From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50858C10F13 for ; Tue, 16 Apr 2019 11:46:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1940F20868 for ; Tue, 16 Apr 2019 11:46:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SMasld1u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728687AbfDPLqs (ORCPT ); Tue, 16 Apr 2019 07:46:48 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:34535 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726907AbfDPLqr (ORCPT ); Tue, 16 Apr 2019 07:46:47 -0400 Received: by mail-pg1-f195.google.com with SMTP id v12so10237250pgq.1; Tue, 16 Apr 2019 04:46:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=SMasld1uVZEpk4UEX00zTMKjN2cLUw5t5lk/rP875Zl7Ld1UD9ODxSW09epwDa4uQj /hdI4CMavMCQGR4K9F6jSPXx+sCJulN7Z3Go41fL6vV89zcZt9uSd+xfST5IB+cj8KDS N1FUTFkBWB5rZl1B8iO9lUoa5CwoWWg3XlUZF4TGl++UHbLkEEGzlcTHYHaa7qAqjmGs Ism4aa2dV2ii3Ies/ixc50ihwnCU0O24lH/WI2cBQJYq/0h3KtgkSQBUCdS/o35tPlHP ORrNYc50yRSTV62Pnj0+VVtPb4lUZiFBc7wcD/YX4cQ6ayuEO1ycd1Po5bAz9ZZbH912 vXHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=QS3mWzK39q3lW8WqJHFL6wuRYacMcGaOmOmP8soCdrs=; b=NYndH37G5D8yNCILN6VMz/fbEf/5F+uoZf9y+laI9Xe/zK89NFPAfHC9po9EEVJnbj CMCYBhJ6TQ9ncAZhqOLT8vqCn67H9ZV4tyHoC/PrKeaoWm+WcSP0IRrhUy8RejxfQQw6 xkNfE+/GClMgRdv/uFDVseIy4v3h3F4YjqMiaAcwiSoG0eEOXB/NwmOj4aBogIHuSOG4 jUBI26I+LrnGKhep3rGMehAanL31NvqSoTL/RxHH/Zsj+j+hINiz3ChR9VuVp7h9Jp2Q 4VYJ8wkVz9CegG+8+rcUEGV3f2wlL1sZz6X/GTCeuq9vIo6XmtX+ow05TV1/Wf6fC8/K 7QIQ== X-Gm-Message-State: APjAAAUQFWgcUumOa4UJKouoRTO58CIGBmTNmZEDupCb0/dHVPtN5c3m XvGFutl7KPVSxfF7O4JzWfA= X-Google-Smtp-Source: APXvYqyWLI4xppoJaNwMmezhBEPAkitBrHOX4rZ8NY0KFqkqU3V5t5n8ALBmwioh0pUr6lOC+xC0Xg== X-Received: by 2002:a65:6655:: with SMTP id z21mr40301407pgv.33.1555415205643; Tue, 16 Apr 2019 04:46:45 -0700 (PDT) Received: from jordon-HP-15-Notebook-PC.domain.name ([49.207.50.11]) by smtp.gmail.com with ESMTPSA id p6sm55942835pfd.122.2019.04.16.04.46.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 16 Apr 2019 04:46:44 -0700 (PDT) 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, Souptick Joarder Subject: [REBASE PATCH v5 1/9] mm: Introduce new vm_map_pages() and vm_map_pages_zero() API Date: Tue, 16 Apr 2019 17:19:42 +0530 Message-Id: <751cb8a0f4c3e67e95c58a3b072937617f338eea.1552921225.git.jrdr.linux@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Message-ID: <20190416114942.Nqs6WwOY9s31LI-7p_MtoXdHOciIbRefPcrUm-MsTDE@z> 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 -- 1.9.1