From patchwork Tue Oct 2 14:27:19 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomasz Stanislawski X-Patchwork-Id: 11929 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 2ADD61A52FC for ; Tue, 2 Oct 2012 14:29:00 +0000 (UTC) Received: from mail-ia0-f180.google.com (mail-ia0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id C049CA186F4 for ; Tue, 2 Oct 2012 14:28:59 +0000 (UTC) Received: by iagf6 with SMTP id f6so796283iag.11 for ; Tue, 02 Oct 2012 07:28:59 -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:x-auditid :from:to:date:message-id:x-mailer:in-reply-to:references :x-brightmail-tracker: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=0nFfn69kw9QGB92qD9H84qz4N/sqyqslQJCIKhIoPt0=; b=Sm90Pde31lspN+s8riH98f0XJbu7t4YZmRGtkBA1wW++plNMZ/aDqK8NNg6uFZI1Xm 8gqkxkS7GkwpiWiJBRwp+JoFhpZN4RVzQEjX/lexmVEg/czGovFYZYpmqHgYEpUfaDFD CHpId4QWHwXXdmMz8D75cWjXsYSvOh3mbFgX9f+Whs1ZNzR35rfesZKXOzFpZS/DOGKQ yugVTGjAf4au9K6wUSqYK7nC6i/8WhKKAjfpYEnQ6OlFFaHz1cMOSYXLqqlw8m2pKJWc PbMpg23ns3dve2xaMalrxNxp93SlMS1U/Om+tu8YcK3NeHppp0fSPMfGBfJLHMGHP2sq tH6A== Received: by 10.50.150.198 with SMTP id uk6mr8946317igb.43.1349188139152; Tue, 02 Oct 2012 07:28:59 -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 10.50.184.232 with SMTP id ex8csp84969igc; Tue, 2 Oct 2012 07:28:58 -0700 (PDT) Received: by 10.204.130.152 with SMTP id t24mr6675097bks.138.1349188137477; Tue, 02 Oct 2012 07:28:57 -0700 (PDT) Received: from mombin.canonical.com (mombin.canonical.com. [91.189.95.16]) by mx.google.com with ESMTP id ie15si1696066bkc.105.2012.10.02.07.28.56; Tue, 02 Oct 2012 07:28:57 -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 1TJ3Sx-0004dB-9q; Tue, 02 Oct 2012 14:28:55 +0000 Received: from mailout1.samsung.com ([203.254.224.24]) by mombin.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TJ3Sv-0004cv-3M for linaro-mm-sig@lists.linaro.org; Tue, 02 Oct 2012 14:28:53 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MB9006XOS839XL0@mailout1.samsung.com> for linaro-mm-sig@lists.linaro.org; Tue, 02 Oct 2012 23:28:51 +0900 (KST) X-AuditID: cbfee61a-b7f726d000000ec7-0b-506afa2310c5 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id 22.9E.03783.32AFA605; Tue, 02 Oct 2012 23:28:51 +0900 (KST) Received: from mcdsrvbld02.digital.local ([106.116.37.23]) by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MB9005A7S65K790@mmp2.samsung.com> for linaro-mm-sig@lists.linaro.org; Tue, 02 Oct 2012 23:28:51 +0900 (KST) From: Tomasz Stanislawski To: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Date: Tue, 02 Oct 2012 16:27:19 +0200 Message-id: <1349188056-4886-9-git-send-email-t.stanislaws@samsung.com> X-Mailer: git-send-email 1.7.10 In-reply-to: <1349188056-4886-1-git-send-email-t.stanislaws@samsung.com> References: <1349188056-4886-1-git-send-email-t.stanislaws@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCJMWRmVeSWpSXmKPExsVy+t9jQV3lX1kBBts2WVp8ufKQyYHR4/a/ x8wBjFFcNimpOZllqUX6dglcGT27L7AV7LSpuP9zCnMD41aDLkZODgkBE4mLk3YzQdhiEhfu rWfrYuTiEBKYzihxbf9rFghnLZPErKlHWECq2IA6ji35zAhiiwg4SJy+O4sZpIhZYA2zxIuV N9hAEsIC0RK7t71hBrFZBFQlzrYeAmvmFXCXeLRoIzPEOnmJp/f7wOo5BTwkfj65AFYjBFSz Z3kT2wRG3gWMDKsYRVMLkguKk9JzDfWKE3OLS/PS9ZLzczcxgv3+TGoH48oGi0OMAhyMSjy8 O09mBgixJpYVV+YeYpTgYFYS4bW+nxUgxJuSWFmVWpQfX1Sak1p8iFGag0VJnLfZIyVASCA9 sSQ1OzW1ILUIJsvEwSnVwLjs2/sNjyufJl97d6+2OviAyq6Uss+He+Xe2fS9DGE2+tanEldh f7zZefaNW8xuaYYFiVGBvxTYNtZWXwn+9dv9X9vTXM9V8dd3Lpr+77uBrVTJvUBjvi977Sep hc74qrvUuttZoPJrM/PKlVntdw44NR/OfdU1MeJZfMp9huQpC2I6td/cklViKc5INNRiLipO BAAJHkDM9wEAAA== Cc: k.debski@samsung.com, s.nawrocki@samsung.com, 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 Subject: [Linaro-mm-sig] [PATCHv9 08/25] 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: ALoCoQkk8kJt430n1RMSNQbxojfCv2D08mcL5f+xyA7krAiSaxs9LVBQtFrUiZIPLbCBLPvWADew 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 | 226 ++++++++++++++++++++++++++-- 1 file changed, 210 insertions(+), 16 deletions(-) diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index daac2b2..8486e06 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 +164,194 @@ 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) { + pr_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) { + pr_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; + pr_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) { + pr_err("no vma for address %lu\n", vaddr); + ret = -EFAULT; + goto fail_pages; + } + + if (vma->vm_end < vaddr + size) { + pr_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) { + pr_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); + pr_err("failed to get user pages\n"); + goto fail_vma; + } + + sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); + if (!sgt) { + pr_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) { + pr_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) { + pr_err("failed to map scatterlist\n"); + ret = -EIO; + goto fail_sgt_init; + } + + contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < size) { + pr_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); } /*********************************************/