include/asm-ppc/system.h

   1 /*
   2  * $Id: system.h,v 1.49 1999/09/11 18:37:54 cort Exp $
   3  *
   4  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
   5  */
   6 #ifdef __KERNEL__
   7 #ifndef __PPC_SYSTEM_H
   8 #define __PPC_SYSTEM_H
   9
  10 #include <linux/config.h>
  11 #include <linux/kdev_t.h>
  12
  13 #include <asm/processor.h>
  14 #include <asm/atomic.h>
  15 #include <asm/hw_irq.h>
  16
  17 /*
  18  * Memory barrier.
  19  * The sync instruction guarantees that all memory accesses initiated
  20  * by this processor have been performed (with respect to all other
  21  * mechanisms that access memory).  The eieio instruction is a barrier
  22  * providing an ordering (separately) for (a) cacheable stores and (b)
  23  * loads and stores to non-cacheable memory (e.g. I/O devices).
  24  *
  25  * mb() prevents loads and stores being reordered across this point.
  26  * rmb() prevents loads being reordered across this point.
  27  * wmb() prevents stores being reordered across this point.
  28  *
  29  * We can use the eieio instruction for wmb, but since it doesn't
  30  * give any ordering guarantees about loads, we have to use the
  31  * stronger but slower sync instruction for mb and rmb.
  32  */
  33 #define mb()  __asm__ __volatile__ ("sync" : : : "memory")
  34 #define rmb()  __asm__ __volatile__ ("sync" : : : "memory")
  35 #define wmb()  __asm__ __volatile__ ("eieio" : : : "memory")
  36
  37 #define set_mb(var, value)      do { var = value; mb(); } while (0)
  38 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
  39
  40 #ifdef CONFIG_SMP
  41 #define smp_mb()        mb()
  42 #define smp_rmb()       rmb()
  43 #define smp_wmb()       wmb()
  44 #else
  45 #define smp_mb()        __asm__ __volatile__("": : :"memory")
  46 #define smp_rmb()       __asm__ __volatile__("": : :"memory")
  47 #define smp_wmb()       __asm__ __volatile__("": : :"memory")
  48 #endif /* CONFIG_SMP */
  49
  50 extern void xmon_irq(int, void *, struct pt_regs *);
  51 extern void xmon(struct pt_regs *excp);
  52
  53
  54 /* Data cache block flush - write out the cache line containing the
  55    specified address and then invalidate it in the cache. */
  56 extern __inline__ void dcbf(void *line)
  57 {
  58         asm("dcbf %0,%1; sync" : : "r" (line), "r" (0));
  59 }
  60
  61 extern void print_backtrace(unsigned long *);
  62 extern void show_regs(struct pt_regs * regs);
  63 extern void flush_instruction_cache(void);
  64 extern void hard_reset_now(void);
  65 extern void poweroff_now(void);
  66 extern int _get_PVR(void);
  67 extern long _get_L2CR(void);
  68 extern void _set_L2CR(unsigned long);
  69 extern void via_cuda_init(void);
  70 extern void pmac_nvram_init(void);
  71 extern void read_rtc_time(void);
  72 extern void pmac_find_display(void);
  73 extern void giveup_fpu(struct task_struct *);
  74 extern void enable_kernel_fp(void);
  75 extern void giveup_altivec(struct task_struct *);
  76 extern void load_up_altivec(struct task_struct *);
  77 extern void cvt_fd(float *from, double *to, unsigned long *fpscr);
  78 extern void cvt_df(double *from, float *to, unsigned long *fpscr);
  79 extern int call_rtas(const char *, int, int, unsigned long *, ...);
  80 extern int abs(int);
  81 extern void cacheable_memzero(void *p, unsigned int nb);
  82
  83 struct device_node;
  84 extern void note_scsi_host(struct device_node *, void *);
  85
  86 struct task_struct;
  87 #define prepare_to_switch()     do { } while(0)
  88 #define switch_to(prev,next,last) _switch_to((prev),(next),&(last))
  89 extern void _switch_to(struct task_struct *, struct task_struct *,
  90                        struct task_struct **);
  91
  92 struct thread_struct;
  93 extern struct task_struct *_switch(struct thread_struct *prev,
  94                                    struct thread_struct *next);
  95
  96 extern unsigned int rtas_data;
  97
  98 struct pt_regs;
  99 extern void dump_regs(struct pt_regs *);
 100
 101 #ifndef CONFIG_SMP
 102
 103 #define cli()   __cli()
 104 #define sti()   __sti()
 105 #define save_flags(flags)       __save_flags(flags)
 106 #define restore_flags(flags)    __restore_flags(flags)
 107 #define save_and_cli(flags)     __save_and_cli(flags)
 108
 109 #else /* CONFIG_SMP */
 110
 111 extern void __global_cli(void);
 112 extern void __global_sti(void);
 113 extern unsigned long __global_save_flags(void);
 114 extern void __global_restore_flags(unsigned long);
 115 #define cli() __global_cli()
 116 #define sti() __global_sti()
 117 #define save_flags(x) ((x)=__global_save_flags())
 118 #define restore_flags(x) __global_restore_flags(x)
 119
 120 #endif /* !CONFIG_SMP */
 121
 122 #define local_irq_disable()             __cli()
 123 #define local_irq_enable()              __sti()
 124 #define local_irq_save(flags)           __save_and_cli(flags)
 125 #define local_irq_restore(flags)        __restore_flags(flags)
 126
 127 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 128
 129 static __inline__ unsigned long
 130 xchg_u32(volatile void *p, unsigned long val)
 131 {
 132         unsigned long prev;
 133
 134         __asm__ __volatile__ ("
 135 1:      lwarx   %0,0,%2
 136         stwcx.  %3,0,%2
 137         bne-    1b"
 138         : "=&r" (prev), "=m" (*(volatile unsigned long *)p)
 139         : "r" (p), "r" (val), "m" (*(volatile unsigned long *)p)
 140         : "cc", "memory");
 141
 142         return prev;
 143 }
 144
 145 /*
 146  * This function doesn't exist, so you'll get a linker error
 147  * if something tries to do an invalid xchg().
 148  */
 149 extern void __xchg_called_with_bad_pointer(void);
 150
 151 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 152 #define tas(ptr) (xchg((ptr),1))
 153
 154 static inline unsigned long __xchg(unsigned long x, void * ptr, int size)
 155 {
 156         switch (size) {
 157         case 4:
 158                 return (unsigned long )xchg_u32(ptr, x);
 159 #if 0   /* xchg_u64 doesn't exist on 32-bit PPC */
 160         case 8:
 161                 return (unsigned long )xchg_u64(ptr, x);
 162 #endif /* 0 */
 163         }
 164         __xchg_called_with_bad_pointer();
 165         return x;
 166
 167
 168 }
 169
 170 extern inline void * xchg_ptr(void * m, void * val)
 171 {
 172         return (void *) xchg_u32(m, (unsigned long) val);
 173 }
 174
 175
 176 #define __HAVE_ARCH_CMPXCHG     1
 177
 178 static __inline__ unsigned long
 179 __cmpxchg_u32(volatile int *p, int old, int new)
 180 {
 181         int prev;
 182
 183         __asm__ __volatile__ ("
 184 1:      lwarx   %0,0,%2
 185         cmpw    0,%0,%3
 186         bne     2f
 187         stwcx.  %4,0,%2
 188         bne-    1b\n"
 189 #ifdef CONFIG_SMP
 190 "       sync\n"
 191 #endif /* CONFIG_SMP */
 192 "2:"
 193         : "=&r" (prev), "=m" (*p)
 194         : "r" (p), "r" (old), "r" (new), "m" (*p)
 195         : "cc", "memory");
 196
 197         return prev;
 198 }
 199
 200 /* This function doesn't exist, so you'll get a linker error
 201    if something tries to do an invalid cmpxchg().  */
 202 extern void __cmpxchg_called_with_bad_pointer(void);
 203
 204 static __inline__ unsigned long
 205 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 206 {
 207         switch (size) {
 208         case 4:
 209                 return __cmpxchg_u32(ptr, old, new);
 210 #if 0   /* we don't have __cmpxchg_u64 on 32-bit PPC */
 211         case 8:
 212                 return __cmpxchg_u64(ptr, old, new);
 213 #endif /* 0 */
 214         }
 215         __cmpxchg_called_with_bad_pointer();
 216         return old;
 217 }
 218
 219 #define cmpxchg(ptr,o,n)                                                 \
 220   ({                                                                     \
 221      __typeof__(*(ptr)) _o_ = (o);                                       \
 222      __typeof__(*(ptr)) _n_ = (n);                                       \
 223      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 224                                     (unsigned long)_n_, sizeof(*(ptr))); \
 225   })
 226
 227 #endif /* __PPC_SYSTEM_H */
 228 #endif /* __KERNEL__ */