/*
* udl_dmabuf.c
*
* Copyright (c) 2014 The Chromium OS Authors
*
* 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; either version 2 of the License, or (at your
* option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <drm/drmP.h>
#include "udl_drv.h"
#include <linux/shmem_fs.h>
#include <linux/dma-buf.h>
struct udl_drm_dmabuf_attachment {
struct sg_table sgt;
enum dma_data_direction dir;
bool is_mapped;
};
static int udl_attach_dma_buf(struct dma_buf *dmabuf,
struct device *dev,
struct dma_buf_attachment *attach)
{
struct udl_drm_dmabuf_attachment *udl_attach;
DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
attach->dmabuf->size);
udl_attach = kzalloc(sizeof(*udl_attach), GFP_KERNEL);
if (!udl_attach)
return -ENOMEM;
udl_attach->dir = DMA_NONE;
attach->priv = udl_attach;
return 0;
}
static void udl_detach_dma_buf(struct dma_buf *dmabuf,
struct dma_buf_attachment *attach)
{
struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
struct sg_table *sgt;
if (!udl_attach)
return;
DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
attach->dmabuf->size);
sgt = &udl_attach->sgt;
if (udl_attach->dir != DMA_NONE)
dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
udl_attach->dir);
sg_free_table(sgt);
kfree(udl_attach);
attach->priv = NULL;
}
static struct sg_table *udl_map_dma_buf(struct dma_buf_attachment *attach,
enum dma_data_direction dir)
{
struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
struct drm_device *dev = obj->base.dev;
struct scatterlist *rd, *wr;
struct sg_table *sgt = NULL;
unsigned int i;
int page_count;
int nents, ret;
DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
attach->dmabuf->size, dir);
/* just return current sgt if already requested. */
if (udl_attach->dir == dir && udl_attach->is_mapped)
return &udl_attach->sgt;
if (!obj->pages) {
ret = udl_gem_get_pages(obj);
if (ret) {
DRM_ERROR("failed to map pages.\n");
return ERR_PTR(ret);
}
}
page_count = obj->base.size / PAGE_SIZE;
obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
if (IS_ERR(obj->sg)) {
DRM_ERROR("failed to allocate sgt.\n");
return ERR_CAST(obj->sg);
}
sgt = &udl_attach->sgt;
ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
if (ret) {
DRM_ERROR("failed to alloc sgt.\n");
return ERR_PTR(-ENOMEM);
}
mutex_lock(&dev->struct_mutex);
rd = obj->sg->sgl;
wr = sgt->sgl;
for (i = 0; i < sgt->orig_nents; ++i) {
sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
rd = sg_next(rd);
wr = sg_next(wr);
}
if (dir != DMA_NONE) {
nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
if (!nents) {
DRM_ERROR("failed to map sgl with iommu.\n");
sg_free_table(sgt);
sgt = ERR_PTR(-EIO);
goto err_unlock;
}
}
udl_attach->is_mapped = true;
udl_attach->dir = dir;
attach->priv = udl_attach;
err_unlock:
mutex_unlock(&dev->struct_mutex);
return sgt;
}
static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
struct sg_table *sgt,
enum dma_data_direction dir)
{
/* Nothing to do. */
DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
attach->dmabuf->size, dir);
}
static void *udl_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
{
/* TODO */
return NULL;
}
static void *udl_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
unsigned long page_num)
{
/* TODO */
return NULL;
}
static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
unsigned long page_num, void *addr)
{
/* TODO */
}
static void udl_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
unsigned long page_num,
void *addr)
{
/* TODO */
}
static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
struct vm_area_struct *vma)
{
/* TODO */
return -EINVAL;
}
static struct dma_buf_ops udl_dmabuf_ops = {
.attach = udl_attach_dma_buf,
.detach = udl_detach_dma_buf,
.map_dma_buf = udl_map_dma_buf,
.unmap_dma_buf = udl_unmap_dma_buf,
.kmap = udl_dmabuf_kmap,
.kmap_atomic = udl_dmabuf_kmap_atomic,
.kunmap = udl_dmabuf_kunmap,
.kunmap_atomic = udl_dmabuf_kunmap_atomic,
.mmap = udl_dmabuf_mmap,
.release = drm_gem_dmabuf_release,
};
struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *obj, int flags)
{
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
exp_info.ops = &udl_dmabuf_ops;
exp_info.size = obj->size;
exp_info.flags = flags;
exp_info.priv = obj;
return dma_buf_export(&exp_info);
}
static int udl_prime_create(struct drm_device *dev,
size_t size,
struct sg_table *sg,
struct udl_gem_object **obj_p)
{
struct udl_gem_object *obj;
int npages;
npages = size / PAGE_SIZE;
*obj_p = NULL;
obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
if (!obj)
return -ENOMEM;
obj->sg = sg;
obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
if (obj->pages == NULL) {
DRM_ERROR("obj pages is NULL %d\n", npages);
return -ENOMEM;
}
drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
*obj_p = obj;
return 0;
}
struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
struct dma_buf *dma_buf)
{
struct dma_buf_attachment *attach;
struct sg_table *sg;
struct udl_gem_object *uobj;
int ret;
/* need to attach */
get_device(dev->dev);
attach = dma_buf_attach(dma_buf, dev->dev);
if (IS_ERR(attach)) {
put_device(dev->dev);
return ERR_CAST(attach);
}
get_dma_buf(dma_buf);
sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
if (IS_ERR(sg)) {
ret = PTR_ERR(sg);
goto fail_detach;
}
ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
if (ret)
goto fail_unmap;
uobj->base.import_attach = attach;
uobj->flags = UDL_BO_WC;
return &uobj->base;
fail_unmap:
dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
fail_detach:
dma_buf_detach(dma_buf, attach);
dma_buf_put(dma_buf);
put_device(dev->dev);
return ERR_PTR(ret);
}