105 	f->head = 0;  in msnd_fifo_alloc()
116 	f->len = f->tail = f->head = 0;  in msnd_fifo_make_empty()
127 		if (f->head <= f->tail) {  in msnd_fifo_write_io()
133 			nwritten = f->head - f->tail;  in msnd_fifo_write_io()
158 		if (f->head <= f->tail) {  in msnd_fifo_write()
164 			nwritten = f->head - f->tail;  in msnd_fifo_write()
189 		if (f->tail <= f->head) {  in msnd_fifo_read_io()
191 			if (nread > f->n - f->head)  in msnd_fifo_read_io()
192 				nread = f->n - f->head;  in msnd_fifo_read_io()
195 			nread = f->tail - f->head;  in msnd_fifo_read_io()
200 		memcpy_toio(buf, f->data + f->head, nread);  in msnd_fifo_read_io()
205 		f->head += nread;  in msnd_fifo_read_io()
206 		f->head %= f->n;  in msnd_fifo_read_io()
220 		if (f->tail <= f->head) {  in msnd_fifo_read()
222 			if (nread > f->n - f->head)  in msnd_fifo_read()
223 				nread = f->n - f->head;  in msnd_fifo_read()
226 			nread = f->tail - f->head;  in msnd_fifo_read()
231 		memcpy(buf, f->data + f->head, nread);  in msnd_fifo_read()
236 		f->head += nread;  in msnd_fifo_read()
237 		f->head %= f->n;  in msnd_fifo_read()