From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Subject: Re: [PATCH v2 1/9] mm: Introduce new vm_insert_range API Date: Sun, 2 Dec 2018 13:13:13 +0200 Message-ID: <20181202111313.GC6959@rapoport-lnx> References: <20181202061944.GA3094@jordon-HP-15-Notebook-PC> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20181202061944.GA3094@jordon-HP-15-Notebook-PC> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Souptick Joarder Cc: mhocko-IBi9RG/b67k@public.gmane.org, heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org, peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux1394-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org, oleksandr_andrushchenko-uRwfk40T5oI@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, airlied-cv59FeDIM0c@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, pawel-FA/gS7QP4orQT0dZR+AlfA@public.gmane.org, riel-ebMLmSuQjDVBDgjK7y7TUQ@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, rppt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, boris.ostrovsky-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, mchehab-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, iamjoonsoo.kim-Hm3cg6mZ9cc@public.gmane.org, vbabka-AlSwsSmVLrQ@public.gmane.org, jgross-IBi9RG/b67k@public.gmane.org, hjc-TNX95d0MmH7DzftRWevZcw@public.gmane.org, xen-devel-GuqFBffKawuEi8DpZVb4nw@public.gmane.org, kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, stefanr-MtYdepGKPcBMYopoZt5u/LNAH6kLmebB@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org, kirill.shutemov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org List-Id: linux-rockchip.vger.kernel.org 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() > 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.