1 /* $NetBSD: clock.c,v 1.24 2011/01/18 01:02:53 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 1.24 2011/01/18 01:02:53 matt Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/kernel.h> 40 #include <sys/systm.h> 41 #include <sys/timetc.h> 42 43 #include <uvm/uvm_extern.h> 44 45 #include <prop/proplib.h> 46 47 #include <machine/cpu.h> 48 49 #include <powerpc/spr.h> 50 #include <powerpc/ibm4xx/spr.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 if (! (ci->ci_cpl & mask_statclock)) 101 statclock(frame); 102 } 103 104 void 105 decr_intr(struct clockframe *frame) 106 { 107 struct cpu_info * const ci = curcpu(); 108 int pri; 109 long tbtick, xticks; 110 int nticks; 111 112 /* 113 * Check whether we are initialized. 114 */ 115 if (!ticks_per_intr) 116 return; 117 118 tbtick = mftbl(); 119 mtspr(SPR_TSR, TSR_PIS); /* Clear TSR[PIS] */ 120 121 xticks = tbtick - lasttb2; /* Number of TLB cycles since last exception */ 122 for (nticks = 0; xticks > ticks_per_intr; nticks++) 123 xticks -= ticks_per_intr; 124 lasttb2 = tbtick - xticks; 125 126 ci->ci_data.cpu_nintr++; 127 ci->ci_ev_clock.ev_count++; 128 pri = splclock(); 129 if (pri & mask_clock) { 130 tickspending += nticks; 131 ticksmissed += nticks; 132 } else { 133 nticks += tickspending; 134 tickspending = 0; 135 136 /* 137 * lasttb is used during microtime. Set it to the virtual 138 * start of this tick interval. 139 */ 140 lasttb = lasttb2; 141 142 /* 143 * Reenable interrupts 144 */ 145 __asm volatile ("wrteei 1"); 146 147 /* 148 * Do standard timer interrupt stuff. 149 * Do softclock stuff only on the last iteration. 150 */ 151 while (--nticks > 0) 152 hardclock(frame); 153 hardclock(frame); 154 } 155 splx(pri); 156 } 157 158 void 159 cpu_initclocks(void) 160 { 161 struct cpu_info * const ci = curcpu(); 162 163 /* Initialized in powerpc/ibm4xx/cpu.c */ 164 evcnt_attach_static(&ci->ci_ev_clock); 165 evcnt_attach_static(&ci->ci_ev_statclock); 166 167 ticks_per_intr = ticks_per_sec / hz; 168 stathz = profhz = ticks_per_sec / (1 << PERIOD_POWER); 169 170 printf("Setting PIT to %ld/%d = %ld\n", ticks_per_sec, hz, 171 ticks_per_intr); 172 173 lasttb2 = lasttb = mftbl(); 174 mtspr(SPR_PIT, ticks_per_intr); 175 176 /* Enable PIT & FIT(2^17c = 0.655ms) interrupts and auto-reload */ 177 mtspr(SPR_TCR, TCR_PIE | TCR_ARE | TCR_FIE | TCR_PERIOD); 178 179 init_ppc4xx_tc(); 180 } 181 182 void 183 calc_delayconst(void) 184 { 185 prop_number_t freq; 186 187 freq = prop_dictionary_get(board_properties, "processor-frequency"); 188 KASSERT(freq != NULL); 189 190 ticks_per_sec = (u_long) prop_number_integer_value(freq); 191 ns_per_tick = 1000000000 / ticks_per_sec; 192 } 193 194 static u_int 195 get_ppc4xx_timecount(struct timecounter *tc) 196 { 197 u_long tb; 198 int msr; 199 200 __asm volatile ("mfmsr %0; wrteei 0" : "=r"(msr) :); 201 tb = mftbl(); 202 __asm volatile ("mtmsr %0" :: "r"(msr)); 203 204 return tb; 205 } 206 207 /* 208 * Wait for about n microseconds (at least!). 209 */ 210 void 211 delay(unsigned int n) 212 { 213 u_quad_t tb; 214 u_long tbh, tbl, scratch; 215 216 tb = mftb(); 217 /* use 1000ULL to force 64 bit math to avoid 32 bit overflows */ 218 tb += (n * 1000ULL + ns_per_tick - 1) / ns_per_tick; 219 tbh = tb >> 32; 220 tbl = tb; 221 __asm volatile ( 222 #ifdef PPC_IBM403 223 "1: mftbhi %0 \n" 224 #else 225 "1: mftbu %0 \n" 226 #endif 227 " cmplw %0,%1 \n" 228 " blt 1b \n" 229 " bgt 2f \n" 230 #ifdef PPC_IBM403 231 " mftblo %0 \n" 232 #else 233 " mftb %0 \n" 234 #endif 235 " cmplw %0,%2 \n" 236 " blt 1b \n" 237 "2: \n" 238 : "=&r"(scratch) : "r"(tbh), "r"(tbl) : "cr0"); 239 } 240 241 /* 242 * Nothing to do. 243 */ 244 void 245 setstatclockrate(int arg) 246 { 247 248 /* Do nothing */ 249 } 250 251 static void 252 init_ppc4xx_tc(void) 253 { 254 /* from machdep initialization */ 255 ppc4xx_timecounter.tc_frequency = ticks_per_sec; 256 tc_init(&ppc4xx_timecounter); 257 } 258