From patchwork Wed Jun 3 09:34:43 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 6533611 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 49F97C0433 for ; Wed, 3 Jun 2015 09:34:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E511C206B7 for ; Wed, 3 Jun 2015 09:34:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5FDF206A9 for ; Wed, 3 Jun 2015 09:34:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754052AbbFCJet (ORCPT ); Wed, 3 Jun 2015 05:34:49 -0400 Received: from cantor2.suse.de ([195.135.220.15]:59432 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752744AbbFCJer (ORCPT ); Wed, 3 Jun 2015 05:34:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D2E0FABB1; Wed, 3 Jun 2015 09:34:44 +0000 (UTC) Received: by quack.suse.cz (Postfix, from userid 1000) id 84A058281E; Wed, 3 Jun 2015 11:34:43 +0200 (CEST) Date: Wed, 3 Jun 2015 11:34:43 +0200 From: Jan Kara To: Andrew Morton Cc: Jan Kara , linux-mm@kvack.org, linux-media@vger.kernel.org, Hans Verkuil , dri-devel@lists.freedesktop.org, Pawel Osciak , Mauro Carvalho Chehab , mgorman@suse.de, Marek Szyprowski , linux-samsung-soc@vger.kernel.org Subject: Re: [PATCH 2/9] mm: Provide new get_vaddr_frames() helper Message-ID: <20150603093443.GF13054@quack.suse.cz> References: <1431522495-4692-1-git-send-email-jack@suse.cz> <1431522495-4692-3-git-send-email-jack@suse.cz> <20150528162402.19a0a26a5b9eae36aa8050e5@linux-foundation.org> <20150602152300.GD17315@quack.suse.cz> <20150602152912.4851e6fd4213828ddf7eb5b2@linux-foundation.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20150602152912.4851e6fd4213828ddf7eb5b2@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, T_TVD_MIME_EPI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue 02-06-15 15:29:12, Andrew Morton wrote: > On Tue, 2 Jun 2015 17:23:00 +0200 Jan Kara wrote: > > > > That's a lump of new code which many kernels won't be needing. Can we > > > put all this in a new .c file and select it within drivers/media > > > Kconfig? > > So the attached patch should do what you had in mind. OK? > > lgtm. > > > drivers/gpu/drm/exynos/Kconfig | 1 + > > drivers/media/platform/omap/Kconfig | 1 + > > drivers/media/v4l2-core/Kconfig | 1 + > > mm/Kconfig | 3 + > > mm/Makefile | 1 + > > mm/frame-vec.c | 233 ++++++++++++++++++++++++++++++++++++ > > But frame_vector.c would be a more pleasing name. For `struct frame_vector'. OK, makes sense. Updated patch attached. Honza From a129ecf637e75421d823d54eab885cd36e54c6ec Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 2 Jun 2015 16:40:32 +0200 Subject: [PATCH] mm: Move get_vaddr_frames() behind a config option get_vaddr_frames() is used by relatively rare drivers so hide it and the related functions behind a config option that is selected only by drivers that need the infrastructure. Suggested-by: Andrew Morton Signed-off-by: Jan Kara --- drivers/gpu/drm/exynos/Kconfig | 1 + drivers/media/platform/omap/Kconfig | 1 + drivers/media/v4l2-core/Kconfig | 1 + mm/Kconfig | 3 + mm/Makefile | 1 + mm/frame_vector.c | 233 ++++++++++++++++++++++++++++++++++++ mm/gup.c | 225 ---------------------------------- 7 files changed, 240 insertions(+), 225 deletions(-) create mode 100644 mm/frame_vector.c diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig index 0a6780367d28..fc678289cf79 100644 --- a/drivers/gpu/drm/exynos/Kconfig +++ b/drivers/gpu/drm/exynos/Kconfig @@ -71,6 +71,7 @@ config DRM_EXYNOS_VIDI config DRM_EXYNOS_G2D bool "Exynos DRM G2D" depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D + select FRAME_VECTOR help Choose this option if you want to use Exynos G2D for DRM. diff --git a/drivers/media/platform/omap/Kconfig b/drivers/media/platform/omap/Kconfig index dc2aaab54aef..217d613b0fe7 100644 --- a/drivers/media/platform/omap/Kconfig +++ b/drivers/media/platform/omap/Kconfig @@ -10,6 +10,7 @@ config VIDEO_OMAP2_VOUT select OMAP2_DSS if HAS_IOMEM && ARCH_OMAP2PLUS select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3 select VIDEO_OMAP2_VOUT_VRFB if VIDEO_OMAP2_VOUT && OMAP2_VRFB + select FRAME_VECTOR default n ---help--- V4L2 Display driver support for OMAP2/3 based boards. diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig index ba7e21a73023..0cb22add650b 100644 --- a/drivers/media/v4l2-core/Kconfig +++ b/drivers/media/v4l2-core/Kconfig @@ -73,6 +73,7 @@ config VIDEOBUF2_CORE config VIDEOBUF2_MEMOPS tristate + select FRAME_VECTOR config VIDEOBUF2_DMA_CONTIG tristate diff --git a/mm/Kconfig b/mm/Kconfig index 390214da4546..2ca52e9986f0 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -635,3 +635,6 @@ config MAX_STACK_SIZE_MB changed to a smaller value in which case that is used. A sane initial value is 80 MB. + +config FRAME_VECTOR + bool diff --git a/mm/Makefile b/mm/Makefile index 98c4eaeabdcb..be5d5c866305 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -78,3 +78,4 @@ obj-$(CONFIG_CMA) += cma.o obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o +obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o diff --git a/mm/frame_vector.c b/mm/frame_vector.c new file mode 100644 index 000000000000..5d85bcd150ae --- /dev/null +++ b/mm/frame_vector.c @@ -0,0 +1,233 @@ +#include +#include +#include +#include +#include +#include +#include + +/* + * get_vaddr_frames() - map virtual addresses to pfns + * @start: starting user address + * @nr_frames: number of pages / pfns from start to map + * @write: whether pages will be written to by the caller + * @force: whether to force write access even if user mapping is + * readonly. See description of the same argument of + get_user_pages(). + * @vec: structure which receives pages / pfns of the addresses mapped. + * It should have space for at least nr_frames entries. + * + * This function maps virtual addresses from @start and fills @vec structure + * with page frame numbers or page pointers to corresponding pages (choice + * depends on the type of the vma underlying the virtual address). If @start + * belongs to a normal vma, the function grabs reference to each of the pages + * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't + * touch page structures and the caller must make sure pfns aren't reused for + * anything else while he is using them. + * + * The function returns number of pages mapped which may be less than + * @nr_frames. In particular we stop mapping if there are more vmas of + * different type underlying the specified range of virtual addresses. + * When the function isn't able to map a single page, it returns error. + * + * This function takes care of grabbing mmap_sem as necessary. + */ +int get_vaddr_frames(unsigned long start, unsigned int nr_frames, + bool write, bool force, struct frame_vector *vec) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int ret = 0; + int err; + int locked; + + if (nr_frames == 0) + return 0; + + if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) + nr_frames = vec->nr_allocated; + + down_read(&mm->mmap_sem); + locked = 1; + vma = find_vma_intersection(mm, start, start + 1); + if (!vma) { + ret = -EFAULT; + goto out; + } + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { + vec->got_ref = true; + vec->is_pfns = false; + ret = get_user_pages_locked(current, mm, start, nr_frames, + write, force, (struct page **)(vec->ptrs), &locked); + goto out; + } + + vec->got_ref = false; + vec->is_pfns = true; + do { + unsigned long *nums = frame_vector_pfns(vec); + + while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { + err = follow_pfn(vma, start, &nums[ret]); + if (err) { + if (ret == 0) + ret = err; + goto out; + } + start += PAGE_SIZE; + ret++; + } + /* + * We stop if we have enough pages or if VMA doesn't completely + * cover the tail page. + */ + if (ret >= nr_frames || start < vma->vm_end) + break; + vma = find_vma_intersection(mm, start, start + 1); + } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); +out: + if (locked) + up_read(&mm->mmap_sem); + if (!ret) + ret = -EFAULT; + if (ret > 0) + vec->nr_frames = ret; + return ret; +} +EXPORT_SYMBOL(get_vaddr_frames); + +/** + * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired + * them + * @vec: frame vector to put + * + * Drop references to pages if get_vaddr_frames() acquired them. We also + * invalidate the frame vector so that it is prepared for the next call into + * get_vaddr_frames(). + */ +void put_vaddr_frames(struct frame_vector *vec) +{ + int i; + struct page **pages; + + if (!vec->got_ref) + goto out; + pages = frame_vector_pages(vec); + /* + * frame_vector_pages() might needed to do a conversion when + * get_vaddr_frames() got pages but vec was later converted to pfns. + * But it shouldn't really fail to convert pfns back... + */ + if (WARN_ON(IS_ERR(pages))) + goto out; + for (i = 0; i < vec->nr_frames; i++) + put_page(pages[i]); + vec->got_ref = false; +out: + vec->nr_frames = 0; +} +EXPORT_SYMBOL(put_vaddr_frames); + +/** + * frame_vector_to_pages - convert frame vector to contain page pointers + * @vec: frame vector to convert + * + * Convert @vec to contain array of page pointers. If the conversion is + * successful, return 0. Otherwise return an error. Note that we do not grab + * page references for the page structures. + */ +int frame_vector_to_pages(struct frame_vector *vec) +{ + int i; + unsigned long *nums; + struct page **pages; + + if (!vec->is_pfns) + return 0; + nums = frame_vector_pfns(vec); + for (i = 0; i < vec->nr_frames; i++) + if (!pfn_valid(nums[i])) + return -EINVAL; + pages = (struct page **)nums; + for (i = 0; i < vec->nr_frames; i++) + pages[i] = pfn_to_page(nums[i]); + vec->is_pfns = false; + return 0; +} +EXPORT_SYMBOL(frame_vector_to_pages); + +/** + * frame_vector_to_pfns - convert frame vector to contain pfns + * @vec: frame vector to convert + * + * Convert @vec to contain array of pfns. + */ +void frame_vector_to_pfns(struct frame_vector *vec) +{ + int i; + unsigned long *nums; + struct page **pages; + + if (vec->is_pfns) + return; + pages = (struct page **)(vec->ptrs); + nums = (unsigned long *)pages; + for (i = 0; i < vec->nr_frames; i++) + nums[i] = page_to_pfn(pages[i]); + vec->is_pfns = true; +} +EXPORT_SYMBOL(frame_vector_to_pfns); + +/** + * frame_vector_create() - allocate & initialize structure for pinned pfns + * @nr_frames: number of pfns slots we should reserve + * + * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns + * pfns. + */ +struct frame_vector *frame_vector_create(unsigned int nr_frames) +{ + struct frame_vector *vec; + int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; + + if (WARN_ON_ONCE(nr_frames == 0)) + return NULL; + /* + * This is absurdly high. It's here just to avoid strange effects when + * arithmetics overflows. + */ + if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) + return NULL; + /* + * Avoid higher order allocations, use vmalloc instead. It should + * be rare anyway. + */ + if (size <= PAGE_SIZE) + vec = kmalloc(size, GFP_KERNEL); + else + vec = vmalloc(size); + if (!vec) + return NULL; + vec->nr_allocated = nr_frames; + vec->nr_frames = 0; + return vec; +} +EXPORT_SYMBOL(frame_vector_create); + +/** + * frame_vector_destroy() - free memory allocated to carry frame vector + * @vec: Frame vector to free + * + * Free structure allocated by frame_vector_create() to carry frames. + */ +void frame_vector_destroy(struct frame_vector *vec) +{ + /* Make sure put_vaddr_frames() got called properly... */ + VM_BUG_ON(vec->nr_frames > 0); + if (!is_vmalloc_addr(vec)) + kfree(vec); + else + vfree(vec); +} +EXPORT_SYMBOL(frame_vector_destroy); + diff --git a/mm/gup.c b/mm/gup.c index 9d7f4fde30cb..222d57e335f9 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -937,231 +937,6 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) return ret; /* 0 or negative error code */ } -/* - * get_vaddr_frames() - map virtual addresses to pfns - * @start: starting user address - * @nr_frames: number of pages / pfns from start to map - * @write: whether pages will be written to by the caller - * @force: whether to force write access even if user mapping is - * readonly. See description of the same argument of - get_user_pages(). - * @vec: structure which receives pages / pfns of the addresses mapped. - * It should have space for at least nr_frames entries. - * - * This function maps virtual addresses from @start and fills @vec structure - * with page frame numbers or page pointers to corresponding pages (choice - * depends on the type of the vma underlying the virtual address). If @start - * belongs to a normal vma, the function grabs reference to each of the pages - * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't - * touch page structures and the caller must make sure pfns aren't reused for - * anything else while he is using them. - * - * The function returns number of pages mapped which may be less than - * @nr_frames. In particular we stop mapping if there are more vmas of - * different type underlying the specified range of virtual addresses. - * When the function isn't able to map a single page, it returns error. - * - * This function takes care of grabbing mmap_sem as necessary. - */ -int get_vaddr_frames(unsigned long start, unsigned int nr_frames, - bool write, bool force, struct frame_vector *vec) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - int ret = 0; - int err; - int locked; - - if (nr_frames == 0) - return 0; - - if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) - nr_frames = vec->nr_allocated; - - down_read(&mm->mmap_sem); - locked = 1; - vma = find_vma_intersection(mm, start, start + 1); - if (!vma) { - ret = -EFAULT; - goto out; - } - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { - vec->got_ref = true; - vec->is_pfns = false; - ret = get_user_pages_locked(current, mm, start, nr_frames, - write, force, (struct page **)(vec->ptrs), &locked); - goto out; - } - - vec->got_ref = false; - vec->is_pfns = true; - do { - unsigned long *nums = frame_vector_pfns(vec); - - while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { - err = follow_pfn(vma, start, &nums[ret]); - if (err) { - if (ret == 0) - ret = err; - goto out; - } - start += PAGE_SIZE; - ret++; - } - /* - * We stop if we have enough pages or if VMA doesn't completely - * cover the tail page. - */ - if (ret >= nr_frames || start < vma->vm_end) - break; - vma = find_vma_intersection(mm, start, start + 1); - } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); -out: - if (locked) - up_read(&mm->mmap_sem); - if (!ret) - ret = -EFAULT; - if (ret > 0) - vec->nr_frames = ret; - return ret; -} -EXPORT_SYMBOL(get_vaddr_frames); - -/** - * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired - * them - * @vec: frame vector to put - * - * Drop references to pages if get_vaddr_frames() acquired them. We also - * invalidate the frame vector so that it is prepared for the next call into - * get_vaddr_frames(). - */ -void put_vaddr_frames(struct frame_vector *vec) -{ - int i; - struct page **pages; - - if (!vec->got_ref) - goto out; - pages = frame_vector_pages(vec); - /* - * frame_vector_pages() might needed to do a conversion when - * get_vaddr_frames() got pages but vec was later converted to pfns. - * But it shouldn't really fail to convert pfns back... - */ - if (WARN_ON(IS_ERR(pages))) - goto out; - for (i = 0; i < vec->nr_frames; i++) - put_page(pages[i]); - vec->got_ref = false; -out: - vec->nr_frames = 0; -} -EXPORT_SYMBOL(put_vaddr_frames); - -/** - * frame_vector_to_pages - convert frame vector to contain page pointers - * @vec: frame vector to convert - * - * Convert @vec to contain array of page pointers. If the conversion is - * successful, return 0. Otherwise return an error. Note that we do not grab - * page references for the page structures. - */ -int frame_vector_to_pages(struct frame_vector *vec) -{ - int i; - unsigned long *nums; - struct page **pages; - - if (!vec->is_pfns) - return 0; - nums = frame_vector_pfns(vec); - for (i = 0; i < vec->nr_frames; i++) - if (!pfn_valid(nums[i])) - return -EINVAL; - pages = (struct page **)nums; - for (i = 0; i < vec->nr_frames; i++) - pages[i] = pfn_to_page(nums[i]); - vec->is_pfns = false; - return 0; -} -EXPORT_SYMBOL(frame_vector_to_pages); - -/** - * frame_vector_to_pfns - convert frame vector to contain pfns - * @vec: frame vector to convert - * - * Convert @vec to contain array of pfns. - */ -void frame_vector_to_pfns(struct frame_vector *vec) -{ - int i; - unsigned long *nums; - struct page **pages; - - if (vec->is_pfns) - return; - pages = (struct page **)(vec->ptrs); - nums = (unsigned long *)pages; - for (i = 0; i < vec->nr_frames; i++) - nums[i] = page_to_pfn(pages[i]); - vec->is_pfns = true; -} -EXPORT_SYMBOL(frame_vector_to_pfns); - -/** - * frame_vector_create() - allocate & initialize structure for pinned pfns - * @nr_frames: number of pfns slots we should reserve - * - * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns - * pfns. - */ -struct frame_vector *frame_vector_create(unsigned int nr_frames) -{ - struct frame_vector *vec; - int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; - - if (WARN_ON_ONCE(nr_frames == 0)) - return NULL; - /* - * This is absurdly high. It's here just to avoid strange effects when - * arithmetics overflows. - */ - if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) - return NULL; - /* - * Avoid higher order allocations, use vmalloc instead. It should - * be rare anyway. - */ - if (size <= PAGE_SIZE) - vec = kmalloc(size, GFP_KERNEL); - else - vec = vmalloc(size); - if (!vec) - return NULL; - vec->nr_allocated = nr_frames; - vec->nr_frames = 0; - return vec; -} -EXPORT_SYMBOL(frame_vector_create); - -/** - * frame_vector_destroy() - free memory allocated to carry frame vector - * @vec: Frame vector to free - * - * Free structure allocated by frame_vector_create() to carry frames. - */ -void frame_vector_destroy(struct frame_vector *vec) -{ - /* Make sure put_vaddr_frames() got called properly... */ - VM_BUG_ON(vec->nr_frames > 0); - if (!is_vmalloc_addr(vec)) - kfree(vec); - else - vfree(vec); -} -EXPORT_SYMBOL(frame_vector_destroy); - /** * get_dump_page() - pin user page in memory while writing it to core dump * @addr: user address -- 2.1.4