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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgcc/] [config/] [arm/] [linux-atomic-64bit.c] - Rev 737
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/* 64bit Linux-specific atomic operations for ARM EABI. Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc. Based on linux-atomic.c 64 bit additions david.gilbert@linaro.org This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC 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 General Public License for more details. Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation. You should have received a copy of the GNU General Public License and a copy of the GCC Runtime Library Exception along with this program; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see <http://www.gnu.org/licenses/>. */ /* 64bit helper functions for atomic operations; the compiler will call these when the code is compiled for a CPU without ldrexd/strexd. (If the CPU had those then the compiler inlines the operation). These helpers require a kernel helper that's only present on newer kernels; we check for that in an init section and bail out rather unceremoneously. */ extern unsigned int __write (int fd, const void *buf, unsigned int count); extern void abort (void); /* Kernel helper for compare-and-exchange. */ typedef int (__kernel_cmpxchg64_t) (const long long* oldval, const long long* newval, long long *ptr); #define __kernel_cmpxchg64 (*(__kernel_cmpxchg64_t *) 0xffff0f60) /* Kernel helper page version number. */ #define __kernel_helper_version (*(unsigned int *)0xffff0ffc) /* Check that the kernel has a new enough version at load. */ static void __check_for_sync8_kernelhelper (void) { if (__kernel_helper_version < 5) { const char err[] = "A newer kernel is required to run this binary. " "(__kernel_cmpxchg64 helper)\n"; /* At this point we need a way to crash with some information for the user - I'm not sure I can rely on much else being available at this point, so do the same as generic-morestack.c write () and abort (). */ __write (2 /* stderr. */, err, sizeof (err)); abort (); } }; static void (*__sync8_kernelhelper_inithook[]) (void) __attribute__ ((used, section (".init_array"))) = { &__check_for_sync8_kernelhelper }; #define HIDDEN __attribute__ ((visibility ("hidden"))) #define FETCH_AND_OP_WORD64(OP, PFX_OP, INF_OP) \ long long HIDDEN \ __sync_fetch_and_##OP##_8 (long long *ptr, long long val) \ { \ int failure; \ long long tmp,tmp2; \ \ do { \ tmp = *ptr; \ tmp2 = PFX_OP (tmp INF_OP val); \ failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \ } while (failure != 0); \ \ return tmp; \ } FETCH_AND_OP_WORD64 (add, , +) FETCH_AND_OP_WORD64 (sub, , -) FETCH_AND_OP_WORD64 (or, , |) FETCH_AND_OP_WORD64 (and, , &) FETCH_AND_OP_WORD64 (xor, , ^) FETCH_AND_OP_WORD64 (nand, ~, &) #define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH #define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH /* Implement both __sync_<op>_and_fetch and __sync_fetch_and_<op> for subword-sized quantities. */ #define OP_AND_FETCH_WORD64(OP, PFX_OP, INF_OP) \ long long HIDDEN \ __sync_##OP##_and_fetch_8 (long long *ptr, long long val) \ { \ int failure; \ long long tmp,tmp2; \ \ do { \ tmp = *ptr; \ tmp2 = PFX_OP (tmp INF_OP val); \ failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \ } while (failure != 0); \ \ return tmp2; \ } OP_AND_FETCH_WORD64 (add, , +) OP_AND_FETCH_WORD64 (sub, , -) OP_AND_FETCH_WORD64 (or, , |) OP_AND_FETCH_WORD64 (and, , &) OP_AND_FETCH_WORD64 (xor, , ^) OP_AND_FETCH_WORD64 (nand, ~, &) long long HIDDEN __sync_val_compare_and_swap_8 (long long *ptr, long long oldval, long long newval) { int failure; long long actual_oldval; while (1) { actual_oldval = *ptr; if (__builtin_expect (oldval != actual_oldval, 0)) return actual_oldval; failure = __kernel_cmpxchg64 (&actual_oldval, &newval, ptr); if (__builtin_expect (!failure, 1)) return oldval; } } typedef unsigned char bool; bool HIDDEN __sync_bool_compare_and_swap_8 (long long *ptr, long long oldval, long long newval) { int failure = __kernel_cmpxchg64 (&oldval, &newval, ptr); return (failure == 0); } long long HIDDEN __sync_lock_test_and_set_8 (long long *ptr, long long val) { int failure; long long oldval; do { oldval = *ptr; failure = __kernel_cmpxchg64 (&oldval, &val, ptr); } while (failure != 0); return oldval; }
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