int drm_mapbufs (struct inode * inode, struct file * filp, unsigned int cmd, unsigned long arg);
\param inode device inode. \param filp file pointer. \param cmd command. \param arg pointer to a drm_buf_map structure. \return zero on success or a negative number on failure.
Maps the AGP or SG buffer region with do_mmap, and copies information about each buffer into user space. The PCI buffers are already mapped on the addbufs_pci call.