1 /*-
2 * Copyright (c) 2016-2018 Netflix, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #ifndef __tcp_hpts_h__
27 #define __tcp_hpts_h__
28
29 /* Number of useconds represented by an hpts slot */
30 #define HPTS_USECS_PER_SLOT 10
31 #define HPTS_USEC_IN_SEC 1000000
32 #define HPTS_MSEC_IN_SEC 1000
33 #define HPTS_USEC_IN_MSEC 1000
34
35 /*
36 * The following functions should also be available
37 * to userspace as well.
38 */
39 static inline uint32_t
tcp_tv_to_usec(const struct timeval * sv)40 tcp_tv_to_usec(const struct timeval *sv)
41 {
42 return ((uint32_t) ((sv->tv_sec * HPTS_USEC_IN_SEC) + sv->tv_usec));
43 }
44
45 static inline uint32_t
tcp_tv_to_msec(const struct timeval * sv)46 tcp_tv_to_msec(const struct timeval *sv)
47 {
48 return ((uint32_t) ((sv->tv_sec * HPTS_MSEC_IN_SEC) + (sv->tv_usec/HPTS_USEC_IN_MSEC)));
49 }
50
51 static inline uint64_t
tcp_tv_to_lusec(const struct timeval * sv)52 tcp_tv_to_lusec(const struct timeval *sv)
53 {
54 return ((uint64_t)((sv->tv_sec * HPTS_USEC_IN_SEC) + sv->tv_usec));
55 }
56
57 static inline uint64_t
tcp_tv_to_lusectick(const struct timeval * sv)58 tcp_tv_to_lusectick(const struct timeval *sv)
59 {
60 return ((uint64_t)((sv->tv_sec * HPTS_USEC_IN_SEC) + sv->tv_usec));
61 }
62
63
64 struct hpts_diag {
65 uint32_t p_hpts_active; /* bbr->flex7 x */
66 uint32_t p_nxt_slot; /* bbr->flex1 x */
67 uint32_t p_cur_slot; /* bbr->flex2 x */
68 uint32_t p_prev_slot; /* bbr->delivered */
69 uint32_t p_runningslot; /* bbr->inflight */
70 uint32_t slot_req; /* bbr->flex3 x */
71 uint32_t inp_hptsslot; /* bbr->flex4 x */
72 uint32_t time_remaining; /* bbr->flex5 x */
73 uint32_t have_slept; /* bbr->epoch x */
74 uint32_t hpts_sleep_time; /* bbr->applimited x */
75 uint32_t yet_to_sleep; /* bbr->lt_epoch x */
76 uint32_t need_new_to; /* bbr->flex6 x */
77 uint32_t wheel_slot; /* bbr->bw_inuse x */
78 uint32_t maxslots; /* bbr->delRate x */
79 uint32_t wheel_cts; /* bbr->rttProp x */
80 int32_t co_ret; /* bbr->pkts_out x */
81 uint8_t p_on_min_sleep; /* bbr->flex8 x */
82 };
83
84 /* Magic flags to tell whats cooking on the pacing wheel */
85 #define PACE_TMR_DELACK 0x01 /* Delayed ack timer running */
86 #define PACE_TMR_RACK 0x02 /* RACK timer running */
87 #define PACE_TMR_TLP 0x04 /* TLP timer running */
88 #define PACE_TMR_RXT 0x08 /* Retransmit timer running */
89 #define PACE_TMR_PERSIT 0x10 /* Persists timer running */
90 #define PACE_TMR_KEEP 0x20 /* Keep alive timer running */
91 #define PACE_PKT_OUTPUT 0x40 /* Output Packets being paced */
92 #define PACE_TMR_MASK (PACE_TMR_KEEP|PACE_TMR_PERSIT|PACE_TMR_RXT|PACE_TMR_TLP|PACE_TMR_RACK|PACE_TMR_DELACK)
93
94 #ifdef _KERNEL
95
96 extern struct tcp_hptsi *tcp_hptsi_pace;
97
98 /*
99 * The following are the definitions for the kernel HPTS interface for managing
100 * the HPTS ring and the TCBs on it.
101 */
102
103 void __tcp_hpts_init(struct tcp_hptsi *pace, struct tcpcb *);
104 #define tcp_hpts_init(tp) __tcp_hpts_init(tcp_hptsi_pace, tp)
105
106 void __tcp_hpts_remove(struct tcp_hptsi *pace, struct tcpcb *);
107 #define tcp_hpts_remove(tp) __tcp_hpts_remove(tcp_hptsi_pace, tp)
108
109 static inline bool
tcp_in_hpts(struct tcpcb * tp)110 tcp_in_hpts(struct tcpcb *tp)
111 {
112 return ((tp->t_in_hpts == IHPTS_ONQUEUE) ||
113 ((tp->t_in_hpts == IHPTS_MOVING) &&
114 (tp->t_hpts_slot != -1)));
115 }
116
117 /*
118 * To insert a TCB on the hpts you *must* be holding the
119 * INP_WLOCK(). The hpts insert code will then acqurire
120 * the hpts's lock and insert the TCB on the requested
121 * slot possibly waking up the hpts if you are requesting
122 * a time earlier than what the hpts is sleeping to (if
123 * the hpts is sleeping). You may check the inp->inp_in_hpts
124 * flag without the hpts lock. The hpts is the only one
125 * that will clear this flag holding only the hpts lock. This
126 * means that in your tcp_output() routine when you test for
127 * it to be 1 (so you wont call output) it may be transitioning
128 * to 0 (by the hpts). That will be fine since that will just
129 * mean an extra call to tcp_output that most likely will find
130 * the call you executed (when the mis-match occurred) will have
131 * put the TCB back on the hpts and it will return. If your
132 * call did not add it back to the hpts then you will either
133 * over-send or the cwnd will block you from sending more.
134 *
135 * Note you should also be holding the INP_WLOCK() when you
136 * call the remove from the hpts as well. Thoug usually
137 * you are either doing this from a timer, where you need
138 * that INP_WLOCK() or from destroying your TCB where again
139 * you should already have the INP_WLOCK().
140 */
141 void __tcp_hpts_insert(struct tcp_hptsi *pace, struct tcpcb *tp, uint32_t usecs,
142 struct hpts_diag *diag);
143 #define tcp_hpts_insert(tp, usecs, diag) \
144 __tcp_hpts_insert(tcp_hptsi_pace, (tp), (usecs), (diag))
145
146 void __tcp_set_hpts(struct tcp_hptsi *pace, struct tcpcb *tp);
147 #define tcp_set_hpts(tp) __tcp_set_hpts(tcp_hptsi_pace, tp)
148
149 extern int32_t tcp_min_hptsi_time;
150
151 static inline int32_t
get_hpts_min_sleep_time(void)152 get_hpts_min_sleep_time(void)
153 {
154 return (tcp_min_hptsi_time + HPTS_USECS_PER_SLOT);
155 }
156
157 static inline uint64_t
tcp_get_u64_usecs(struct timeval * tv)158 tcp_get_u64_usecs(struct timeval *tv)
159 {
160 struct timeval tvd;
161
162 if (tv == NULL)
163 tv = &tvd;
164 microuptime(tv);
165 return (tcp_tv_to_lusec(tv));
166 }
167
168 static inline uint32_t
tcp_get_usecs(struct timeval * tv)169 tcp_get_usecs(struct timeval *tv)
170 {
171 struct timeval tvd;
172
173 if (tv == NULL)
174 tv = &tvd;
175 microuptime(tv);
176 return (tcp_tv_to_usec(tv));
177 }
178
179 #endif /* _KERNEL */
180 #endif /* __tcp_hpts_h__ */
181