include/asm-ia64/delay.h

   1 #ifndef _ASM_IA64_DELAY_H
   2 #define _ASM_IA64_DELAY_H
   3
   4 /*
   5  * Delay routines using a pre-computed "cycles/usec" value.
   6  *
   7  * Copyright (C) 1998, 1999 Hewlett-Packard Co
   8  *      David Mosberger-Tang <davidm@hpl.hp.com>
   9  * Copyright (C) 1999 VA Linux Systems
  10  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
  11  * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
  12  * Copyright (C) 1999 Don Dugger <don.dugger@intel.com>
  13  */
  14
  15 #include <linux/config.h>
  16 #include <linux/kernel.h>
  17 #include <linux/sched.h>
  18 #include <linux/compiler.h>
  19
  20 #include <asm/intrinsics.h>
  21 #include <asm/processor.h>
  22
  23 static __inline__ void
  24 ia64_set_itm (unsigned long val)
  25 {
  26         ia64_setreg(_IA64_REG_CR_ITM, val);
  27         ia64_srlz_d();
  28 }
  29
  30 static __inline__ unsigned long
  31 ia64_get_itm (void)
  32 {
  33         unsigned long result;
  34
  35         result = ia64_getreg(_IA64_REG_CR_ITM);
  36         ia64_srlz_d();
  37         return result;
  38 }
  39
  40 static __inline__ void
  41 ia64_set_itv (unsigned long val)
  42 {
  43         ia64_setreg(_IA64_REG_CR_ITV, val);
  44         ia64_srlz_d();
  45 }
  46
  47 static __inline__ void
  48 ia64_set_itc (unsigned long val)
  49 {
  50         ia64_setreg(_IA64_REG_AR_ITC, val);
  51         ia64_srlz_d();
  52 }
  53
  54 static __inline__ unsigned long
  55 ia64_get_itc (void)
  56 {
  57         unsigned long result;
  58
  59         result = ia64_getreg(_IA64_REG_AR_ITC);
  60         ia64_barrier();
  61 #ifdef CONFIG_ITANIUM
  62         while (unlikely((__s32) result == -1)) {
  63                 result = ia64_getreg(_IA64_REG_AR_ITC);
  64                 ia64_barrier();
  65         }
  66 #endif
  67         return result;
  68 }
  69
  70 extern void ia64_delay_loop (unsigned long loops);
  71
  72 static __inline__ void
  73 __delay (unsigned long loops)
  74 {
  75         if (unlikely(loops < 1))
  76                 return;
  77
  78         ia64_delay_loop (loops - 1);
  79 }
  80
  81 static __inline__ void
  82 udelay (unsigned long usecs)
  83 {
  84         unsigned long start = ia64_get_itc();
  85         unsigned long cycles = usecs*local_cpu_data->cyc_per_usec;
  86
  87         while (ia64_get_itc() - start < cycles)
  88                 /* skip */;
  89 }
  90
  91 #endif /* _ASM_IA64_DELAY_H */