include/asm-ppc64/system.h

   1 #ifndef __PPC64_SYSTEM_H
   2 #define __PPC64_SYSTEM_H
   3
   4 /*
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version
   8  * 2 of the License, or (at your option) any later version.
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/compiler.h>
  13 #include <asm/page.h>
  14 #include <asm/processor.h>
  15 #include <asm/hw_irq.h>
  16 #include <asm/synch.h>
  17
  18 /*
  19  * Memory barrier.
  20  * The sync instruction guarantees that all memory accesses initiated
  21  * by this processor have been performed (with respect to all other
  22  * mechanisms that access memory).  The eieio instruction is a barrier
  23  * providing an ordering (separately) for (a) cacheable stores and (b)
  24  * loads and stores to non-cacheable memory (e.g. I/O devices).
  25  *
  26  * mb() prevents loads and stores being reordered across this point.
  27  * rmb() prevents loads being reordered across this point.
  28  * wmb() prevents stores being reordered across this point.
  29  * read_barrier_depends() prevents data-dependent loads being reordered
  30  *      across this point (nop on PPC).
  31  *
  32  * We have to use the sync instructions for mb(), since lwsync doesn't
  33  * order loads with respect to previous stores.  Lwsync is fine for
  34  * rmb(), though.
  35  * For wmb(), we use sync since wmb is used in drivers to order
  36  * stores to system memory with respect to writes to the device.
  37  * However, smp_wmb() can be a lighter-weight eieio barrier on
  38  * SMP since it is only used to order updates to system memory.
  39  */
  40 #define mb()   __asm__ __volatile__ ("sync" : : : "memory")
  41 #define rmb()  __asm__ __volatile__ ("lwsync" : : : "memory")
  42 #define wmb()  __asm__ __volatile__ ("sync" : : : "memory")
  43 #define read_barrier_depends()  do { } while(0)
  44
  45 #define set_mb(var, value)      do { var = value; smp_mb(); } while (0)
  46 #define set_wmb(var, value)     do { var = value; smp_wmb(); } while (0)
  47
  48 #ifdef CONFIG_SMP
  49 #define smp_mb()        mb()
  50 #define smp_rmb()       rmb()
  51 #define smp_wmb()       eieio()
  52 #define smp_read_barrier_depends()  read_barrier_depends()
  53 #else
  54 #define smp_mb()        __asm__ __volatile__("": : :"memory")
  55 #define smp_rmb()       __asm__ __volatile__("": : :"memory")
  56 #define smp_wmb()       __asm__ __volatile__("": : :"memory")
  57 #define smp_read_barrier_depends()  do { } while(0)
  58 #endif /* CONFIG_SMP */
  59
  60 #ifdef __KERNEL__
  61 struct task_struct;
  62 struct pt_regs;
  63
  64 #ifdef CONFIG_DEBUGGER
  65
  66 extern int (*__debugger)(struct pt_regs *regs);
  67 extern int (*__debugger_ipi)(struct pt_regs *regs);
  68 extern int (*__debugger_bpt)(struct pt_regs *regs);
  69 extern int (*__debugger_sstep)(struct pt_regs *regs);
  70 extern int (*__debugger_iabr_match)(struct pt_regs *regs);
  71 extern int (*__debugger_dabr_match)(struct pt_regs *regs);
  72 extern int (*__debugger_fault_handler)(struct pt_regs *regs);
  73
  74 #define DEBUGGER_BOILERPLATE(__NAME) \
  75 static inline int __NAME(struct pt_regs *regs) \
  76 { \
  77         if (unlikely(__ ## __NAME)) \
  78                 return __ ## __NAME(regs); \
  79         return 0; \
  80 }
  81
  82 DEBUGGER_BOILERPLATE(debugger)
  83 DEBUGGER_BOILERPLATE(debugger_ipi)
  84 DEBUGGER_BOILERPLATE(debugger_bpt)
  85 DEBUGGER_BOILERPLATE(debugger_sstep)
  86 DEBUGGER_BOILERPLATE(debugger_iabr_match)
  87 DEBUGGER_BOILERPLATE(debugger_dabr_match)
  88 DEBUGGER_BOILERPLATE(debugger_fault_handler)
  89
  90 #ifdef CONFIG_XMON
  91 extern void xmon_init(int enable);
  92 #endif
  93
  94 #else
  95 static inline int debugger(struct pt_regs *regs) { return 0; }
  96 static inline int debugger_ipi(struct pt_regs *regs) { return 0; }
  97 static inline int debugger_bpt(struct pt_regs *regs) { return 0; }
  98 static inline int debugger_sstep(struct pt_regs *regs) { return 0; }
  99 static inline int debugger_iabr_match(struct pt_regs *regs) { return 0; }
 100 static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; }
 101 static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
 102 #endif
 103
 104 extern int set_dabr(unsigned long dabr);
 105 extern void _exception(int signr, struct pt_regs *regs, int code,
 106                        unsigned long addr);
 107 extern int fix_alignment(struct pt_regs *regs);
 108 extern void bad_page_fault(struct pt_regs *regs, unsigned long address,
 109                            int sig);
 110 extern void show_regs(struct pt_regs * regs);
 111 extern void low_hash_fault(struct pt_regs *regs, unsigned long address);
 112 extern int die(const char *str, struct pt_regs *regs, long err);
 113
 114 extern int _get_PVR(void);
 115 extern void giveup_fpu(struct task_struct *);
 116 extern void disable_kernel_fp(void);
 117 extern void flush_fp_to_thread(struct task_struct *);
 118 extern void enable_kernel_fp(void);
 119 extern void giveup_altivec(struct task_struct *);
 120 extern void disable_kernel_altivec(void);
 121 extern void enable_kernel_altivec(void);
 122 extern int emulate_altivec(struct pt_regs *);
 123 extern void cvt_fd(float *from, double *to, unsigned long *fpscr);
 124 extern void cvt_df(double *from, float *to, unsigned long *fpscr);
 125
 126 #ifdef CONFIG_ALTIVEC
 127 extern void flush_altivec_to_thread(struct task_struct *);
 128 #else
 129 static inline void flush_altivec_to_thread(struct task_struct *t)
 130 {
 131 }
 132 #endif
 133
 134 extern int mem_init_done;       /* set on boot once kmalloc can be called */
 135
 136 /* EBCDIC -> ASCII conversion for [0-9A-Z] on iSeries */
 137 extern unsigned char e2a(unsigned char);
 138
 139 extern struct task_struct *__switch_to(struct task_struct *,
 140                                        struct task_struct *);
 141 #define switch_to(prev, next, last)     ((last) = __switch_to((prev), (next)))
 142
 143 struct thread_struct;
 144 extern struct task_struct * _switch(struct thread_struct *prev,
 145                                     struct thread_struct *next);
 146
 147 static inline int __is_processor(unsigned long pv)
 148 {
 149         unsigned long pvr;
 150         asm("mfspr %0, 0x11F" : "=r" (pvr));
 151         return(PVR_VER(pvr) == pv);
 152 }
 153
 154 /*
 155  * Atomic exchange
 156  *
 157  * Changes the memory location '*ptr' to be val and returns
 158  * the previous value stored there.
 159  *
 160  * Inline asm pulled from arch/ppc/kernel/misc.S so ppc64
 161  * is more like most of the other architectures.
 162  */
 163 static __inline__ unsigned long
 164 __xchg_u32(volatile unsigned int *m, unsigned long val)
 165 {
 166         unsigned long dummy;
 167
 168         __asm__ __volatile__(
 169         EIEIO_ON_SMP
 170 "1:     lwarx %0,0,%3           # __xchg_u32\n\
 171         stwcx. %2,0,%3\n\
 172 2:      bne- 1b"
 173         ISYNC_ON_SMP
 174         : "=&r" (dummy), "=m" (*m)
 175         : "r" (val), "r" (m)
 176         : "cc", "memory");
 177
 178         return (dummy);
 179 }
 180
 181 static __inline__ unsigned long
 182 __xchg_u64(volatile long *m, unsigned long val)
 183 {
 184         unsigned long dummy;
 185
 186         __asm__ __volatile__(
 187         EIEIO_ON_SMP
 188 "1:     ldarx %0,0,%3           # __xchg_u64\n\
 189         stdcx. %2,0,%3\n\
 190 2:      bne- 1b"
 191         ISYNC_ON_SMP
 192         : "=&r" (dummy), "=m" (*m)
 193         : "r" (val), "r" (m)
 194         : "cc", "memory");
 195
 196         return (dummy);
 197 }
 198
 199 /*
 200  * This function doesn't exist, so you'll get a linker error
 201  * if something tries to do an invalid xchg().
 202  */
 203 extern void __xchg_called_with_bad_pointer(void);
 204
 205 static __inline__ unsigned long
 206 __xchg(volatile void *ptr, unsigned long x, unsigned int size)
 207 {
 208         switch (size) {
 209         case 4:
 210                 return __xchg_u32(ptr, x);
 211         case 8:
 212                 return __xchg_u64(ptr, x);
 213         }
 214         __xchg_called_with_bad_pointer();
 215         return x;
 216 }
 217
 218 #define xchg(ptr,x)                                                          \
 219   ({                                                                         \
 220      __typeof__(*(ptr)) _x_ = (x);                                           \
 221      (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
 222   })
 223
 224 #define tas(ptr) (xchg((ptr),1))
 225
 226 #define __HAVE_ARCH_CMPXCHG     1
 227
 228 static __inline__ unsigned long
 229 __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
 230 {
 231         unsigned int prev;
 232
 233         __asm__ __volatile__ (
 234         EIEIO_ON_SMP
 235 "1:     lwarx   %0,0,%2         # __cmpxchg_u32\n\
 236         cmpw    0,%0,%3\n\
 237         bne-    2f\n\
 238         stwcx.  %4,0,%2\n\
 239         bne-    1b"
 240         ISYNC_ON_SMP
 241         "\n\
 242 2:"
 243         : "=&r" (prev), "=m" (*p)
 244         : "r" (p), "r" (old), "r" (new), "m" (*p)
 245         : "cc", "memory");
 246
 247         return prev;
 248 }
 249
 250 static __inline__ unsigned long
 251 __cmpxchg_u64(volatile long *p, unsigned long old, unsigned long new)
 252 {
 253         unsigned long prev;
 254
 255         __asm__ __volatile__ (
 256         EIEIO_ON_SMP
 257 "1:     ldarx   %0,0,%2         # __cmpxchg_u64\n\
 258         cmpd    0,%0,%3\n\
 259         bne-    2f\n\
 260         stdcx.  %4,0,%2\n\
 261         bne-    1b"
 262         ISYNC_ON_SMP
 263         "\n\
 264 2:"
 265         : "=&r" (prev), "=m" (*p)
 266         : "r" (p), "r" (old), "r" (new), "m" (*p)
 267         : "cc", "memory");
 268
 269         return prev;
 270 }
 271
 272 /* This function doesn't exist, so you'll get a linker error
 273    if something tries to do an invalid cmpxchg().  */
 274 extern void __cmpxchg_called_with_bad_pointer(void);
 275
 276 static __inline__ unsigned long
 277 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
 278           unsigned int size)
 279 {
 280         switch (size) {
 281         case 4:
 282                 return __cmpxchg_u32(ptr, old, new);
 283         case 8:
 284                 return __cmpxchg_u64(ptr, old, new);
 285         }
 286         __cmpxchg_called_with_bad_pointer();
 287         return old;
 288 }
 289
 290 #define cmpxchg(ptr,o,n)\
 291         ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
 292         (unsigned long)(n),sizeof(*(ptr))))
 293
 294 /*
 295  * We handle most unaligned accesses in hardware. On the other hand
 296  * unaligned DMA can be very expensive on some ppc64 IO chips (it does
 297  * powers of 2 writes until it reaches sufficient alignment).
 298  *
 299  * Based on this we disable the IP header alignment in network drivers.
 300  */
 301 #define NET_IP_ALIGN   0
 302
 303 #define arch_align_stack(x) (x)
 304
 305 extern unsigned long reloc_offset(void);
 306
 307 #endif /* __KERNEL__ */
 308 #endif