/**
* rppc_map_page - import and map a kernel page in a dma_buf
* @rpc - rppc instance handle
* @fd: file descriptor of the dma_buf to import
* @offset: offset of the translate location within the buffer
* @base_ptr: pointer for returning mapped kernel address
* @dmabuf: pointer for returning the imported dma_buf
*
* A helper function to import the dma_buf buffer and map into kernel
* the page containing the offset within the buffer. The function is
* called by rppc_xlate_buffers and returns the pointers to the kernel
* mapped address and the imported dma_buf handle in arguments. The
* mapping is used for performing in-place translation of the user
* provided pointer at location @offset within the buffer.
*
* The mapping is achieved through the appropriate dma_buf ops, and
* the page will be unmapped after performing the translation. See
* also rppc_unmap_page.
*
* Return: 0 on success, or an appropriate failure code otherwise
*/
static int rppc_map_page(struct rppc_instance *rpc, int fd, u32 offset,
uint8_t **base_ptr, struct dma_buf **dmabuf)
{
int ret = 0;
uint8_t *ptr = NULL;
struct dma_buf *dbuf = NULL;
uint32_t pg_offset;
unsigned long pg_num;
size_t begin, end = PAGE_SIZE;
struct device *dev = rpc->dev;
if (!base_ptr || !dmabuf)
return -EINVAL;
pg_offset = (offset & (PAGE_SIZE - 1));
begin = offset & PAGE_MASK;
pg_num = offset >> PAGE_SHIFT;
dbuf = dma_buf_get(fd);
if (IS_ERR(dbuf)) {
ret = PTR_ERR(dbuf);
dev_err(dev, "invalid dma_buf file descriptor passed! fd = %d ret = %d\n",
fd, ret);
goto out;
}
ret = dma_buf_begin_cpu_access(dbuf, begin, end, DMA_BIDIRECTIONAL);
if (ret < 0) {
dev_err(dev, "failed to acquire cpu access to the dma buf fd = %d offset = 0x%x, ret = %d\n",
fd, offset, ret);
goto put_dmabuf;
}
ptr = dma_buf_kmap(dbuf, pg_num);
if (!ptr) {
ret = -ENOBUFS;
dev_err(dev, "failed to map the page containing the translation into kernel fd = %d offset = 0x%x\n",
fd, offset);
goto end_cpuaccess;
}
*base_ptr = ptr;
*dmabuf = dbuf;
dev_dbg(dev, "kmap'd base_ptr = %p buf = %p into kernel from %zu for %zu bytes, pg_offset = 0x%x\n",
ptr, dbuf, begin, end, pg_offset);
return 0;
end_cpuaccess:
dma_buf_end_cpu_access(dbuf, begin, end, DMA_BIDIRECTIONAL);
put_dmabuf:
dma_buf_put(dbuf);
out:
return ret;
}
static void *vb2_ion_vaddr(void *buf_priv)
{
struct vb2_ion_buf *buf = buf_priv;
if (WARN_ON(!buf))
return NULL;
if (buf->kva != NULL)
return buf->kva;
if (dma_buf_begin_cpu_access(buf->dma_buf,
0, buf->size, buf->direction))
return NULL;
buf->kva = dma_buf_kmap(buf->dma_buf, 0);
if (buf->kva == NULL)
dma_buf_end_cpu_access(buf->dma_buf,
0, buf->size, buf->direction);
return buf->kva;
}
void *nvhost_dmabuf_kmap(struct mem_handle *handle, unsigned int pagenum)
{
return dma_buf_kmap(to_dmabuf(handle), pagenum);
}
static int igt_dmabuf_export_kmap(void *arg)
{
struct drm_i915_private *i915 = arg;
struct drm_i915_gem_object *obj;
struct dma_buf *dmabuf;
void *ptr;
int err;
obj = i915_gem_object_create(i915, 2*PAGE_SIZE);
if (IS_ERR(obj))
return PTR_ERR(obj);
dmabuf = i915_gem_prime_export(&i915->drm, &obj->base, 0);
i915_gem_object_put(obj);
if (IS_ERR(dmabuf)) {
err = PTR_ERR(dmabuf);
pr_err("i915_gem_prime_export failed with err=%d\n", err);
return err;
}
ptr = dma_buf_kmap(dmabuf, 0);
if (!ptr) {
pr_err("dma_buf_kmap failed\n");
err = -ENOMEM;
goto err;
}
if (memchr_inv(ptr, 0, PAGE_SIZE)) {
dma_buf_kunmap(dmabuf, 0, ptr);
pr_err("Exported page[0] not initialiased to zero!\n");
err = -EINVAL;
goto err;
}
memset(ptr, 0xc5, PAGE_SIZE);
dma_buf_kunmap(dmabuf, 0, ptr);
ptr = i915_gem_object_pin_map(obj, I915_MAP_WB);
if (IS_ERR(ptr)) {
err = PTR_ERR(ptr);
pr_err("i915_gem_object_pin_map failed with err=%d\n", err);
goto err;
}
memset(ptr + PAGE_SIZE, 0xaa, PAGE_SIZE);
i915_gem_object_unpin_map(obj);
ptr = dma_buf_kmap(dmabuf, 1);
if (!ptr) {
pr_err("dma_buf_kmap failed\n");
err = -ENOMEM;
goto err;
}
if (memchr_inv(ptr, 0xaa, PAGE_SIZE)) {
dma_buf_kunmap(dmabuf, 1, ptr);
pr_err("Exported page[1] not set to 0xaa!\n");
err = -EINVAL;
goto err;
}
memset(ptr, 0xc5, PAGE_SIZE);
dma_buf_kunmap(dmabuf, 1, ptr);
ptr = dma_buf_kmap(dmabuf, 0);
if (!ptr) {
pr_err("dma_buf_kmap failed\n");
err = -ENOMEM;
goto err;
}
if (memchr_inv(ptr, 0xc5, PAGE_SIZE)) {
dma_buf_kunmap(dmabuf, 0, ptr);
pr_err("Exported page[0] did not retain 0xc5!\n");
err = -EINVAL;
goto err;
}
dma_buf_kunmap(dmabuf, 0, ptr);
ptr = dma_buf_kmap(dmabuf, 2);
if (ptr) {
pr_err("Erroneously kmapped beyond the end of the object!\n");
dma_buf_kunmap(dmabuf, 2, ptr);
err = -EINVAL;
goto err;
}
ptr = dma_buf_kmap(dmabuf, -1);
if (ptr) {
pr_err("Erroneously kmapped before the start of the object!\n");
dma_buf_kunmap(dmabuf, -1, ptr);
err = -EINVAL;
goto err;
}
err = 0;
err:
dma_buf_put(dmabuf);
return err;
}
