rdtsc.h

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/*
 * (c) 2003-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>,
 *               Torsten Frenzel <frenzel@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU Lesser General Public License 2.1.
 * Please see the COPYING-LGPL-2.1 file for details.
 */
 
#ifndef __l4_rdtsc_h
#define __l4_rdtsc_h
 
#include <l4/sys/compiler.h>
#include <l4/sys/l4int.h>
#include <l4/sys/kip.h>
 
EXTERN_C_BEGIN
 
/* interface */
extern l4_uint32_t l4_scaler_tsc_to_ns;
extern l4_uint32_t l4_scaler_tsc_to_us;
extern l4_uint32_t l4_scaler_ns_to_tsc;
extern l4_uint32_t l4_scaler_tsc_linux;
 
L4_INLINE l4_cpu_time_t
l4_rdtsc (void);
 
L4_INLINE
l4_uint32_t l4_rdtsc_32(void);
 
L4_INLINE l4_uint64_t
l4_rdpmc (int ecx);
 
L4_INLINE
l4_uint32_t l4_rdpmc_32(int ecx);
 
L4_INLINE l4_uint64_t
l4_tsc_to_ns (l4_cpu_time_t tsc);
 
L4_INLINE l4_uint64_t
l4_tsc_to_us (l4_cpu_time_t tsc);
 
L4_INLINE void
l4_tsc_to_s_and_ns (l4_cpu_time_t tsc, l4_uint32_t *s, l4_uint32_t *ns);
 
L4_INLINE l4_cpu_time_t
l4_ns_to_tsc (l4_uint64_t ns);
 
L4_INLINE void
l4_busy_wait_ns (l4_uint64_t ns);
 
L4_INLINE void
l4_busy_wait_us (l4_uint64_t us);
 
L4_INLINE l4_uint32_t
l4_calibrate_tsc(l4_kernel_info_t const *kip);
 
L4_CV l4_uint32_t
l4_tsc_init(l4_kernel_info_t const *kip);
 
L4_CV l4_uint32_t
l4_get_hz (void);
 
EXTERN_C_END
 
/* implementation */
 
L4_INLINE l4_uint32_t
l4_calibrate_tsc(l4_kernel_info_t const *kip)
{
  return l4_tsc_init(kip);
}
 
L4_INLINE l4_cpu_time_t
l4_rdtsc (void)
{
  l4_umword_t lo, hi;
 
  __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
 
  return ((l4_cpu_time_t)hi << 32) | lo;
}
 
L4_INLINE l4_uint64_t
l4_rdpmc (int ecx)
{
  l4_umword_t lo, hi;
 
  __asm__ __volatile__ ("rdpmc" : "=a"(lo), "=d"(hi) : "c"(ecx));
 
  return ((l4_cpu_time_t)hi << 32) | lo;
}
 
L4_INLINE
l4_uint32_t l4_rdtsc_32(void)
{
  l4_umword_t lo, hi;
 
  __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
 
  return lo;
}
 
L4_INLINE
l4_uint32_t l4_rdpmc_32(int ecx)
{
  l4_umword_t lo, hi;
 
  __asm__ __volatile__ ("rdpmc" : "=a"(lo), "=d"(hi) : "c"(ecx));
 
  return lo;
}
 
L4_INLINE l4_uint64_t
l4_tsc_to_ns (l4_cpu_time_t tsc)
{
    l4_uint64_t ns, dummy;
    __asm__
  ("        \n\t"
   "mulq  %3      \n\t"
         "shrd  $27, %%rdx, %%rax       \n\t"
  :"=a" (ns), "=d"(dummy)
  :"a" (tsc), "r" ((l4_uint64_t)l4_scaler_tsc_to_ns)
  );
    return ns;
}
 
L4_INLINE l4_uint64_t
l4_tsc_to_us (l4_cpu_time_t tsc)
{
    l4_uint64_t ns, dummy;
    __asm__
  ("        \n\t"
   "mulq  %3      \n\t"
         "shrd  $32, %%rdx, %%rax       \n\t"
  :"=a" (ns), "=d" (dummy)
  :"a" (tsc), "r" ((l4_uint64_t)l4_scaler_tsc_to_us)
  );
    return ns;
}
 
L4_INLINE void
l4_tsc_to_s_and_ns (l4_cpu_time_t tsc, l4_uint32_t *s, l4_uint32_t *ns)
{
    __asm__
  ("        \n\t"
   "mulq  %3      \n\t"
         "shrd  $27, %%rdx, %%rax       \n\t"
         "xorq  %%rdx, %%rdx            \n\t"
   "divq  %4      \n\t"
  :"=a" (*s), "=&d" (*ns)
  : "a" (tsc), "r" ((l4_uint64_t)l4_scaler_tsc_to_ns),
          "rm"(1000000000ULL)
  );
}
 
L4_INLINE l4_cpu_time_t
l4_ns_to_tsc (l4_uint64_t ns)
{
    l4_uint64_t tsc, dummy;
    __asm__
        ("                              \n\t"
   "mulq  %3      \n\t"
         "shrd  $27, %%rdx, %%rax       \n\t"
  :"=a" (tsc), "=d" (dummy)
  :"a" (ns), "r" ((l4_uint64_t)l4_scaler_ns_to_tsc)
  );
    return tsc;
}
 
L4_INLINE void
l4_busy_wait_ns (l4_uint64_t ns)
{
  l4_cpu_time_t stop = l4_rdtsc();
  stop += l4_ns_to_tsc(ns);
 
  while (l4_rdtsc() < stop)
    ;
}
 
L4_INLINE void
l4_busy_wait_us (l4_uint64_t us)
{
  l4_cpu_time_t stop = l4_rdtsc ();
  stop += l4_ns_to_tsc(us*1000ULL);
 
  while (l4_rdtsc() < stop)
    ;
}
 
#endif /* __l4_rdtsc_h */