From patchwork Wed Feb 13 14:02:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Souptick Joarder X-Patchwork-Id: 10809967 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 6C6FD922 for ; Wed, 13 Feb 2019 13:57:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5626C2D0B4 for ; Wed, 13 Feb 2019 13:57:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4A3492D0CE; Wed, 13 Feb 2019 13:57:59 +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 814CE2D0CA for ; Wed, 13 Feb 2019 13:57:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733120AbfBMN55 (ORCPT ); Wed, 13 Feb 2019 08:57:57 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:42399 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732034AbfBMN55 (ORCPT ); Wed, 13 Feb 2019 08:57:57 -0500 Received: by mail-pg1-f193.google.com with SMTP id d72so1162744pga.9; Wed, 13 Feb 2019 05:57:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=UHbAr6VjHIA6sKDIJjq+403Y2d7WPguSXt3rzmIl6IBY6SSfTp0rLgonfEf6lGHpCs CrqhOWcnJqtDs+YhZFN5PrBEiC74DnXBT4v+K/jsCvtxEA8T8Scf5lmzpX7lohjU+xvl A2rPHRTJZmYRrO65TcR9WlQZvULjczqLPmErv17xJYk9d75MdbexEIZI5clY7YNBgJ49 Zp9HE2xqWl71SvZmGVzA+KbEUvV+xrOI14XqbKjbaXYpQXQawuxYvX7APazz3N9/jRar pL73Tp4ZQMXOJ3AmD52pjLwG6s9XYcngHbZ5fEeW1hxuJ4Tzz1denDq6BM6ddw761yqb zHSw== 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:mime-version :content-disposition:user-agent; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=sIR2YrBKXTthwSeJziaWUUc0v+wmUGUvnQw7fEnDXrwaovaWHE7+X9Q2zDU7Jy//uM VsuW/zzOU9y6oZeDg2hV7mZ+znNQ1PSnVauPTQe6wrW8uYNxPV2lu7Monpn/LuDuu8sN JtgL7VrwmoylGS4FrBfovkIBWtlAyKtV46OQHIFG5rZydofkV0h+pWnlNQu8r31Y919i RjaNttC34z/LCffCbpjWa1xbBDftqhQk2J3Zf8CL3bKfScLGPsbudHJURYLrzH6UVNpN fTrzjv9Gi+TJZMiLoBep3ivnnVHV9cQWxSyvt2Clfz8VwO1u8xKtoh1WeJcFy7wqjtN5 UkAw== X-Gm-Message-State: AHQUAuYqxE5ibjpBJJGfJKj8N3CVz2Ih9FcJ2WR6VP6GMOUP5Bsom6sU jTfoikz4x+z8LWzO7loqCobm6ncD X-Google-Smtp-Source: AHgI3IbsRbeaAyePsoPA34qPEwK9ju+Mwor/j+wcsqcPpuYwN399ocFJJNJYAe7AZfgfl6MyXeqd2Q== X-Received: by 2002:aa7:838b:: with SMTP id u11mr644881pfm.254.1550066275977; Wed, 13 Feb 2019 05:57:55 -0800 (PST) Received: from jordon-HP-15-Notebook-PC ([49.207.48.54]) by smtp.gmail.com with ESMTPSA id g14sm33624506pfg.27.2019.02.13.05.57.54 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 13 Feb 2019 05:57:55 -0800 (PST) Date: Wed, 13 Feb 2019 19:32:14 +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: [PATCH v3 1/9] mm: Introduce new vm_map_pages() and vm_map_pages_zero() API Message-ID: <20190213140214.GA21954@jordon-HP-15-Notebook-PC> MIME-Version: 1.0 Content-Disposition: inline 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