Commit 62c22274 authored by Gerd Knorr's avatar Gerd Knorr Committed by Linus Torvalds

[PATCH] v4l: new videobuf helper module

This patch adds a helper module to manage pci dma buffers for video
frames.  I've recently started writing a driver for another frame
grabber / TV card chip and tried to separate out common code to avoid
duplicating code.  The bttv core update (next mail) depends this patch.
parent a7856647
......@@ -25,7 +25,7 @@ O_TARGET := video.o
# All of the (potential) objects that export symbols.
# This list comes from 'grep -l EXPORT_SYMBOL *.[hc]'.
export-objs := i2c-old.o videodev.o bttv-if.o cpia.o
export-objs := i2c-old.o videodev.o bttv-if.o cpia.o video-buf.o
list-multi := bttv.o zoran.o
bttv-objs := bttv-driver.o bttv-cards.o bttv-if.o
......@@ -35,7 +35,7 @@ obj-$(CONFIG_VIDEO_DEV) += videodev.o
obj-$(CONFIG_BUS_I2C) += i2c-old.o
obj-$(CONFIG_VIDEO_BT848) += bttv.o msp3400.o tvaudio.o \
tda7432.o tda9875.o tuner.o
tda7432.o tda9875.o tuner.o video-buf.o
obj-$(CONFIG_SOUND_TVMIXER) += tvmixer.o
obj-$(CONFIG_VIDEO_ZR36120) += zoran.o
......
/*
* generic helper functions for video4linux capture buffers, to handle
* memory management and PCI DMA. Right now bttv + saa7134 use it.
*
* The functions expect the hardware being able to scatter gatter
* (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 (thus it is probably not useful for USB as
* data often must be uncompressed by the drivers).
*
* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
*
* 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 of the License, or
* (at your option) any later version.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/iobuf.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include "video-buf.h"
static int debug = 0;
MODULE_DESCRIPTION("helper module to manage video4linux pci dma buffers");
MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
MODULE_LICENSE("GPL");
MODULE_PARM(debug,"i");
#define dprintk(level, fmt, arg...) if (debug >= level) \
printk(KERN_DEBUG "vbuf: " fmt, ## arg)
struct scatterlist*
videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
{
struct scatterlist *sglist;
struct page *pg;
int i;
sglist = kmalloc(sizeof(struct scatterlist)*nr_pages, GFP_KERNEL);
if (NULL == sglist)
return NULL;
memset(sglist,0,sizeof(struct scatterlist)*nr_pages);
for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
pg = vmalloc_to_page(virt);
if (NULL == pg)
goto err;
if (PageHighMem(pg))
BUG();
sglist[i].page = pg;
sglist[i].length = PAGE_SIZE;
}
return sglist;
err:
kfree(sglist);
return NULL;
}
struct scatterlist*
videobuf_iobuf_to_sg(struct kiobuf *iobuf)
{
struct scatterlist *sglist;
int i = 0;
sglist = kmalloc(sizeof(struct scatterlist) * iobuf->nr_pages,
GFP_KERNEL);
if (NULL == sglist)
return NULL;
memset(sglist,0,sizeof(struct scatterlist) * iobuf->nr_pages);
if (NULL == iobuf->maplist[0])
goto err;
if (PageHighMem(iobuf->maplist[0]))
/* DMA to highmem pages might not work */
goto err;
sglist[0].page = iobuf->maplist[0];
sglist[0].offset = iobuf->offset;
sglist[0].length = PAGE_SIZE - iobuf->offset;
for (i = 1; i < iobuf->nr_pages; i++) {
if (NULL == iobuf->maplist[i])
goto err;
if (PageHighMem(iobuf->maplist[i]))
goto err;
sglist[i].page = iobuf->maplist[i];
sglist[i].length = PAGE_SIZE;
}
return sglist;
err:
kfree(sglist);
return NULL;
}
/* --------------------------------------------------------------------- */
int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
unsigned long data, unsigned long size)
{
int err, rw = 0;
dma->direction = direction;
switch (dma->direction) {
case PCI_DMA_FROMDEVICE: rw = READ; break;
case PCI_DMA_TODEVICE: rw = WRITE; break;
default: BUG();
}
if (0 != (err = alloc_kiovec(1,&dma->iobuf)))
return err;
if (0 != (err = map_user_kiobuf(rw, dma->iobuf, data, size))) {
dprintk(1,"map_user_kiobuf: %d\n",err);
return err;
}
dma->nr_pages = dma->iobuf->nr_pages;
return 0;
}
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
int nr_pages)
{
dma->direction = direction;
dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
if (NULL == dma->vmalloc) {
dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
return -ENOMEM;
}
memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
dma->nr_pages = nr_pages;
return 0;
}
int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
{
int err;
if (0 == dma->nr_pages)
BUG();
if (dma->iobuf) {
if (0 != (err = lock_kiovec(1,&dma->iobuf,1))) {
dprintk(1,"lock_kiovec: %d\n",err);
return err;
}
dma->sglist = videobuf_iobuf_to_sg(dma->iobuf);
}
if (dma->vmalloc) {
dma->sglist = videobuf_vmalloc_to_sg
(dma->vmalloc,dma->nr_pages);
}
if (NULL == dma->sglist) {
dprintk(1,"scatterlist is NULL\n");
return -ENOMEM;
}
dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
dma->direction);
return 0;
}
int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
{
if (!dma->sglen)
BUG();
pci_dma_sync_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
return 0;
}
int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
{
if (!dma->sglen)
return 0;
pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
kfree(dma->sglist);
dma->sglist = NULL;
dma->sglen = 0;
if (dma->iobuf)
unlock_kiovec(1,&dma->iobuf);
return 0;
}
int videobuf_dma_free(struct videobuf_dmabuf *dma)
{
if (dma->sglen)
BUG();
if (dma->iobuf) {
unmap_kiobuf(dma->iobuf);
free_kiovec(1,&dma->iobuf);
dma->iobuf = NULL;
}
if (dma->vmalloc) {
vfree(dma->vmalloc);
dma->vmalloc = NULL;
}
dma->direction = PCI_DMA_NONE;
return 0;
}
/* --------------------------------------------------------------------- */
void* videobuf_alloc(int size, int type)
{
struct videobuf_buffer *vb;
vb = kmalloc(size,GFP_KERNEL);
if (NULL != vb) {
memset(vb,0,size);
vb->type = type;
init_waitqueue_head(&vb->done);
}
return vb;
}
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
{
int retval = 0;
DECLARE_WAITQUEUE(wait, current);
add_wait_queue(&vb->done, &wait);
while (vb->state == STATE_ACTIVE ||
vb->state == STATE_QUEUED) {
if (non_blocking) {
retval = -EAGAIN;
break;
}
current->state = intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
schedule();
if (intr && signal_pending(current)) {
dprintk(1,"buffer waiton: -EINTR\n");
retval = -EINTR;
break;
}
}
remove_wait_queue(&vb->done, &wait);
return retval;
}
int
videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb)
{
int err,pages;
if (0 == vb->baddr) {
/* no userspace addr -- kernel bounce buffer */
pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
dprintk(1,"kernel buf size=%ld (%d pages)\n",
vb->size,pages);
err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
pages);
if (0 != err)
return err;
} else {
/* dma directly to userspace */
dprintk(1,"user buf addr=%08lx size=%ld\n",
vb->baddr,vb->bsize);
err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
vb->baddr,vb->bsize);
if (0 != err)
return err;
}
err = videobuf_dma_pci_map(pci,&vb->dma);
if (0 != err)
return err;
return 0;
}
#ifdef HAVE_V4L2
extern void
videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb)
{
b->index = vb->i;
b->type = vb->type;
b->offset = vb->boff;
b->length = vb->bsize;
b->flags = 0;
if (vb->map)
b->flags |= V4L2_BUF_FLAG_MAPPED;
switch (vb->state) {
case STATE_PREPARED:
case STATE_QUEUED:
case STATE_ACTIVE:
b->flags |= V4L2_BUF_FLAG_QUEUED;
break;
case STATE_DONE:
case STATE_ERROR:
b->flags |= V4L2_BUF_FLAG_DONE;
break;
case STATE_NEEDS_INIT:
case STATE_IDLE:
/* nothing */
break;
}
if (!(vb->field & VBUF_FIELD_INTER)) {
if (vb->field & VBUF_FIELD_ODD)
b->flags |= V4L2_BUF_FLAG_TOPFIELD;
if (vb->field & VBUF_FIELD_EVEN)
b->flags |= V4L2_BUF_FLAG_BOTFIELD;
}
b->timestamp = vb->ts;
b->bytesused = vb->size;
b->sequence = vb->field_count >> 1;
}
#endif /* HAVE_V4L2 */
/* --------------------------------------------------------------------- */
static void
videobuf_vm_open(struct vm_area_struct *vma)
{
struct videobuf_mapping *map = vma->vm_private_data;
map->count++;
}
static void
videobuf_vm_close(struct vm_area_struct *vma)
{
struct videobuf_mapping *map = vma->vm_private_data;
int i;
/* down(&fh->lock); FIXME */
map->count--;
if (0 == map->count) {
dprintk(1,"munmap %p\n",map);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (NULL == map->buflist[i])
continue;
if (map->buflist[i]->map != map)
continue;
map->buflist[i]->map = NULL;
map->buflist[i]->baddr = 0;
if (map->buflist[i]->free)
map->buflist[i]->free(vma->vm_file,map->buflist[i]);
}
kfree(map);
}
/* up(&fh->lock); FIXME */
return;
}
/*
* Get a anonymous page for the mapping. Make sure we can DMA to that
* memory location with 32bit PCI devices (i.e. don't use highmem for
* now ...). Bounce buffers don't work very well for the data rates
* video capture has.
*/
static struct page*
videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
int write_access)
{
struct page *page;
dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
vaddr,vma->vm_start,vma->vm_end);
if (vaddr > vma->vm_end)
return NOPAGE_SIGBUS;
page = alloc_page(GFP_USER);
if (!page)
return NOPAGE_OOM;
clear_user_page(page_address(page), vaddr);
return page;
}
static struct vm_operations_struct videobuf_vm_ops =
{
open: videobuf_vm_open,
close: videobuf_vm_close,
nopage: videobuf_vm_nopage,
};
int videobuf_mmap_setup(struct file *file, struct videobuf_buffer **buflist,
int msize, int bcount, int bsize, int type,
videobuf_buffer_free free)
{
int i,err;
err = videobuf_mmap_free(file,buflist);
if (0 != err)
return err;
for (i = 0; i < bcount; i++) {
buflist[i] = videobuf_alloc(msize,type);
buflist[i]->i = i;
buflist[i]->boff = bsize * i;
buflist[i]->bsize = bsize;
buflist[i]->free = free;
}
dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
bcount,bsize);
return 0;
}
int videobuf_mmap_free(struct file *file, struct videobuf_buffer **buflist)
{
int i;
for (i = 0; i < VIDEO_MAX_FRAME; i++)
if (buflist[i] && buflist[i]->map)
return -EBUSY;
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (NULL == buflist[i])
continue;
if (buflist[i]->free)
buflist[i]->free(file,buflist[i]);
kfree(buflist[i]);
buflist[i] = NULL;
}
return 0;
}
int videobuf_mmap_mapper(struct vm_area_struct *vma,
struct videobuf_buffer **buflist)
{
struct videobuf_mapping *map;
int first,last,size,i;
if (!(vma->vm_flags & VM_WRITE)) {
dprintk(1,"mmap app bug: PROT_WRITE please\n");
return -EINVAL;
}
if (!(vma->vm_flags & VM_SHARED)) {
dprintk(1,"mmap app bug: MAP_SHARED please\n");
return -EINVAL;
}
/* look for first buffer to map */
for (first = 0; first < VIDEO_MAX_FRAME; first++) {
if (NULL == buflist[first])
continue;
if (buflist[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
break;
}
if (VIDEO_MAX_FRAME == first) {
dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
(vma->vm_pgoff << PAGE_SHIFT));
return -EINVAL;
}
/* look for last buffer to map */
for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
if (NULL == buflist[last])
continue;
if (buflist[last]->map)
return -EBUSY;
size += buflist[last]->bsize;
if (size == (vma->vm_end - vma->vm_start))
break;
}
if (VIDEO_MAX_FRAME == last) {
dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
(vma->vm_end - vma->vm_start));
return -EINVAL;
}
/* create mapping + update buffer list */
map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
if (NULL == map)
return -ENOMEM;
for (size = 0, i = first; i <= last; size += buflist[i++]->bsize) {
buflist[i]->map = map;
buflist[i]->baddr = vma->vm_start + size;
}
map->count = 1;
map->start = vma->vm_start;
map->end = vma->vm_end;
map->buflist = buflist;
vma->vm_ops = &videobuf_vm_ops;
vma->vm_flags |= VM_DONTEXPAND;
vma->vm_private_data = map;
dprintk(1,"mmap %p: %08lx-%08lx pgoff %08lx bufs %d-%d\n",
map,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
return 0;
}
/* --------------------------------------------------------------------- */
EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
EXPORT_SYMBOL_GPL(videobuf_iobuf_to_sg);
EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
EXPORT_SYMBOL_GPL(videobuf_dma_free);
EXPORT_SYMBOL_GPL(videobuf_alloc);
EXPORT_SYMBOL_GPL(videobuf_waiton);
EXPORT_SYMBOL_GPL(videobuf_iolock);
#ifdef HAVE_V4L2
EXPORT_SYMBOL_GPL(videobuf_status);
#endif
EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
EXPORT_SYMBOL_GPL(videobuf_mmap_free);
EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
/*
* generic helper functions for video4linux capture buffers, to handle
* memory management and PCI DMA. Right now bttv + saa7134 use it.
*
* The functions expect the hardware being able to scatter gatter
* (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 (thus it is probably not useful for USB as
* data often must be uncompressed by the drivers).
*
* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
*
* 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 of the License, or
* (at your option) any later version.
*/
#include <linux/videodev.h>
/* --------------------------------------------------------------------- */
/*
* Return a scatterlist for some page-aligned vmalloc()'ed memory
* block (NULL on errors). Memory for the scatterlist is allocated
* using kmalloc. The caller must free the memory.
*/
struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
/*
* Return a scatterlist for a locked iobuf (NULL on errors). Memory
* for the scatterlist is allocated using kmalloc. The caller must
* free the memory.
*/
struct scatterlist* videobuf_iobuf_to_sg(struct kiobuf *iobuf);
/* --------------------------------------------------------------------- */
/*
* A small set of helper functions to manage buffers (both userland
* and kernel) for DMA.
*
* videobuf_init_*_dmabuf()
* 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_pci_*_dmabuf()
* see Documentation/DMA-mapping.txt, these functions to
* basically the same. The map function does also build a
* scatterlist for the buffer (and unmap frees it ...)
*
* videobuf_free_dmabuf()
* no comment ...
*
*/
struct videobuf_dmabuf {
/* for userland buffer */
struct kiobuf *iobuf;
/* for kernel buffers */
void *vmalloc;
/* common */
struct scatterlist *sglist;
int sglen;
int nr_pages;
int direction;
};
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_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma);
int videobuf_dma_pci_sync(struct pci_dev *dev,
struct videobuf_dmabuf *dma);
int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma);
int videobuf_dma_free(struct videobuf_dmabuf *dma);
/* --------------------------------------------------------------------- */
/*
* A small set of helper functions to manage video4linux buffers.
*
* struct videobuf_buffer holds the data structures used by the helper
* functions, additionally some commonly used fields for v4l buffers
* (width, height, lists, waitqueue) are in there. That struct should
* be used as first element in the drivers buffer struct.
*
* about the mmap helpers (videobuf_mmap_*):
*
* The mmaper function allows to map any subset of contingous buffers.
* This includes one mmap() call for all buffers (which the original
* video4linux API uses) as well as one mmap() for every single buffer
* (which v4l2 uses).
*
* If there is a valid mapping for a buffer, buffer->baddr/bsize holds
* userspace address + size which can be feeded into the
* videobuf_dma_init_user function listed above.
*
*/
struct videobuf_buffer;
typedef void (*videobuf_buffer_free)(struct file *file,
struct videobuf_buffer *vb);
struct videobuf_mapping {
int count;
int highmem_ok;
unsigned long start;
unsigned long end;
struct videobuf_buffer **buflist;
};
#define VBUF_FIELD_EVEN 1
#define VBUF_FIELD_ODD 2
#define VBUF_FIELD_INTER 4
enum videobuf_state {
STATE_NEEDS_INIT = 0,
STATE_PREPARED = 1,
STATE_QUEUED = 2,
STATE_ACTIVE = 3,
STATE_DONE = 4,
STATE_ERROR = 5,
STATE_IDLE = 6,
};
struct videobuf_buffer {
int i;
/* info about the buffer */
int type;
int width;
int height;
long size;
int field;
enum videobuf_state state;
struct videobuf_dmabuf dma;
struct list_head stream; /* QBUF/DQBUF list */
/* for mmap'ed buffers */
unsigned long boff; /* buffer offset (mmap) */
unsigned long bsize; /* buffer size */
unsigned long baddr; /* buffer addr (userland ptr!) */
struct videobuf_mapping *map;
videobuf_buffer_free free;
/* touched by irq handler */
struct list_head queue;
wait_queue_head_t done;
int field_count;
#ifdef HAVE_V4L2
stamp_t ts;
#endif
};
void* videobuf_alloc(int size, int type);
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
int videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb);
#ifdef HAVE_V4L2
void videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb);
#endif
int videobuf_mmap_setup(struct file *file, struct videobuf_buffer **buflist,
int msize, int bcount, int bsize, int type,
videobuf_buffer_free free);
int videobuf_mmap_free(struct file *file, struct videobuf_buffer **buflist);
int videobuf_mmap_mapper(struct vm_area_struct *vma,
struct videobuf_buffer **buflist);
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
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