Contributors: 21
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Magnus Damm |
1316 |
84.58% |
2 |
6.45% |
| Federico Vaga |
88 |
5.66% |
1 |
3.23% |
| Hans Verkuil |
38 |
2.44% |
7 |
22.58% |
| Lad Prabhakar |
30 |
1.93% |
1 |
3.23% |
| Murali Karicheri |
16 |
1.03% |
1 |
3.23% |
| Andrey Konovalov |
15 |
0.96% |
1 |
3.23% |
| Christoph Hellwig |
11 |
0.71% |
1 |
3.23% |
| Pawel Osciak |
9 |
0.58% |
2 |
6.45% |
| Fancy Fang |
6 |
0.39% |
1 |
3.23% |
| Guennadi Liakhovetski |
4 |
0.26% |
2 |
6.45% |
| Suren Baghdasaryan |
4 |
0.26% |
1 |
3.23% |
| Mauro Carvalho Chehab |
3 |
0.19% |
2 |
6.45% |
| Al Viro |
3 |
0.19% |
1 |
3.23% |
| Ma Haijun |
2 |
0.13% |
1 |
3.23% |
| Michel Lespinasse |
2 |
0.13% |
1 |
3.23% |
| Linus Torvalds (pre-git) |
2 |
0.13% |
1 |
3.23% |
| Andrew F. Davis |
2 |
0.13% |
1 |
3.23% |
| Thomas Gleixner |
2 |
0.13% |
1 |
3.23% |
| Linus Torvalds |
1 |
0.06% |
1 |
3.23% |
| Jonathan Corbet |
1 |
0.06% |
1 |
3.23% |
| Alexey Dobriyan |
1 |
0.06% |
1 |
3.23% |
| Total |
1556 |
|
31 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* helper functions for physically contiguous capture buffers
*
* The functions support hardware lacking scatter gather support
* (i.e. the buffers must be linear in physical memory)
*
* Copyright (c) 2008 Magnus Damm
*
* Based on videobuf-vmalloc.c,
* (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/dma-mapping.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <media/videobuf-dma-contig.h>
struct videobuf_dma_contig_memory {
u32 magic;
void *vaddr;
dma_addr_t dma_handle;
unsigned long size;
};
#define MAGIC_DC_MEM 0x0733ac61
#define MAGIC_CHECK(is, should) \
if (unlikely((is) != (should))) { \
pr_err("magic mismatch: %x expected %x\n", (is), (should)); \
BUG(); \
}
static int __videobuf_dc_alloc(struct device *dev,
struct videobuf_dma_contig_memory *mem,
unsigned long size)
{
mem->size = size;
mem->vaddr = dma_alloc_coherent(dev, mem->size, &mem->dma_handle,
GFP_KERNEL);
if (!mem->vaddr) {
dev_err(dev, "memory alloc size %ld failed\n", mem->size);
return -ENOMEM;
}
dev_dbg(dev, "dma mapped data is at %p (%ld)\n", mem->vaddr, mem->size);
return 0;
}
static void __videobuf_dc_free(struct device *dev,
struct videobuf_dma_contig_memory *mem)
{
dma_free_coherent(dev, mem->size, mem->vaddr, mem->dma_handle);
mem->vaddr = NULL;
}
static void videobuf_vm_open(struct vm_area_struct *vma)
{
struct videobuf_mapping *map = vma->vm_private_data;
dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n",
map, map->count, vma->vm_start, vma->vm_end);
map->count++;
}
static void videobuf_vm_close(struct vm_area_struct *vma)
{
struct videobuf_mapping *map = vma->vm_private_data;
struct videobuf_queue *q = map->q;
int i;
dev_dbg(q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n",
map, map->count, vma->vm_start, vma->vm_end);
map->count--;
if (0 == map->count) {
struct videobuf_dma_contig_memory *mem;
dev_dbg(q->dev, "munmap %p q=%p\n", map, q);
videobuf_queue_lock(q);
/* We need first to cancel streams, before unmapping */
if (q->streaming)
videobuf_queue_cancel(q);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (NULL == q->bufs[i])
continue;
if (q->bufs[i]->map != map)
continue;
mem = q->bufs[i]->priv;
if (mem) {
/* This callback is called only if kernel has
allocated memory and this memory is mmapped.
In this case, memory should be freed,
in order to do memory unmap.
*/
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
/* vfree is not atomic - can't be
called with IRQ's disabled
*/
dev_dbg(q->dev, "buf[%d] freeing %p\n",
i, mem->vaddr);
__videobuf_dc_free(q->dev, mem);
mem->vaddr = NULL;
}
q->bufs[i]->map = NULL;
q->bufs[i]->baddr = 0;
}
kfree(map);
videobuf_queue_unlock(q);
}
}
static const struct vm_operations_struct videobuf_vm_ops = {
.open = videobuf_vm_open,
.close = videobuf_vm_close,
};
/**
* videobuf_dma_contig_user_put() - reset pointer to user space buffer
* @mem: per-buffer private videobuf-dma-contig data
*
* This function resets the user space pointer
*/
static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem)
{
mem->dma_handle = 0;
mem->size = 0;
}
/**
* videobuf_dma_contig_user_get() - setup user space memory pointer
* @mem: per-buffer private videobuf-dma-contig data
* @vb: video buffer to map
*
* This function validates and sets up a pointer to user space memory.
* Only physically contiguous pfn-mapped memory is accepted.
*
* Returns 0 if successful.
*/
static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
struct videobuf_buffer *vb)
{
unsigned long untagged_baddr = untagged_addr(vb->baddr);
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long prev_pfn, this_pfn;
unsigned long pages_done, user_address;
unsigned int offset;
int ret;
offset = untagged_baddr & ~PAGE_MASK;
mem->size = PAGE_ALIGN(vb->size + offset);
ret = -EINVAL;
mmap_read_lock(mm);
vma = find_vma(mm, untagged_baddr);
if (!vma)
goto out_up;
if ((untagged_baddr + mem->size) > vma->vm_end)
goto out_up;
pages_done = 0;
prev_pfn = 0; /* kill warning */
user_address = untagged_baddr;
while (pages_done < (mem->size >> PAGE_SHIFT)) {
ret = follow_pfn(vma, user_address, &this_pfn);
if (ret)
break;
if (pages_done == 0)
mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset;
else if (this_pfn != (prev_pfn + 1))
ret = -EFAULT;
if (ret)
break;
prev_pfn = this_pfn;
user_address += PAGE_SIZE;
pages_done++;
}
out_up:
mmap_read_unlock(current->mm);
return ret;
}
static struct videobuf_buffer *__videobuf_alloc(size_t size)
{
struct videobuf_dma_contig_memory *mem;
struct videobuf_buffer *vb;
vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
if (vb) {
vb->priv = ((char *)vb) + size;
mem = vb->priv;
mem->magic = MAGIC_DC_MEM;
}
return vb;
}
static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
{
struct videobuf_dma_contig_memory *mem = buf->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
return mem->vaddr;
}
static int __videobuf_iolock(struct videobuf_queue *q,
struct videobuf_buffer *vb,
struct v4l2_framebuffer *fbuf)
{
struct videobuf_dma_contig_memory *mem = vb->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
switch (vb->memory) {
case V4L2_MEMORY_MMAP:
dev_dbg(q->dev, "%s memory method MMAP\n", __func__);
/* All handling should be done by __videobuf_mmap_mapper() */
if (!mem->vaddr) {
dev_err(q->dev, "memory is not allocated/mmapped.\n");
return -EINVAL;
}
break;
case V4L2_MEMORY_USERPTR:
dev_dbg(q->dev, "%s memory method USERPTR\n", __func__);
/* handle pointer from user space */
if (vb->baddr)
return videobuf_dma_contig_user_get(mem, vb);
/* allocate memory for the read() method */
if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size)))
return -ENOMEM;
break;
case V4L2_MEMORY_OVERLAY:
default:
dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", __func__);
return -EINVAL;
}
return 0;
}
static int __videobuf_mmap_mapper(struct videobuf_queue *q,
struct videobuf_buffer *buf,
struct vm_area_struct *vma)
{
struct videobuf_dma_contig_memory *mem;
struct videobuf_mapping *map;
int retval;
dev_dbg(q->dev, "%s\n", __func__);
/* create mapping + update buffer list */
map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
if (!map)
return -ENOMEM;
buf->map = map;
map->q = q;
buf->baddr = vma->vm_start;
mem = buf->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize)))
goto error;
/* the "vm_pgoff" is just used in v4l2 to find the
* corresponding buffer data structure which is allocated
* earlier and it does not mean the offset from the physical
* buffer start address as usual. So set it to 0 to pass
* the sanity check in dma_mmap_coherent().
*/
vma->vm_pgoff = 0;
retval = dma_mmap_coherent(q->dev, vma, mem->vaddr, mem->dma_handle,
mem->size);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
dma_free_coherent(q->dev, mem->size,
mem->vaddr, mem->dma_handle);
goto error;
}
vma->vm_ops = &videobuf_vm_ops;
vm_flags_set(vma, VM_DONTEXPAND);
vma->vm_private_data = map;
dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
map, q, vma->vm_start, vma->vm_end,
(long int)buf->bsize, vma->vm_pgoff, buf->i);
videobuf_vm_open(vma);
return 0;
error:
kfree(map);
return -ENOMEM;
}
static struct videobuf_qtype_ops qops = {
.magic = MAGIC_QTYPE_OPS,
.alloc_vb = __videobuf_alloc,
.iolock = __videobuf_iolock,
.mmap_mapper = __videobuf_mmap_mapper,
.vaddr = __videobuf_to_vaddr,
};
void videobuf_queue_dma_contig_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)
{
videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
priv, &qops, ext_lock);
}
EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init);
dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf)
{
struct videobuf_dma_contig_memory *mem = buf->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
return mem->dma_handle;
}
EXPORT_SYMBOL_GPL(videobuf_to_dma_contig);
void videobuf_dma_contig_free(struct videobuf_queue *q,
struct videobuf_buffer *buf)
{
struct videobuf_dma_contig_memory *mem = buf->priv;
/* mmapped memory can't be freed here, otherwise mmapped region
would be released, while still needed. In this case, the memory
release should happen inside videobuf_vm_close().
So, it should free memory only if the memory were allocated for
read() operation.
*/
if (buf->memory != V4L2_MEMORY_USERPTR)
return;
if (!mem)
return;
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
/* handle user space pointer case */
if (buf->baddr) {
videobuf_dma_contig_user_put(mem);
return;
}
/* read() method */
if (mem->vaddr) {
__videobuf_dc_free(q->dev, mem);
mem->vaddr = NULL;
}
}
EXPORT_SYMBOL_GPL(videobuf_dma_contig_free);
MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers");
MODULE_AUTHOR("Magnus Damm");
MODULE_LICENSE("GPL");