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 unsigned long tb_ticks_per_jiffy;
  22 extern unsigned long tb_ticks_per_usec;
  23 extern unsigned long tb_ticks_per_sec;
  24 extern struct clock_event_device decrementer_clockevent;
  25
  26
  27 extern void generic_calibrate_decr(void);
  28
  29 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
  30 extern unsigned long ppc_proc_freq;
  31 #define DEFAULT_PROC_FREQ       (DEFAULT_TB_FREQ * 8)
  32 extern unsigned long ppc_tb_freq;
  33 #define DEFAULT_TB_FREQ         125000000UL
  34
  35 extern bool tb_invalid;
  36
  37 struct div_result {
  38         u64 result_high;
  39         u64 result_low;
  40 };
  41
  42 static inline u64 get_vtb(void)
  43 {
  44         if (cpu_has_feature(CPU_FTR_ARCH_207S))
  45                 return mfspr(SPRN_VTB);
  46
  47         return 0;
  48 }
  49
  50 /* Accessor functions for the decrementer register.
  51  * The 4xx doesn't even have a decrementer.  I tried to use the
  52  * generic timer interrupt code, which seems OK, with the 4xx PIT
  53  * in auto-reload mode.  The problem is PIT stops counting when it
  54  * hits zero.  If it would wrap, we could use it just like a decrementer.
  55  */
  56 static inline u64 get_dec(void)
  57 {
  58         if (IS_ENABLED(CONFIG_40x))
  59                 return mfspr(SPRN_PIT);
  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_40x))
  72                 mtspr(SPRN_PIT, (u32)val);
  73         else if (IS_ENABLED(CONFIG_BOOKE))
  74                 mtspr(SPRN_DEC, val);
  75         else
  76                 mtspr(SPRN_DEC, val - 1);
  77 }
  78
  79 static inline unsigned long tb_ticks_since(unsigned long tstamp)
  80 {
  81         return mftb() - tstamp;
  82 }
  83
  84 #define mulhwu(x,y) \
  85 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  86
  87 #ifdef CONFIG_PPC64
  88 #define mulhdu(x,y) \
  89 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  90 #else
  91 extern u64 mulhdu(u64, u64);
  92 #endif
  93
  94 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
  95                          unsigned divisor, struct div_result *dr);
  96
  97 extern void secondary_cpu_time_init(void);
  98 extern void __init time_init(void);
  99
 100 #ifdef CONFIG_PPC64
 101 static inline unsigned long test_irq_work_pending(void)
 102 {
 103         unsigned long x;
 104
 105         asm volatile("lbz %0,%1(13)"
 106                 : "=r" (x)
 107                 : "i" (offsetof(struct paca_struct, irq_work_pending)));
 108         return x;
 109 }
 110 #endif
 111
 112 DECLARE_PER_CPU(u64, decrementers_next_tb);
 113
 114 /* Convert timebase ticks to nanoseconds */
 115 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 116
 117 void timer_broadcast_interrupt(void);
 118
 119 /* SPLPAR */
 120 void accumulate_stolen_time(void);
 121
 122 #endif /* __KERNEL__ */
 123 #endif /* __POWERPC_TIME_H */