linuxthreads/sysdeps/alpha/pt-machine.h

   1 /* Machine-dependent pthreads configuration and inline functions.
   2    Alpha version.
   3    Copyright (C) 1996, 1997, 1998, 2000, 2002, 2003
   4    Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6    Contributed by Richard Henderson <rth@tamu.edu>.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public License as
  10    published by the Free Software Foundation; either version 2.1 of the
  11    License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Lesser General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public
  19    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  20    write to the Free Software Foundation, Inc.,  59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #ifndef _PT_MACHINE_H
  24 #define _PT_MACHINE_H   1
  25
  26 #ifndef PT_EI
  27 # define PT_EI extern inline __attribute__ ((always_inline))
  28 #endif
  29
  30 #ifdef __linux__
  31 # include <asm/pal.h>
  32 #else
  33 # include <machine/pal.h>
  34 #endif
  35
  36 extern long int testandset (int *spinlock);
  37 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  38
  39 /* Get some notion of the current stack.  Need not be exactly the top
  40    of the stack, just something somewhere in the current frame.  */
  41 #define CURRENT_STACK_FRAME  stack_pointer
  42 register char *stack_pointer __asm__("$30");
  43
  44
  45 /* Memory barrier; default is to do nothing */
  46 #define MEMORY_BARRIER() __asm__ __volatile__("mb" : : : "memory")
  47 /* Write barrier.  */
  48 #define WRITE_MEMORY_BARRIER() __asm__ __volatile__("wmb" : : : "memory")
  49
  50
  51 /* Spinlock implementation; required.  */
  52 PT_EI long int
  53 testandset (int *spinlock)
  54 {
  55   long int ret, temp;
  56
  57   __asm__ __volatile__(
  58         "/* Inline spinlock test & set */\n"
  59         "1:\t"
  60         "ldl_l %0,%3\n\t"
  61         "bne %0,2f\n\t"
  62         "or $31,1,%1\n\t"
  63         "stl_c %1,%2\n\t"
  64         "beq %1,1b\n"
  65         "2:\tmb\n"
  66         "/* End spinlock test & set */"
  67         : "=&r"(ret), "=&r"(temp), "=m"(*spinlock)
  68         : "m"(*spinlock)
  69         : "memory");
  70
  71   return ret;
  72 }
  73
  74
  75 /* Begin allocating thread stacks at this address.  Default is to allocate
  76    them just below the initial program stack.  */
  77 #define THREAD_STACK_START_ADDRESS  0x40000000000
  78
  79
  80 /* Return the thread descriptor for the current thread.  */
  81 #define THREAD_SELF \
  82 ({                                                                            \
  83   register pthread_descr __self __asm__("$0");                                \
  84   __asm__ ("call_pal %1" : "=r"(__self) : "i"(PAL_rduniq));                   \
  85   __self;                                                                     \
  86 })
  87
  88 /* Initialize the thread-unique value.  */
  89 #define INIT_THREAD_SELF(descr, nr) \
  90 {                                                                             \
  91   register pthread_descr __self __asm__("$16") = (descr);                     \
  92   __asm__ __volatile__ ("call_pal %1" : : "r"(__self), "i"(PAL_wruniq));      \
  93 }
  94
  95
  96 /* Compare-and-swap for semaphores. */
  97
  98 #define HAS_COMPARE_AND_SWAP
  99 PT_EI int
 100 __compare_and_swap (long int *p, long int oldval, long int newval)
 101 {
 102   long int ret;
 103
 104   __asm__ __volatile__ (
 105         "/* Inline compare & swap */\n"
 106         "1:\t"
 107         "ldq_l %0,%4\n\t"
 108         "cmpeq %0,%2,%0\n\t"
 109         "beq %0,2f\n\t"
 110         "mov %3,%0\n\t"
 111         "stq_c %0,%1\n\t"
 112         "beq %0,1b\n\t"
 113         "2:\tmb\n"
 114         "/* End compare & swap */"
 115         : "=&r"(ret), "=m"(*p)
 116         : "r"(oldval), "r"(newval), "m"(*p)
 117         : "memory");
 118
 119   return ret;
 120 }
 121
 122 /* We want the OS to assign stack addresses.  */
 123 #define FLOATING_STACKS 1
 124
 125 /* Maximum size of the stack if the rlimit is unlimited.  */
 126 #define ARCH_STACK_MAX_SIZE     32*1024*1024
 127
 128 #endif /* pt-machine.h */