/* Low-level functions for atomic operations. Mips version. Copyright (C) 2005-2017 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_ATOMIC_MACHINE_H #define _MIPS_ATOMIC_MACHINE_H 1 #include <stdint.h> #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 && __mips < 2 #define MIPS_PUSH_MIPS2 ".set mips2\n\t" #else #define MIPS_PUSH_MIPS2 #endif #if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32 #define __HAVE_64B_ATOMICS 0 #else #define __HAVE_64B_ATOMICS 1 #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) #if __GNUC_PREREQ (4, 8) || defined __mips16 /* The __atomic_* builtins are available in GCC 4.7 and later, but MIPS support for their efficient implementation was added only in GCC 4.8. We still want to use them even with GCC 4.7 for MIPS16 code where we have no assembly alternative available and want to avoid the __sync_* builtins if at all possible. */ #define USE_ATOMIC_COMPILER_BUILTINS 1 /* Compare and exchange. For all "bool" routines, we return FALSE if exchange succesful. */ # define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \ (abort (), 0) # define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \ (abort (), 0) # define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \ ({ \ typeof (*mem) __oldval = (oldval); \ !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ model, __ATOMIC_RELAXED); \ }) # define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \ (abort (), (typeof(*mem)) 0) # define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \ (abort (), (typeof(*mem)) 0) # define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \ ({ \ typeof (*mem) __oldval = (oldval); \ __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ model, __ATOMIC_RELAXED); \ __oldval; \ }) # if _MIPS_SIM == _ABIO32 /* We can't do an atomic 64-bit operation in O32. */ # define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \ (abort (), 0) # define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \ (abort (), (typeof(*mem)) 0) # else # define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \ __arch_compare_and_exchange_bool_32_int (mem, newval, oldval, model) # define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \ __arch_compare_and_exchange_val_32_int (mem, newval, oldval, model) # endif /* 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, __ATOMIC_ACQUIRE) # define atomic_compare_and_exchange_val_acq(mem, new, old) \ __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ mem, new, old, __ATOMIC_ACQUIRE) /* Compare and exchange with "release" semantics, ie barrier before. */ # define atomic_compare_and_exchange_val_rel(mem, new, old) \ __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ mem, new, old, __ATOMIC_RELEASE) /* Atomic exchange (without compare). */ # define __arch_exchange_8_int(mem, newval, model) \ (abort (), (typeof(*mem)) 0) # define __arch_exchange_16_int(mem, newval, model) \ (abort (), (typeof(*mem)) 0) # define __arch_exchange_32_int(mem, newval, model) \ __atomic_exchange_n (mem, newval, model) # if _MIPS_SIM == _ABIO32 /* We can't do an atomic 64-bit operation in O32. */ # define __arch_exchange_64_int(mem, newval, model) \ (abort (), (typeof(*mem)) 0) # else # define __arch_exchange_64_int(mem, newval, model) \ __atomic_exchange_n (mem, newval, model) # endif # define atomic_exchange_acq(mem, value) \ __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_ACQUIRE) # define atomic_exchange_rel(mem, value) \ __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_RELEASE) /* Atomically add value and return the previous (unincremented) value. */ # define __arch_exchange_and_add_8_int(mem, value, model) \ (abort (), (typeof(*mem)) 0) # define __arch_exchange_and_add_16_int(mem, value, model) \ (abort (), (typeof(*mem)) 0) # define __arch_exchange_and_add_32_int(mem, value, model) \ __atomic_fetch_add (mem, value, model) # if _MIPS_SIM == _ABIO32 /* We can't do an atomic 64-bit operation in O32. */ # define __arch_exchange_and_add_64_int(mem, value, model) \ (abort (), (typeof(*mem)) 0) # else # define __arch_exchange_and_add_64_int(mem, value, model) \ __atomic_fetch_add (mem, value, model) # endif # define atomic_exchange_and_add_acq(mem, value) \ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ __ATOMIC_ACQUIRE) # define atomic_exchange_and_add_rel(mem, value) \ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ __ATOMIC_RELEASE) #else /* !__mips16 && !__GNUC_PREREQ (4, 8) */ /* This implementation using inline assembly will be removed once glibc requires GCC 4.8 or later to build. */ #define USE_ATOMIC_COMPILER_BUILTINS 0 /* 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 = 0, __cmp = 0, (void) __cmp) # define __arch_compare_and_exchange_xxx_16_int(mem, newval, oldval, rel, acq) \ (abort (), __prev = 0, __cmp = 0, (void) __cmp) # 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 = 0, __cmp = 0, (void) __cmp) # 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 __attribute__ ((unused)); 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 __attribute__ ((unused)); 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 __attribute__ ((unused)); 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 __attribute__ ((unused)); 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_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 (), (typeof(*mem)) 0) # define __arch_exchange_xxx_16_int(mem, newval, rel, acq) \ (abort (), (typeof(*mem)) 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 (), (typeof(*mem)) 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 # define atomic_exchange_and_add_acq(mem, value) \ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ "", MIPS_SYNC_STR) # define atomic_exchange_and_add_rel(mem, value) \ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ MIPS_SYNC_STR, "") #endif /* !__mips16 && !__GNUC_PREREQ (4, 8) */ /* TODO: More atomic operations could be implemented efficiently; only the basic requirements are done. */ #ifdef __mips16 # define atomic_full_barrier() __sync_synchronize () #else /* !__mips16 */ # define atomic_full_barrier() \ __asm__ __volatile__ (".set push\n\t" \ MIPS_PUSH_MIPS2 \ MIPS_SYNC_STR "\n\t" \ ".set pop" : : : "memory") #endif /* !__mips16 */ #endif /* atomic-machine.h */