5428 static int append_to_buffer(const char __user *ubp, struct osst_buffer *st_bp, int do_count)  in append_to_buffer()  argument
5432 	for (i=0, offset=st_bp->buffer_bytes;  in append_to_buffer()
5433 	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)  in append_to_buffer()
5434 	offset -= st_bp->sg[i].length;  in append_to_buffer()
5435 	if (i == st_bp->sg_segs) {  /* Should never happen */  in append_to_buffer()
5439 	for ( ; i < st_bp->sg_segs && do_count > 0; i++) {  in append_to_buffer()
5440 		cnt = st_bp->sg[i].length - offset < do_count ?  in append_to_buffer()
5441 		      st_bp->sg[i].length - offset : do_count;  in append_to_buffer()
5442 		res = copy_from_user(page_address(sg_page(&st_bp->sg[i])) + offset, ubp, cnt);  in append_to_buffer()
5446 		st_bp->buffer_bytes += cnt;  in append_to_buffer()
5461 static int from_buffer(struct osst_buffer *st_bp, char __user *ubp, int do_count)  in from_buffer()  argument
5465 	for (i=0, offset=st_bp->read_pointer;  in from_buffer()
5466 	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)  in from_buffer()
5467 		offset -= st_bp->sg[i].length;  in from_buffer()
5468 	if (i == st_bp->sg_segs) {  /* Should never happen */  in from_buffer()
5472 	for ( ; i < st_bp->sg_segs && do_count > 0; i++) {  in from_buffer()
5473 		cnt = st_bp->sg[i].length - offset < do_count ?  in from_buffer()
5474 		      st_bp->sg[i].length - offset : do_count;  in from_buffer()
5475 		res = copy_to_user(ubp, page_address(sg_page(&st_bp->sg[i])) + offset, cnt);  in from_buffer()
5479 		st_bp->buffer_bytes -= cnt;  in from_buffer()
5480 		st_bp->read_pointer += cnt;  in from_buffer()
5493 static int osst_zero_buffer_tail(struct osst_buffer *st_bp)  in osst_zero_buffer_tail()  argument
5497 	for (i = 0, offset = st_bp->buffer_bytes;  in osst_zero_buffer_tail()
5498 	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)  in osst_zero_buffer_tail()
5499 		offset -= st_bp->sg[i].length;  in osst_zero_buffer_tail()
5500 	if (i == st_bp->sg_segs) {  /* Should never happen */  in osst_zero_buffer_tail()
5504 	for (do_count = OS_DATA_SIZE - st_bp->buffer_bytes;  in osst_zero_buffer_tail()
5505 	     i < st_bp->sg_segs && do_count > 0; i++) {  in osst_zero_buffer_tail()
5506 		cnt = st_bp->sg[i].length - offset < do_count ?  in osst_zero_buffer_tail()
5507 		      st_bp->sg[i].length - offset : do_count ;  in osst_zero_buffer_tail()
5508 		memset(page_address(sg_page(&st_bp->sg[i])) + offset, 0, cnt);  in osst_zero_buffer_tail()
5521 static int osst_copy_to_buffer(struct osst_buffer *st_bp, unsigned char *ptr)  in osst_copy_to_buffer()  argument
5525 	for (i = 0; i < st_bp->sg_segs && do_count > 0; i++) {  in osst_copy_to_buffer()
5526 		cnt = st_bp->sg[i].length < do_count ?  in osst_copy_to_buffer()
5527 		      st_bp->sg[i].length : do_count ;  in osst_copy_to_buffer()
5528 		memcpy(page_address(sg_page(&st_bp->sg[i])), ptr, cnt);  in osst_copy_to_buffer()
5532 	if (do_count || i != st_bp->sg_segs-1) {  /* Should never happen */  in osst_copy_to_buffer()
5542 static int osst_copy_from_buffer(struct osst_buffer *st_bp, unsigned char *ptr)  in osst_copy_from_buffer()  argument
5546 	for (i = 0; i < st_bp->sg_segs && do_count > 0; i++) {  in osst_copy_from_buffer()
5547 		cnt = st_bp->sg[i].length < do_count ?  in osst_copy_from_buffer()
5548 		      st_bp->sg[i].length : do_count ;  in osst_copy_from_buffer()
5549 		memcpy(ptr, page_address(sg_page(&st_bp->sg[i])), cnt);  in osst_copy_from_buffer()
5553 	if (do_count || i != st_bp->sg_segs-1) {  /* Should never happen */  in osst_copy_from_buffer()