From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 4A6186B61F8 for ; Sun, 2 Dec 2018 01:16:02 -0500 (EST) Received: by mail-pl1-f199.google.com with SMTP id v12so7483764plp.16 for ; Sat, 01 Dec 2018 22:16:02 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id v191sor12663918pgb.53.2018.12.01.22.16.00 for (Google Transport Security); Sat, 01 Dec 2018 22:16:00 -0800 (PST) Date: Sun, 2 Dec 2018 11:49:44 +0530 From: Souptick Joarder Subject: [PATCH v2 1/9] mm: Introduce new vm_insert_range API Message-ID: <20181202061944.GA3094@jordon-HP-15-Notebook-PC> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: 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 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 a new function and use it across the drivers. vm_insert_range is the new API which will be used to map a range of kernel memory/pages to user vma. This API is tested by Heiko for Rockchip drm driver, on rk3188, rk3288, rk3328 and rk3399 with graphics. Signed-off-by: Souptick Joarder Reviewed-by: Matthew Wilcox Tested-by: Heiko Stuebner --- include/linux/mm_types.h | 3 +++ mm/memory.c | 38 ++++++++++++++++++++++++++++++++++++++ mm/nommu.c | 7 +++++++ 3 files changed, 48 insertions(+) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5ed8f62..15ae24f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -523,6 +523,9 @@ extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, extern void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end); +int vm_insert_range(struct vm_area_struct *vma, unsigned long addr, + struct page **pages, unsigned long page_count); + static inline void init_tlb_flush_pending(struct mm_struct *mm) { atomic_set(&mm->tlb_flush_pending, 0); diff --git a/mm/memory.c b/mm/memory.c index 15c417e..84ea46c 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1478,6 +1478,44 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, } /** + * vm_insert_range - insert range of kernel pages into user vma + * @vma: user vma to map to + * @addr: target user address of this page + * @pages: pointer to array of source kernel pages + * @page_count: number of pages need to insert into user vma + * + * This allows drivers to insert range of kernel pages they've allocated + * into a user vma. This is a generic function which drivers can use + * rather than using their own way of mapping range of kernel pages into + * user vma. + * + * 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_insert_range(struct vm_area_struct *vma, unsigned long addr, + struct page **pages, unsigned long page_count) +{ + unsigned long uaddr = addr; + int ret = 0, i; + + for (i = 0; i < page_count; i++) { + ret = vm_insert_page(vma, uaddr, pages[i]); + if (ret < 0) + return ret; + uaddr += PAGE_SIZE; + } + + return ret; +} +EXPORT_SYMBOL(vm_insert_range); + +/** * vm_insert_page - insert single page into user vma * @vma: user vma to map to * @addr: target user address of this page diff --git a/mm/nommu.c b/mm/nommu.c index 749276b..d6ef5c7 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -473,6 +473,13 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, } EXPORT_SYMBOL(vm_insert_page); +int vm_insert_range(struct vm_area_struct *vma, unsigned long addr, + struct page **pages, unsigned long page_count) +{ + return -EINVAL; +} +EXPORT_SYMBOL(vm_insert_range); + /* * sys_brk() for the most part doesn't need the global kernel * lock, except when an application is doing something nasty -- 1.9.1