mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 04:42:12 +00:00
950720840f
Signed-off-by: Pawel Osciak <pawel@osciak.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
133 lines
2.9 KiB
C
133 lines
2.9 KiB
C
/*
|
|
* videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
|
|
*
|
|
* Copyright (C) 2010 Samsung Electronics
|
|
*
|
|
* Author: Pawel Osciak <pawel@osciak.com>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include <media/videobuf2-core.h>
|
|
#include <media/videobuf2-memops.h>
|
|
|
|
struct vb2_vmalloc_buf {
|
|
void *vaddr;
|
|
unsigned long size;
|
|
atomic_t refcount;
|
|
struct vb2_vmarea_handler handler;
|
|
};
|
|
|
|
static void vb2_vmalloc_put(void *buf_priv);
|
|
|
|
static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
|
|
{
|
|
struct vb2_vmalloc_buf *buf;
|
|
|
|
buf = kzalloc(sizeof *buf, GFP_KERNEL);
|
|
if (!buf)
|
|
return NULL;
|
|
|
|
buf->size = size;
|
|
buf->vaddr = vmalloc_user(buf->size);
|
|
buf->handler.refcount = &buf->refcount;
|
|
buf->handler.put = vb2_vmalloc_put;
|
|
buf->handler.arg = buf;
|
|
|
|
if (!buf->vaddr) {
|
|
printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
|
|
kfree(buf);
|
|
return NULL;
|
|
}
|
|
|
|
atomic_inc(&buf->refcount);
|
|
printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
|
|
buf->size, buf->vaddr);
|
|
|
|
return buf;
|
|
}
|
|
|
|
static void vb2_vmalloc_put(void *buf_priv)
|
|
{
|
|
struct vb2_vmalloc_buf *buf = buf_priv;
|
|
|
|
if (atomic_dec_and_test(&buf->refcount)) {
|
|
printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n",
|
|
__func__, buf->vaddr);
|
|
vfree(buf->vaddr);
|
|
kfree(buf);
|
|
}
|
|
}
|
|
|
|
static void *vb2_vmalloc_vaddr(void *buf_priv)
|
|
{
|
|
struct vb2_vmalloc_buf *buf = buf_priv;
|
|
|
|
BUG_ON(!buf);
|
|
|
|
if (!buf->vaddr) {
|
|
printk(KERN_ERR "Address of an unallocated plane requested\n");
|
|
return NULL;
|
|
}
|
|
|
|
return buf->vaddr;
|
|
}
|
|
|
|
static unsigned int vb2_vmalloc_num_users(void *buf_priv)
|
|
{
|
|
struct vb2_vmalloc_buf *buf = buf_priv;
|
|
return atomic_read(&buf->refcount);
|
|
}
|
|
|
|
static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
|
|
{
|
|
struct vb2_vmalloc_buf *buf = buf_priv;
|
|
int ret;
|
|
|
|
if (!buf) {
|
|
printk(KERN_ERR "No memory to map\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = remap_vmalloc_range(vma, buf->vaddr, 0);
|
|
if (ret) {
|
|
printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Make sure that vm_areas for 2 buffers won't be merged together
|
|
*/
|
|
vma->vm_flags |= VM_DONTEXPAND;
|
|
|
|
/*
|
|
* Use common vm_area operations to track buffer refcount.
|
|
*/
|
|
vma->vm_private_data = &buf->handler;
|
|
vma->vm_ops = &vb2_common_vm_ops;
|
|
|
|
vma->vm_ops->open(vma);
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct vb2_mem_ops vb2_vmalloc_memops = {
|
|
.alloc = vb2_vmalloc_alloc,
|
|
.put = vb2_vmalloc_put,
|
|
.vaddr = vb2_vmalloc_vaddr,
|
|
.mmap = vb2_vmalloc_mmap,
|
|
.num_users = vb2_vmalloc_num_users,
|
|
};
|
|
EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
|
|
|
|
MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
|
|
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
|
|
MODULE_LICENSE("GPL");
|