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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 | /* * arch/s390/kernel/time.c * * S390 version * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Hartmut Penner (hp@de.ibm.com), * Martin Schwidefsky (schwidefsky@de.ibm.com), * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) * * Derived from "arch/i386/kernel/time.c" * Copyright (C) 1991, 1992, 1995 Linus Torvalds */ #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/param.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/time.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/smp.h> #include <linux/types.h> #include <asm/uaccess.h> #include <asm/delay.h> #include <linux/timex.h> #include <linux/config.h> #include <asm/irq.h> #include <asm/s390_ext.h> /* change this if you have some constant time drift */ #define USECS_PER_JIFFY ((signed long)1000000/HZ) #define CLK_TICKS_PER_JIFFY ((signed long)USECS_PER_JIFFY<<12) #define TICK_SIZE tick static uint64_t init_timer_cc, last_timer_cc; extern rwlock_t xtime_lock; extern unsigned long wall_jiffies; void tod_to_timeval(uint64_t todval, struct timeval *xtime) { #if 0 const int high_bit = 0x80000000L; const int c_f4240 = 0xf4240L; const int c_7a120 = 0x7a120; /* We have to divide the 64 bit value todval by 4096 * (because the 2^12 bit is the one that changes every * microsecond) and then split it into seconds and * microseconds. A value of max (2^52-1) divided by * the value 0xF4240 can yield a max result of approx * (2^32.068). Thats to big to fit into a signed int * ... hacking time! */ asm volatile ("L 2,%1\n\t" "LR 3,2\n\t" "SRL 2,12\n\t" "SLL 3,20\n\t" "L 4,%O1+4(%R1)\n\t" "SRL 4,12\n\t" "OR 3,4\n\t" /* now R2/R3 contain (todval >> 12) */ "SR 4,4\n\t" "CL 2,%2\n\t" "JL .+12\n\t" "S 2,%2\n\t" "L 4,%3\n\t" "D 2,%4\n\t" "OR 3,4\n\t" "ST 2,%O0+4(%R0)\n\t" "ST 3,%0" : "=m" (*xtime) : "m" (todval), "m" (c_7a120), "m" (high_bit), "m" (c_f4240) : "cc", "memory", "2", "3", "4" ); #else todval >>= 12; xtime->tv_sec = todval / 1000000; xtime->tv_usec = todval % 1000000; #endif } unsigned long do_gettimeoffset(void) { __u64 timer_cc; asm volatile ("STCK %0" : "=m" (timer_cc)); /* We require the offset from the previous interrupt */ return ((unsigned long)((timer_cc - last_timer_cc)>>12)); } /* * This version of gettimeofday has microsecond resolution. */ void do_gettimeofday(struct timeval *tv) { unsigned long flags; unsigned long usec, sec; unsigned long lost_ticks = jiffies - wall_jiffies; read_lock_irqsave(&xtime_lock, flags); usec = do_gettimeoffset(); if (lost_ticks) usec +=(USECS_PER_JIFFY*lost_ticks); sec = xtime.tv_sec; usec += xtime.tv_usec; read_unlock_irqrestore(&xtime_lock, flags); while (usec >= 1000000) { usec -= 1000000; sec++; } tv->tv_sec = sec; tv->tv_usec = usec; } void do_settimeofday(struct timeval *tv) { write_lock_irq(&xtime_lock); /* This is revolting. We need to set the xtime.tv_usec * correctly. However, the value in this location is * is value at the last tick. * Discover what correction gettimeofday * would have done, and then undo it! */ tv->tv_usec -= do_gettimeoffset(); while (tv->tv_usec < 0) { tv->tv_usec += 1000000; tv->tv_sec--; } xtime = *tv; time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; write_unlock_irq(&xtime_lock); } /* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ #ifdef CONFIG_SMP extern __u16 boot_cpu_addr; #endif void do_timer_interrupt(struct pt_regs *regs,int error_code) { unsigned long flags; /* * reset timer to 10ms minus time already elapsed * since timer-interrupt pending */ save_flags(flags); cli(); #ifdef CONFIG_SMP if(S390_lowcore.cpu_data.cpu_addr==boot_cpu_addr) { write_lock(&xtime_lock); last_timer_cc = S390_lowcore.jiffy_timer_cc; } #else last_timer_cc = S390_lowcore.jiffy_timer_cc; #endif /* set clock comparator */ S390_lowcore.jiffy_timer_cc += CLK_TICKS_PER_JIFFY; asm volatile ("SCKC %0" : : "m" (S390_lowcore.jiffy_timer_cc)); /* * In the SMP case we use the local timer interrupt to do the * profiling, except when we simulate SMP mode on a uniprocessor * system, in that case we have to call the local interrupt handler. */ #ifdef CONFIG_SMP /* when SMP, do smp_local_timer_interrupt for *all* CPUs, but only do the rest for the boot CPU */ smp_local_timer_interrupt(regs); #else if (!user_mode(regs)) s390_do_profile(regs->psw.addr); #endif #ifdef CONFIG_SMP if(S390_lowcore.cpu_data.cpu_addr==boot_cpu_addr) #endif { do_timer(regs); #ifdef CONFIG_SMP write_unlock(&xtime_lock); #endif } restore_flags(flags); } /* * Start the clock comparator on the current CPU */ static unsigned long cr0 __attribute__ ((aligned (8))); void init_100hz_timer(void) { /* allow clock comparator timer interrupt */ asm volatile ("STCTG 0,0,%0" : "=m" (cr0) : : "memory"); cr0 |= 0x800; asm volatile ("LCTLG 0,0,%0" : : "m" (cr0) : "memory"); /* set clock comparator */ /* read the TOD clock */ asm volatile ("STCK %0" : "=m" (S390_lowcore.jiffy_timer_cc)); S390_lowcore.jiffy_timer_cc += CLK_TICKS_PER_JIFFY; asm volatile ("SCKC %0" : : "m" (S390_lowcore.jiffy_timer_cc)); } /* * Initialize the TOD clock and the CPU timer of * the boot cpu. */ void __init time_init(void) { int cc; /* kick the TOD clock */ asm volatile ("STCK %1\n\t" "IPM %0\n\t" "SRL %0,28" : "=r" (cc), "=m" (init_timer_cc)); switch (cc) { case 0: /* clock in set state: all is fine */ break; case 1: /* clock in non-set state: FIXME */ printk("time_init: TOD clock in non-set state\n"); break; case 2: /* clock in error state: FIXME */ printk("time_init: TOD clock in error state\n"); break; case 3: /* clock in stopped or not-operational state: FIXME */ printk("time_init: TOD clock stopped/non-operational\n"); break; } /* request the 0x1004 external interrupt */ if (register_external_interrupt(0x1004, do_timer_interrupt) != 0) panic("Couldn't request external interrupts 0x1004"); init_100hz_timer(); init_timer_cc = S390_lowcore.jiffy_timer_cc; init_timer_cc -= 0x8126d60e46000000LL - (0x3c26700LL*1000000*4096); tod_to_timeval(init_timer_cc, &xtime); } |