1545 	struct st_buffer *STbp = STp->buffer;  in setup_buffering()  local
1554 		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,  in setup_buffering()
1557 			STbp->do_dio = i;  in setup_buffering()
1558 			STbp->buffer_bytes = 0;   /* can be used as transfer counter */  in setup_buffering()
1561 			STbp->do_dio = 0;  /* fall back to buffering with any error */  in setup_buffering()
1562 		STbp->sg_segs = STbp->do_dio;  in setup_buffering()
1564 		     if (STbp->do_dio) {  in setup_buffering()
1566 			STp->nbr_pages += STbp->do_dio;  in setup_buffering()
1570 		STbp->do_dio = 0;  in setup_buffering()
1573 	if (!STbp->do_dio) {  in setup_buffering()
1581 			if (is_read && STp->sili && !STbp->cleared)  in setup_buffering()
1582 				clear_buffer(STbp);  in setup_buffering()
1585 		if (bufsize > STbp->buffer_size &&  in setup_buffering()
1586 		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {  in setup_buffering()
1594 			STbp->buffer_blocks = bufsize / STp->block_size;  in setup_buffering()
1605 	struct st_buffer *STbp;  in release_buffering()  local
1607 	STbp = STp->buffer;  in release_buffering()
1608 	if (STbp->do_dio) {  in release_buffering()
1609 		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);  in release_buffering()
1610 		STbp->do_dio = 0;  in release_buffering()
1611 		STbp->sg_segs = 0;  in release_buffering()
1631 	struct st_buffer *STbp;  in st_write()  local
1679 	STbp = STp->buffer;  in st_write()
1701 	    !STbp->do_dio &&  in st_write()
1723 		if (STbp->do_dio) {  in st_write()
1730 				do_count = STbp->buffer_blocks * STp->block_size -  in st_write()
1731 					STbp->buffer_bytes;  in st_write()
1736 			i = append_to_buffer(b_point, STbp, do_count);  in st_write()
1745 		async_write = STp->block_size == 0 && !STbp->do_dio &&  in st_write()
1750 		    STbp->buffer_bytes < STbp->buffer_size) {  in st_write()
1761 			if (!STbp->do_dio)  in st_write()
1762 				blks = STbp->buffer_bytes;  in st_write()
1776 			retval = STbp->syscall_result;  in st_write()
1779 		if (async_write && !STbp->syscall_result) {  in st_write()
1780 			STbp->writing = transfer;  in st_write()
1781 			STp->dirty = !(STbp->writing ==  in st_write()
1782 				       STbp->buffer_bytes);  in st_write()
1788 		if (STbp->syscall_result != 0) {  in st_write()
1854 				retval = STbp->syscall_result;  in st_write()
1866 		STbp->buffer_bytes = 0;  in st_write()
1905 	struct st_buffer *STbp;  in read_tape()  local
1915 	STbp = STp->buffer;  in read_tape()
1925 			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)  in read_tape()
1948 		return STbp->syscall_result;  in read_tape()
1950 	STbp->read_pointer = 0;  in read_tape()
1954 	if (STbp->syscall_result) {  in read_tape()
1993 						STbp->buffer_bytes = 0;  in read_tape()
1996 						STbp->buffer_bytes = bytes - transfer;  in read_tape()
2010 						STbp->buffer_bytes = (blks - transfer) *  in read_tape()
2016 							    STbp->buffer_bytes);  in read_tape()
2028 						STbp->buffer_bytes = 0;  in read_tape()
2030 						STbp->buffer_bytes =  in read_tape()
2034 						    STbp->buffer_bytes);  in read_tape()
2041 						STbp->buffer_bytes = bytes - transfer;  in read_tape()
2043 						STbp->buffer_bytes =  in read_tape()
2048 						    STbp->buffer_bytes);  in read_tape()
2065 			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */  in read_tape()
2066 				STbp->buffer_bytes = 0;  in read_tape()
2070 			retval = STbp->syscall_result;  in read_tape()
2076 		STbp->buffer_bytes = bytes;  in read_tape()
2078 			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;  in read_tape()
2085 			STps->drv_block += STbp->buffer_bytes / STp->block_size;  in read_tape()
2103 	struct st_buffer *STbp = STp->buffer;  in st_read()  local
2132 			  STps->eof, STbp->buffer_bytes);  in st_read()
2138 	do_dio = STbp->do_dio;  in st_read()
2140 	if (STbp->buffer_bytes == 0 &&  in st_read()
2170 		if (STbp->buffer_bytes == 0) {  in st_read()
2179 		if (STbp->buffer_bytes > 0) {  in st_read()
2184 					  STps->eof, STbp->buffer_bytes,  in st_read()
2187 			transfer = STbp->buffer_bytes < count - total ?  in st_read()
2188 			    STbp->buffer_bytes : count - total;  in st_read()
2190 				i = from_buffer(STbp, buf, transfer);  in st_read()
2231 		STbp->buffer_bytes = 0;  in st_read()
4892 static int sgl_map_user_pages(struct st_buffer *STbp,  in sgl_map_user_pages()  argument
4901 	struct rq_map_data *mdata = &STbp->map_data;  in sgl_map_user_pages()
4935 	STbp->mapped_pages = pages;  in sgl_map_user_pages()
4950 static int sgl_unmap_user_pages(struct st_buffer *STbp,  in sgl_unmap_user_pages()  argument
4956 		struct page *page = STbp->mapped_pages[i];  in sgl_unmap_user_pages()
4965 	kfree(STbp->mapped_pages);  in sgl_unmap_user_pages()
4966 	STbp->mapped_pages = NULL;  in sgl_unmap_user_pages()