128 #define FRONT_RING_INIT(_r, _s, __size) do {				\  argument
129     (_r)->req_prod_pvt = 0;						\
130     (_r)->rsp_cons = 0;							\
131     (_r)->nr_ents = __RING_SIZE(_s, __size);				\
132     (_r)->sring = (_s);							\
135 #define BACK_RING_INIT(_r, _s, __size) do {				\  argument
136     (_r)->rsp_prod_pvt = 0;						\
137     (_r)->req_cons = 0;							\
138     (_r)->nr_ents = __RING_SIZE(_s, __size);				\
139     (_r)->sring = (_s);							\
143 #define FRONT_RING_ATTACH(_r, _s, __size) do {				\  argument
144     (_r)->sring = (_s);							\
145     (_r)->req_prod_pvt = (_s)->req_prod;				\
146     (_r)->rsp_cons = (_s)->rsp_prod;					\
147     (_r)->nr_ents = __RING_SIZE(_s, __size);				\
150 #define BACK_RING_ATTACH(_r, _s, __size) do {				\  argument
151     (_r)->sring = (_s);							\
152     (_r)->rsp_prod_pvt = (_s)->rsp_prod;				\
153     (_r)->req_cons = (_s)->req_prod;					\
154     (_r)->nr_ents = __RING_SIZE(_s, __size);				\
158 #define RING_SIZE(_r)							\  argument
159     ((_r)->nr_ents)
162 #define RING_FREE_REQUESTS(_r)						\  argument
163     (RING_SIZE(_r) - ((_r)->req_prod_pvt - (_r)->rsp_cons))
168 #define RING_FULL(_r)							\  argument
169     (RING_FREE_REQUESTS(_r) == 0)
172 #define RING_HAS_UNCONSUMED_RESPONSES(_r)				\  argument
173     ((_r)->sring->rsp_prod - (_r)->rsp_cons)
175 #define RING_HAS_UNCONSUMED_REQUESTS(_r)				\  argument
177 	unsigned int req = (_r)->sring->req_prod - (_r)->req_cons;	\
178 	unsigned int rsp = RING_SIZE(_r) -				\
179 			   ((_r)->req_cons - (_r)->rsp_prod_pvt);	\
184 #define RING_GET_REQUEST(_r, _idx)					\  argument
185     (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req))
196 #define RING_COPY_REQUEST(_r, _idx, _req) do {				\  argument
198 	*(_req) = *(volatile typeof(_req))RING_GET_REQUEST(_r, _idx);	\
201 #define RING_GET_RESPONSE(_r, _idx)					\  argument
202     (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp))
205 #define RING_REQUEST_CONS_OVERFLOW(_r, _cons)				\  argument
206     (((_cons) - (_r)->rsp_prod_pvt) >= RING_SIZE(_r))
209 #define RING_REQUEST_PROD_OVERFLOW(_r, _prod)               \  argument
210     (((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r))
213 #define RING_PUSH_REQUESTS(_r) do {					\  argument
215     (_r)->sring->req_prod = (_r)->req_prod_pvt;				\
218 #define RING_PUSH_RESPONSES(_r) do {					\  argument
220     (_r)->sring->rsp_prod = (_r)->rsp_prod_pvt;				\
253 #define RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(_r, _notify) do {		\  argument
254     RING_IDX __old = (_r)->sring->req_prod;				\
255     RING_IDX __new = (_r)->req_prod_pvt;				\
257     (_r)->sring->req_prod = __new;					\
259     (_notify) = ((RING_IDX)(__new - (_r)->sring->req_event) <		\
263 #define RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(_r, _notify) do {		\  argument
264     RING_IDX __old = (_r)->sring->rsp_prod;				\
265     RING_IDX __new = (_r)->rsp_prod_pvt;				\
267     (_r)->sring->rsp_prod = __new;					\
269     (_notify) = ((RING_IDX)(__new - (_r)->sring->rsp_event) <		\
273 #define RING_FINAL_CHECK_FOR_REQUESTS(_r, _work_to_do) do {		\  argument
274     (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r);			\
276     (_r)->sring->req_event = (_r)->req_cons + 1;			\
278     (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r);			\
281 #define RING_FINAL_CHECK_FOR_RESPONSES(_r, _work_to_do) do {		\  argument
282     (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r);			\
284     (_r)->sring->rsp_event = (_r)->rsp_cons + 1;			\
286     (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r);			\