forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
326 lines
7.7 KiB
326 lines
7.7 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* helper functions for vmalloc 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 <[email protected]> |
|
*/ |
|
|
|
#include <linux/init.h> |
|
#include <linux/module.h> |
|
#include <linux/moduleparam.h> |
|
#include <linux/slab.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/pgtable.h> |
|
|
|
#include <linux/pci.h> |
|
#include <linux/vmalloc.h> |
|
#include <linux/pagemap.h> |
|
#include <asm/page.h> |
|
|
|
#include <media/videobuf-vmalloc.h> |
|
|
|
#define MAGIC_DMABUF 0x17760309 |
|
#define MAGIC_VMAL_MEM 0x18221223 |
|
|
|
#define MAGIC_CHECK(is, should) \ |
|
if (unlikely((is) != (should))) { \ |
|
printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \ |
|
is, should); \ |
|
BUG(); \ |
|
} |
|
|
|
static int debug; |
|
module_param(debug, int, 0644); |
|
|
|
MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers"); |
|
MODULE_AUTHOR("Mauro Carvalho Chehab <[email protected]>"); |
|
MODULE_LICENSE("GPL"); |
|
|
|
#define dprintk(level, fmt, arg...) \ |
|
if (debug >= level) \ |
|
printk(KERN_DEBUG "vbuf-vmalloc: " fmt , ## arg) |
|
|
|
|
|
/***************************************************************************/ |
|
|
|
static void videobuf_vm_open(struct vm_area_struct *vma) |
|
{ |
|
struct videobuf_mapping *map = vma->vm_private_data; |
|
|
|
dprintk(2, "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; |
|
|
|
dprintk(2, "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_vmalloc_memory *mem; |
|
|
|
dprintk(1, "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_VMAL_MEM); |
|
|
|
/* vfree is not atomic - can't be |
|
called with IRQ's disabled |
|
*/ |
|
dprintk(1, "%s: buf[%d] freeing (%p)\n", |
|
__func__, i, mem->vaddr); |
|
|
|
vfree(mem->vaddr); |
|
mem->vaddr = NULL; |
|
} |
|
|
|
q->bufs[i]->map = NULL; |
|
q->bufs[i]->baddr = 0; |
|
} |
|
|
|
kfree(map); |
|
|
|
videobuf_queue_unlock(q); |
|
} |
|
|
|
return; |
|
} |
|
|
|
static const struct vm_operations_struct videobuf_vm_ops = { |
|
.open = videobuf_vm_open, |
|
.close = videobuf_vm_close, |
|
}; |
|
|
|
/* --------------------------------------------------------------------- |
|
* vmalloc handlers for the generic methods |
|
*/ |
|
|
|
/* Allocated area consists on 3 parts: |
|
struct video_buffer |
|
struct <driver>_buffer (cx88_buffer, saa7134_buf, ...) |
|
struct videobuf_dma_sg_memory |
|
*/ |
|
|
|
static struct videobuf_buffer *__videobuf_alloc_vb(size_t size) |
|
{ |
|
struct videobuf_vmalloc_memory *mem; |
|
struct videobuf_buffer *vb; |
|
|
|
vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); |
|
if (!vb) |
|
return vb; |
|
|
|
mem = vb->priv = ((char *)vb) + size; |
|
mem->magic = MAGIC_VMAL_MEM; |
|
|
|
dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n", |
|
__func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb), |
|
mem, (long)sizeof(*mem)); |
|
|
|
return vb; |
|
} |
|
|
|
static int __videobuf_iolock(struct videobuf_queue *q, |
|
struct videobuf_buffer *vb, |
|
struct v4l2_framebuffer *fbuf) |
|
{ |
|
struct videobuf_vmalloc_memory *mem = vb->priv; |
|
int pages; |
|
|
|
BUG_ON(!mem); |
|
|
|
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM); |
|
|
|
switch (vb->memory) { |
|
case V4L2_MEMORY_MMAP: |
|
dprintk(1, "%s memory method MMAP\n", __func__); |
|
|
|
/* All handling should be done by __videobuf_mmap_mapper() */ |
|
if (!mem->vaddr) { |
|
printk(KERN_ERR "memory is not allocated/mmapped.\n"); |
|
return -EINVAL; |
|
} |
|
break; |
|
case V4L2_MEMORY_USERPTR: |
|
pages = PAGE_ALIGN(vb->size); |
|
|
|
dprintk(1, "%s memory method USERPTR\n", __func__); |
|
|
|
if (vb->baddr) { |
|
printk(KERN_ERR "USERPTR is currently not supported\n"); |
|
return -EINVAL; |
|
} |
|
|
|
/* The only USERPTR currently supported is the one needed for |
|
* read() method. |
|
*/ |
|
|
|
mem->vaddr = vmalloc_user(pages); |
|
if (!mem->vaddr) { |
|
printk(KERN_ERR "vmalloc (%d pages) failed\n", pages); |
|
return -ENOMEM; |
|
} |
|
dprintk(1, "vmalloc is at addr %p (%d pages)\n", |
|
mem->vaddr, pages); |
|
break; |
|
case V4L2_MEMORY_OVERLAY: |
|
default: |
|
dprintk(1, "%s memory method OVERLAY/unknown\n", __func__); |
|
|
|
/* Currently, doesn't support V4L2_MEMORY_OVERLAY */ |
|
printk(KERN_ERR "Memory method currently unsupported.\n"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
|
struct videobuf_buffer *buf, |
|
struct vm_area_struct *vma) |
|
{ |
|
struct videobuf_vmalloc_memory *mem; |
|
struct videobuf_mapping *map; |
|
int retval, pages; |
|
|
|
dprintk(1, "%s\n", __func__); |
|
|
|
/* create mapping + update buffer list */ |
|
map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); |
|
if (NULL == 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_VMAL_MEM); |
|
|
|
pages = PAGE_ALIGN(vma->vm_end - vma->vm_start); |
|
mem->vaddr = vmalloc_user(pages); |
|
if (!mem->vaddr) { |
|
printk(KERN_ERR "vmalloc (%d pages) failed\n", pages); |
|
goto error; |
|
} |
|
dprintk(1, "vmalloc is at addr %p (%d pages)\n", mem->vaddr, pages); |
|
|
|
/* Try to remap memory */ |
|
retval = remap_vmalloc_range(vma, mem->vaddr, 0); |
|
if (retval < 0) { |
|
printk(KERN_ERR "mmap: remap failed with error %d. ", retval); |
|
vfree(mem->vaddr); |
|
goto error; |
|
} |
|
|
|
vma->vm_ops = &videobuf_vm_ops; |
|
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
|
vma->vm_private_data = map; |
|
|
|
dprintk(1, "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: |
|
mem = NULL; |
|
kfree(map); |
|
return -ENOMEM; |
|
} |
|
|
|
static struct videobuf_qtype_ops qops = { |
|
.magic = MAGIC_QTYPE_OPS, |
|
|
|
.alloc_vb = __videobuf_alloc_vb, |
|
.iolock = __videobuf_iolock, |
|
.mmap_mapper = __videobuf_mmap_mapper, |
|
.vaddr = videobuf_to_vmalloc, |
|
}; |
|
|
|
void videobuf_queue_vmalloc_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_vmalloc_init); |
|
|
|
void *videobuf_to_vmalloc(struct videobuf_buffer *buf) |
|
{ |
|
struct videobuf_vmalloc_memory *mem = buf->priv; |
|
BUG_ON(!mem); |
|
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM); |
|
|
|
return mem->vaddr; |
|
} |
|
EXPORT_SYMBOL_GPL(videobuf_to_vmalloc); |
|
|
|
void videobuf_vmalloc_free(struct videobuf_buffer *buf) |
|
{ |
|
struct videobuf_vmalloc_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) || buf->baddr) |
|
return; |
|
|
|
if (!mem) |
|
return; |
|
|
|
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM); |
|
|
|
vfree(mem->vaddr); |
|
mem->vaddr = NULL; |
|
|
|
return; |
|
} |
|
EXPORT_SYMBOL_GPL(videobuf_vmalloc_free); |
|
|
|
|