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Diffstat (limited to 'sysdeps/powerpc/powerpc32/atomic-machine.h')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/atomic-machine.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/atomic-machine.h b/sysdeps/powerpc/powerpc32/atomic-machine.h new file mode 100644 index 0000000000..1d407b3490 --- /dev/null +++ b/sysdeps/powerpc/powerpc32/atomic-machine.h @@ -0,0 +1,144 @@ +/* Atomic operations. PowerPC32 version. + Copyright (C) 2003-2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* POWER6 adds a "Mutex Hint" to the Load and Reserve instruction. + This is a hint to the hardware to expect additional updates adjacent + to the lock word or not. If we are acquiring a Mutex, the hint + should be true. Otherwise we releasing a Mutex or doing a simple + atomic operation. In that case we don't expect additional updates + adjacent to the lock word after the Store Conditional and the hint + should be false. */ + +#if defined _ARCH_PWR6 || defined _ARCH_PWR6X +# define MUTEX_HINT_ACQ ",1" +# define MUTEX_HINT_REL ",0" +#else +# define MUTEX_HINT_ACQ +# define MUTEX_HINT_REL +#endif + +#define __HAVE_64B_ATOMICS 0 +#define USE_ATOMIC_COMPILER_BUILTINS 0 + +/* + * The 32-bit exchange_bool is different on powerpc64 because the subf + * does signed 64-bit arithmetic while the lwarx is 32-bit unsigned + * (a load word and zero (high 32) form). So powerpc64 has a slightly + * different version in sysdeps/powerpc/powerpc64/atomic-machine.h. + */ +#define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \ +({ \ + unsigned int __tmp; \ + __asm __volatile ( \ + "1: lwarx %0,0,%1" MUTEX_HINT_ACQ "\n" \ + " subf. %0,%2,%0\n" \ + " bne 2f\n" \ + " stwcx. %3,0,%1\n" \ + " bne- 1b\n" \ + "2: " __ARCH_ACQ_INSTR \ + : "=&r" (__tmp) \ + : "b" (mem), "r" (oldval), "r" (newval) \ + : "cr0", "memory"); \ + __tmp != 0; \ +}) + +#define __arch_compare_and_exchange_bool_32_rel(mem, newval, oldval) \ +({ \ + unsigned int __tmp; \ + __asm __volatile (__ARCH_REL_INSTR "\n" \ + "1: lwarx %0,0,%1" MUTEX_HINT_REL "\n" \ + " subf. %0,%2,%0\n" \ + " bne 2f\n" \ + " stwcx. %3,0,%1\n" \ + " bne- 1b\n" \ + "2: " \ + : "=&r" (__tmp) \ + : "b" (mem), "r" (oldval), "r" (newval) \ + : "cr0", "memory"); \ + __tmp != 0; \ +}) + +/* Powerpc32 processors don't implement the 64-bit (doubleword) forms of + load and reserve (ldarx) and store conditional (stdcx.) instructions. + So for powerpc32 we stub out the 64-bit forms. */ +#define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \ + (abort (), 0) + +#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \ + (abort (), (__typeof (*mem)) 0) + +#define __arch_compare_and_exchange_bool_64_rel(mem, newval, oldval) \ + (abort (), 0) + +#define __arch_compare_and_exchange_val_64_rel(mem, newval, oldval) \ + (abort (), (__typeof (*mem)) 0) + +#define __arch_atomic_exchange_64_acq(mem, value) \ + ({ abort (); (*mem) = (value); }) + +#define __arch_atomic_exchange_64_rel(mem, value) \ + ({ abort (); (*mem) = (value); }) + +#define __arch_atomic_exchange_and_add_64(mem, value) \ + ({ abort (); (*mem) = (value); }) + +#define __arch_atomic_exchange_and_add_64_acq(mem, value) \ + ({ abort (); (*mem) = (value); }) + +#define __arch_atomic_exchange_and_add_64_rel(mem, value) \ + ({ abort (); (*mem) = (value); }) + +#define __arch_atomic_increment_val_64(mem) \ + ({ abort (); (*mem)++; }) + +#define __arch_atomic_decrement_val_64(mem) \ + ({ abort (); (*mem)--; }) + +#define __arch_atomic_decrement_if_positive_64(mem) \ + ({ abort (); (*mem)--; }) + +#ifdef _ARCH_PWR4 +/* + * Newer powerpc64 processors support the new "light weight" sync (lwsync) + * So if the build is using -mcpu=[power4,power5,power5+,970] we can + * safely use lwsync. + */ +# define atomic_read_barrier() __asm ("lwsync" ::: "memory") +/* + * "light weight" sync can also be used for the release barrier. + */ +# ifndef UP +# define __ARCH_REL_INSTR "lwsync" +# endif +# define atomic_write_barrier() __asm ("lwsync" ::: "memory") +#else +/* + * Older powerpc32 processors don't support the new "light weight" + * sync (lwsync). So the only safe option is to use normal sync + * for all powerpc32 applications. + */ +# define atomic_read_barrier() __asm ("sync" ::: "memory") +# define atomic_write_barrier() __asm ("sync" ::: "memory") +#endif + +/* + * Include the rest of the atomic ops macros which are common to both + * powerpc32 and powerpc64. + */ +#include_next <atomic-machine.h> |