1 /**
2 * \internal
3 * \file
4 * Timeout definitions.
5 */
6 /*
7 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
8 * Alexander Warg <warg@os.inf.tu-dresden.de>,
9 * Torsten Frenzel <frenzel@os.inf.tu-dresden.de>
10 * economic rights: Technische Universität Dresden (Germany)
11 *
12 * This file is part of TUD:OS and distributed under the terms of the
13 * GNU General Public License 2.
14 * Please see the COPYING-GPL-2 file for details.
15 *
16 * As a special exception, you may use this file as part of a free software
17 * library without restriction. Specifically, if other files instantiate
18 * templates or use macros or inline functions from this file, or you compile
19 * this file and link it with other files to produce an executable, this
20 * file does not by itself cause the resulting executable to be covered by
21 * the GNU General Public License. This exception does not however
22 * invalidate any other reasons why the executable file might be covered by
23 * the GNU General Public License.
24 */
25 #ifndef L4_SYS_TIMEOUT_H__
26 #define L4_SYS_TIMEOUT_H__
27
28 #include <l4/sys/l4int.h>
29
30 /**
31 * \defgroup l4_timeout_api Timeouts
32 * \ingroup l4_ipc_api
33 * All kinds of timeouts and time related functions.
34 */
35
36 /**
37 * Basic timeout specification.
38 * \ingroup l4_timeout_api
39 *
40 * Basically a floating point number with 10 bits mantissa and
41 * 5 bits exponent (t = m*2^e).
42 *
43 * If bit 15 == 1 the timeout is absolute and the lower 6 bits encode the index
44 * of the UTCB buffer register(s) holding the absolute 64-bit timeout value. On
45 * 32-bit systems, two consecutive UTCB buffer registers are used.
46 */
47 typedef struct l4_timeout_s {
48 l4_uint16_t t; /**< timeout value */
49 } __attribute__((packed)) l4_timeout_s;
50
51
52 /**
53 * Timeout pair.
54 * \ingroup l4_timeout_api
55 *
56 * For IPC there are usually a send and a receive timeout.
57 * So this structure contains a pair of timeouts.
58 */
59 typedef union l4_timeout_t {
60 l4_uint32_t raw; /**< raw value */
61 struct
62 {
63 #ifdef __BIG_ENDIAN__
64 l4_timeout_s snd; /**< send timeout */
65 l4_timeout_s rcv; /**< receive timeout */
66 #else
67 l4_timeout_s rcv; /**< receive timeout */
68 l4_timeout_s snd; /**< send timeout */
69 #endif
70 } p; /**< combined timeout */
71 } l4_timeout_t;
72
73
74 /**
75 * Timeout constants.
76 * \ingroup l4_timeout_api
77 */
78 /*@{*/
79 #define L4_IPC_TIMEOUT_0 ((l4_timeout_s){0x0400}) /**< 0 timeout */
80 #define L4_IPC_TIMEOUT_NEVER ((l4_timeout_s){0}) /**< never timeout */
81 #define L4_IPC_NEVER_INITIALIZER {0} /**< never timeout, init */
82 #define L4_IPC_NEVER ((l4_timeout_t){0}) /**< never timeout */
83 #define L4_IPC_RECV_TIMEOUT_0 ((l4_timeout_t){0x00000400}) /**< 0 receive timeout */
84 #define L4_IPC_SEND_TIMEOUT_0 ((l4_timeout_t){0x04000000}) /**< 0 send timeout */
85 #define L4_IPC_BOTH_TIMEOUT_0 ((l4_timeout_t){0x04000400}) /**< 0 receive and send timeout */
86 /*@}*/
87
88 /**
89 * Get relative timeout consisting of mantissa and exponent.
90 * \ingroup l4_timeout_api
91 *
92 * \param man Mantissa of timeout
93 * \param exp Exponent of timeout
94 *
95 * \return timeout value
96 */
97 L4_INLINE
98 l4_timeout_s l4_timeout_rel(unsigned man, unsigned exp) L4_NOTHROW;
99
100
101 /**
102 * Convert explicit timeout values to l4_timeout_t type.
103 * \ingroup l4_timeout_api
104 *
105 * \param snd_man Mantissa of send timeout.
106 * \param snd_exp Exponent of send timeout.
107 * \param rcv_man Mantissa of receive timeout.
108 * \param rcv_exp Exponent of receive timeout.
109 */
110 L4_INLINE
111 l4_timeout_t l4_ipc_timeout(unsigned snd_man, unsigned snd_exp,
112 unsigned rcv_man, unsigned rcv_exp) L4_NOTHROW;
113
114 /**
115 * Combine send and receive timeout in a timeout.
116 * \ingroup l4_timeout_api
117 *
118 * \param snd Send timeout
119 * \param rcv Receive timeout
120 *
121 * \return L4 timeout
122 */
123 L4_INLINE
124 l4_timeout_t l4_timeout(l4_timeout_s snd, l4_timeout_s rcv) L4_NOTHROW;
125
126 /**
127 * Set send timeout in given to timeout.
128 * \ingroup l4_timeout_api
129 *
130 * \param snd Send timeout
131 * \retval to L4 timeout
132 */
133 L4_INLINE
134 void l4_snd_timeout(l4_timeout_s snd, l4_timeout_t *to) L4_NOTHROW;
135
136 /**
137 * Set receive timeout in given to timeout.
138 * \ingroup l4_timeout_api
139 *
140 * \param rcv Receive timeout
141 * \retval to L4 timeout
142 */
143 L4_INLINE
144 void l4_rcv_timeout(l4_timeout_s rcv, l4_timeout_t *to) L4_NOTHROW;
145
146 /**
147 * Get clock value of out timeout.
148 * \ingroup l4_timeout_api
149 *
150 * \param to L4 timeout
151 *
152 * \return Clock value
153 */
154 L4_INLINE
155 l4_kernel_clock_t l4_timeout_rel_get(l4_timeout_s to) L4_NOTHROW;
156
157
158 /**
159 * Return whether the given timeout is absolute or not.
160 * \ingroup l4_timeout_api
161 *
162 * \param to L4 timeout
163 *
164 * \return != 0 if absolute, 0 if relative
165 */
166 L4_INLINE
167 unsigned l4_timeout_is_absolute(l4_timeout_s to) L4_NOTHROW;
168
169 /**
170 * Get clock value for a clock + a timeout.
171 * \ingroup l4_timeout_api
172 *
173 * \param cur Clock value
174 * \param to L4 timeout
175 *
176 * \return Clock sum
177 */
178 L4_INLINE
179 l4_kernel_clock_t l4_timeout_get(l4_kernel_clock_t cur, l4_timeout_s to) L4_NOTHROW;
180
181
182 /*
183 * Implementation
184 */
185
186 L4_INLINE
l4_ipc_timeout(unsigned snd_man,unsigned snd_exp,unsigned rcv_man,unsigned rcv_exp)187 l4_timeout_t l4_ipc_timeout(unsigned snd_man, unsigned snd_exp,
188 unsigned rcv_man, unsigned rcv_exp) L4_NOTHROW
189 {
190 l4_timeout_t t;
191 t.p.snd.t = (snd_man & 0x3ff) | ((snd_exp << 10) & 0x7c00);
192 t.p.rcv.t = (rcv_man & 0x3ff) | ((rcv_exp << 10) & 0x7c00);
193 return t;
194 }
195
196
197 L4_INLINE
l4_timeout(l4_timeout_s snd,l4_timeout_s rcv)198 l4_timeout_t l4_timeout(l4_timeout_s snd, l4_timeout_s rcv) L4_NOTHROW
199 {
200 l4_timeout_t t;
201 t.p.snd = snd;
202 t.p.rcv = rcv;
203 return t;
204 }
205
206
207 L4_INLINE
l4_snd_timeout(l4_timeout_s snd,l4_timeout_t * to)208 void l4_snd_timeout(l4_timeout_s snd, l4_timeout_t *to) L4_NOTHROW
209 {
210 to->p.snd = snd;
211 }
212
213
214 L4_INLINE
l4_rcv_timeout(l4_timeout_s rcv,l4_timeout_t * to)215 void l4_rcv_timeout(l4_timeout_s rcv, l4_timeout_t *to) L4_NOTHROW
216 {
217 to->p.rcv = rcv;
218 }
219
220
221 L4_INLINE
l4_timeout_rel(unsigned man,unsigned exp)222 l4_timeout_s l4_timeout_rel(unsigned man, unsigned exp) L4_NOTHROW
223 {
224 return (l4_timeout_s){(l4_uint16_t)((man & 0x3ff) | ((exp << 10) & 0x7c00))};
225 }
226
227
228 L4_INLINE
l4_timeout_rel_get(l4_timeout_s to)229 l4_kernel_clock_t l4_timeout_rel_get(l4_timeout_s to) L4_NOTHROW
230 {
231 if (to.t == 0)
232 return ~0ULL;
233 return (l4_kernel_clock_t)(to.t & 0x3ff) << ((to.t >> 10) & 0x1f);
234 }
235
236
237 L4_INLINE
l4_timeout_is_absolute(l4_timeout_s to)238 unsigned l4_timeout_is_absolute(l4_timeout_s to) L4_NOTHROW
239 {
240 return to.t & 0x8000;
241 }
242
243
244 L4_INLINE
l4_timeout_get(l4_kernel_clock_t cur,l4_timeout_s to)245 l4_kernel_clock_t l4_timeout_get(l4_kernel_clock_t cur, l4_timeout_s to) L4_NOTHROW
246 {
247 if (l4_timeout_is_absolute(to))
248 return 0; /* We cannot retrieve the value ... */
249 else
250 return cur + l4_timeout_rel_get(to);
251 }
252
253
254 #endif
255