Commit | Line | Data |
---|---|---|
5f08318f UB |
1 | /* |
2 | * Shared Memory Communications over RDMA (SMC-R) and RoCE | |
3 | * | |
4 | * Connection Data Control (CDC) | |
5 | * | |
6 | * Copyright IBM Corp. 2016 | |
7 | * | |
8 | * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> | |
9 | */ | |
10 | ||
11 | #ifndef SMC_CDC_H | |
12 | #define SMC_CDC_H | |
13 | ||
14 | #include <linux/kernel.h> /* max_t */ | |
15 | #include <linux/atomic.h> | |
16 | #include <linux/in.h> | |
17 | #include <linux/compiler.h> | |
18 | ||
19 | #include "smc.h" | |
20 | #include "smc_core.h" | |
21 | #include "smc_wr.h" | |
22 | ||
23 | #define SMC_CDC_MSG_TYPE 0xFE | |
24 | ||
25 | /* in network byte order */ | |
26 | union smc_cdc_cursor { /* SMC cursor */ | |
27 | struct { | |
28 | __be16 reserved; | |
29 | __be16 wrap; | |
30 | __be32 count; | |
31 | }; | |
32 | #ifdef KERNEL_HAS_ATOMIC64 | |
33 | atomic64_t acurs; /* for atomic processing */ | |
34 | #else | |
35 | u64 acurs; /* for atomic processing */ | |
36 | #endif | |
37 | } __aligned(8); | |
38 | ||
39 | /* in network byte order */ | |
40 | struct smc_cdc_msg { | |
41 | struct smc_wr_rx_hdr common; /* .type = 0xFE */ | |
42 | u8 len; /* 44 */ | |
43 | __be16 seqno; | |
44 | __be32 token; | |
45 | union smc_cdc_cursor prod; | |
46 | union smc_cdc_cursor cons; /* piggy backed "ack" */ | |
47 | struct smc_cdc_producer_flags prod_flags; | |
48 | struct smc_cdc_conn_state_flags conn_state_flags; | |
49 | u8 reserved[18]; | |
50 | } __aligned(8); | |
51 | ||
52 | static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn) | |
53 | { | |
54 | return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort || | |
55 | conn->local_rx_ctrl.conn_state_flags.peer_conn_closed; | |
56 | } | |
57 | ||
58 | static inline bool smc_cdc_rxed_any_close_or_senddone( | |
59 | struct smc_connection *conn) | |
60 | { | |
61 | return smc_cdc_rxed_any_close(conn) || | |
62 | conn->local_rx_ctrl.conn_state_flags.peer_done_writing; | |
63 | } | |
64 | ||
65 | static inline void smc_curs_add(int size, union smc_host_cursor *curs, | |
66 | int value) | |
67 | { | |
68 | curs->count += value; | |
69 | if (curs->count >= size) { | |
70 | curs->wrap++; | |
71 | curs->count -= size; | |
72 | } | |
73 | } | |
74 | ||
75 | /* SMC cursors are 8 bytes long and require atomic reading and writing */ | |
76 | static inline u64 smc_curs_read(union smc_host_cursor *curs, | |
77 | struct smc_connection *conn) | |
78 | { | |
79 | #ifndef KERNEL_HAS_ATOMIC64 | |
80 | unsigned long flags; | |
81 | u64 ret; | |
82 | ||
83 | spin_lock_irqsave(&conn->acurs_lock, flags); | |
84 | ret = curs->acurs; | |
85 | spin_unlock_irqrestore(&conn->acurs_lock, flags); | |
86 | return ret; | |
87 | #else | |
88 | return atomic64_read(&curs->acurs); | |
89 | #endif | |
90 | } | |
91 | ||
92 | static inline u64 smc_curs_read_net(union smc_cdc_cursor *curs, | |
93 | struct smc_connection *conn) | |
94 | { | |
95 | #ifndef KERNEL_HAS_ATOMIC64 | |
96 | unsigned long flags; | |
97 | u64 ret; | |
98 | ||
99 | spin_lock_irqsave(&conn->acurs_lock, flags); | |
100 | ret = curs->acurs; | |
101 | spin_unlock_irqrestore(&conn->acurs_lock, flags); | |
102 | return ret; | |
103 | #else | |
104 | return atomic64_read(&curs->acurs); | |
105 | #endif | |
106 | } | |
107 | ||
108 | static inline void smc_curs_write(union smc_host_cursor *curs, u64 val, | |
109 | struct smc_connection *conn) | |
110 | { | |
111 | #ifndef KERNEL_HAS_ATOMIC64 | |
112 | unsigned long flags; | |
113 | ||
114 | spin_lock_irqsave(&conn->acurs_lock, flags); | |
115 | curs->acurs = val; | |
116 | spin_unlock_irqrestore(&conn->acurs_lock, flags); | |
117 | #else | |
118 | atomic64_set(&curs->acurs, val); | |
119 | #endif | |
120 | } | |
121 | ||
122 | static inline void smc_curs_write_net(union smc_cdc_cursor *curs, u64 val, | |
123 | struct smc_connection *conn) | |
124 | { | |
125 | #ifndef KERNEL_HAS_ATOMIC64 | |
126 | unsigned long flags; | |
127 | ||
128 | spin_lock_irqsave(&conn->acurs_lock, flags); | |
129 | curs->acurs = val; | |
130 | spin_unlock_irqrestore(&conn->acurs_lock, flags); | |
131 | #else | |
132 | atomic64_set(&curs->acurs, val); | |
133 | #endif | |
134 | } | |
135 | ||
136 | /* calculate cursor difference between old and new, where old <= new */ | |
137 | static inline int smc_curs_diff(unsigned int size, | |
138 | union smc_host_cursor *old, | |
139 | union smc_host_cursor *new) | |
140 | { | |
141 | if (old->wrap != new->wrap) | |
142 | return max_t(int, 0, | |
143 | ((size - old->count) + new->count)); | |
144 | ||
145 | return max_t(int, 0, (new->count - old->count)); | |
146 | } | |
147 | ||
148 | static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer, | |
149 | union smc_host_cursor *local, | |
150 | struct smc_connection *conn) | |
151 | { | |
152 | union smc_host_cursor temp; | |
153 | ||
154 | smc_curs_write(&temp, smc_curs_read(local, conn), conn); | |
155 | peer->count = htonl(temp.count); | |
156 | peer->wrap = htons(temp.wrap); | |
157 | /* peer->reserved = htons(0); must be ensured by caller */ | |
158 | } | |
159 | ||
160 | static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer, | |
161 | struct smc_host_cdc_msg *local, | |
162 | struct smc_connection *conn) | |
163 | { | |
164 | peer->common.type = local->common.type; | |
165 | peer->len = local->len; | |
166 | peer->seqno = htons(local->seqno); | |
167 | peer->token = htonl(local->token); | |
168 | smc_host_cursor_to_cdc(&peer->prod, &local->prod, conn); | |
169 | smc_host_cursor_to_cdc(&peer->cons, &local->cons, conn); | |
170 | peer->prod_flags = local->prod_flags; | |
171 | peer->conn_state_flags = local->conn_state_flags; | |
172 | } | |
173 | ||
174 | static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local, | |
175 | union smc_cdc_cursor *peer, | |
176 | struct smc_connection *conn) | |
177 | { | |
178 | union smc_host_cursor temp, old; | |
179 | union smc_cdc_cursor net; | |
180 | ||
181 | smc_curs_write(&old, smc_curs_read(local, conn), conn); | |
182 | smc_curs_write_net(&net, smc_curs_read_net(peer, conn), conn); | |
183 | temp.count = ntohl(net.count); | |
184 | temp.wrap = ntohs(net.wrap); | |
185 | if ((old.wrap > temp.wrap) && temp.wrap) | |
186 | return; | |
187 | if ((old.wrap == temp.wrap) && | |
188 | (old.count > temp.count)) | |
189 | return; | |
190 | smc_curs_write(local, smc_curs_read(&temp, conn), conn); | |
191 | } | |
192 | ||
193 | static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local, | |
194 | struct smc_cdc_msg *peer, | |
195 | struct smc_connection *conn) | |
196 | { | |
197 | local->common.type = peer->common.type; | |
198 | local->len = peer->len; | |
199 | local->seqno = ntohs(peer->seqno); | |
200 | local->token = ntohl(peer->token); | |
201 | smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn); | |
202 | smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn); | |
203 | local->prod_flags = peer->prod_flags; | |
204 | local->conn_state_flags = peer->conn_state_flags; | |
205 | } | |
206 | ||
207 | struct smc_cdc_tx_pend; | |
208 | ||
209 | int smc_cdc_get_free_slot(struct smc_link *link, struct smc_wr_buf **wr_buf, | |
210 | struct smc_cdc_tx_pend **pend); | |
211 | void smc_cdc_tx_dismiss_slots(struct smc_connection *conn); | |
212 | int smc_cdc_msg_send(struct smc_connection *conn, struct smc_wr_buf *wr_buf, | |
213 | struct smc_cdc_tx_pend *pend); | |
214 | int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn); | |
b38d7324 | 215 | bool smc_cdc_tx_has_pending(struct smc_connection *conn); |
5f08318f UB |
216 | int smc_cdc_init(void) __init; |
217 | ||
218 | #endif /* SMC_CDC_H */ |