1 /* 2 * Kernel interface to machine-dependent clock driver. 3 * Garrett Wollman, September 1994. 4 * This file is in the public domain. 5 * 6 * $Id: clock.h,v 1.8 1995/12/24 08:10:49 davidg Exp $ 7 */ 8 9 #ifndef _MACHINE_CLOCK_H_ 10 #define _MACHINE_CLOCK_H_ 11 12 #if defined(I586_CPU) || defined(I686_CPU) 13 14 #define I586_CYCLECTR(x) \ 15 __asm __volatile(".byte 0x0f, 0x31" : "=A" (x)) 16 17 /* 18 * When we update the clock, we also update this bias value which is 19 * automatically subtracted in microtime(). We assume that CPU_THISTICKLEN() 20 * has been called at some point in the past, so that an appropriate value is 21 * set up in i586_last_tick. (This works even if we are not being called 22 * from hardclock because hardclock will have run before and will made the 23 * call.) 24 */ 25 #define CPU_CLOCKUPDATE(otime, ntime) \ 26 do { \ 27 if(i586_ctr_rate) { \ 28 disable_intr(); \ 29 i586_ctr_bias = i586_last_tick; \ 30 *(otime) = *(ntime); \ 31 enable_intr(); \ 32 } else { \ 33 *(otime) = *(ntime); \ 34 } \ 35 } while(0) 36 37 #define CPU_THISTICKLEN(dflt) cpu_thisticklen(dflt) 38 #else 39 #define CPU_CLOCKUPDATE(otime, ntime) \ 40 (*(otime) = *(ntime)) 41 #define CPU_THISTICKLEN(dflt) dflt 42 #endif 43 44 #define I586_CTR_RATE_SHIFT 8 45 46 #if defined(KERNEL) && !defined(LOCORE) 47 #include <sys/cdefs.h> 48 #include <machine/frame.h> 49 50 /* 51 * i386 to clock driver interface. 52 * XXX almost all of it is misplaced. i586 stuff is done in isa/clock.c 53 * and isa stuff is done in i386/microtime.s and i386/support.s. 54 */ 55 extern int adjkerntz; 56 extern int disable_rtc_set; 57 #if defined(I586_CPU) || defined(I686_CPU) 58 extern unsigned i586_ctr_rate; /* fixed point */ 59 extern long long i586_last_tick; 60 extern long long i586_ctr_bias; 61 extern unsigned long i586_avg_tick; 62 #endif 63 extern int timer0_max_count; 64 extern u_int timer0_overflow_threshold; 65 extern u_int timer0_prescaler_count; 66 67 #if defined(I586_CPU) || defined(I686_CPU) 68 void calibrate_cyclecounter __P((void)); 69 #endif 70 71 #if defined(I586_CPU) || defined(I686_CPU) 72 static __inline u_long 73 cpu_thisticklen(u_long dflt) 74 { 75 long long old; 76 long len; 77 78 if (i586_ctr_rate) { 79 old = i586_last_tick; 80 I586_CYCLECTR(i586_last_tick); 81 len = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT) 82 / i586_ctr_rate; 83 i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16; 84 } 85 return dflt; 86 } 87 #endif 88 89 /* 90 * Driver to clock driver interface. 91 */ 92 void DELAY __P((int usec)); 93 int acquire_timer0 __P((int rate, 94 void (*function)(struct clockframe *frame))); 95 int acquire_timer2 __P((int mode)); 96 int release_timer0 __P((void)); 97 int release_timer2 __P((void)); 98 int sysbeep __P((int pitch, int period)); 99 100 #endif /* KERNEL && !LOCORE */ 101 102 #endif /* !_MACHINE_CLOCK_H_ */ 103