1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Shared Memory Communications over RDMA (SMC-R) and RoCE 4 * 5 * Connection Data Control (CDC) 6 * 7 * Copyright IBM Corp. 2016 8 * 9 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> 10 */ 11 12 #ifndef SMC_CDC_H 13 #define SMC_CDC_H 14 15 #include <linux/kernel.h> /* max_t */ 16 #include <linux/atomic.h> 17 #include <linux/in.h> 18 #include <linux/compiler.h> 19 20 #include "smc.h" 21 #include "smc_core.h" 22 #include "smc_wr.h" 23 24 #define SMC_CDC_MSG_TYPE 0xFE 25 26 /* in network byte order */ 27 union smc_cdc_cursor { /* SMC cursor */ 28 struct { 29 __be16 reserved; 30 __be16 wrap; 31 __be32 count; 32 }; 33 #ifdef KERNEL_HAS_ATOMIC64 34 atomic64_t acurs; /* for atomic processing */ 35 #else 36 u64 acurs; /* for atomic processing */ 37 #endif 38 } __aligned(8); 39 40 /* in network byte order */ 41 struct smc_cdc_msg { 42 struct smc_wr_rx_hdr common; /* .type = 0xFE */ 43 u8 len; /* 44 */ 44 __be16 seqno; 45 __be32 token; 46 union smc_cdc_cursor prod; 47 union smc_cdc_cursor cons; /* piggy backed "ack" */ 48 struct smc_cdc_producer_flags prod_flags; 49 struct smc_cdc_conn_state_flags conn_state_flags; 50 u8 reserved[18]; 51 }; 52 53 /* SMC-D cursor format */ 54 union smcd_cdc_cursor { 55 struct { 56 u16 wrap; 57 u32 count; 58 struct smc_cdc_producer_flags prod_flags; 59 struct smc_cdc_conn_state_flags conn_state_flags; 60 } __packed; 61 #ifdef KERNEL_HAS_ATOMIC64 62 atomic64_t acurs; /* for atomic processing */ 63 #else 64 u64 acurs; /* for atomic processing */ 65 #endif 66 } __aligned(8); 67 68 /* CDC message for SMC-D */ 69 struct smcd_cdc_msg { 70 struct smc_wr_rx_hdr common; /* Type = 0xFE */ 71 u8 res1[7]; 72 union smcd_cdc_cursor prod; 73 union smcd_cdc_cursor cons; 74 u8 res3[8]; 75 } __aligned(8); 76 77 static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn) 78 { 79 return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort || 80 conn->local_rx_ctrl.conn_state_flags.peer_conn_closed; 81 } 82 83 static inline bool smc_cdc_rxed_any_close_or_senddone( 84 struct smc_connection *conn) 85 { 86 return smc_cdc_rxed_any_close(conn) || 87 conn->local_rx_ctrl.conn_state_flags.peer_done_writing; 88 } 89 90 static inline void smc_curs_add(int size, union smc_host_cursor *curs, 91 int value) 92 { 93 curs->count += value; 94 if (curs->count >= size) { 95 curs->wrap++; 96 curs->count -= size; 97 } 98 } 99 100 /* Copy cursor src into tgt */ 101 static inline void smc_curs_copy(union smc_host_cursor *tgt, 102 union smc_host_cursor *src, 103 struct smc_connection *conn) 104 { 105 #ifndef KERNEL_HAS_ATOMIC64 106 unsigned long flags; 107 108 spin_lock_irqsave(&conn->acurs_lock, flags); 109 tgt->acurs = src->acurs; 110 spin_unlock_irqrestore(&conn->acurs_lock, flags); 111 #else 112 atomic64_set(&tgt->acurs, atomic64_read(&src->acurs)); 113 #endif 114 } 115 116 static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt, 117 union smc_cdc_cursor *src, 118 struct smc_connection *conn) 119 { 120 #ifndef KERNEL_HAS_ATOMIC64 121 unsigned long flags; 122 123 spin_lock_irqsave(&conn->acurs_lock, flags); 124 tgt->acurs = src->acurs; 125 spin_unlock_irqrestore(&conn->acurs_lock, flags); 126 #else 127 atomic64_set(&tgt->acurs, atomic64_read(&src->acurs)); 128 #endif 129 } 130 131 static inline void smcd_curs_copy(union smcd_cdc_cursor *tgt, 132 union smcd_cdc_cursor *src, 133 struct smc_connection *conn) 134 { 135 #ifndef KERNEL_HAS_ATOMIC64 136 unsigned long flags; 137 138 spin_lock_irqsave(&conn->acurs_lock, flags); 139 tgt->acurs = src->acurs; 140 spin_unlock_irqrestore(&conn->acurs_lock, flags); 141 #else 142 atomic64_set(&tgt->acurs, atomic64_read(&src->acurs)); 143 #endif 144 } 145 146 /* calculate cursor difference between old and new, where old <= new and 147 * difference cannot exceed size 148 */ 149 static inline int smc_curs_diff(unsigned int size, 150 union smc_host_cursor *old, 151 union smc_host_cursor *new) 152 { 153 if (old->wrap != new->wrap) 154 return max_t(int, 0, 155 ((size - old->count) + new->count)); 156 157 return max_t(int, 0, (new->count - old->count)); 158 } 159 160 /* calculate cursor difference between old and new - returns negative 161 * value in case old > new 162 */ 163 static inline int smc_curs_comp(unsigned int size, 164 union smc_host_cursor *old, 165 union smc_host_cursor *new) 166 { 167 if (old->wrap > new->wrap || 168 (old->wrap == new->wrap && old->count > new->count)) 169 return -smc_curs_diff(size, new, old); 170 return smc_curs_diff(size, old, new); 171 } 172 173 /* calculate cursor difference between old and new, where old <= new and 174 * difference may exceed size 175 */ 176 static inline int smc_curs_diff_large(unsigned int size, 177 union smc_host_cursor *old, 178 union smc_host_cursor *new) 179 { 180 if (old->wrap < new->wrap) 181 return min_t(int, 182 (size - old->count) + new->count + 183 (new->wrap - old->wrap - 1) * size, 184 size); 185 186 if (old->wrap > new->wrap) /* wrap has switched from 0xffff to 0x0000 */ 187 return min_t(int, 188 (size - old->count) + new->count + 189 (new->wrap + 0xffff - old->wrap) * size, 190 size); 191 192 return max_t(int, 0, (new->count - old->count)); 193 } 194 195 static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer, 196 union smc_host_cursor *local, 197 union smc_host_cursor *save, 198 struct smc_connection *conn) 199 { 200 smc_curs_copy(save, local, conn); 201 peer->count = htonl(save->count); 202 peer->wrap = htons(save->wrap); 203 /* peer->reserved = htons(0); must be ensured by caller */ 204 } 205 206 static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer, 207 struct smc_connection *conn, 208 union smc_host_cursor *save) 209 { 210 struct smc_host_cdc_msg *local = &conn->local_tx_ctrl; 211 212 peer->common.type = local->common.type; 213 peer->len = local->len; 214 peer->seqno = htons(local->seqno); 215 peer->token = htonl(local->token); 216 smc_host_cursor_to_cdc(&peer->prod, &local->prod, save, conn); 217 smc_host_cursor_to_cdc(&peer->cons, &local->cons, save, conn); 218 peer->prod_flags = local->prod_flags; 219 peer->conn_state_flags = local->conn_state_flags; 220 } 221 222 static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local, 223 union smc_cdc_cursor *peer, 224 struct smc_connection *conn) 225 { 226 union smc_host_cursor temp, old; 227 union smc_cdc_cursor net; 228 229 smc_curs_copy(&old, local, conn); 230 smc_curs_copy_net(&net, peer, conn); 231 temp.count = ntohl(net.count); 232 temp.wrap = ntohs(net.wrap); 233 if ((old.wrap > temp.wrap) && temp.wrap) 234 return; 235 if ((old.wrap == temp.wrap) && 236 (old.count > temp.count)) 237 return; 238 smc_curs_copy(local, &temp, conn); 239 } 240 241 static inline void smcr_cdc_msg_to_host(struct smc_host_cdc_msg *local, 242 struct smc_cdc_msg *peer, 243 struct smc_connection *conn) 244 { 245 local->common.type = peer->common.type; 246 local->len = peer->len; 247 local->seqno = ntohs(peer->seqno); 248 local->token = ntohl(peer->token); 249 smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn); 250 smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn); 251 local->prod_flags = peer->prod_flags; 252 local->conn_state_flags = peer->conn_state_flags; 253 } 254 255 static inline void smcd_cdc_msg_to_host(struct smc_host_cdc_msg *local, 256 struct smcd_cdc_msg *peer, 257 struct smc_connection *conn) 258 { 259 union smc_host_cursor temp; 260 261 temp.wrap = peer->prod.wrap; 262 temp.count = peer->prod.count; 263 smc_curs_copy(&local->prod, &temp, conn); 264 265 temp.wrap = peer->cons.wrap; 266 temp.count = peer->cons.count; 267 smc_curs_copy(&local->cons, &temp, conn); 268 local->prod_flags = peer->cons.prod_flags; 269 local->conn_state_flags = peer->cons.conn_state_flags; 270 } 271 272 static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local, 273 struct smc_cdc_msg *peer, 274 struct smc_connection *conn) 275 { 276 if (conn->lgr->is_smcd) 277 smcd_cdc_msg_to_host(local, (struct smcd_cdc_msg *)peer, conn); 278 else 279 smcr_cdc_msg_to_host(local, peer, conn); 280 } 281 282 struct smc_cdc_tx_pend { 283 struct smc_connection *conn; /* socket connection */ 284 union smc_host_cursor cursor; /* tx sndbuf cursor sent */ 285 union smc_host_cursor p_cursor; /* rx RMBE cursor produced */ 286 u16 ctrl_seq; /* conn. tx sequence # */ 287 }; 288 289 int smc_cdc_get_free_slot(struct smc_connection *conn, 290 struct smc_link *link, 291 struct smc_wr_buf **wr_buf, 292 struct smc_rdma_wr **wr_rdma_buf, 293 struct smc_cdc_tx_pend **pend); 294 void smc_cdc_tx_dismiss_slots(struct smc_connection *conn); 295 int smc_cdc_msg_send(struct smc_connection *conn, struct smc_wr_buf *wr_buf, 296 struct smc_cdc_tx_pend *pend); 297 int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn); 298 int smcd_cdc_msg_send(struct smc_connection *conn); 299 int smcr_cdc_msg_send_validation(struct smc_connection *conn, 300 struct smc_cdc_tx_pend *pend, 301 struct smc_wr_buf *wr_buf); 302 int smc_cdc_init(void) __init; 303 void smcd_cdc_rx_init(struct smc_connection *conn); 304 305 #endif /* SMC_CDC_H */ 306