![James Harper](/assets/img/avatar_default.png)
Patch originally written by Konrad. Rebased on current linux media tree. Under Xen, vmalloc_32() isn't guaranteed to return pages which are really under 4G in machine physical addresses (only in virtual pseudo-physical addresses). To work around this, implement a vmalloc variant which allocates each page with dma_alloc_coherent() to guarantee that each page is suitable for the device in question. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: James Harper <james.harper@ejbdigital.com.au> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
114 lines
3.4 KiB
C
114 lines
3.4 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
void videobuf_dma_init(struct videobuf_dmabuf *dma);
|
|
int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
|
|
unsigned long data, unsigned long size);
|
|
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
|
|
int nr_pages);
|
|
int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
|
|
dma_addr_t addr, int nr_pages);
|
|
int videobuf_dma_free(struct videobuf_dmabuf *dma);
|
|
|
|
int videobuf_dma_map(struct device *dev, 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 */
|
|
|