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