arch/powerpc/include/asm/time.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Common time prototypes and such for all ppc machines.
   4  *
   5  * Written by Cort Dougan (cort@cs.nmt.edu) to merge
   6  * Paul Mackerras' version and mine for PReP and Pmac.
   7  */
   8
   9 #ifndef __POWERPC_TIME_H
  10 #define __POWERPC_TIME_H
  11
  12 #ifdef __KERNEL__
  13 #include <linux/types.h>
  14 #include <linux/percpu.h>
  15
  16 #include <asm/processor.h>
  17 #include <asm/cpu_has_feature.h>
  18 #include <asm/vdso/timebase.h>
  19
  20 /* time.c */
  21 extern u64 decrementer_max;
  22
  23 extern unsigned long tb_ticks_per_jiffy;
  24 extern unsigned long tb_ticks_per_usec;
  25 extern unsigned long tb_ticks_per_sec;
  26 extern struct clock_event_device decrementer_clockevent;
  27 extern u64 decrementer_max;
  28
  29
  30 extern void generic_calibrate_decr(void);
  31
  32 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
  33 extern unsigned long ppc_proc_freq;
  34 #define DEFAULT_PROC_FREQ       (DEFAULT_TB_FREQ * 8)
  35 extern unsigned long ppc_tb_freq;
  36 #define DEFAULT_TB_FREQ         125000000UL
  37
  38 extern bool tb_invalid;
  39
  40 struct div_result {
  41         u64 result_high;
  42         u64 result_low;
  43 };
  44
  45 static inline u64 get_vtb(void)
  46 {
  47         if (cpu_has_feature(CPU_FTR_ARCH_207S))
  48                 return mfspr(SPRN_VTB);
  49
  50         return 0;
  51 }
  52
  53 /* Accessor functions for the decrementer register.
  54  * The 4xx doesn't even have a decrementer.  I tried to use the
  55  * generic timer interrupt code, which seems OK, with the 4xx PIT
  56  * in auto-reload mode.  The problem is PIT stops counting when it
  57  * hits zero.  If it would wrap, we could use it just like a decrementer.
  58  */
  59 static inline u64 get_dec(void)
  60 {
  61         return mfspr(SPRN_DEC);
  62 }
  63
  64 /*
  65  * Note: Book E and 4xx processors differ from other PowerPC processors
  66  * in when the decrementer generates its interrupt: on the 1 to 0
  67  * transition for Book E/4xx, but on the 0 to -1 transition for others.
  68  */
  69 static inline void set_dec(u64 val)
  70 {
  71         if (IS_ENABLED(CONFIG_BOOKE))
  72                 mtspr(SPRN_DEC, val);
  73         else
  74                 mtspr(SPRN_DEC, val - 1);
  75 }
  76
  77 static inline unsigned long tb_ticks_since(unsigned long tstamp)
  78 {
  79         return mftb() - tstamp;
  80 }
  81
  82 #define mulhwu(x,y) \
  83 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  84
  85 #ifdef CONFIG_PPC64
  86 #define mulhdu(x,y) \
  87 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  88 #else
  89 extern u64 mulhdu(u64, u64);
  90 #endif
  91
  92 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
  93                          unsigned divisor, struct div_result *dr);
  94
  95 extern void secondary_cpu_time_init(void);
  96 extern void __init time_init(void);
  97
  98 DECLARE_PER_CPU(u64, decrementers_next_tb);
  99
 100 static inline u64 timer_get_next_tb(void)
 101 {
 102         return __this_cpu_read(decrementers_next_tb);
 103 }
 104
 105 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 106 void timer_rearm_host_dec(u64 now);
 107 #endif
 108
 109 /* Convert timebase ticks to nanoseconds */
 110 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 111
 112 void timer_broadcast_interrupt(void);
 113
 114 /* SPLPAR and VIRT_CPU_ACCOUNTING_NATIVE */
 115 void pseries_accumulate_stolen_time(void);
 116 u64 pseries_calculate_stolen_time(u64 stop_tb);
 117
 118 #endif /* __KERNEL__ */
 119 #endif /* __POWERPC_TIME_H */