchehab@kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux1394-devel@lists.sourceforge.net, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, xen-devel@lists.xen.org, iommu@lists.linux-foundation.org, linux-media@vger.kernel.org Subject: [RESEND PATCH v4 1/9] mm: Introduce new vm_map_pages() and vm_map_pages_zero() API Message-ID: <751cb8a0f4c3e67e95c58a3b072937617f338eea.1552921225.git.jrdr.linux@gmail.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Previouly drivers have their own way of mapping range of kernel pages/memory into user vma and this was done by invoking vm_insert_page() within a loop. As this pattern is common across different drivers, it can be generalized by creating new functions and use it across the drivers. vm_map_pages() is the API which could be used to mapped kernel memory/pages in drivers which has considered vm_pgoff vm_map_pages_zero() is the API which could be used to map range of kernel memory/pages in drivers which has not considered vm_pgoff. vm_pgoff is passed default as 0 for those drivers. We _could_ then at a later "fix" these drivers which are using vm_map_pages_zero() to behave according to the normal vm_pgoff offsetting simply by removing the _zero suffix on the function name and if that causes regressions, it gives us an easy way to revert. Tested on Rockchip hardware and display is working, including talking to Lima via prime. Signed-off-by: Souptick Joarder Suggested-by: Russell King Suggested-by: Matthew Wilcox Reviewed-by: Mike Rapoport Tested-by: Heiko Stuebner --- include/linux/mm.h | 4 +++ mm/memory.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ mm/nommu.c | 14 ++++++++++ 3 files changed, 99 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 80bb640..e0aaa73 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, int remap_pfn_range(struct vm_area_struct *, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t); int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *); +int vm_map_pages(struct vm_area_struct *vma, struct page **pages, + unsigned long num); +int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, + unsigned long num); vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn); vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, diff --git a/mm/memory.c b/mm/memory.c index e11ca9d..cad3e27 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, } EXPORT_SYMBOL(vm_insert_page); +/* + * __vm_map_pages - maps range of kernel pages into user vma + * @vma: user vma to map to + * @pages: pointer to array of source kernel pages + * @num: number of pages in page array + * @offset: user's requested vm_pgoff + * + * This allows drivers to map range of kernel pages into a user vma. + * + * Return: 0 on success and error code otherwise. + */ +static int __vm_map_pages(struct vm_area_struct *vma, struct page **pages, + unsigned long num, unsigned long offset) +{ + unsigned long count = vma_pages(vma); + unsigned long uaddr = vma->vm_start; + int ret, i; + + /* Fail if the user requested offset is beyond the end of the object */ + if (offset > num) + return -ENXIO; + + /* Fail if the user requested size exceeds available object size */ + if (count > num - offset) + return -ENXIO; + + for (i = 0; i < count; i++) { + ret = vm_insert_page(vma, uaddr, pages[offset + i]); + if (ret < 0) + return ret; + uaddr += PAGE_SIZE; + } + + return 0; +} + +/** + * vm_map_pages - maps range of kernel pages starts with non zero offset + * @vma: user vma to map to + * @pages: pointer to array of source kernel pages + * @num: number of pages in page array + * + * Maps an object consisting of @num pages, catering for the user's + * requested vm_pgoff + * + * If we fail to insert any page into the vma, the function will return + * immediately leaving any previously inserted pages present. Callers + * from the mmap handler may immediately return the error as their caller + * will destroy the vma, removing any successfully inserted pages. Other + * callers should make their own arrangements for calling unmap_region(). + * + * Context: Process context. Called by mmap handlers. + * Return: 0 on success and error code otherwise. + */ +int vm_map_pages(struct vm_area_struct *vma, struct page **pages, + unsigned long num) +{ + return __vm_map_pages(vma, pages, num, vma->vm_pgoff); +} +EXPORT_SYMBOL(vm_map_pages); + +/** + * vm_map_pages_zero - map range of kernel pages starts with zero offset + * @vma: user vma to map to + * @pages: pointer to array of source kernel pages + * @num: number of pages in page array + * + * Similar to vm_map_pages(), except that it explicitly sets the offset + * to 0. This function is intended for the drivers that did not consider + * vm_pgoff. + * + * Context: Process context. Called by mmap handlers. + * Return: 0 on success and error code otherwise. + */ +int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, + unsigned long num) +{ + return __vm_map_pages(vma, pages, num, 0); +} +EXPORT_SYMBOL(vm_map_pages_zero); + static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr, pfn_t pfn, pgprot_t prot, bool mkwrite) { diff --git a/mm/nommu.c b/mm/nommu.c index 749276b..b492fd1 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -473,6 +473,20 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, } EXPORT_SYMBOL(vm_insert_page); +int vm_map_pages(struct vm_area_struct *vma, struct page **pages, + unsigned long num) +{ + return -EINVAL; +} +EXPORT_SYMBOL(vm_map_pages); + +int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, + unsigned long num) +{ + return -EINVAL; +} +EXPORT_SYMBOL(vm_map_pages_zero); + /* * sys_brk() for the most part doesn't need the global kernel * lock, except when an application is doing something nasty