/* $Id: system.h,v 1.20 1999/12/06 23:13:21 ralf Exp $ * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1994 - 1999 by Ralf Baechle * Copyright (C) 1996 by Paul M. Antoine * Copyright (C) 1994 - 1999 by Ralf Baechle */ #ifndef _ASM_SYSTEM_H #define _ASM_SYSTEM_H #include #include #include #include extern __inline__ void __sti(void) { __asm__ __volatile__( ".set\tpush\n\t" ".set\treorder\n\t" ".set\tnoat\n\t" "mfc0\t$1,$12\n\t" "ori\t$1,0x1f\n\t" "xori\t$1,0x1e\n\t" "mtc0\t$1,$12\n\t" ".set\tpop\n\t" : /* no outputs */ : /* no inputs */ : "$1", "memory"); } /* * For cli() we have to insert nops to make shure that the new value * has actually arrived in the status register before the end of this * macro. * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs * no nops at all. */ extern __inline__ void __cli(void) { __asm__ __volatile__( ".set\tpush\n\t" ".set\treorder\n\t" ".set\tnoat\n\t" "mfc0\t$1,$12\n\t" "ori\t$1,1\n\t" "xori\t$1,1\n\t" ".set\tnoreorder\n\t" "mtc0\t$1,$12\n\t" "nop\n\t" "nop\n\t" "nop\n\t" ".set\tpop\n\t" : /* no outputs */ : /* no inputs */ : "$1", "memory"); } #define __save_flags(x) \ __asm__ __volatile__( \ ".set\tpush\n\t" \ ".set\treorder\n\t" \ "mfc0\t%0,$12\n\t" \ ".set\tpop\n\t" \ : "=r" (x) \ : /* no inputs */ \ : "memory") #define __save_and_cli(x) \ __asm__ __volatile__( \ ".set\tpush\n\t" \ ".set\treorder\n\t" \ ".set\tnoat\n\t" \ "mfc0\t%0,$12\n\t" \ "ori\t$1,%0,1\n\t" \ "xori\t$1,1\n\t" \ ".set\tnoreorder\n\t" \ "mtc0\t$1,$12\n\t" \ "nop\n\t" \ "nop\n\t" \ "nop\n\t" \ ".set\tpop\n\t" \ : "=r" (x) \ : /* no inputs */ \ : "$1", "memory") extern void __inline__ __restore_flags(int flags) { __asm__ __volatile__( ".set\tpush\n\t" ".set\treorder\n\t" "mfc0\t$8,$12\n\t" "li\t$9,0xff00\n\t" "and\t$8,$9\n\t" "nor\t$9,$0,$9\n\t" "and\t%0,$9\n\t" "or\t%0,$8\n\t" ".set\tnoreorder\n\t" "mtc0\t%0,$12\n\t" "nop\n\t" "nop\n\t" "nop\n\t" ".set\tpop\n\t" : : "r" (flags) : "$8", "$9", "memory"); } /* * Non-SMP versions ... */ #define sti() __sti() #define cli() __cli() #define save_flags(x) __save_flags(x) #define save_and_cli(x) __save_and_cli(x) #define restore_flags(x) __restore_flags(x) /* For spinlocks etc */ #define local_irq_save(x) __save_and_cli(x); #define local_irq_restore(x) __restore_flags(x); #define local_irq_disable() __cli(); #define local_irq_enable() __sti(); /* * These are probably defined overly paranoid ... */ #ifdef CONFIG_CPU_HAS_WB #include #define rmb() #define wmb() wbflush() #define mb() wbflush() #else #define mb() \ __asm__ __volatile__( \ "# prevent instructions being moved around\n\t" \ ".set\tnoreorder\n\t" \ "# 8 nops to fool the R4400 pipeline\n\t" \ "nop;nop;nop;nop;nop;nop;nop;nop\n\t" \ ".set\treorder" \ : /* no output */ \ : /* no input */ \ : "memory") #define rmb() mb() #define wmb() mb() #endif #define set_mb(var, value) \ do { var = value; mb(); } while (0) #define set_rmb(var, value) \ do { var = value; rmb(); } while (0) #define set_wmb(var, value) \ do { var = value; wmb(); } while (0) #if !defined (_LANGUAGE_ASSEMBLY) /* * switch_to(n) should switch tasks to task nr n, first * checking that n isn't the current task, in which case it does nothing. */ extern asmlinkage void *resume(void *last, void *next); #endif /* !defined (_LANGUAGE_ASSEMBLY) */ #define prepare_to_switch() do { } while(0) #define switch_to(prev,next,last) \ do { \ (last) = resume(prev, next); \ } while(0) /* * For 32 and 64 bit operands we can take advantage of ll and sc. * FIXME: This doesn't work for R3000 machines. */ extern __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val) { #if defined(CONFIG_CPU_HAS_LLSC) unsigned long dummy; __asm__ __volatile__( ".set\tnoreorder\n\t" ".set\tnoat\n\t" "ll\t%0,(%1)\n" "1:\tmove\t$1,%2\n\t" "sc\t$1,(%1)\n\t" "beqzl\t$1,1b\n\t" "ll\t%0,(%1)\n\t" ".set\tat\n\t" ".set\treorder" : "=r" (val), "=r" (m), "=r" (dummy) : "1" (m), "2" (val) : "memory"); return val; #else unsigned long flags, retval; save_flags(flags); cli(); retval = *m; *m = val; restore_flags(flags); return retval; #endif /* Processor-dependent optimization */ } /* * Only used for 64 bit kernel. */ extern __inline__ unsigned long xchg_u64(volatile long * m, unsigned long val) { unsigned long dummy; __asm__ __volatile__( ".set\tnoreorder\n\t" ".set\tnoat\n\t" "lld\t%0,(%1)\n" "1:\tmove\t$1,%2\n\t" "scd\t$1,(%1)\n\t" "beqzl\t$1,1b\n\t" "lld\t%0,(%1)\n\t" ".set\tat\n\t" ".set\treorder" : "=r" (val), "=r" (m), "=r" (dummy) : "1" (m), "2" (val) : "memory"); return val; } #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) #define tas(ptr) (xchg((ptr),1)) /* * This function doesn't exist, so you'll get a linker error * if something tries to do an invalid xchg(). * * This only works if the compiler isn't horribly bad at optimizing. * gcc-2.5.8 reportedly can't handle this, but I define that one to * be dead anyway. */ extern void __xchg_called_with_bad_pointer(void); static __inline__ unsigned long __xchg(unsigned long x, volatile void * ptr, int size) { switch (size) { case 4: return xchg_u32(ptr, x); #if defined(__mips64) case 8: return xchg_u64(ptr, x); #endif } __xchg_called_with_bad_pointer(); return x; } extern void set_except_vector(int n, void *addr); extern void __die(const char *, struct pt_regs *, const char *where, unsigned long line) __attribute__((noreturn)); extern void __die_if_kernel(const char *, struct pt_regs *, const char *where, unsigned long line); extern int abs(int); #define die(msg, regs) \ __die(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__) #define die_if_kernel(msg, regs) \ __die_if_kernel(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__) #endif /* _ASM_SYSTEM_H */