linux/drivers/ieee1394/dma.c
Philippe De Muyter 435f972697 ieee1394: dump mmapped iso buffers in core files
Currently, core files do not contain the mmapped memory of the video1394
or dv1394 devices, which contain the actual video input, making it
impossible to analyse the cause of abnormal program termination for
image analysis or (de)compression software.  Fix that.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>

Also affects users of the rawiso ioctl API of raw1394.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-07-14 13:06:02 +02:00

290 lines
6.2 KiB
C

/*
* DMA region bookkeeping routines
*
* Copyright (C) 2002 Maas Digital LLC
*
* This code is licensed under the GPL. See the file COPYING in the root
* directory of the kernel sources for details.
*/
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/scatterlist.h>
#include "dma.h"
/* dma_prog_region */
void dma_prog_region_init(struct dma_prog_region *prog)
{
prog->kvirt = NULL;
prog->dev = NULL;
prog->n_pages = 0;
prog->bus_addr = 0;
}
int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
struct pci_dev *dev)
{
/* round up to page size */
n_bytes = PAGE_ALIGN(n_bytes);
prog->n_pages = n_bytes >> PAGE_SHIFT;
prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
if (!prog->kvirt) {
printk(KERN_ERR
"dma_prog_region_alloc: pci_alloc_consistent() failed\n");
dma_prog_region_free(prog);
return -ENOMEM;
}
prog->dev = dev;
return 0;
}
void dma_prog_region_free(struct dma_prog_region *prog)
{
if (prog->kvirt) {
pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
prog->kvirt, prog->bus_addr);
}
prog->kvirt = NULL;
prog->dev = NULL;
prog->n_pages = 0;
prog->bus_addr = 0;
}
/* dma_region */
/**
* dma_region_init - clear out all fields but do not allocate anything
*/
void dma_region_init(struct dma_region *dma)
{
dma->kvirt = NULL;
dma->dev = NULL;
dma->n_pages = 0;
dma->n_dma_pages = 0;
dma->sglist = NULL;
}
/**
* dma_region_alloc - allocate the buffer and map it to the IOMMU
*/
int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
struct pci_dev *dev, int direction)
{
unsigned int i;
/* round up to page size */
n_bytes = PAGE_ALIGN(n_bytes);
dma->n_pages = n_bytes >> PAGE_SHIFT;
dma->kvirt = vmalloc_32(n_bytes);
if (!dma->kvirt) {
printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
goto err;
}
/* Clear the ram out, no junk to the user */
memset(dma->kvirt, 0, n_bytes);
/* allocate scatter/gather list */
dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
if (!dma->sglist) {
printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
goto err;
}
sg_init_table(dma->sglist, dma->n_pages);
/* fill scatter/gather list with pages */
for (i = 0; i < dma->n_pages; i++) {
unsigned long va =
(unsigned long)dma->kvirt + (i << PAGE_SHIFT);
sg_set_page(&dma->sglist[i], vmalloc_to_page((void *)va),
PAGE_SIZE, 0);
}
/* map sglist to the IOMMU */
dma->n_dma_pages =
pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
if (dma->n_dma_pages == 0) {
printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
goto err;
}
dma->dev = dev;
dma->direction = direction;
return 0;
err:
dma_region_free(dma);
return -ENOMEM;
}
/**
* dma_region_free - unmap and free the buffer
*/
void dma_region_free(struct dma_region *dma)
{
if (dma->n_dma_pages) {
pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
dma->direction);
dma->n_dma_pages = 0;
dma->dev = NULL;
}
vfree(dma->sglist);
dma->sglist = NULL;
vfree(dma->kvirt);
dma->kvirt = NULL;
dma->n_pages = 0;
}
/* find the scatterlist index and remaining offset corresponding to a
given offset from the beginning of the buffer */
static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
unsigned int start, unsigned long *rem)
{
int i;
unsigned long off = offset;
for (i = start; i < dma->n_dma_pages; i++) {
if (off < sg_dma_len(&dma->sglist[i])) {
*rem = off;
break;
}
off -= sg_dma_len(&dma->sglist[i]);
}
BUG_ON(i >= dma->n_dma_pages);
return i;
}
/**
* dma_region_offset_to_bus - get bus address of an offset within a DMA region
*
* Returns the DMA bus address of the byte with the given @offset relative to
* the beginning of the @dma.
*/
dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
unsigned long offset)
{
unsigned long rem = 0;
struct scatterlist *sg =
&dma->sglist[dma_region_find(dma, offset, 0, &rem)];
return sg_dma_address(sg) + rem;
}
/**
* dma_region_sync_for_cpu - sync the CPU's view of the buffer
*/
void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
unsigned long len)
{
int first, last;
unsigned long rem = 0;
if (!len)
len = 1;
first = dma_region_find(dma, offset, 0, &rem);
last = dma_region_find(dma, rem + len - 1, first, &rem);
pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
dma->direction);
}
/**
* dma_region_sync_for_device - sync the IO bus' view of the buffer
*/
void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
unsigned long len)
{
int first, last;
unsigned long rem = 0;
if (!len)
len = 1;
first = dma_region_find(dma, offset, 0, &rem);
last = dma_region_find(dma, rem + len - 1, first, &rem);
pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
last - first + 1, dma->direction);
}
#ifdef CONFIG_MMU
static int dma_region_pagefault(struct vm_area_struct *vma,
struct vm_fault *vmf)
{
struct dma_region *dma = (struct dma_region *)vma->vm_private_data;
if (!dma->kvirt)
return VM_FAULT_SIGBUS;
if (vmf->pgoff >= dma->n_pages)
return VM_FAULT_SIGBUS;
vmf->page = vmalloc_to_page(dma->kvirt + (vmf->pgoff << PAGE_SHIFT));
get_page(vmf->page);
return 0;
}
static struct vm_operations_struct dma_region_vm_ops = {
.fault = dma_region_pagefault,
};
/**
* dma_region_mmap - map the buffer into a user space process
*/
int dma_region_mmap(struct dma_region *dma, struct file *file,
struct vm_area_struct *vma)
{
unsigned long size;
if (!dma->kvirt)
return -EINVAL;
/* must be page-aligned (XXX: comment is wrong, we could allow pgoff) */
if (vma->vm_pgoff != 0)
return -EINVAL;
/* check the length */
size = vma->vm_end - vma->vm_start;
if (size > (dma->n_pages << PAGE_SHIFT))
return -EINVAL;
vma->vm_ops = &dma_region_vm_ops;
vma->vm_private_data = dma;
vma->vm_file = file;
vma->vm_flags |= VM_RESERVED | VM_ALWAYSDUMP;
return 0;
}
#else /* CONFIG_MMU */
int dma_region_mmap(struct dma_region *dma, struct file *file,
struct vm_area_struct *vma)
{
return -EINVAL;
}
#endif /* CONFIG_MMU */