diff options
Diffstat (limited to 'gcc-4.9/libgcc/config/arm/linux-atomic.c')
| -rw-r--r-- | gcc-4.9/libgcc/config/arm/linux-atomic.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/arm/linux-atomic.c b/gcc-4.9/libgcc/config/arm/linux-atomic.c new file mode 100644 index 000000000..e2817058d --- /dev/null +++ b/gcc-4.9/libgcc/config/arm/linux-atomic.c @@ -0,0 +1,279 @@ +/* Linux-specific atomic operations for ARM EABI. + Copyright (C) 2008-2014 Free Software Foundation, Inc. + Contributed by CodeSourcery. + +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/>. */ + +/* Kernel helper for compare-and-exchange. */ +typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr); +#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0) + +/* Kernel helper for memory barrier. */ +typedef void (__kernel_dmb_t) (void); +#define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0) + +/* Note: we implement byte, short and int versions of atomic operations using + the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit) + operations. */ + +#define HIDDEN __attribute__ ((visibility ("hidden"))) + +#ifdef __ARMEL__ +#define INVERT_MASK_1 0 +#define INVERT_MASK_2 0 +#else +#define INVERT_MASK_1 24 +#define INVERT_MASK_2 16 +#endif + +#define MASK_1 0xffu +#define MASK_2 0xffffu + +#define FETCH_AND_OP_WORD(OP, PFX_OP, INF_OP) \ + int HIDDEN \ + __sync_fetch_and_##OP##_4 (int *ptr, int val) \ + { \ + int failure, tmp; \ + \ + do { \ + tmp = *ptr; \ + failure = __kernel_cmpxchg (tmp, PFX_OP (tmp INF_OP val), ptr); \ + } while (failure != 0); \ + \ + return tmp; \ + } + +FETCH_AND_OP_WORD (add, , +) +FETCH_AND_OP_WORD (sub, , -) +FETCH_AND_OP_WORD (or, , |) +FETCH_AND_OP_WORD (and, , &) +FETCH_AND_OP_WORD (xor, , ^) +FETCH_AND_OP_WORD (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 SUBWORD_SYNC_OP(OP, PFX_OP, INF_OP, TYPE, WIDTH, RETURN) \ + TYPE HIDDEN \ + NAME##_##RETURN (OP, WIDTH) (TYPE *ptr, TYPE val) \ + { \ + int *wordptr = (int *) ((unsigned int) ptr & ~3); \ + unsigned int mask, shift, oldval, newval; \ + int failure; \ + \ + shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \ + mask = MASK_##WIDTH << shift; \ + \ + do { \ + oldval = *wordptr; \ + newval = ((PFX_OP (((oldval & mask) >> shift) \ + INF_OP (unsigned int) val)) << shift) & mask; \ + newval |= oldval & ~mask; \ + failure = __kernel_cmpxchg (oldval, newval, wordptr); \ + } while (failure != 0); \ + \ + return (RETURN & mask) >> shift; \ + } + +SUBWORD_SYNC_OP (add, , +, short, 2, oldval) +SUBWORD_SYNC_OP (sub, , -, short, 2, oldval) +SUBWORD_SYNC_OP (or, , |, short, 2, oldval) +SUBWORD_SYNC_OP (and, , &, short, 2, oldval) +SUBWORD_SYNC_OP (xor, , ^, short, 2, oldval) +SUBWORD_SYNC_OP (nand, ~, &, short, 2, oldval) + +SUBWORD_SYNC_OP (add, , +, signed char, 1, oldval) +SUBWORD_SYNC_OP (sub, , -, signed char, 1, oldval) +SUBWORD_SYNC_OP (or, , |, signed char, 1, oldval) +SUBWORD_SYNC_OP (and, , &, signed char, 1, oldval) +SUBWORD_SYNC_OP (xor, , ^, signed char, 1, oldval) +SUBWORD_SYNC_OP (nand, ~, &, signed char, 1, oldval) + +#define OP_AND_FETCH_WORD(OP, PFX_OP, INF_OP) \ + int HIDDEN \ + __sync_##OP##_and_fetch_4 (int *ptr, int val) \ + { \ + int tmp, failure; \ + \ + do { \ + tmp = *ptr; \ + failure = __kernel_cmpxchg (tmp, PFX_OP (tmp INF_OP val), ptr); \ + } while (failure != 0); \ + \ + return PFX_OP (tmp INF_OP val); \ + } + +OP_AND_FETCH_WORD (add, , +) +OP_AND_FETCH_WORD (sub, , -) +OP_AND_FETCH_WORD (or, , |) +OP_AND_FETCH_WORD (and, , &) +OP_AND_FETCH_WORD (xor, , ^) +OP_AND_FETCH_WORD (nand, ~, &) + +SUBWORD_SYNC_OP (add, , +, short, 2, newval) +SUBWORD_SYNC_OP (sub, , -, short, 2, newval) +SUBWORD_SYNC_OP (or, , |, short, 2, newval) +SUBWORD_SYNC_OP (and, , &, short, 2, newval) +SUBWORD_SYNC_OP (xor, , ^, short, 2, newval) +SUBWORD_SYNC_OP (nand, ~, &, short, 2, newval) + +SUBWORD_SYNC_OP (add, , +, signed char, 1, newval) +SUBWORD_SYNC_OP (sub, , -, signed char, 1, newval) +SUBWORD_SYNC_OP (or, , |, signed char, 1, newval) +SUBWORD_SYNC_OP (and, , &, signed char, 1, newval) +SUBWORD_SYNC_OP (xor, , ^, signed char, 1, newval) +SUBWORD_SYNC_OP (nand, ~, &, signed char, 1, newval) + +int HIDDEN +__sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval) +{ + int actual_oldval, fail; + + while (1) + { + actual_oldval = *ptr; + + if (__builtin_expect (oldval != actual_oldval, 0)) + return actual_oldval; + + fail = __kernel_cmpxchg (actual_oldval, newval, ptr); + + if (__builtin_expect (!fail, 1)) + return oldval; + } +} + +#define SUBWORD_VAL_CAS(TYPE, WIDTH) \ + TYPE HIDDEN \ + __sync_val_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval, \ + TYPE newval) \ + { \ + int *wordptr = (int *)((unsigned int) ptr & ~3), fail; \ + unsigned int mask, shift, actual_oldval, actual_newval; \ + \ + shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \ + mask = MASK_##WIDTH << shift; \ + \ + while (1) \ + { \ + actual_oldval = *wordptr; \ + \ + if (__builtin_expect (((actual_oldval & mask) >> shift) != \ + ((unsigned int) oldval & MASK_##WIDTH), 0)) \ + return (actual_oldval & mask) >> shift; \ + \ + actual_newval = (actual_oldval & ~mask) \ + | (((unsigned int) newval << shift) & mask); \ + \ + fail = __kernel_cmpxchg (actual_oldval, actual_newval, \ + wordptr); \ + \ + if (__builtin_expect (!fail, 1)) \ + return oldval; \ + } \ + } + +SUBWORD_VAL_CAS (short, 2) +SUBWORD_VAL_CAS (signed char, 1) + +typedef unsigned char bool; + +bool HIDDEN +__sync_bool_compare_and_swap_4 (int *ptr, int oldval, int newval) +{ + int failure = __kernel_cmpxchg (oldval, newval, ptr); + return (failure == 0); +} + +#define SUBWORD_BOOL_CAS(TYPE, WIDTH) \ + bool HIDDEN \ + __sync_bool_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval, \ + TYPE newval) \ + { \ + TYPE actual_oldval \ + = __sync_val_compare_and_swap_##WIDTH (ptr, oldval, newval); \ + return (oldval == actual_oldval); \ + } + +SUBWORD_BOOL_CAS (short, 2) +SUBWORD_BOOL_CAS (signed char, 1) + +void HIDDEN +__sync_synchronize (void) +{ + __kernel_dmb (); +} + +int HIDDEN +__sync_lock_test_and_set_4 (int *ptr, int val) +{ + int failure, oldval; + + do { + oldval = *ptr; + failure = __kernel_cmpxchg (oldval, val, ptr); + } while (failure != 0); + + return oldval; +} + +#define SUBWORD_TEST_AND_SET(TYPE, WIDTH) \ + TYPE HIDDEN \ + __sync_lock_test_and_set_##WIDTH (TYPE *ptr, TYPE val) \ + { \ + int failure; \ + unsigned int oldval, newval, shift, mask; \ + int *wordptr = (int *) ((unsigned int) ptr & ~3); \ + \ + shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \ + mask = MASK_##WIDTH << shift; \ + \ + do { \ + oldval = *wordptr; \ + newval = (oldval & ~mask) \ + | (((unsigned int) val << shift) & mask); \ + failure = __kernel_cmpxchg (oldval, newval, wordptr); \ + } while (failure != 0); \ + \ + return (oldval & mask) >> shift; \ + } + +SUBWORD_TEST_AND_SET (short, 2) +SUBWORD_TEST_AND_SET (signed char, 1) + +#define SYNC_LOCK_RELEASE(TYPE, WIDTH) \ + void HIDDEN \ + __sync_lock_release_##WIDTH (TYPE *ptr) \ + { \ + /* All writes before this point must be seen before we release \ + the lock itself. */ \ + __kernel_dmb (); \ + *ptr = 0; \ + } + +SYNC_LOCK_RELEASE (long long, 8) +SYNC_LOCK_RELEASE (int, 4) +SYNC_LOCK_RELEASE (short, 2) +SYNC_LOCK_RELEASE (char, 1) |