include/asm-ppc/system.h

   1 /*
   2  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
   3  */
   4 #ifndef __PPC_SYSTEM_H
   5 #define __PPC_SYSTEM_H
   6
   7 #include <linux/config.h>
   8 #include <linux/kernel.h>
   9
  10 #include <asm/atomic.h>
  11 #include <asm/hw_irq.h>
  12
  13 /*
  14  * Memory barrier.
  15  * The sync instruction guarantees that all memory accesses initiated
  16  * by this processor have been performed (with respect to all other
  17  * mechanisms that access memory).  The eieio instruction is a barrier
  18  * providing an ordering (separately) for (a) cacheable stores and (b)
  19  * loads and stores to non-cacheable memory (e.g. I/O devices).
  20  *
  21  * mb() prevents loads and stores being reordered across this point.
  22  * rmb() prevents loads being reordered across this point.
  23  * wmb() prevents stores being reordered across this point.
  24  * read_barrier_depends() prevents data-dependent loads being reordered
  25  *      across this point (nop on PPC).
  26  *
  27  * We can use the eieio instruction for wmb, but since it doesn't
  28  * give any ordering guarantees about loads, we have to use the
  29  * stronger but slower sync instruction for mb and rmb.
  30  */
  31 #define mb()  __asm__ __volatile__ ("sync" : : : "memory")
  32 #define rmb()  __asm__ __volatile__ ("sync" : : : "memory")
  33 #define wmb()  __asm__ __volatile__ ("eieio" : : : "memory")
  34 #define read_barrier_depends()  do { } while(0)
  35
  36 #define set_mb(var, value)      do { var = value; mb(); } while (0)
  37 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
  38
  39 #ifdef CONFIG_SMP
  40 #define smp_mb()        mb()
  41 #define smp_rmb()       rmb()
  42 #define smp_wmb()       wmb()
  43 #define smp_read_barrier_depends()      read_barrier_depends()
  44 #else
  45 #define smp_mb()        barrier()
  46 #define smp_rmb()       barrier()
  47 #define smp_wmb()       barrier()
  48 #define smp_read_barrier_depends()      do { } while(0)
  49 #endif /* CONFIG_SMP */
  50
  51 #ifdef __KERNEL__
  52 struct task_struct;
  53 struct pt_regs;
  54
  55 extern void print_backtrace(unsigned long *);
  56 extern void show_regs(struct pt_regs * regs);
  57 extern void flush_instruction_cache(void);
  58 extern void hard_reset_now(void);
  59 extern void poweroff_now(void);
  60 #ifdef CONFIG_6xx
  61 extern long _get_L2CR(void);
  62 extern long _get_L3CR(void);
  63 extern void _set_L2CR(unsigned long);
  64 extern void _set_L3CR(unsigned long);
  65 #else
  66 #define _get_L2CR()     0L
  67 #define _get_L3CR()     0L
  68 #define _set_L2CR(val)  do { } while(0)
  69 #define _set_L3CR(val)  do { } while(0)
  70 #endif
  71 extern void via_cuda_init(void);
  72 extern void pmac_nvram_init(void);
  73 extern void read_rtc_time(void);
  74 extern void pmac_find_display(void);
  75 extern void giveup_fpu(struct task_struct *);
  76 extern void enable_kernel_fp(void);
  77 extern void enable_kernel_altivec(void);
  78 extern void giveup_altivec(struct task_struct *);
  79 extern void load_up_altivec(struct task_struct *);
  80 extern void giveup_spe(struct task_struct *);
  81 extern void load_up_spe(struct task_struct *);
  82 extern int fix_alignment(struct pt_regs *);
  83 extern void cvt_fd(float *from, double *to, unsigned long *fpscr);
  84 extern void cvt_df(double *from, float *to, unsigned long *fpscr);
  85 extern int call_rtas(const char *, int, int, unsigned long *, ...);
  86 extern void cacheable_memzero(void *p, unsigned int nb);
  87 extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
  88 extern void bad_page_fault(struct pt_regs *, unsigned long, int);
  89 extern void die(const char *, struct pt_regs *, long);
  90
  91 struct device_node;
  92 extern void note_scsi_host(struct device_node *, void *);
  93
  94 extern struct task_struct *__switch_to(struct task_struct *,
  95         struct task_struct *);
  96 #define switch_to(prev, next, last)     ((last) = __switch_to((prev), (next)))
  97
  98 struct thread_struct;
  99 extern struct task_struct *_switch(struct thread_struct *prev,
 100                                    struct thread_struct *next);
 101
 102 extern unsigned int rtas_data;
 103
 104 static __inline__ unsigned long
 105 xchg_u32(volatile void *p, unsigned long val)
 106 {
 107         unsigned long prev;
 108
 109         __asm__ __volatile__ ("\n\
 110 1:      lwarx   %0,0,%2 \n"
 111         PPC405_ERR77(0,%2)
 112 "       stwcx.  %3,0,%2 \n\
 113         bne-    1b"
 114         : "=&r" (prev), "=m" (*(volatile unsigned long *)p)
 115         : "r" (p), "r" (val), "m" (*(volatile unsigned long *)p)
 116         : "cc", "memory");
 117
 118         return prev;
 119 }
 120
 121 /*
 122  * This function doesn't exist, so you'll get a linker error
 123  * if something tries to do an invalid xchg().
 124  */
 125 extern void __xchg_called_with_bad_pointer(void);
 126
 127 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 128 #define tas(ptr) (xchg((ptr),1))
 129
 130 static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
 131 {
 132         switch (size) {
 133         case 4:
 134                 return (unsigned long) xchg_u32(ptr, x);
 135 #if 0   /* xchg_u64 doesn't exist on 32-bit PPC */
 136         case 8:
 137                 return (unsigned long) xchg_u64(ptr, x);
 138 #endif /* 0 */
 139         }
 140         __xchg_called_with_bad_pointer();
 141         return x;
 142
 143
 144 }
 145
 146 extern inline void * xchg_ptr(void * m, void * val)
 147 {
 148         return (void *) xchg_u32(m, (unsigned long) val);
 149 }
 150
 151
 152 #define __HAVE_ARCH_CMPXCHG     1
 153
 154 static __inline__ unsigned long
 155 __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
 156 {
 157         unsigned int prev;
 158
 159         __asm__ __volatile__ ("\n\
 160 1:      lwarx   %0,0,%2 \n\
 161         cmpw    0,%0,%3 \n\
 162         bne     2f \n"
 163         PPC405_ERR77(0,%2)
 164 "       stwcx.  %4,0,%2 \n\
 165         bne-    1b\n"
 166 #ifdef CONFIG_SMP
 167 "       sync\n"
 168 #endif /* CONFIG_SMP */
 169 "2:"
 170         : "=&r" (prev), "=m" (*p)
 171         : "r" (p), "r" (old), "r" (new), "m" (*p)
 172         : "cc", "memory");
 173
 174         return prev;
 175 }
 176
 177 /* This function doesn't exist, so you'll get a linker error
 178    if something tries to do an invalid cmpxchg().  */
 179 extern void __cmpxchg_called_with_bad_pointer(void);
 180
 181 static __inline__ unsigned long
 182 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 183 {
 184         switch (size) {
 185         case 4:
 186                 return __cmpxchg_u32(ptr, old, new);
 187 #if 0   /* we don't have __cmpxchg_u64 on 32-bit PPC */
 188         case 8:
 189                 return __cmpxchg_u64(ptr, old, new);
 190 #endif /* 0 */
 191         }
 192         __cmpxchg_called_with_bad_pointer();
 193         return old;
 194 }
 195
 196 #define cmpxchg(ptr,o,n)                                                 \
 197   ({                                                                     \
 198      __typeof__(*(ptr)) _o_ = (o);                                       \
 199      __typeof__(*(ptr)) _n_ = (n);                                       \
 200      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 201                                     (unsigned long)_n_, sizeof(*(ptr))); \
 202   })
 203
 204 #define arch_align_stack(x) (x)
 205
 206 #endif /* __KERNEL__ */
 207 #endif /* __PPC_SYSTEM_H */