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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/include/media/videobuf-dma-sg.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/include/media/videobuf-dma-sg.h')
-rw-r--r--kernel/include/media/videobuf-dma-sg.h105
1 files changed, 105 insertions, 0 deletions
diff --git a/kernel/include/media/videobuf-dma-sg.h b/kernel/include/media/videobuf-dma-sg.h
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+++ b/kernel/include/media/videobuf-dma-sg.h
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+/*
+ * helper functions for SG DMA video4linux capture buffers
+ *
+ * The functions expect the hardware being able to scatter gather
+ * (i.e. the buffers are not linear in physical memory, but fragmented
+ * into PAGE_SIZE chunks). They also assume the driver does not need
+ * to touch the video data.
+ *
+ * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ *
+ * Highly based on video-buf written originally by:
+ * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
+ * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ * (c) 2006 Ted Walther and John Sokol
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2
+ */
+#ifndef _VIDEOBUF_DMA_SG_H
+#define _VIDEOBUF_DMA_SG_H
+
+#include <media/videobuf-core.h>
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * A small set of helper functions to manage buffers (both userland
+ * and kernel) for DMA.
+ *
+ * videobuf_dma_init_*()
+ * creates a buffer. The userland version takes a userspace
+ * pointer + length. The kernel version just wants the size and
+ * does memory allocation too using vmalloc_32().
+ *
+ * videobuf_dma_*()
+ * see Documentation/DMA-API-HOWTO.txt, these functions to
+ * basically the same. The map function does also build a
+ * scatterlist for the buffer (and unmap frees it ...)
+ *
+ * videobuf_dma_free()
+ * no comment ...
+ *
+ */
+
+struct videobuf_dmabuf {
+ u32 magic;
+
+ /* for userland buffer */
+ int offset;
+ size_t size;
+ struct page **pages;
+
+ /* for kernel buffers */
+ void *vaddr;
+ struct page **vaddr_pages;
+ dma_addr_t *dma_addr;
+ struct device *dev;
+
+ /* for overlay buffers (pci-pci dma) */
+ dma_addr_t bus_addr;
+
+ /* common */
+ struct scatterlist *sglist;
+ int sglen;
+ int nr_pages;
+ int direction;
+};
+
+struct videobuf_dma_sg_memory {
+ u32 magic;
+
+ /* for mmap'ed buffers */
+ struct videobuf_dmabuf dma;
+};
+
+/*
+ * Scatter-gather DMA buffer API.
+ *
+ * These functions provide a simple way to create a page list and a
+ * scatter-gather list from a kernel, userspace of physical address and map the
+ * memory for DMA operation.
+ *
+ * Despite the name, this is totally unrelated to videobuf, except that
+ * videobuf-dma-sg uses the same API internally.
+ */
+int videobuf_dma_free(struct videobuf_dmabuf *dma);
+
+int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma);
+struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf);
+
+void *videobuf_sg_alloc(size_t size);
+
+void videobuf_queue_sg_init(struct videobuf_queue *q,
+ const struct videobuf_queue_ops *ops,
+ struct device *dev,
+ spinlock_t *irqlock,
+ enum v4l2_buf_type type,
+ enum v4l2_field field,
+ unsigned int msize,
+ void *priv,
+ struct mutex *ext_lock);
+
+#endif /* _VIDEOBUF_DMA_SG_H */
+