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   1 /* $Id: system.h,v 1.69 2002/02/09 19:49:31 davem Exp $ */
   2 #ifndef __SPARC64_SYSTEM_H
   3 #define __SPARC64_SYSTEM_H
   4
   5 #include <linux/config.h>
   6 #include <asm/ptrace.h>
   7 #include <asm/processor.h>
   8 #include <asm/visasm.h>
   9
  10 #ifndef __ASSEMBLY__
  11 /*
  12  * Sparc (general) CPU types
  13  */
  14 enum sparc_cpu {
  15   sun4        = 0x00,
  16   sun4c       = 0x01,
  17   sun4m       = 0x02,
  18   sun4d       = 0x03,
  19   sun4e       = 0x04,
  20   sun4u       = 0x05, /* V8 ploos ploos */
  21   sun_unknown = 0x06,
  22   ap1000      = 0x07, /* almost a sun4m */
  23 };
  24
  25 #define sparc_cpu_model sun4u
  26
  27 /* This cannot ever be a sun4c nor sun4 :) That's just history. */
  28 #define ARCH_SUN4C_SUN4 0
  29 #define ARCH_SUN4 0
  30
  31 /* These are here in an effort to more fully work around Spitfire Errata
  32  * #51.  Essentially, if a memory barrier occurs soon after a mispredicted
  33  * branch, the chip can stop executing instructions until a trap occurs.
  34  * Therefore, if interrupts are disabled, the chip can hang forever.
  35  *
  36  * It used to be believed that the memory barrier had to be right in the
  37  * delay slot, but a case has been traced recently wherein the memory barrier
  38  * was one instruction after the branch delay slot and the chip still hung.
  39  * The offending sequence was the following in sym_wakeup_done() of the
  40  * sym53c8xx_2 driver:
  41  *
  42  *      call    sym_ccb_from_dsa, 0
  43  *       movge  %icc, 0, %l0
  44  *      brz,pn  %o0, .LL1303
  45  *       mov    %o0, %l2
  46  *      membar  #LoadLoad
  47  *
  48  * The branch has to be mispredicted for the bug to occur.  Therefore, we put
  49  * the memory barrier explicitly into a "branch always, predicted taken"
  50  * delay slot to avoid the problem case.
  51  */
  52 #define membar_safe(type) \
  53 do {    __asm__ __volatile__("ba,pt     %%xcc, 1f\n\t" \
  54                              " membar   " type "\n" \
  55                              "1:\n" \
  56                              : : : "memory"); \
  57 } while (0)
  58
  59 #define mb()    \
  60         membar_safe("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
  61 #define rmb()   \
  62         membar_safe("#LoadLoad")
  63 #define wmb()   \
  64         membar_safe("#StoreStore")
  65 #define membar_storeload() \
  66         membar_safe("#StoreLoad")
  67 #define membar_storeload_storestore() \
  68         membar_safe("#StoreLoad | #StoreStore")
  69 #define membar_storeload_loadload() \
  70         membar_safe("#StoreLoad | #LoadLoad")
  71 #define membar_storestore_loadstore() \
  72         membar_safe("#StoreStore | #LoadStore")
  73
  74 #endif
  75
  76 #define setipl(__new_ipl) \
  77         __asm__ __volatile__("wrpr      %0, %%pil"  : : "r" (__new_ipl) : "memory")
  78
  79 #define local_irq_disable() \
  80         __asm__ __volatile__("wrpr      15, %%pil" : : : "memory")
  81
  82 #define local_irq_enable() \
  83         __asm__ __volatile__("wrpr      0, %%pil" : : : "memory")
  84
  85 #define getipl() \
  86 ({ unsigned long retval; __asm__ __volatile__("rdpr     %%pil, %0" : "=r" (retval)); retval; })
  87
  88 #define swap_pil(__new_pil) \
  89 ({      unsigned long retval; \
  90         __asm__ __volatile__("rdpr      %%pil, %0\n\t" \
  91                              "wrpr      %1, %%pil" \
  92                              : "=&r" (retval) \
  93                              : "r" (__new_pil) \
  94                              : "memory"); \
  95         retval; \
  96 })
  97
  98 #define read_pil_and_cli() \
  99 ({      unsigned long retval; \
 100         __asm__ __volatile__("rdpr      %%pil, %0\n\t" \
 101                              "wrpr      15, %%pil" \
 102                              : "=r" (retval) \
 103                              : : "memory"); \
 104         retval; \
 105 })
 106
 107 #define local_save_flags(flags)         ((flags) = getipl())
 108 #define local_irq_save(flags)           ((flags) = read_pil_and_cli())
 109 #define local_irq_restore(flags)                setipl((flags))
 110
 111 /* On sparc64 IRQ flags are the PIL register.  A value of zero
 112  * means all interrupt levels are enabled, any other value means
 113  * only IRQ levels greater than that value will be received.
 114  * Consequently this means that the lowest IRQ level is one.
 115  */
 116 #define irqs_disabled()         \
 117 ({      unsigned long flags;    \
 118         local_save_flags(flags);\
 119         (flags > 0);            \
 120 })
 121
 122 #define nop()           __asm__ __volatile__ ("nop")
 123
 124 #define read_barrier_depends()          do { } while(0)
 125 #define set_mb(__var, __value) \
 126         do { __var = __value; membar_storeload_storestore(); } while(0)
 127 #define set_wmb(__var, __value) \
 128         do { __var = __value; wmb(); } while(0)
 129
 130 #ifdef CONFIG_SMP
 131 #define smp_mb()        mb()
 132 #define smp_rmb()       rmb()
 133 #define smp_wmb()       wmb()
 134 #define smp_read_barrier_depends()      read_barrier_depends()
 135 #else
 136 #define smp_mb()        __asm__ __volatile__("":::"memory")
 137 #define smp_rmb()       __asm__ __volatile__("":::"memory")
 138 #define smp_wmb()       __asm__ __volatile__("":::"memory")
 139 #define smp_read_barrier_depends()      do { } while(0)
 140 #endif
 141
 142 #define flushi(addr)    __asm__ __volatile__ ("flush %0" : : "r" (addr) : "memory")
 143
 144 #define flushw_all()    __asm__ __volatile__("flushw")
 145
 146 /* Performance counter register access. */
 147 #define read_pcr(__p)  __asm__ __volatile__("rd %%pcr, %0" : "=r" (__p))
 148 #define write_pcr(__p) __asm__ __volatile__("wr %0, 0x0, %%pcr" : : "r" (__p))
 149 #define read_pic(__p)  __asm__ __volatile__("rd %%pic, %0" : "=r" (__p))
 150
 151 /* Blackbird errata workaround.  See commentary in
 152  * arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
 153  * for more information.
 154  */
 155 #define reset_pic()                                             \
 156         __asm__ __volatile__("ba,pt     %xcc, 99f\n\t"          \
 157                              ".align    64\n"                   \
 158                           "99:wr        %g0, 0x0, %pic\n\t"     \
 159                              "rd        %pic, %g0")
 160
 161 #ifndef __ASSEMBLY__
 162
 163 extern void sun_do_break(void);
 164 extern int serial_console;
 165 extern int stop_a_enabled;
 166
 167 static __inline__ int con_is_present(void)
 168 {
 169         return serial_console ? 0 : 1;
 170 }
 171
 172 extern void synchronize_user_stack(void);
 173
 174 extern void __flushw_user(void);
 175 #define flushw_user() __flushw_user()
 176
 177 #define flush_user_windows flushw_user
 178 #define flush_register_windows flushw_all
 179
 180 /* Don't hold the runqueue lock over context switch */
 181 #define __ARCH_WANT_UNLOCKED_CTXSW
 182 #define prepare_arch_switch(next)               \
 183 do {                                            \
 184         flushw_all();                           \
 185 } while (0)
 186
 187         /* See what happens when you design the chip correctly?
 188          *
 189          * We tell gcc we clobber all non-fixed-usage registers except
 190          * for l0/l1.  It will use one for 'next' and the other to hold
 191          * the output value of 'last'.  'next' is not referenced again
 192          * past the invocation of switch_to in the scheduler, so we need
 193          * not preserve it's value.  Hairy, but it lets us remove 2 loads
 194          * and 2 stores in this critical code path.  -DaveM
 195          */
 196 #if __GNUC__ >= 3
 197 #define EXTRA_CLOBBER ,"%l1"
 198 #else
 199 #define EXTRA_CLOBBER
 200 #endif
 201 #define switch_to(prev, next, last)                                     \
 202 do {    if (test_thread_flag(TIF_PERFCTR)) {                            \
 203                 unsigned long __tmp;                                    \
 204                 read_pcr(__tmp);                                        \
 205                 current_thread_info()->pcr_reg = __tmp;                 \
 206                 read_pic(__tmp);                                        \
 207                 current_thread_info()->kernel_cntd0 += (unsigned int)(__tmp);\
 208                 current_thread_info()->kernel_cntd1 += ((__tmp) >> 32); \
 209         }                                                               \
 210         flush_tlb_pending();                                            \
 211         save_and_clear_fpu();                                           \
 212         /* If you are tempted to conditionalize the following */        \
 213         /* so that ASI is only written if it changes, think again. */   \
 214         __asm__ __volatile__("wr %%g0, %0, %%asi"                       \
 215         : : "r" (__thread_flag_byte_ptr(next->thread_info)[TI_FLAG_BYTE_CURRENT_DS]));\
 216         __asm__ __volatile__(                                           \
 217         "mov    %%g4, %%g7\n\t"                                         \
 218         "wrpr   %%g0, 0x95, %%pstate\n\t"                               \
 219         "stx    %%i6, [%%sp + 2047 + 0x70]\n\t"                         \
 220         "stx    %%i7, [%%sp + 2047 + 0x78]\n\t"                         \
 221         "rdpr   %%wstate, %%o5\n\t"                                     \
 222         "stx    %%o6, [%%g6 + %3]\n\t"                                  \
 223         "stb    %%o5, [%%g6 + %2]\n\t"                                  \
 224         "rdpr   %%cwp, %%o5\n\t"                                        \
 225         "stb    %%o5, [%%g6 + %5]\n\t"                                  \
 226         "mov    %1, %%g6\n\t"                                           \
 227         "ldub   [%1 + %5], %%g1\n\t"                                    \
 228         "wrpr   %%g1, %%cwp\n\t"                                        \
 229         "ldx    [%%g6 + %3], %%o6\n\t"                                  \
 230         "ldub   [%%g6 + %2], %%o5\n\t"                                  \
 231         "ldub   [%%g6 + %4], %%o7\n\t"                                  \
 232         "mov    %%g6, %%l2\n\t"                                         \
 233         "wrpr   %%o5, 0x0, %%wstate\n\t"                                \
 234         "ldx    [%%sp + 2047 + 0x70], %%i6\n\t"                         \
 235         "ldx    [%%sp + 2047 + 0x78], %%i7\n\t"                         \
 236         "wrpr   %%g0, 0x94, %%pstate\n\t"                               \
 237         "mov    %%l2, %%g6\n\t"                                         \
 238         "ldx    [%%g6 + %6], %%g4\n\t"                                  \
 239         "wrpr   %%g0, 0x96, %%pstate\n\t"                               \
 240         "brz,pt %%o7, 1f\n\t"                                           \
 241         " mov   %%g7, %0\n\t"                                           \
 242         "b,a ret_from_syscall\n\t"                                      \
 243         "1:\n\t"                                                        \
 244         : "=&r" (last)                                                  \
 245         : "0" (next->thread_info),                                      \
 246           "i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD),            \
 247           "i" (TI_CWP), "i" (TI_TASK)                                   \
 248         : "cc",                                                         \
 249                 "g1", "g2", "g3",                   "g7",               \
 250                       "l2", "l3", "l4", "l5", "l6", "l7",               \
 251           "i0", "i1", "i2", "i3", "i4", "i5",                           \
 252           "o0", "o1", "o2", "o3", "o4", "o5",       "o7" EXTRA_CLOBBER);\
 253         /* If you fuck with this, update ret_from_syscall code too. */  \
 254         if (test_thread_flag(TIF_PERFCTR)) {                            \
 255                 write_pcr(current_thread_info()->pcr_reg);              \
 256                 reset_pic();                                            \
 257         }                                                               \
 258 } while(0)
 259
 260 static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
 261 {
 262         unsigned long tmp1, tmp2;
 263
 264         __asm__ __volatile__(
 265 "       membar          #StoreLoad | #LoadLoad\n"
 266 "       mov             %0, %1\n"
 267 "1:     lduw            [%4], %2\n"
 268 "       cas             [%4], %2, %0\n"
 269 "       cmp             %2, %0\n"
 270 "       bne,a,pn        %%icc, 1b\n"
 271 "        mov            %1, %0\n"
 272 "       membar          #StoreLoad | #StoreStore\n"
 273         : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
 274         : "0" (val), "r" (m)
 275         : "cc", "memory");
 276         return val;
 277 }
 278
 279 static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
 280 {
 281         unsigned long tmp1, tmp2;
 282
 283         __asm__ __volatile__(
 284 "       membar          #StoreLoad | #LoadLoad\n"
 285 "       mov             %0, %1\n"
 286 "1:     ldx             [%4], %2\n"
 287 "       casx            [%4], %2, %0\n"
 288 "       cmp             %2, %0\n"
 289 "       bne,a,pn        %%xcc, 1b\n"
 290 "        mov            %1, %0\n"
 291 "       membar          #StoreLoad | #StoreStore\n"
 292         : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
 293         : "0" (val), "r" (m)
 294         : "cc", "memory");
 295         return val;
 296 }
 297
 298 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 299 #define tas(ptr) (xchg((ptr),1))
 300
 301 extern void __xchg_called_with_bad_pointer(void);
 302
 303 static __inline__ unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
 304                                        int size)
 305 {
 306         switch (size) {
 307         case 4:
 308                 return xchg32(ptr, x);
 309         case 8:
 310                 return xchg64(ptr, x);
 311         };
 312         __xchg_called_with_bad_pointer();
 313         return x;
 314 }
 315
 316 extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
 317
 318 /*
 319  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 320  * store NEW in MEM.  Return the initial value in MEM.  Success is
 321  * indicated by comparing RETURN with OLD.
 322  */
 323
 324 #define __HAVE_ARCH_CMPXCHG 1
 325
 326 static __inline__ unsigned long
 327 __cmpxchg_u32(volatile int *m, int old, int new)
 328 {
 329         __asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
 330                              "cas [%2], %3, %0\n\t"
 331                              "membar #StoreLoad | #StoreStore"
 332                              : "=&r" (new)
 333                              : "0" (new), "r" (m), "r" (old)
 334                              : "memory");
 335
 336         return new;
 337 }
 338
 339 static __inline__ unsigned long
 340 __cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
 341 {
 342         __asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
 343                              "casx [%2], %3, %0\n\t"
 344                              "membar #StoreLoad | #StoreStore"
 345                              : "=&r" (new)
 346                              : "0" (new), "r" (m), "r" (old)
 347                              : "memory");
 348
 349         return new;
 350 }
 351
 352 /* This function doesn't exist, so you'll get a linker error
 353    if something tries to do an invalid cmpxchg().  */
 354 extern void __cmpxchg_called_with_bad_pointer(void);
 355
 356 static __inline__ unsigned long
 357 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 358 {
 359         switch (size) {
 360                 case 4:
 361                         return __cmpxchg_u32(ptr, old, new);
 362                 case 8:
 363                         return __cmpxchg_u64(ptr, old, new);
 364         }
 365         __cmpxchg_called_with_bad_pointer();
 366         return old;
 367 }
 368
 369 #define cmpxchg(ptr,o,n)                                                 \
 370   ({                                                                     \
 371      __typeof__(*(ptr)) _o_ = (o);                                       \
 372      __typeof__(*(ptr)) _n_ = (n);                                       \
 373      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 374                                     (unsigned long)_n_, sizeof(*(ptr))); \
 375   })
 376
 377 #endif /* !(__ASSEMBLY__) */
 378
 379 #define arch_align_stack(x) (x)
 380
 381 #endif /* !(__SPARC64_SYSTEM_H) */