- 根目录:
- drivers
- media
- v4l2-core
- videobuf2-vmalloc.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/io.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>
#include <media/videobuf2-memops.h>
struct vb2_vmalloc_buf {
void *vaddr;
struct frame_vector *vec;
enum dma_data_direction dma_dir;
unsigned long size;
atomic_t refcount;
struct vb2_vmarea_handler handler;
struct dma_buf *dbuf;
};
static void vb2_vmalloc_put(void *buf_priv);
static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size,
enum dma_data_direction dma_dir, gfp_t gfp_flags)
{
struct vb2_vmalloc_buf *buf;
buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
if (!buf)
return NULL;
buf->size = size;
buf->vaddr = vmalloc_user(buf->size);
buf->dma_dir = dma_dir;
buf->handler.refcount = &buf->refcount;
buf->handler.put = vb2_vmalloc_put;
buf->handler.arg = buf;
if (!buf->vaddr) {
pr_debug("vmalloc of size %ld failed\n", buf->size);
kfree(buf);
return NULL;
}
atomic_inc(&buf->refcount);
return buf;
}
static void vb2_vmalloc_put(void *buf_priv)
{
struct vb2_vmalloc_buf *buf = buf_priv;
if (atomic_dec_and_test(&buf->refcount)) {
vfree(buf->vaddr);
kfree(buf);
}
}
static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
unsigned long size,
enum dma_data_direction dma_dir)
{
struct vb2_vmalloc_buf *buf;
struct frame_vector *vec;
int n_pages, offset, i;
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return NULL;
buf->dma_dir = dma_dir;
offset = vaddr & ~PAGE_MASK;
buf->size = size;
vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
if (IS_ERR(vec))
goto fail_pfnvec_create;
buf->vec = vec;
n_pages = frame_vector_count(vec);
if (frame_vector_to_pages(vec) < 0) {
unsigned long *nums = frame_vector_pfns(vec);
/*
* We cannot get page pointers for these pfns. Check memory is
* physically contiguous and use direct mapping.
*/
for (i = 1; i < n_pages; i++)
if (nums[i-1] + 1 != nums[i])
goto fail_map;
buf->vaddr = (__force void *)
ioremap_nocache(nums[0] << PAGE_SHIFT, size);
} else {
buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
PAGE_KERNEL);
}
if (!buf->vaddr)
goto fail_map;
buf->vaddr += offset;
return buf;
fail_map:
vb2_destroy_framevec(vec);
fail_pfnvec_create:
kfree(buf);
return NULL;
}
static void vb2_vmalloc_put_userptr(void *buf_priv)
{
struct vb2_vmalloc_buf *buf = buf_priv;
unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
unsigned int i;
struct page **pages;
unsigned int n_pages;
if (!buf->vec->is_pfns) {
n_pages = frame_vector_count(buf->vec);
pages = frame_vector_pages(buf->vec);
if (vaddr)
vm_unmap_ram((void *)vaddr, n_pages);
if (buf->dma_dir == DMA_FROM_DEVICE)
for (i = 0; i < n_pages; i++)
set_page_dirty_lock(pages[i]);
} else {
iounmap((__force void __iomem *)buf->vaddr);
}
vb2_destroy_framevec(buf->vec);
kfree(buf);
}
static void *vb2_vmalloc_vaddr(void *buf_priv)
{
struct vb2_vmalloc_buf *buf = buf_priv;
if (!buf->vaddr) {
pr_err("Address of an unallocated plane requested "
"or cannot map user pointer\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) {
pr_err("No memory to map\n");
return -EINVAL;
}
ret = remap_vmalloc_range(vma, buf->vaddr, 0);
if (ret) {
pr_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;
}
#ifdef CONFIG_HAS_DMA
/*********************************************/
/* DMABUF ops for exporters */
/*********************************************/
struct vb2_vmalloc_attachment {
struct sg_table sgt;
enum dma_data_direction dma_dir;
};
static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
struct dma_buf_attachment *dbuf_attach)
{
struct vb2_vmalloc_attachment *attach;
struct vb2_vmalloc_buf *buf = dbuf->priv;
int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
struct sg_table *sgt;
struct scatterlist *sg;
void *vaddr = buf->vaddr;
int ret;
int i;
attach = kzalloc(sizeof(*attach), GFP_KERNEL);
if (!attach)
return -ENOMEM;
sgt = &attach->sgt;
ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
if (ret) {
kfree(attach);
return ret;
}
for_each_sg(sgt->sgl, sg, sgt->nents, i) {
struct page *page = vmalloc_to_page(vaddr);
if (!page) {
sg_free_table(sgt);
kfree(attach);
return -ENOMEM;
}
sg_set_page(sg, page, PAGE_SIZE, 0);
vaddr += PAGE_SIZE;
}
attach->dma_dir = DMA_NONE;
dbuf_attach->priv = attach;
return 0;
}
static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
struct dma_buf_attachment *db_attach)
{
struct vb2_vmalloc_attachment *attach = db_attach->priv;
struct sg_table *sgt;
if (!attach)
return;
sgt = &attach->sgt;
/* release the scatterlist cache */
if (attach->dma_dir != DMA_NONE)
dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
attach->dma_dir);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
}
static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
{
struct vb2_vmalloc_attachment *attach = db_attach->priv;
/* stealing dmabuf mutex to serialize map/unmap operations */
struct mutex *lock = &db_attach->dmabuf->lock;
struct sg_table *sgt;
mutex_lock(lock);
sgt = &attach->sgt;
/* return previously mapped sg table */
if (attach->dma_dir == dma_dir) {
mutex_unlock(lock);
return sgt;
}
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
attach->dma_dir);
attach->dma_dir = DMA_NONE;
}
/* mapping to the client with new direction */
sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
dma_dir);
if (!sgt->nents) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
}
attach->dma_dir = dma_dir;
mutex_unlock(lock);
return sgt;
}
static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
struct sg_table *sgt, enum dma_data_direction dma_dir)
{
/* nothing to be done here */
}
static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
{
/* drop reference obtained in vb2_vmalloc_get_dmabuf */
vb2_vmalloc_put(dbuf->priv);
}
static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
{
struct vb2_vmalloc_buf *buf = dbuf->priv;
return buf->vaddr + pgnum * PAGE_SIZE;
}
static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
{
struct vb2_vmalloc_buf *buf = dbuf->priv;
return buf->vaddr;
}
static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
struct vm_area_struct *vma)
{
return vb2_vmalloc_mmap(dbuf->priv, vma);
}
static struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
.attach = vb2_vmalloc_dmabuf_ops_attach,
.detach = vb2_vmalloc_dmabuf_ops_detach,
.map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
.unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
.kmap = vb2_vmalloc_dmabuf_ops_kmap,
.kmap_atomic = vb2_vmalloc_dmabuf_ops_kmap,
.vmap = vb2_vmalloc_dmabuf_ops_vmap,
.mmap = vb2_vmalloc_dmabuf_ops_mmap,
.release = vb2_vmalloc_dmabuf_ops_release,
};
static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
{
struct vb2_vmalloc_buf *buf = buf_priv;
struct dma_buf *dbuf;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
exp_info.ops = &vb2_vmalloc_dmabuf_ops;
exp_info.size = buf->size;
exp_info.flags = flags;
exp_info.priv = buf;
if (WARN_ON(!buf->vaddr))
return NULL;
dbuf = dma_buf_export(&exp_info);
if (IS_ERR(dbuf))
return NULL;
/* dmabuf keeps reference to vb2 buffer */
atomic_inc(&buf->refcount);
return dbuf;
}
#endif /* CONFIG_HAS_DMA */
/*********************************************/
/* callbacks for DMABUF buffers */
/*********************************************/
static int vb2_vmalloc_map_dmabuf(void *mem_priv)
{
struct vb2_vmalloc_buf *buf = mem_priv;
buf->vaddr = dma_buf_vmap(buf->dbuf);
return buf->vaddr ? 0 : -EFAULT;
}
static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
{
struct vb2_vmalloc_buf *buf = mem_priv;
dma_buf_vunmap(buf->dbuf, buf->vaddr);
buf->vaddr = NULL;
}
static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
{
struct vb2_vmalloc_buf *buf = mem_priv;
if (buf->vaddr)
dma_buf_vunmap(buf->dbuf, buf->vaddr);
kfree(buf);
}
static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
unsigned long size, enum dma_data_direction dma_dir)
{
struct vb2_vmalloc_buf *buf;
if (dbuf->size < size)
return ERR_PTR(-EFAULT);
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
buf->dbuf = dbuf;
buf->dma_dir = dma_dir;
buf->size = size;
return buf;
}
const struct vb2_mem_ops vb2_vmalloc_memops = {
.alloc = vb2_vmalloc_alloc,
.put = vb2_vmalloc_put,
.get_userptr = vb2_vmalloc_get_userptr,
.put_userptr = vb2_vmalloc_put_userptr,
#ifdef CONFIG_HAS_DMA
.get_dmabuf = vb2_vmalloc_get_dmabuf,
#endif
.map_dmabuf = vb2_vmalloc_map_dmabuf,
.unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
.attach_dmabuf = vb2_vmalloc_attach_dmabuf,
.detach_dmabuf = vb2_vmalloc_detach_dmabuf,
.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");