arch/tile/include/asm/timex.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_TIMEX_H
  16 #define _ASM_TILE_TIMEX_H
  17
  18 /*
  19  * This rate should be a multiple of the possible HZ values (100, 250, 1000)
  20  * and a fraction of the possible hardware timer frequencies.  Our timer
  21  * frequency is highly tunable but also quite precise, so for the primary use
  22  * of this value (setting ACT_HZ from HZ) we just pick a value that causes
  23  * ACT_HZ to be set to HZ.  We make the value somewhat large just to be
  24  * more robust in case someone tries out a new value of HZ.
  25  */
  26 #define CLOCK_TICK_RATE 1000000
  27
  28 typedef unsigned long long cycles_t;
  29
  30 #if CHIP_HAS_SPLIT_CYCLE()
  31 cycles_t get_cycles(void);
  32 #else
  33 static inline cycles_t get_cycles(void)
  34 {
  35         return __insn_mfspr(SPR_CYCLE);
  36 }
  37 #endif
  38
  39 cycles_t get_clock_rate(void);
  40
  41 /* Convert nanoseconds to core clock cycles. */
  42 cycles_t ns2cycles(unsigned long nsecs);
  43
  44 /* Called at cpu initialization to set some low-level constants. */
  45 void setup_clock(void);
  46
  47 /* Called at cpu initialization to start the tile-timer clock device. */
  48 void setup_tile_timer(void);
  49
  50 #endif /* _ASM_TILE_TIMEX_H */