src/patches/glibc-arm-dont-use-swp.patch

   1 commit 1ba025a9a21eda65d8c36cc0dbb51d214a3ebb1a
   2 Author: Daniel Jacobowitz <dan@codesourcery.com>
   3 Date:   Mon Jun 2 01:57:03 2008 +0000
   4
   5     2008-06-01  Paul Brook  <paul@codesourcery.com>
   6             Zack Weinberg  <zack@codesourcery.com>
   7             Daniel Jacobowitz  <dan@codesourcery.com>
   8
   9         * sysdeps/arm/nptl/pthread_spin_lock.S,
  10         sysdeps/arm/nptl/pthread_spin_trylock.S: Delete.
  11         * sysdeps/arm/nptl/pthread_spin_lock.c,
  12         sysdeps/arm/nptl/pthread_spin_trylock.c: New files using
  13         atomic_compare_and_exchange_val_acq to take spinlocks.
  14         * sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h (lll_trylock,
  15         lll_cond_trylock): Use atomic_compare_and_exchange_val_acq.
  16         (__lll_trylock, __lll_cond_trylock): Delete.
  17         * sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
  18         (atomic_exchange_acq): Delete.
  19         (atomic_full_barrier): Define.
  20         (__arch_compare_and_exchange_val_32_acq): Use named operands.
  21         * sysdeps/unix/sysv/linux/arm/eabi/configure.in: Update
  22         arch_minimum_kernel to 2.6.16.
  23         * sysdeps/unix/sysv/linux/arm/eabi/configure: Regenerated.
  24
  25 diff --git a/sysdeps/arm/nptl/pthread_spin_lock.S b/sysdeps/arm/nptl/pthread_spin_lock.S
  26 deleted file mode 100644
  27 index bd6adf7..0000000
  28 --- a/sysdeps/arm/nptl/pthread_spin_lock.S
  29 +++ /dev/null
  30 @@ -1,31 +0,0 @@
  31 -/* Copyright (C) 2005 Free Software Foundation, Inc.
  32 -   This file is part of the GNU C Library.
  33 -
  34 -   The GNU C Library is free software; you can redistribute it and/or
  35 -   modify it under the terms of the GNU Lesser General Public
  36 -   License as published by the Free Software Foundation; either
  37 -   version 2.1 of the License, or (at your option) any later version.
  38 -
  39 -   The GNU C Library is distributed in the hope that it will be useful,
  40 -   but WITHOUT ANY WARRANTY; without even the implied warranty of
  41 -   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  42 -   Lesser General Public License for more details.
  43 -
  44 -   You should have received a copy of the GNU Lesser General Public
  45 -   License along with the GNU C Library; if not, write to the Free
  46 -   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  47 -   02111-1307 USA.  */
  48 -
  49 -#include <sysdep.h>
  50 -
  51 -       .text
  52 -       .align  4
  53 -
  54 -ENTRY (pthread_spin_lock)
  55 -       mov     r1, #1
  56 -1:     swp     r2, r1, [r0]
  57 -       teq     r2, #0
  58 -       bne     1b
  59 -       mov     r0, #0
  60 -       PSEUDO_RET_NOERRNO
  61 -END (pthread_spin_lock)
  62 diff --git a/sysdeps/arm/nptl/pthread_spin_lock.c b/sysdeps/arm/nptl/pthread_spin_lock.c
  63 new file mode 100644
  64 index 0000000..1217b89
  65 --- /dev/null
  66 +++ b/sysdeps/arm/nptl/pthread_spin_lock.c
  67 @@ -0,0 +1,30 @@
  68 +/* Copyright (C) 2008 Free Software Foundation, Inc.
  69 +   This file is part of the GNU C Library.
  70 +
  71 +   The GNU C Library is free software; you can redistribute it and/or
  72 +   modify it under the terms of the GNU Lesser General Public
  73 +   License as published by the Free Software Foundation; either
  74 +   version 2.1 of the License, or (at your option) any later version.
  75 +
  76 +   The GNU C Library is distributed in the hope that it will be useful,
  77 +   but WITHOUT ANY WARRANTY; without even the implied warranty of
  78 +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  79 +   Lesser General Public License for more details.
  80 +
  81 +   You should have received a copy of the GNU Lesser General Public
  82 +   License along with the GNU C Library; if not, write to the Free
  83 +   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  84 +   02111-1307 USA.  */
  85 +
  86 +#include <atomic.h>
  87 +#include "pthreadP.h"
  88 +
  89 +int
  90 +pthread_spin_lock (pthread_spinlock_t *lock)
  91 +{
  92 +  while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0)
  93 +   while (*lock != 0)
  94 +    ;
  95 +
  96 +  return 0;
  97 +}
  98 diff --git a/sysdeps/arm/nptl/pthread_spin_trylock.S b/sysdeps/arm/nptl/pthread_spin_trylock.S
  99 deleted file mode 100644
 100 index 8593150..0000000
 101 --- a/sysdeps/arm/nptl/pthread_spin_trylock.S
 102 +++ /dev/null
 103 @@ -1,34 +0,0 @@
 104 -/* Copyright (C) 2005 Free Software Foundation, Inc.
 105 -   This file is part of the GNU C Library.
 106 -
 107 -   The GNU C Library is free software; you can redistribute it and/or
 108 -   modify it under the terms of the GNU Lesser General Public
 109 -   License as published by the Free Software Foundation; either
 110 -   version 2.1 of the License, or (at your option) any later version.
 111 -
 112 -   The GNU C Library is distributed in the hope that it will be useful,
 113 -   but WITHOUT ANY WARRANTY; without even the implied warranty of
 114 -   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 115 -   Lesser General Public License for more details.
 116 -
 117 -   You should have received a copy of the GNU Lesser General Public
 118 -   License along with the GNU C Library; if not, write to the Free
 119 -   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 120 -   02111-1307 USA.  */
 121 -
 122 -#define _ERRNO_H 1
 123 -#include <bits/errno.h>
 124 -
 125 -#include <sysdep.h>
 126 -
 127 -       .text
 128 -       .align  4
 129 -
 130 -ENTRY (pthread_spin_trylock)
 131 -       mov     r1, #1
 132 -       swp     r2, r1, [r0]
 133 -       teq     r2, #0
 134 -       moveq   r0, #0
 135 -       movne   r0, #EBUSY
 136 -       PSEUDO_RET_NOERRNO
 137 -END (pthread_spin_trylock)
 138 diff --git a/sysdeps/arm/nptl/pthread_spin_trylock.c b/sysdeps/arm/nptl/pthread_spin_trylock.c
 139 new file mode 100644
 140 index 0000000..fb998d2
 141 --- /dev/null
 142 +++ b/sysdeps/arm/nptl/pthread_spin_trylock.c
 143 @@ -0,0 +1,27 @@
 144 +/* Copyright (C) 2008 Free Software Foundation, Inc.
 145 +   This file is part of the GNU C Library.
 146 +
 147 +   The GNU C Library is free software; you can redistribute it and/or
 148 +   modify it under the terms of the GNU Lesser General Public
 149 +   License as published by the Free Software Foundation; either
 150 +   version 2.1 of the License, or (at your option) any later version.
 151 +
 152 +   The GNU C Library is distributed in the hope that it will be useful,
 153 +   but WITHOUT ANY WARRANTY; without even the implied warranty of
 154 +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 155 +   Lesser General Public License for more details.
 156 +
 157 +   You should have received a copy of the GNU Lesser General Public
 158 +   License along with the GNU C Library; if not, write to the Free
 159 +   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 160 +   02111-1307 USA.  */
 161 +
 162 +#include <errno.h>
 163 +#include <atomic.h>
 164 +#include "pthreadP.h"
 165 +
 166 +int
 167 +pthread_spin_trylock (pthread_spinlock_t *lock)
 168 +{
 169 +  return atomic_compare_and_exchange_val_acq (lock, 1, 0) ? EBUSY : 0;
 170 +}
 171 diff --git a/sysdeps/unix/sysv/linux/arm/eabi/configure b/sysdeps/unix/sysv/linux/arm/eabi/configure
 172 index ab83048..28fb9ef 100644
 173 --- a/sysdeps/unix/sysv/linux/arm/eabi/configure
 174 +++ b/sysdeps/unix/sysv/linux/arm/eabi/configure
 175 @@ -1,5 +1,5 @@
 176  # This file is generated from configure.in by Autoconf.  DO NOT EDIT!
 177   # Local configure fragment for sysdeps/unix/sysv/linux/arm/eabi.
 178
 179 -arch_minimum_kernel=2.6.14
 180 +arch_minimum_kernel=2.6.16
 181  libc_cv_gcc_unwind_find_fde=no
 182 diff --git a/sysdeps/unix/sysv/linux/arm/eabi/configure.in b/sysdeps/unix/sysv/linux/arm/eabi/configure.in
 183 index 83aa8fc..d1fb7f4 100644
 184 --- a/sysdeps/unix/sysv/linux/arm/eabi/configure.in
 185 +++ b/sysdeps/unix/sysv/linux/arm/eabi/configure.in
 186 @@ -1,5 +1,5 @@
 187  GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
 188  # Local configure fragment for sysdeps/unix/sysv/linux/arm/eabi.
 189
 190 -arch_minimum_kernel=2.6.14
 191 +arch_minimum_kernel=2.6.16
 192  libc_cv_gcc_unwind_find_fde=no
 193 diff --git a/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h b/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
 194 index 71ed714..247ddd3 100644
 195 --- a/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
 196 +++ b/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
 197 @@ -37,22 +37,12 @@ typedef uintmax_t uatomic_max_t;
 198
 199  void __arm_link_error (void);
 200
 201 -#define atomic_exchange_acq(mem, newvalue)                                   \
 202 -  ({ __typeof (*mem) result;                                                 \
 203 -     if (sizeof (*mem) == 1)                                                 \
 204 -       __asm__ __volatile__ ("swpb %0, %1, [%2]"                             \
 205 -                            : "=&r,&r" (result)                              \
 206 -                            : "r,0" (newvalue), "r,r" (mem) : "memory");     \
 207 -     else if (sizeof (*mem) == 4)                                            \
 208 -       __asm__ __volatile__ ("swp %0, %1, [%2]"                                      \
 209 -                            : "=&r,&r" (result)                              \
 210 -                            : "r,0" (newvalue), "r,r" (mem) : "memory");     \
 211 -     else                                                                    \
 212 -       {                                                                     \
 213 -        result = 0;                                                          \
 214 -        abort ();                                                            \
 215 -       }                                                                     \
 216 -     result; })
 217 +#define atomic_full_barrier() \
 218 +     __asm__ __volatile__                                                    \
 219 +            ("mov\tip, #0xffff0fff\n\t"                                      \
 220 +             "mov\tlr, pc\n\t"                                               \
 221 +             "add\tpc, ip, #(0xffff0fa0 - 0xffff0fff)"                       \
 222 +             : : : "ip", "lr", "cc", "memory");
 223
 224  /* Atomic compare and exchange.  This sequence relies on the kernel to
 225     provide a compare and exchange operation which is atomic on the
 226 @@ -76,18 +66,19 @@ void __arm_link_error (void);
 227       register __typeof (oldval) a_tmp asm ("r3");                            \
 228       register __typeof (oldval) a_oldval2 asm ("r4") = (oldval);             \
 229       __asm__ __volatile__                                                    \
 230 -            ("0:\tldr\t%1,[%3]\n\t"                                          \
 231 -             "cmp\t%1, %4\n\t"                                               \
 232 +            ("0:\tldr\t%[tmp],[%[ptr]]\n\t"                                  \
 233 +             "cmp\t%[tmp], %[old2]\n\t"                                      \
 234               "bne\t1f\n\t"                                                   \
 235 -             "mov\t%0, %4\n\t"                                               \
 236 -             "mov\t%1, #0xffff0fff\n\t"                                      \
 237 +             "mov\t%[old], %[old2]\n\t"                                      \
 238 +             "mov\t%[tmp], #0xffff0fff\n\t"                                  \
 239               "mov\tlr, pc\n\t"                                               \
 240 -             "add\tpc, %1, #(0xffff0fc0 - 0xffff0fff)\n\t"                   \
 241 +             "add\tpc, %[tmp], #(0xffff0fc0 - 0xffff0fff)\n\t"               \
 242               "bcc\t0b\n\t"                                                   \
 243 -             "mov\t%1, %4\n\t"                                               \
 244 +             "mov\t%[tmp], %[old2]\n\t"                                      \
 245               "1:"                                                            \
 246 -             : "=&r" (a_oldval), "=&r" (a_tmp)                               \
 247 -             : "r" (a_newval), "r" (a_ptr), "r" (a_oldval2)                  \
 248 +             : [old] "=&r" (a_oldval), [tmp] "=&r" (a_tmp)                   \
 249 +             : [new] "r" (a_newval), [ptr] "r" (a_ptr),                      \
 250 +               [old2] "r" (a_oldval2)                                        \
 251               : "ip", "lr", "cc", "memory");                                  \
 252       a_tmp; })
 253
 254 diff --git a/sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h b/sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h
 255 index f48e867..889f97c 100644
 256 --- a/sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h
 257 +++ b/sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h
 258 @@ -126,43 +126,11 @@
 259    })
 260
 261
 262 -static inline int __attribute__((always_inline))
 263 -__lll_mutex_trylock (int *futex)
 264 -{
 265 -  int flag = 1, old;
 266 -  asm volatile (
 267 -    "\tswp     %[old], %[flag], [%[futex]]     @ try to take the lock\n"
 268 -    "\tcmp     %[old], #1                      @ check old lock value\n"
 269 -    "\tmovlo   %[flag], #0                     @ if we got it, return 0\n"
 270 -    "\tswphi   %[flag], %[old], [%[futex]]     @ if it was contested,\n"
 271 -    "                                          @ restore the contested flag,\n"
 272 -    "                                          @ and check whether that won."
 273 -    : [futex] "+&r" (futex), [flag] "+&r" (flag), [old] "=&r" (old)
 274 -    : : "memory" );
 275 -
 276 -  return flag;
 277 -}
 278 -#define lll_mutex_trylock(lock)        __lll_mutex_trylock (&(lock))
 279 -
 280 -
 281 -static inline int __attribute__((always_inline))
 282 -__lll_mutex_cond_trylock (int *futex)
 283 -{
 284 -  int flag = 2, old;
 285 -  asm volatile (
 286 -    "\tswp     %[old], %[flag], [%[futex]]     @ try to take the lock\n"
 287 -    "\tcmp     %[old], #1                      @ check old lock value\n"
 288 -    "\tmovlo   %[flag], #0                     @ if we got it, return 0\n"
 289 -    "\tswphi   %[flag], %[old], [%[futex]]     @ if it was contested,\n"
 290 -    "                                          @ restore the contested flag,\n"
 291 -    "                                          @ and check whether that won."
 292 -    : [futex] "+&r" (futex), [flag] "+&r" (flag), [old] "=&r" (old)
 293 -    : : "memory" );
 294 -
 295 -  return flag;
 296 -}
 297 -#define lll_mutex_cond_trylock(lock)   __lll_mutex_cond_trylock (&(lock))
 298 +#define lll_mutex_trylock(lock)        \
 299 +  atomic_compare_and_exchange_val_acq(&(lock), 1, 0)
 300
 301 +#define lll_mutex_cond_trylock(lock)   \
 302 +  atomic_compare_and_exchange_val_acq(&(lock), 2, 0)
 303
 304  #define __lll_robust_trylock(futex, id) \
 305    (atomic_compare_and_exchange_val_acq (futex, id, 0) != 0)