/* * sysdeps/microblaze/pt-machine.h -- microblaze-specific pthread definitions * * Copyright (C) 2003 John Williams <jwilliams@itee.uq.edu.au> * Copyright (C) 2002 NEC Electronics Corporation * Copyright (C) 2002 Miles Bader <miles@gnu.org> * * 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. * * Written by Miles Bader <miles@gnu.org> */ #ifndef _PT_MACHINE_H #define _PT_MACHINE_H 1 #include <features.h> #ifndef PT_EI # define PT_EI extern inline #endif extern long int testandset (int *spinlock); extern int __compare_and_swap (long *ptr, long old, long new); /* Get some notion of the current stack. Need not be exactly the top of the stack, just something somewhere in the current frame. */ #define CURRENT_STACK_FRAME __stack_pointer register char *__stack_pointer __asm__ ("r1"); #define HAS_COMPARE_AND_SWAP #define HAS_COMPARE_AND_SWAP_WITH_RELEASE_SEMANTICS #define IMPLEMENT_TAS_WITH_CAS /* Atomically: If *PTR == OLD, set *PTR to NEW and return true, otherwise do nothing and return false. */ PT_EI int __compare_and_swap (long *ptr, long old, long new) { unsigned long psw; /* disable interrupts */ /* This is ugly ugly ugly! */ __asm__ __volatile__ ("mfs %0, rmsr;" "andi r3, %0, ~2;" "mts rmsr, r3;" : "=&r" (psw) : : "r3"); if (likely (*ptr == old)) { *ptr = new; __asm__ __volatile__ ("mts rmsr, %0;" :: "r" (psw)); /* re-enable */ return 1; } else { __asm__ __volatile__ ("mts rmsr, %0;" :: "r" (psw)); /* re-enable */ return 0; } } /* like above's __compare_and_swap() but it first syncs the memory (This is also the difference between both functions in e.g. ../powerpc/pt-machine.h) Doing this additional sync fixes a hang of __pthread_alt_unlock() (Falk Brettschneider <fbrettschneider@baumeroptronic.de>) */ PT_EI int __compare_and_swap_with_release_semantics (long *p, long oldval, long newval) { __asm__ __volatile__ ("" : : : "memory"); /*MEMORY_BARRIER ();*/ return __compare_and_swap (p, oldval, newval); } #ifndef IMPLEMENT_TAS_WITH_CAS /* Spinlock implementation; required. */ PT_EI long int testandset (int *spinlock) { unsigned psw; /* disable interrupts */ __asm__ __volatile__ ("mfs %0, rmsr;" "andi r3, %0, ~2;" "mts rmsr, r3;" : "=&r" (psw) : : "r3"); if (*spinlock) { /* Enable ints */ __asm__ __volatile__ ("mts rmsr, %0;" :: "r" (psw)); return 1; } else { *spinlock=1; /* Enable ints */ __asm__ __volatile__ ("mts rmsr, %0;" :: "r" (psw)); return 0; } } #endif #endif /* pt-machine.h */