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Diffstat (limited to 'ports/sysdeps/mips/bits/atomic.h')
| -rw-r--r-- | ports/sysdeps/mips/bits/atomic.h | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/ports/sysdeps/mips/bits/atomic.h b/ports/sysdeps/mips/bits/atomic.h new file mode 100644 index 0000000000..4d51d7fa2f --- /dev/null +++ b/ports/sysdeps/mips/bits/atomic.h @@ -0,0 +1,328 @@ +/* Low-level functions for atomic operations. Mips version. + Copyright (C) 2005 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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/>. */ + +#ifndef _MIPS_BITS_ATOMIC_H +#define _MIPS_BITS_ATOMIC_H 1 + +#include <inttypes.h> +#include <sgidefs.h> + +typedef int32_t atomic32_t; +typedef uint32_t uatomic32_t; +typedef int_fast32_t atomic_fast32_t; +typedef uint_fast32_t uatomic_fast32_t; + +typedef int64_t atomic64_t; +typedef uint64_t uatomic64_t; +typedef int_fast64_t atomic_fast64_t; +typedef uint_fast64_t uatomic_fast64_t; + +typedef intptr_t atomicptr_t; +typedef uintptr_t uatomicptr_t; +typedef intmax_t atomic_max_t; +typedef uintmax_t uatomic_max_t; + +#if _MIPS_SIM == _ABIO32 +#define MIPS_PUSH_MIPS2 ".set mips2\n\t" +#else +#define MIPS_PUSH_MIPS2 +#endif + +/* See the comments in <sys/asm.h> about the use of the sync instruction. */ +#ifndef MIPS_SYNC +# define MIPS_SYNC sync +#endif + +/* Certain revisions of the R10000 Processor need an LL/SC Workaround + enabled. Revisions before 3.0 misbehave on atomic operations, and + Revs 2.6 and lower deadlock after several seconds due to other errata. + + To quote the R10K Errata: + Workaround: The basic idea is to inhibit the four instructions + from simultaneously becoming active in R10000. Padding all + ll/sc sequences with nops or changing the looping branch in the + routines to a branch likely (which is always predicted taken + by R10000) will work. The nops should go after the loop, and the + number of them should be 28. This number could be decremented for + each additional instruction in the ll/sc loop such as the lock + modifier(s) between the ll and sc, the looping branch and its + delay slot. For typical short routines with one ll/sc loop, any + instructions after the loop could also count as a decrement. The + nop workaround pollutes the cache more but would be a few cycles + faster if all the code is in the cache and the looping branch + is predicted not taken. */ + + +#ifdef _MIPS_ARCH_R10000 +#define R10K_BEQZ_INSN "beqzl" +#else +#define R10K_BEQZ_INSN "beqz" +#endif + +#define MIPS_SYNC_STR_2(X) #X +#define MIPS_SYNC_STR_1(X) MIPS_SYNC_STR_2(X) +#define MIPS_SYNC_STR MIPS_SYNC_STR_1(MIPS_SYNC) + +/* Compare and exchange. For all of the "xxx" routines, we expect a + "__prev" and a "__cmp" variable to be provided by the enclosing scope, + in which values are returned. */ + +#define __arch_compare_and_exchange_xxx_8_int(mem, newval, oldval, rel, acq) \ + (abort (), __prev = __cmp = 0) + +#define __arch_compare_and_exchange_xxx_16_int(mem, newval, oldval, rel, acq) \ + (abort (), __prev = __cmp = 0) + +#define __arch_compare_and_exchange_xxx_32_int(mem, newval, oldval, rel, acq) \ + __asm__ __volatile__ ( \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\t" \ + "ll %0,%5\n\t" \ + "move %1,$0\n\t" \ + "bne %0,%3,2f\n\t" \ + "move %1,%4\n\t" \ + "sc %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (oldval), "r" (newval), "m" (*mem) \ + : "memory") + +#if _MIPS_SIM == _ABIO32 +/* We can't do an atomic 64-bit operation in O32. */ +#define __arch_compare_and_exchange_xxx_64_int(mem, newval, oldval, rel, acq) \ + (abort (), __prev = __cmp = 0) +#else +#define __arch_compare_and_exchange_xxx_64_int(mem, newval, oldval, rel, acq) \ + __asm__ __volatile__ ("\n" \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\t" \ + "lld %0,%5\n\t" \ + "move %1,$0\n\t" \ + "bne %0,%3,2f\n\t" \ + "move %1,%4\n\t" \ + "scd %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (oldval), "r" (newval), "m" (*mem) \ + : "memory") +#endif + +/* For all "bool" routines, we return FALSE if exchange succesful. */ + +#define __arch_compare_and_exchange_bool_8_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_8_int(mem, new, old, rel, acq); \ + !__cmp; }) + +#define __arch_compare_and_exchange_bool_16_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_16_int(mem, new, old, rel, acq); \ + !__cmp; }) + +#define __arch_compare_and_exchange_bool_32_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_32_int(mem, new, old, rel, acq); \ + !__cmp; }) + +#define __arch_compare_and_exchange_bool_64_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_64_int(mem, new, old, rel, acq); \ + !__cmp; }) + +/* For all "val" routines, return the old value whether exchange + successful or not. */ + +#define __arch_compare_and_exchange_val_8_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_8_int(mem, new, old, rel, acq); \ + (typeof (*mem))__prev; }) + +#define __arch_compare_and_exchange_val_16_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_16_int(mem, new, old, rel, acq); \ + (typeof (*mem))__prev; }) + +#define __arch_compare_and_exchange_val_32_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_32_int(mem, new, old, rel, acq); \ + (typeof (*mem))__prev; }) + +#define __arch_compare_and_exchange_val_64_int(mem, new, old, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __arch_compare_and_exchange_xxx_64_int(mem, new, old, rel, acq); \ + (typeof (*mem))__prev; }) + +/* Compare and exchange with "acquire" semantics, ie barrier after. */ + +#define atomic_compare_and_exchange_bool_acq(mem, new, old) \ + __atomic_bool_bysize (__arch_compare_and_exchange_bool, int, \ + mem, new, old, "", MIPS_SYNC_STR) + +#define atomic_compare_and_exchange_val_acq(mem, new, old) \ + __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ + mem, new, old, "", MIPS_SYNC_STR) + +/* Compare and exchange with "release" semantics, ie barrier before. */ + +#define atomic_compare_and_exchange_bool_rel(mem, new, old) \ + __atomic_bool_bysize (__arch_compare_and_exchange_bool, int, \ + mem, new, old, MIPS_SYNC_STR, "") + +#define atomic_compare_and_exchange_val_rel(mem, new, old) \ + __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ + mem, new, old, MIPS_SYNC_STR, "") + + + +/* Atomic exchange (without compare). */ + +#define __arch_exchange_xxx_8_int(mem, newval, rel, acq) \ + (abort (), 0) + +#define __arch_exchange_xxx_16_int(mem, newval, rel, acq) \ + (abort (), 0) + +#define __arch_exchange_xxx_32_int(mem, newval, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __asm__ __volatile__ ("\n" \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\t" \ + "ll %0,%4\n\t" \ + "move %1,%3\n\t" \ + "sc %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (newval), "m" (*mem) \ + : "memory"); \ + __prev; }) + +#if _MIPS_SIM == _ABIO32 +/* We can't do an atomic 64-bit operation in O32. */ +#define __arch_exchange_xxx_64_int(mem, newval, rel, acq) \ + (abort (), 0) +#else +#define __arch_exchange_xxx_64_int(mem, newval, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __asm__ __volatile__ ("\n" \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\n" \ + "lld %0,%4\n\t" \ + "move %1,%3\n\t" \ + "scd %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (newval), "m" (*mem) \ + : "memory"); \ + __prev; }) +#endif + +#define atomic_exchange_acq(mem, value) \ + __atomic_val_bysize (__arch_exchange_xxx, int, mem, value, "", MIPS_SYNC_STR) + +#define atomic_exchange_rel(mem, value) \ + __atomic_val_bysize (__arch_exchange_xxx, int, mem, value, MIPS_SYNC_STR, "") + + +/* Atomically add value and return the previous (unincremented) value. */ + +#define __arch_exchange_and_add_8_int(mem, newval, rel, acq) \ + (abort (), (typeof(*mem)) 0) + +#define __arch_exchange_and_add_16_int(mem, newval, rel, acq) \ + (abort (), (typeof(*mem)) 0) + +#define __arch_exchange_and_add_32_int(mem, value, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __asm__ __volatile__ ("\n" \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\t" \ + "ll %0,%4\n\t" \ + "addu %1,%0,%3\n\t" \ + "sc %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (value), "m" (*mem) \ + : "memory"); \ + __prev; }) + +#if _MIPS_SIM == _ABIO32 +/* We can't do an atomic 64-bit operation in O32. */ +#define __arch_exchange_and_add_64_int(mem, value, rel, acq) \ + (abort (), (typeof(*mem)) 0) +#else +#define __arch_exchange_and_add_64_int(mem, value, rel, acq) \ +({ typeof (*mem) __prev; int __cmp; \ + __asm__ __volatile__ ( \ + ".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + rel "\n" \ + "1:\t" \ + "lld %0,%4\n\t" \ + "daddu %1,%0,%3\n\t" \ + "scd %1,%2\n\t" \ + R10K_BEQZ_INSN" %1,1b\n" \ + acq "\n\t" \ + ".set pop\n" \ + "2:\n\t" \ + : "=&r" (__prev), "=&r" (__cmp), "=m" (*mem) \ + : "r" (value), "m" (*mem) \ + : "memory"); \ + __prev; }) +#endif + +/* ??? Barrier semantics for atomic_exchange_and_add appear to be + undefined. Use full barrier for now, as that's safe. */ +#define atomic_exchange_and_add(mem, value) \ + __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ + MIPS_SYNC_STR, MIPS_SYNC_STR) + +/* TODO: More atomic operations could be implemented efficiently; only the + basic requirements are done. */ + +#define atomic_full_barrier() \ + __asm__ __volatile__ (".set push\n\t" \ + MIPS_PUSH_MIPS2 \ + MIPS_SYNC_STR "\n\t" \ + ".set pop" : : : "memory") + +#endif /* bits/atomic.h */ |