From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:21916 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755876Ab2FNOcn (ORCPT ); Thu, 14 Jun 2012 10:32:43 -0400 Received: from euspt1 (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0M5M001TQ3398Z70@mailout1.w1.samsung.com> for linux-media@vger.kernel.org; Thu, 14 Jun 2012 15:33:09 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0M5M00I7V32DBI@spt1.w1.samsung.com> for linux-media@vger.kernel.org; Thu, 14 Jun 2012 15:32:38 +0100 (BST) Date: Thu, 14 Jun 2012 16:32:29 +0200 From: Tomasz Stanislawski Subject: [PATCHv2 9/9] v4l: vb2-dma-contig: use dma_get_sgtable In-reply-to: <1339684349-28882-1-git-send-email-t.stanislaws@samsung.com> To: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: airlied@redhat.com, m.szyprowski@samsung.com, t.stanislaws@samsung.com, kyungmin.park@samsung.com, laurent.pinchart@ideasonboard.com, sumit.semwal@ti.com, daeinki@gmail.com, daniel.vetter@ffwll.ch, robdclark@gmail.com, pawel@osciak.com, linaro-mm-sig@lists.linaro.org, hverkuil@xs4all.nl, remi@remlab.net, subashrp@gmail.com, mchehab@redhat.com, g.liakhovetski@gmx.de Message-id: <1339684349-28882-10-git-send-email-t.stanislaws@samsung.com> Content-transfer-encoding: 7BIT References: <1339684349-28882-1-git-send-email-t.stanislaws@samsung.com> Sender: linux-media-owner@vger.kernel.org List-ID: This patch removes a workaround for extraction of struct pages from DMA buffer. The method of using follow_pfn for artificial VMA is dropped in favour of dma_get_sgtable function. Signed-off-by: Tomasz Stanislawski Signed-off-by: Kyungmin Park --- drivers/media/video/videobuf2-dma-contig.c | 60 ++-------------------------- 1 file changed, 4 insertions(+), 56 deletions(-) diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index a845ff7..73297b7 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -361,73 +361,21 @@ static struct dma_buf_ops vb2_dc_dmabuf_ops = { .release = vb2_dc_dmabuf_ops_release, }; -/** - * vb2_dc_kaddr_to_pages() - extract list of struct pages from a kernel - * pointer. This function is a workaround to extract pages from a pointer - * returned by dma_alloc_coherent. The pages are obtained by creating an - * artificial vma and using follow_pfn to do a page walk to find a PFN - */ -static int vb2_dc_kaddr_to_pages(unsigned long kaddr, - struct page **pages, unsigned int n_pages) -{ - unsigned int i; - unsigned long pfn; - /* create an artificial VMA */ - struct vm_area_struct vma = { - .vm_flags = VM_IO | VM_PFNMAP, - .vm_mm = &init_mm, - }; - - for (i = 0; i < n_pages; ++i, kaddr += PAGE_SIZE) { - if (follow_pfn(&vma, kaddr, &pfn)) - break; - pages[i] = pfn_to_page(pfn); - } - - return i; -} - static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) { - int n_pages; - struct page **pages = NULL; int ret; struct sg_table *sgt; - n_pages = PAGE_ALIGN(buf->size) >> PAGE_SHIFT; - - pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL); - if (!pages) { - dev_err(buf->dev, "failed to alloc page table\n"); - return ERR_PTR(-ENOMEM); - } - - ret = vb2_dc_kaddr_to_pages((unsigned long)buf->vaddr, pages, n_pages); - if (ret < 0) { - dev_err(buf->dev, "failed to get buffer pages from DMA API\n"); - kfree(pages); - return ERR_PTR(ret); - } - if (ret != n_pages) { - dev_err(buf->dev, "got only %d of %d pages from DMA API\n", - ret, n_pages); - kfree(pages); - return ERR_PTR(-EFAULT); - } - sgt = kmalloc(sizeof *sgt, GFP_KERNEL); if (!sgt) { dev_err(buf->dev, "failed to alloc sg table\n"); - kfree(pages); return ERR_PTR(-ENOMEM); } - ret = sg_alloc_table_from_pages(sgt, pages, n_pages, 0, - buf->size, GFP_KERNEL); - /* failure or not, pages are no longer needed */ - kfree(pages); - if (ret) { - dev_err(buf->dev, "failed to covert pages to sg table\n"); + ret = dma_get_sgtable(buf->dev, sgt, buf->vaddr, buf->dma_addr, + buf->size, NULL); + if (ret < 0) { + dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); kfree(sgt); return ERR_PTR(ret); } -- 1.7.9.5