/drivers/media/video/videobuf2-vmalloc.c
https://bitbucket.org/ndreys/linux-sunxi · C · 132 lines · 89 code · 26 blank · 17 comment · 6 complexity · b82648067c028f03a06d9e4c19af303c MD5 · raw file
- /*
- * 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");