include/asm-ppc/time.h

   1 /*
   2  * Common time prototypes and such for all ppc machines.
   3  *
   4  * Written by Cort Dougan (cort@fsmlabs.com) to merge
   5  * Paul Mackerras' version and mine for PReP and Pmac.
   6  */
   7
   8 #ifdef __KERNEL__
   9 #ifndef __ASM_TIME_H__
  10 #define __ASM_TIME_H__
  11
  12 #include <linux/config.h>
  13 #include <linux/types.h>
  14 #include <linux/rtc.h>
  15 #include <linux/threads.h>
  16
  17 #include <asm/reg.h>
  18
  19 /* time.c */
  20 extern unsigned tb_ticks_per_jiffy;
  21 extern unsigned tb_to_us;
  22 extern unsigned tb_last_stamp;
  23 extern unsigned long disarm_decr[NR_CPUS];
  24
  25 extern void to_tm(int tim, struct rtc_time * tm);
  26 extern time_t last_rtc_update;
  27
  28 extern void set_dec_cpu6(unsigned int val);
  29
  30 int via_calibrate_decr(void);
  31
  32 /* Accessor functions for the decrementer register.
  33  * The 4xx doesn't even have a decrementer.  I tried to use the
  34  * generic timer interrupt code, which seems OK, with the 4xx PIT
  35  * in auto-reload mode.  The problem is PIT stops counting when it
  36  * hits zero.  If it would wrap, we could use it just like a decrementer.
  37  */
  38 static __inline__ unsigned int get_dec(void)
  39 {
  40 #if defined(CONFIG_40x)
  41         return (mfspr(SPRN_PIT));
  42 #else
  43         return (mfspr(SPRN_DEC));
  44 #endif
  45 }
  46
  47 static __inline__ void set_dec(unsigned int val)
  48 {
  49 #if defined(CONFIG_40x)
  50         return;         /* Have to let it auto-reload */
  51 #elif defined(CONFIG_8xx_CPU6)
  52         set_dec_cpu6(val);
  53 #else
  54         mtspr(SPRN_DEC, val);
  55 #endif
  56 }
  57
  58 /* Accessor functions for the timebase (RTC on 601) registers. */
  59 /* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
  60 #ifdef CONFIG_6xx
  61 extern __inline__ int __attribute_pure__ __USE_RTC(void) {
  62         return (mfspr(SPRN_PVR)>>16) == 1;
  63 }
  64 #else
  65 #define __USE_RTC() 0
  66 #endif
  67
  68 extern __inline__ unsigned long get_tbl(void) {
  69         unsigned long tbl;
  70 #if defined(CONFIG_403GCX)
  71         asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
  72 #else
  73         asm volatile("mftb %0" : "=r" (tbl));
  74 #endif
  75         return tbl;
  76 }
  77
  78 extern __inline__ unsigned long get_tbu(void) {
  79         unsigned long tbl;
  80 #if defined(CONFIG_403GCX)
  81         asm volatile("mfspr %0, 0x3dc" : "=r" (tbl));
  82 #else
  83         asm volatile("mftbu %0" : "=r" (tbl));
  84 #endif
  85         return tbl;
  86 }
  87
  88 extern __inline__ void set_tb(unsigned int upper, unsigned int lower)
  89 {
  90         mtspr(SPRN_TBWL, 0);
  91         mtspr(SPRN_TBWU, upper);
  92         mtspr(SPRN_TBWL, lower);
  93 }
  94
  95 extern __inline__ unsigned long get_rtcl(void) {
  96         unsigned long rtcl;
  97         asm volatile("mfrtcl %0" : "=r" (rtcl));
  98         return rtcl;
  99 }
 100
 101 extern __inline__ unsigned long get_rtcu(void)
 102 {
 103         unsigned long rtcu;
 104         asm volatile("mfrtcu %0" : "=r" (rtcu));
 105         return rtcu;
 106 }
 107
 108 extern __inline__ unsigned get_native_tbl(void) {
 109         if (__USE_RTC())
 110                 return get_rtcl();
 111         else
 112                 return get_tbl();
 113 }
 114
 115 /* On machines with RTC, this function can only be used safely
 116  * after the timestamp and for 1 second. It is only used by gettimeofday
 117  * however so it should not matter.
 118  */
 119 extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
 120         if (__USE_RTC()) {
 121                 int delta = get_rtcl() - tstamp;
 122                 return delta<0 ? delta + 1000000000 : delta;
 123         } else {
 124                 return get_tbl() - tstamp;
 125         }
 126 }
 127
 128 #if 0
 129 extern __inline__ unsigned long get_bin_rtcl(void) {
 130       unsigned long rtcl, rtcu1, rtcu2;
 131       asm volatile("\
 132 1:    mfrtcu  %0\n\
 133       mfrtcl  %1\n\
 134       mfrtcu  %2\n\
 135       cmpw    %0,%2\n\
 136       bne-    1b\n"
 137       : "=r" (rtcu1), "=r" (rtcl), "=r" (rtcu2)
 138       : : "cr0");
 139       return rtcu2*1000000000+rtcl;
 140 }
 141
 142 extern __inline__ unsigned binary_tbl(void) {
 143       if (__USE_RTC())
 144               return get_bin_rtcl();
 145       else
 146               return get_tbl();
 147 }
 148 #endif
 149
 150 /* Use mulhwu to scale processor timebase to timeval */
 151 /* Specifically, this computes (x * y) / 2^32.  -- paulus */
 152 #define mulhwu(x,y) \
 153 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
 154
 155 unsigned mulhwu_scale_factor(unsigned, unsigned);
 156 #endif /* __ASM_TIME_H__ */
 157 #endif /* __KERNEL__ */