124 строки
2.6 KiB
C
124 строки
2.6 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* DMABUF System heap exporter
|
||
|
|
*
|
||
|
|
* Copyright (C) 2011 Google, Inc.
|
||
|
|
* Copyright (C) 2019 Linaro Ltd.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/dma-buf.h>
|
||
|
|
#include <linux/dma-mapping.h>
|
||
|
|
#include <linux/dma-heap.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/highmem.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/scatterlist.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/sched/signal.h>
|
||
|
|
#include <asm/page.h>
|
||
|
|
|
||
|
|
#include "heap-helpers.h"
|
||
|
|
|
||
|
|
struct dma_heap *sys_heap;
|
||
|
|
|
||
|
|
static void system_heap_free(struct heap_helper_buffer *buffer)
|
||
|
|
{
|
||
|
|
pgoff_t pg;
|
||
|
|
|
||
|
|
for (pg = 0; pg < buffer->pagecount; pg++)
|
||
|
|
__free_page(buffer->pages[pg]);
|
||
|
|
kfree(buffer->pages);
|
||
|
|
kfree(buffer);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int system_heap_allocate(struct dma_heap *heap,
|
||
|
|
unsigned long len,
|
||
|
|
unsigned long fd_flags,
|
||
|
|
unsigned long heap_flags)
|
||
|
|
{
|
||
|
|
struct heap_helper_buffer *helper_buffer;
|
||
|
|
struct dma_buf *dmabuf;
|
||
|
|
int ret = -ENOMEM;
|
||
|
|
pgoff_t pg;
|
||
|
|
|
||
|
|
helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
|
||
|
|
if (!helper_buffer)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
init_heap_helper_buffer(helper_buffer, system_heap_free);
|
||
|
|
helper_buffer->heap = heap;
|
||
|
|
helper_buffer->size = len;
|
||
|
|
|
||
|
|
helper_buffer->pagecount = len / PAGE_SIZE;
|
||
|
|
helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
|
||
|
|
sizeof(*helper_buffer->pages),
|
||
|
|
GFP_KERNEL);
|
||
|
|
if (!helper_buffer->pages) {
|
||
|
|
ret = -ENOMEM;
|
||
|
|
goto err0;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (pg = 0; pg < helper_buffer->pagecount; pg++) {
|
||
|
|
/*
|
||
|
|
* Avoid trying to allocate memory if the process
|
||
|
|
* has been killed by by SIGKILL
|
||
|
|
*/
|
||
|
|
if (fatal_signal_pending(current))
|
||
|
|
goto err1;
|
||
|
|
|
||
|
|
helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO);
|
||
|
|
if (!helper_buffer->pages[pg])
|
||
|
|
goto err1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* create the dmabuf */
|
||
|
|
dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags);
|
||
|
|
if (IS_ERR(dmabuf)) {
|
||
|
|
ret = PTR_ERR(dmabuf);
|
||
|
|
goto err1;
|
||
|
|
}
|
||
|
|
|
||
|
|
helper_buffer->dmabuf = dmabuf;
|
||
|
|
|
||
|
|
ret = dma_buf_fd(dmabuf, fd_flags);
|
||
|
|
if (ret < 0) {
|
||
|
|
dma_buf_put(dmabuf);
|
||
|
|
/* just return, as put will call release and that will free */
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
err1:
|
||
|
|
while (pg > 0)
|
||
|
|
__free_page(helper_buffer->pages[--pg]);
|
||
|
|
kfree(helper_buffer->pages);
|
||
|
|
err0:
|
||
|
|
kfree(helper_buffer);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct dma_heap_ops system_heap_ops = {
|
||
|
|
.allocate = system_heap_allocate,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int system_heap_create(void)
|
||
|
|
{
|
||
|
|
struct dma_heap_export_info exp_info;
|
||
|
|
int ret = 0;
|
||
|
|
|
||
|
|
exp_info.name = "system_heap";
|
||
|
|
exp_info.ops = &system_heap_ops;
|
||
|
|
exp_info.priv = NULL;
|
||
|
|
|
||
|
|
sys_heap = dma_heap_add(&exp_info);
|
||
|
|
if (IS_ERR(sys_heap))
|
||
|
|
ret = PTR_ERR(sys_heap);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
module_init(system_heap_create);
|
||
|
|
MODULE_LICENSE("GPL v2");
|