--- /dev/null 2008-09-18 06:50:54.356228028 -0700 +++ uClibc-0.9.29/libc/sysdeps/linux/xtensa/bits/atomic.h 2008-10-04 11:40:21.000000000 -0700 @@ -0,0 +1,162 @@ +/* + * Copyright (C) 2008 Tensilica, Inc. + * Contributed by Joe Taylor 2008 + * + * This file is subject to the terms and conditions of the GNU Lesser General + * Public License. See the file "COPYING.LIB" in the main directory of this + * archive for more details. + */ + +#ifndef _XTENSA_BITS_ATOMIC_H +#define _XTENSA_BITS_ATOMIC_H 1 + +/* Xtensa has only a 32-bit form of a store-conditional instruction, + so just stub out the rest. */ + +/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. + Return the old *MEM value. */ + +#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %1, %2, 0 \n" \ + " bne %1, %4, 2f \n" \ + " wsr %1, SCOMPARE1 \n" \ + " mov %0, %1 \n" \ + " mov %1, %3 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + "2: \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem), "a" (newval), "a" (oldval) \ + : "memory" ); \ + __tmp; \ + }) + +/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL. + Return zero if *MEM was changed or non-zero if no exchange happened. */ + +#define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %0, %2, 0 \n" \ + " sub %1, %4, %0 \n" \ + " bnez %1, 2f \n" \ + " wsr %0, SCOMPARE1 \n" \ + " mov %1, %3 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + " movi %1, 0 \n" \ + "2: \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem), "a" (newval), "a" (oldval) \ + : "memory" ); \ + __tmp != 0; \ + }) + +/* Store NEWVALUE in *MEM and return the old value. */ + +#define __arch_exchange_32_acq(mem, newval) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %0, %2, 0 \n" \ + " wsr %0, SCOMPARE1 \n" \ + " mov %1, %3 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem), "a" (newval) \ + : "memory" ); \ + __tmp; \ + }) + +/* Add VALUE to *MEM and return the old value of *MEM. */ + +#define __arch_atomic_exchange_and_add_32(mem, value) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %0, %2, 0 \n" \ + " wsr %0, SCOMPARE1 \n" \ + " add %1, %0, %3 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem), "a" (value) \ + : "memory" ); \ + __tmp; \ + }) + +/* Subtract VALUE from *MEM and return the old value of *MEM. */ + +#define __arch_atomic_exchange_and_sub_32(mem, value) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %0, %2, 0 \n" \ + " wsr %0, SCOMPARE1 \n" \ + " sub %1, %0, %3 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem), "a" (value) \ + : "memory" ); \ + __tmp; \ + }) + +/* Decrement *MEM if it is > 0, and return the old value. */ + +#define __arch_atomic_decrement_if_positive_32(mem) \ + ({__typeof__(*(mem)) __tmp, __value; \ + __asm__ __volatile__( \ + "1: l32i %0, %2, 0 \n" \ + " blti %0, 1, 2f \n" \ + " wsr %0, SCOMPARE1 \n" \ + " addi %1, %0, -1 \n" \ + " s32c1i %1, %2, 0 \n" \ + " bne %0, %1, 1b \n" \ + "2: \n" \ + : "=&a" (__value), "=&a" (__tmp) \ + : "a" (mem) \ + : "memory" ); \ + __tmp; \ + }) + + +/* These are the preferred public interfaces: */ + +#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + ({ \ + if (sizeof (*mem) != 4) \ + abort(); \ + __arch_compare_and_exchange_val_32_acq(mem, newval, oldval); \ + }) + +#define atomic_exchange_acq(mem, newval) \ + ({ \ + if (sizeof(*(mem)) != 4) \ + abort(); \ + __arch_exchange_32_acq(mem, newval); \ + }) + +#define atomic_exchange_and_add(mem, newval) \ + ({ \ + if (sizeof(*(mem)) != 4) \ + abort(); \ + __arch_atomic_exchange_and_add_32(mem, newval); \ + }) + +#define atomic_exchange_and_sub(mem, newval) \ + ({ \ + if (sizeof(*(mem)) != 4) \ + abort(); \ + __arch_atomic_exchange_and_sub_32(mem, newval); \ + }) + +#define atomic_decrement_if_positive(mem) \ + ({ \ + if (sizeof(*(mem)) != 4) \ + abort(); \ + __arch_atomic_decrement_if_positive_32(mem); \ + }) + +#endif /* _XTENSA_BITS_ATOMIC_H */ +