blob: 3c99f27388db4f2f668ea8001fe841f1fc3033a0 [file] [log] [blame]
/*
* Copyright (C) 2013 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/dma-buf.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
struct adf_memblock_pdata {
phys_addr_t base;
};
static struct sg_table *adf_memblock_map(struct dma_buf_attachment *attach,
enum dma_data_direction direction)
{
struct adf_memblock_pdata *pdata = attach->dmabuf->priv;
unsigned long pfn = PFN_DOWN(pdata->base);
struct page *page = pfn_to_page(pfn);
struct sg_table *table;
int ret;
table = kzalloc(sizeof(*table), GFP_KERNEL);
if (!table)
return ERR_PTR(-ENOMEM);
ret = sg_alloc_table(table, 1, GFP_KERNEL);
if (ret < 0)
goto err;
sg_set_page(table->sgl, page, attach->dmabuf->size, 0);
return table;
err:
kfree(table);
return ERR_PTR(ret);
}
static void adf_memblock_unmap(struct dma_buf_attachment *attach,
struct sg_table *table, enum dma_data_direction direction)
{
sg_free_table(table);
}
static void __init_memblock adf_memblock_release(struct dma_buf *buf)
{
struct adf_memblock_pdata *pdata = buf->priv;
int err = memblock_free(pdata->base, buf->size);
if (err < 0)
pr_warn("%s: freeing memblock failed: %d\n", __func__, err);
kfree(pdata);
}
static void *adf_memblock_do_kmap(struct dma_buf *buf, unsigned long pgoffset,
bool atomic)
{
struct adf_memblock_pdata *pdata = buf->priv;
unsigned long pfn = PFN_DOWN(pdata->base) + pgoffset;
struct page *page = pfn_to_page(pfn);
if (atomic)
return kmap_atomic(page);
else
return kmap(page);
}
static void *adf_memblock_kmap_atomic(struct dma_buf *buf,
unsigned long pgoffset)
{
return adf_memblock_do_kmap(buf, pgoffset, true);
}
static void adf_memblock_kunmap_atomic(struct dma_buf *buf,
unsigned long pgoffset, void *vaddr)
{
kunmap_atomic(vaddr);
}
static void *adf_memblock_kmap(struct dma_buf *buf, unsigned long pgoffset)
{
return adf_memblock_do_kmap(buf, pgoffset, false);
}
static void adf_memblock_kunmap(struct dma_buf *buf, unsigned long pgoffset,
void *vaddr)
{
kunmap(vaddr);
}
static int adf_memblock_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
{
struct adf_memblock_pdata *pdata = buf->priv;
return remap_pfn_range(vma, vma->vm_start, PFN_DOWN(pdata->base),
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}
struct dma_buf_ops adf_memblock_ops = {
.map_dma_buf = adf_memblock_map,
.unmap_dma_buf = adf_memblock_unmap,
.release = adf_memblock_release,
.kmap_atomic = adf_memblock_kmap_atomic,
.kunmap_atomic = adf_memblock_kunmap_atomic,
.kmap = adf_memblock_kmap,
.kunmap = adf_memblock_kunmap,
.mmap = adf_memblock_mmap,
};
/**
* adf_memblock_export - export a memblock reserved area as a dma-buf
*
* @base: base physical address
* @size: memblock size
* @flags: mode flags for the dma-buf's file
*
* @base and @size must be page-aligned.
*
* Returns a dma-buf on success or ERR_PTR(-errno) on failure.
*/
struct dma_buf *adf_memblock_export(phys_addr_t base, size_t size, int flags)
{
struct adf_memblock_pdata *pdata;
struct dma_buf *buf;
if (PAGE_ALIGN(base) != base || PAGE_ALIGN(size) != size)
return ERR_PTR(-EINVAL);
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->base = base;
buf = dma_buf_export(pdata, &adf_memblock_ops, size, flags);
if (IS_ERR(buf))
kfree(pdata);
return buf;
}