From 8b3614270744a5f5ded9a269b2edadc6108ff7d9 Mon Sep 17 00:00:00 2001 From: Nitin Garg Date: Tue, 1 Feb 2011 10:08:29 -0600 Subject: [PATCH] [SIGNED-FF] Add ARM atomic functions Signed-off-by: Nitin Garg --- uClibc/libc/sysdeps/linux/arm/bits/atomic.h | 110 +++++++++++++++++++++++++++ 1 files changed, 110 insertions(+), 0 deletions(-) create mode 100644 uClibc/libc/sysdeps/linux/arm/bits/atomic.h diff --git a/uClibc/libc/sysdeps/linux/arm/bits/atomic.h b/uClibc/libc/sysdeps/linux/arm/bits/atomic.h new file mode 100644 index 0000000..523c3be --- /dev/null +++ b/uClibc/libc/sysdeps/linux/arm/bits/atomic.h @@ -0,0 +1,110 @@ +/* Copyright (C) 2002, 2003, 2004, 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include +#include + + +typedef int8_t atomic8_t; +typedef uint8_t uatomic8_t; +typedef int_fast8_t atomic_fast8_t; +typedef uint_fast8_t uatomic_fast8_t; + +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 intptr_t atomicptr_t; +typedef uintptr_t uatomicptr_t; +typedef intmax_t atomic_max_t; +typedef uintmax_t uatomic_max_t; + +void __arm_link_error (void); + +#define atomic_exchange_acq(mem, newvalue) \ + ({ __typeof (*mem) _xchg_result; \ + if (sizeof (*mem) == 1) \ + __asm__ __volatile__ ("swpb %0, %1, [%2]" \ + : "=&r,&r" (_xchg_result) \ + : "r,0" (newvalue), "r,r" (mem) : "memory"); \ + else if (sizeof (*mem) == 4) \ + __asm__ __volatile__ ("swp %0, %1, [%2]" \ + : "=&r,&r" (_xchg_result) \ + : "r,0" (newvalue), "r,r" (mem) : "memory"); \ + else \ + { \ + _xchg_result = 0; \ + abort (); \ + } \ + _xchg_result; }) + +/* Atomic compare and exchange. These sequences are not actually atomic; + there is a race if *MEM != OLDVAL and we are preempted between the two + swaps. However, they are very close to atomic, and are the best that a + pre-ARMv6 implementation can do without operating system support. + LinuxThreads has been using these sequences for many years. */ + +#define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \ + ({ __typeof (oldval) _xchg_result, tmp; \ + __asm__ ("\n" \ + "0:\tldr\t%1,[%2]\n\t" \ + "cmp\t%1,%4\n\t" \ + "movne\t%0,%1\n\t" \ + "bne\t1f\n\t" \ + "swpb\t%0,%3,[%2]\n\t" \ + "cmp\t%1,%0\n\t" \ + "swpbne\t%1,%0,[%2]\n\t" \ + "bne\t0b\n\t" \ + "1:" \ + : "=&r" (_xchg_result), "=&r" (tmp) \ + : "r" (mem), "r" (newval), "r" (oldval) \ + : "cc", "memory"); \ + _xchg_result; }) + + +#define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \ + ({ __arm_link_error (); oldval; }) + +#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ + ({ __typeof (oldval) _xchg_result, tmp; \ + __asm__ ("\n" \ + "0:\tldr\t%1,[%2]\n\t" \ + "cmp\t%1,%4\n\t" \ + "movne\t%0,%1\n\t" \ + "bne\t1f\n\t" \ + "swp\t%0,%3,[%2]\n\t" \ + "cmp\t%1,%0\n\t" \ + "swpne\t%1,%0,[%2]\n\t" \ + "bne\t0b\n\t" \ + "1:" \ + : "=&r" (_xchg_result), "=&r" (tmp) \ + : "r" (mem), "r" (newval), "r" (oldval) \ + : "cc", "memory"); \ + _xchg_result; }) + +#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \ + ({ __arm_link_error (); oldval; }) + +#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + __atomic_val_bysize (__arch_compare_and_exchange_val,acq, \ + mem, newval, oldval) + +#define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \ + __atomic_val_bysize (__arch_compare_and_exchange_val,acq, \ + mem, newval, oldval) -- 1.5.5.6