From patchwork Thu Jun 14 13:37:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomasz Stanislawski X-Patchwork-Id: 9292 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 4BD1A23E1B for ; Thu, 14 Jun 2012 13:38:33 +0000 (UTC) Received: from mail-gh0-f180.google.com (mail-gh0-f180.google.com [209.85.160.180]) by fiordland.canonical.com (Postfix) with ESMTP id 1AFE8A189E3 for ; Thu, 14 Jun 2012 13:38:33 +0000 (UTC) Received: by mail-gh0-f180.google.com with SMTP id z12so1434559ghb.11 for ; Thu, 14 Jun 2012 06:38:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:date:from :in-reply-to:to:message-id:x-mailer:references:x-tm-as-mml:cc :subject:x-beenthere:x-mailman-version:precedence:list-id :list-unsubscribe:list-archive:list-post:list-help:list-subscribe :mime-version:content-type:content-transfer-encoding:sender :errors-to:x-gm-message-state; bh=M4SSUfpibMgGsjG9XVcpd4k2oJ+v1RJXPhGPM3FVnG0=; b=QF7o6n0EeV8WlU5gLHdWewJPJwVEfJsXroN5ZBvTOKGLMdI/4b16DMHxdOFA3r6Hk4 735L1jn4xi8WwcazDoHXcAqZw8KR4zE8bSSOq3BYQmRJoQdnXYnunOhDjTdZFZXGF4nH Vzg12He+wZ/6gCXXo2/HwTu36jMPlsDIbEs8BY86ZSGBPgV9zrsc1qBhp9hPYRrTmap3 ueNCm6WPGmNW7+Gc4dhtspUYx8Miiff4oKYXq9+vq1+MuPdXZ0/UD9mM8oggKSwy6YLR ijdDXF+4pYI+Nycd3Z+i7kTfrtjOukufuV9sPDL4KyZKhKa5Tifiu/xpuotqHJKWq9Fw MUdw== Received: by 10.50.46.232 with SMTP id y8mr768312igm.57.1339681112451; Thu, 14 Jun 2012 06:38:32 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.24.148 with SMTP id v20csp85269ibb; Thu, 14 Jun 2012 06:38:29 -0700 (PDT) Received: by 10.180.107.99 with SMTP id hb3mr47130206wib.0.1339681107861; Thu, 14 Jun 2012 06:38:27 -0700 (PDT) Received: from mombin.canonical.com (mombin.canonical.com. [91.189.95.16]) by mx.google.com with ESMTP id m8si12447784wiy.27.2012.06.14.06.38.26; Thu, 14 Jun 2012 06:38:27 -0700 (PDT) Received-SPF: neutral (google.com: 91.189.95.16 is neither permitted nor denied by best guess record for domain of linaro-mm-sig-bounces@lists.linaro.org) client-ip=91.189.95.16; Authentication-Results: mx.google.com; spf=neutral (google.com: 91.189.95.16 is neither permitted nor denied by best guess record for domain of linaro-mm-sig-bounces@lists.linaro.org) smtp.mail=linaro-mm-sig-bounces@lists.linaro.org Received: from localhost ([127.0.0.1] helo=mombin.canonical.com) by mombin.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1SfAFl-0006vT-Lf; Thu, 14 Jun 2012 13:38:25 +0000 Received: from mailout3.w1.samsung.com ([210.118.77.13]) by mombin.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1SfAFZ-0006q8-Jr for linaro-mm-sig@lists.linaro.org; Thu, 14 Jun 2012 13:38:13 +0000 Received: from euspt2 (mailout3.w1.samsung.com [210.118.77.13]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0M5M006UL0KNVP60@mailout3.w1.samsung.com> for linaro-mm-sig@lists.linaro.org; Thu, 14 Jun 2012 14:38:47 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0M5M00GT30JJ22@spt2.w1.samsung.com> for linaro-mm-sig@lists.linaro.org; Thu, 14 Jun 2012 14:38:08 +0100 (BST) Received: from mcdsrvbld02.digital.local (unknown [106.116.37.23]) by linux.samsung.com (Postfix) with ESMTP id 47E7827016B; Thu, 14 Jun 2012 15:42:38 +0200 (CEST) Date: Thu, 14 Jun 2012 15:37:42 +0200 From: Tomasz Stanislawski In-reply-to: <1339681069-8483-1-git-send-email-t.stanislaws@samsung.com> To: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Message-id: <1339681069-8483-9-git-send-email-t.stanislaws@samsung.com> X-Mailer: git-send-email 1.7.10 References: <1339681069-8483-1-git-send-email-t.stanislaws@samsung.com> X-TM-AS-MML: No Cc: pawel@osciak.com, sumit.semwal@ti.com, mchehab@redhat.com, robdclark@gmail.com, linaro-mm-sig@lists.linaro.org, kyungmin.park@samsung.com, laurent.pinchart@ideasonboard.com, airlied@redhat.com, remi@remlab.net, g.liakhovetski@gmx.de Subject: [Linaro-mm-sig] [PATCHv7 08/15] v4l: vb2-dma-contig: add support for scatterlist in userptr mode X-BeenThere: linaro-mm-sig@lists.linaro.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Unified memory management interest group." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linaro-mm-sig-bounces@lists.linaro.org Errors-To: linaro-mm-sig-bounces@lists.linaro.org X-Gm-Message-State: ALoCoQlK1pj3dh1h0I4WGIT/FuJk2QrEuxvfAfAAzcdaetGS7AlV0kNbHgNpo86PNCtx+4FKXLfD This patch introduces usage of dma_map_sg to map memory behind a userspace pointer to a device as dma-contiguous mapping. This patch contains some of the code kindly provided by Marek Szyprowski and Kamil Debski and Andrzej Pietrasiewicz . Kind thanks for bug reports from Laurent Pinchart and Seung-Woo Kim . Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park Acked-by: Laurent Pinchart --- drivers/media/video/videobuf2-dma-contig.c | 229 ++++++++++++++++++++++++++-- 1 file changed, 213 insertions(+), 16 deletions(-) diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index daac2b2..94f0874 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -11,6 +11,8 @@ */ #include +#include +#include #include #include @@ -27,6 +29,8 @@ struct vb2_dc_buf { void *vaddr; unsigned long size; dma_addr_t dma_addr; + enum dma_data_direction dma_dir; + struct sg_table *dma_sgt; /* MMAP related */ struct vb2_vmarea_handler handler; @@ -37,6 +41,44 @@ struct vb2_dc_buf { }; /*********************************************/ +/* scatterlist table functions */ +/*********************************************/ + + +static void vb2_dc_sgt_foreach_page(struct sg_table *sgt, + void (*cb)(struct page *pg)) +{ + struct scatterlist *s; + unsigned int i; + + for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { + struct page *page = sg_page(s); + unsigned int n_pages = PAGE_ALIGN(s->offset + s->length) + >> PAGE_SHIFT; + unsigned int j; + + for (j = 0; j < n_pages; ++j, ++page) + cb(page); + } +} + +static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) +{ + struct scatterlist *s; + dma_addr_t expected = sg_dma_address(sgt->sgl); + unsigned int i; + unsigned long size = 0; + + for_each_sg(sgt->sgl, s, sgt->nents, i) { + if (sg_dma_address(s) != expected) + break; + expected = sg_dma_address(s) + sg_dma_len(s); + size += sg_dma_len(s); + } + return size; +} + +/*********************************************/ /* callbacks for all buffers */ /*********************************************/ @@ -122,42 +164,197 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) /* callbacks for USERPTR buffers */ /*********************************************/ +static inline int vma_is_io(struct vm_area_struct *vma) +{ + return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); +} + +static int vb2_dc_get_user_pages(unsigned long start, struct page **pages, + int n_pages, struct vm_area_struct *vma, int write) +{ + if (vma_is_io(vma)) { + unsigned int i; + + for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) { + unsigned long pfn; + int ret = follow_pfn(vma, start, &pfn); + + if (ret) { + printk(KERN_ERR "no page for address %lu\n", + start); + return ret; + } + pages[i] = pfn_to_page(pfn); + } + } else { + int n; + + n = get_user_pages(current, current->mm, start & PAGE_MASK, + n_pages, write, 1, pages, NULL); + /* negative error means that no page was pinned */ + n = max(n, 0); + if (n != n_pages) { + printk(KERN_ERR "got only %d of %d user pages\n", + n, n_pages); + while (n) + put_page(pages[--n]); + return -EFAULT; + } + } + + return 0; +} + +static void vb2_dc_put_dirty_page(struct page *page) +{ + set_page_dirty_lock(page); + put_page(page); +} + +static void vb2_dc_put_userptr(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); + if (!vma_is_io(buf->vma)) + vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page); + + sg_free_table(sgt); + kfree(sgt); + vb2_put_vma(buf->vma); + kfree(buf); +} + static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, - unsigned long size, int write) + unsigned long size, int write) { + struct vb2_dc_conf *conf = alloc_ctx; struct vb2_dc_buf *buf; + unsigned long start; + unsigned long end; + unsigned long offset; + struct page **pages; + int n_pages; + int ret = 0; struct vm_area_struct *vma; - dma_addr_t dma_addr = 0; - int ret; + struct sg_table *sgt; + unsigned long contig_size; buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) return ERR_PTR(-ENOMEM); - ret = vb2_get_contig_userptr(vaddr, size, &vma, &dma_addr); + buf->dev = conf->dev; + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + + start = vaddr & PAGE_MASK; + offset = vaddr & ~PAGE_MASK; + end = PAGE_ALIGN(vaddr + size); + n_pages = (end - start) >> PAGE_SHIFT; + + pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL); + if (!pages) { + ret = -ENOMEM; + printk(KERN_ERR "failed to allocate pages table\n"); + goto fail_buf; + } + + /* current->mm->mmap_sem is taken by videobuf2 core */ + vma = find_vma(current->mm, vaddr); + if (!vma) { + printk(KERN_ERR "no vma for address %lu\n", vaddr); + ret = -EFAULT; + goto fail_pages; + } + + if (vma->vm_end < vaddr + size) { + printk(KERN_ERR "vma at %lu is too small for %lu bytes\n", + vaddr, size); + ret = -EFAULT; + goto fail_pages; + } + + buf->vma = vb2_get_vma(vma); + if (!buf->vma) { + printk(KERN_ERR "failed to copy vma\n"); + ret = -ENOMEM; + goto fail_pages; + } + + /* extract page list from userspace mapping */ + ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, write); if (ret) { - printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n", - vaddr); - kfree(buf); - return ERR_PTR(ret); + printk(KERN_ERR "failed to get user pages\n"); + goto fail_vma; + } + + sgt = kzalloc(sizeof *sgt, GFP_KERNEL); + if (!sgt) { + printk(KERN_ERR "failed to allocate sg table\n"); + ret = -ENOMEM; + goto fail_get_user_pages; + } + + ret = sg_alloc_table_from_pages(sgt, pages, n_pages, + offset, size, GFP_KERNEL); + if (ret) { + printk(KERN_ERR "failed to initialize sg table\n"); + goto fail_sgt; + } + + /* pages are no longer needed */ + kfree(pages); + pages = NULL; + + sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents, + buf->dma_dir); + if (sgt->nents <= 0) { + printk(KERN_ERR "failed to map scatterlist\n"); + ret = -EIO; + goto fail_sgt_init; + } + + contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < size) { + printk(KERN_ERR "contiguous mapping is too small %lu/%lu\n", + contig_size, size); + ret = -EFAULT; + goto fail_map_sg; } + buf->dma_addr = sg_dma_address(sgt->sgl); buf->size = size; - buf->dma_addr = dma_addr; - buf->vma = vma; + buf->dma_sgt = sgt; return buf; -} -static void vb2_dc_put_userptr(void *mem_priv) -{ - struct vb2_dc_buf *buf = mem_priv; +fail_map_sg: + dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); - if (!buf) - return; +fail_sgt_init: + if (!vma_is_io(buf->vma)) + vb2_dc_sgt_foreach_page(sgt, put_page); + sg_free_table(sgt); + +fail_sgt: + kfree(sgt); +fail_get_user_pages: + if (pages && !vma_is_io(buf->vma)) + while (n_pages) + put_page(pages[--n_pages]); + +fail_vma: vb2_put_vma(buf->vma); + +fail_pages: + kfree(pages); /* kfree is NULL-proof */ + +fail_buf: kfree(buf); + + return ERR_PTR(ret); } /*********************************************/