1 /* $NetBSD: timer.c,v 1.6 2005/12/11 12:16:37 christos Exp $ */ 2 /* NetBSD: clock.c,v 1.31 2001/05/27 13:53:24 sommerfeld Exp */ 3 4 /* 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department and Ralph Campbell. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: Utah Hdr: clock.c 1.18 91/01/21 37 * 38 * @(#)clock.c 8.1 (Berkeley) 6/10/93 39 */ 40 /* 41 * Copyright (c) 1988 University of Utah. 42 * 43 * This code is derived from software contributed to Berkeley by 44 * the Systems Programming Group of the University of Utah Computer 45 * Science Department and Ralph Campbell. 46 * 47 * Redistribution and use in source and binary forms, with or without 48 * modification, are permitted provided that the following conditions 49 * are met: 50 * 1. Redistributions of source code must retain the above copyright 51 * notice, this list of conditions and the following disclaimer. 52 * 2. Redistributions in binary form must reproduce the above copyright 53 * notice, this list of conditions and the following disclaimer in the 54 * documentation and/or other materials provided with the distribution. 55 * 3. All advertising materials mentioning features or use of this software 56 * must display the following acknowledgement: 57 * This product includes software developed by the University of 58 * California, Berkeley and its contributors. 59 * 4. Neither the name of the University nor the names of its contributors 60 * may be used to endorse or promote products derived from this software 61 * without specific prior written permission. 62 * 63 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 64 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 65 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 66 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 67 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 68 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 69 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 70 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 71 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 72 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 73 * SUCH DAMAGE. 74 * 75 * from: Utah Hdr: clock.c 1.18 91/01/21 76 * 77 * @(#)clock.c 8.1 (Berkeley) 6/10/93 78 */ 79 80 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 81 82 __KERNEL_RCSID(0, "$NetBSD: timer.c,v 1.6 2005/12/11 12:16:37 christos Exp $"); 83 84 #include <sys/param.h> 85 #include <sys/kernel.h> 86 #include <sys/systm.h> 87 88 #include <mips/locore.h> 89 90 #include <arc/arc/timervar.h> 91 92 struct device *timerdev; 93 const struct timerfns *timerfns; 94 int timerinitted; 95 uint32_t last_cp0_count; 96 97 void 98 timerattach(struct device *dev, const struct timerfns *fns) 99 { 100 101 /* 102 * Just bookkeeping. 103 */ 104 105 if (timerfns != NULL) 106 panic("timerattach: multiple timers"); 107 timerdev = dev; 108 timerfns = fns; 109 } 110 111 /* 112 * Machine-dependent clock routines. 113 */ 114 115 /* 116 * Start the real-time and statistics clocks. Leave stathz 0 since there 117 * are no other timers available. 118 */ 119 void 120 cpu_initclocks(void) 121 { 122 if (timerfns == NULL) 123 panic("cpu_initclocks: no timer attached"); 124 125 tick = 1000000 / hz; /* number of microseconds between interrupts */ 126 tickfix = 1000000 - (hz * tick); 127 if (tickfix) { 128 int ftp; 129 130 ftp = min(ffs(tickfix), ffs(hz)); 131 tickfix >>= (ftp - 1); 132 tickfixinterval = hz >> (ftp - 1); 133 } 134 135 /* 136 * Get the clock started. 137 */ 138 (*timerfns->tf_init)(timerdev); 139 } 140 141 /* 142 * We assume newhz is either stathz or profhz, and that neither will 143 * change after being set up above. Could recalculate intervals here 144 * but that would be a drag. 145 */ 146 void 147 setstatclockrate(int newhz) 148 { 149 150 /* nothing we can do */ 151 } 152 153 /* 154 * Wait "n" microseconds. 155 */ 156 void 157 delay(unsigned int n) 158 { 159 uint32_t cur, last, delta, usecs; 160 161 last = mips3_cp0_count_read(); 162 delta = usecs = 0; 163 164 while (n > usecs) { 165 cur = mips3_cp0_count_read(); 166 167 /* Check to see if the timer has wrapped around. */ 168 if (cur < last) 169 delta += ((curcpu()->ci_cycles_per_hz - last) + cur); 170 else 171 delta += (cur - last); 172 173 last = cur; 174 175 if (delta >= curcpu()->ci_divisor_delay) { 176 usecs += delta / curcpu()->ci_divisor_delay; 177 delta %= curcpu()->ci_divisor_delay; 178 } 179 } 180 } 181