From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f199.google.com (mail-lj1-f199.google.com [209.85.208.199]) by kanga.kvack.org (Postfix) with ESMTP id B9D546B6725 for ; Sun, 2 Dec 2018 23:21:58 -0500 (EST) Received: by mail-lj1-f199.google.com with SMTP id l4-v6so3262886lji.5 for ; Sun, 02 Dec 2018 20:21:58 -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 e11-v6sor6618238ljg.24.2018.12.02.20.21.56 for (Google Transport Security); Sun, 02 Dec 2018 20:21:56 -0800 (PST) MIME-Version: 1.0 References: <20181202061944.GA3094@jordon-HP-15-Notebook-PC> <20181202111313.GC6959@rapoport-lnx> In-Reply-To: <20181202111313.GC6959@rapoport-lnx> From: Souptick Joarder Date: Mon, 3 Dec 2018 09:51:45 +0530 Message-ID: Subject: Re: [PATCH v2 1/9] mm: Introduce new vm_insert_range API Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: rppt@linux.ibm.com Cc: Andrew Morton , Matthew Wilcox , Michal Hocko , "Kirill A. Shutemov" , vbabka@suse.cz, Rik van Riel , Stephen Rothwell , rppt@linux.vnet.ibm.com, Peter Zijlstra , Russell King - ARM Linux , robin.murphy@arm.com, iamjoonsoo.kim@lge.com, treding@nvidia.com, Kees Cook , Marek Szyprowski , stefanr@s5r6.in-berlin.de, hjc@rock-chips.com, Heiko Stuebner , airlied@linux.ie, oleksandr_andrushchenko@epam.com, joro@8bytes.org, pawel@osciak.com, Kyungmin Park , mchehab@kernel.org, Boris Ostrovsky , Juergen Gross , linux-kernel@vger.kernel.org, Linux-MM , 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 Hi Mike, On Sun, Dec 2, 2018 at 4:43 PM Mike Rapoport wrote: > > On Sun, Dec 02, 2018 at 11:49:44AM +0530, Souptick Joarder wrote: > > 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); > > + > > This seem to belong to include/linux/mm.h, near vm_insert_page() Ok, I will change it. Apart from this change does it looks good ? > > > 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 > > > > -- > Sincerely yours, > Mike. >