1 /* $NetBSD: clock.c,v 1.26 2011/06/20 17:44:33 matt Exp $ */ 2 /* $OpenBSD: clock.c,v 1.3 1997/10/13 13:42:53 pefo Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 6 * Copyright (C) 1995, 1996 TooLs GmbH. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by TooLs GmbH. 20 * 4. The name of TooLs GmbH may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.26 2011/06/20 17:44:33 matt Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/kernel.h> 40 #include <sys/systm.h> 41 #include <sys/timetc.h> 42 #include <sys/cpu.h> 43 44 #include <uvm/uvm_extern.h> 45 46 #include <prop/proplib.h> 47 48 #include <powerpc/spr.h> 49 #include <powerpc/ibm4xx/spr.h> 50 #include <powerpc/ibm4xx/cpu.h> 51 52 /* 53 * Initially we assume a processor with a bus frequency of 12.5 MHz. 54 */ 55 static u_long ticks_per_sec; 56 static u_long ns_per_tick; 57 static long ticks_per_intr; 58 static volatile u_long lasttb, lasttb2; 59 static u_long ticksmissed; 60 static volatile int tickspending; 61 62 static void init_ppc4xx_tc(void); 63 static u_int get_ppc4xx_timecount(struct timecounter *); 64 65 static struct timecounter ppc4xx_timecounter = { 66 get_ppc4xx_timecount, /* get_timecount */ 67 0, /* no poll_pps */ 68 ~0u, /* counter_mask */ 69 0, /* frequency */ 70 "ppc_timebase", /* name */ 71 100, /* quality */ 72 NULL, /* tc_priv */ 73 NULL /* tc_next */ 74 }; 75 76 void decr_intr(struct clockframe *); /* called from trap_subr.S */ 77 void stat_intr(struct clockframe *); /* called from trap_subr.S */ 78 79 #ifdef FAST_STAT_CLOCK 80 /* Stat clock runs at ~ 1.5 kHz */ 81 #define PERIOD_POWER 17 82 #define TCR_PERIOD TCR_FP_2_17 83 #else 84 /* Stat clock runs at ~ 95Hz */ 85 #define PERIOD_POWER 21 86 #define TCR_PERIOD TCR_FP_2_21 87 #endif 88 89 90 void 91 stat_intr(struct clockframe *frame) 92 { 93 struct cpu_info * const ci = curcpu(); 94 95 mtspr(SPR_TSR, TSR_FIS); /* Clear TSR[FIS] */ 96 ci->ci_data.cpu_nintr++; 97 ci->ci_ev_statclock.ev_count++; 98 99 /* Nobody can interrupt us, but see if we're allowed to run. */ 100 int s = splclock(); 101 if (IPL_CLOCK > s) 102 statclock(frame); 103 splx(s); 104 } 105 106 void 107 decr_intr(struct clockframe *frame) 108 { 109 struct cpu_info * const ci = curcpu(); 110 int pcpl; 111 long tbtick, xticks; 112 int nticks; 113 114 /* 115 * Check whether we are initialized. 116 */ 117 if (!ticks_per_intr) 118 return; 119 120 tbtick = mftbl(); 121 mtspr(SPR_TSR, TSR_PIS); /* Clear TSR[PIS] */ 122 123 xticks = tbtick - lasttb2; /* Number of TLB cycles since last exception */ 124 for (nticks = 0; xticks > ticks_per_intr; nticks++) 125 xticks -= ticks_per_intr; 126 lasttb2 = tbtick - xticks; 127 128 ci->ci_data.cpu_nintr++; 129 ci->ci_ev_clock.ev_count++; 130 pcpl = splclock(); 131 if (pcpl >= IPL_CLOCK) { 132 tickspending += nticks; 133 ticksmissed += nticks; 134 } else { 135 nticks += tickspending; 136 tickspending = 0; 137 138 /* 139 * lasttb is used during microtime. Set it to the virtual 140 * start of this tick interval. 141 */ 142 lasttb = lasttb2; 143 144 /* 145 * Reenable interrupts 146 */ 147 __asm volatile ("wrteei 1"); 148 149 /* 150 * Do standard timer interrupt stuff. 151 * Do softclock stuff only on the last iteration. 152 */ 153 while (--nticks > 0) 154 hardclock(frame); 155 hardclock(frame); 156 } 157 splx(pcpl); 158 } 159 160 void 161 cpu_initclocks(void) 162 { 163 struct cpu_info * const ci = curcpu(); 164 165 /* Initialized in powerpc/ibm4xx/cpu.c */ 166 evcnt_attach_static(&ci->ci_ev_clock); 167 evcnt_attach_static(&ci->ci_ev_statclock); 168 169 ticks_per_intr = ticks_per_sec / hz; 170 stathz = profhz = ticks_per_sec / (1 << PERIOD_POWER); 171 172 printf("Setting PIT to %ld/%d = %ld\n", ticks_per_sec, hz, 173 ticks_per_intr); 174 175 lasttb2 = lasttb = mftbl(); 176 mtspr(SPR_PIT, ticks_per_intr); 177 178 /* Enable PIT & FIT(2^17c = 0.655ms) interrupts and auto-reload */ 179 mtspr(SPR_TCR, TCR_PIE | TCR_ARE | TCR_FIE | TCR_PERIOD); 180 181 init_ppc4xx_tc(); 182 } 183 184 void 185 calc_delayconst(void) 186 { 187 prop_number_t freq; 188 189 freq = prop_dictionary_get(board_properties, "processor-frequency"); 190 KASSERT(freq != NULL); 191 192 ticks_per_sec = (u_long) prop_number_integer_value(freq); 193 ns_per_tick = 1000000000 / ticks_per_sec; 194 } 195 196 static u_int 197 get_ppc4xx_timecount(struct timecounter *tc) 198 { 199 u_long tb; 200 int msr; 201 202 __asm volatile ("mfmsr %0; wrteei 0" : "=r"(msr) :); 203 tb = mftbl(); 204 __asm volatile ("mtmsr %0" :: "r"(msr)); 205 206 return tb; 207 } 208 209 /* 210 * Wait for about n microseconds (at least!). 211 */ 212 void 213 delay(unsigned int n) 214 { 215 u_quad_t tb; 216 u_long tbh, tbl, scratch; 217 218 tb = mftb(); 219 /* use 1000ULL to force 64 bit math to avoid 32 bit overflows */ 220 tb += (n * 1000ULL + ns_per_tick - 1) / ns_per_tick; 221 tbh = tb >> 32; 222 tbl = tb; 223 __asm volatile ( 224 #ifdef PPC_IBM403 225 "1: mftbhi %0 \n" 226 #else 227 "1: mftbu %0 \n" 228 #endif 229 " cmplw %0,%1 \n" 230 " blt 1b \n" 231 " bgt 2f \n" 232 #ifdef PPC_IBM403 233 " mftblo %0 \n" 234 #else 235 " mftb %0 \n" 236 #endif 237 " cmplw %0,%2 \n" 238 " blt 1b \n" 239 "2: \n" 240 : "=&r"(scratch) : "r"(tbh), "r"(tbl) : "cr0"); 241 } 242 243 /* 244 * Nothing to do. 245 */ 246 void 247 setstatclockrate(int arg) 248 { 249 250 /* Do nothing */ 251 } 252 253 static void 254 init_ppc4xx_tc(void) 255 { 256 /* from machdep initialization */ 257 ppc4xx_timecounter.tc_frequency = ticks_per_sec; 258 tc_init(&ppc4xx_timecounter); 259 } 260