linux/arch/sparc/include/asm/system_64.h
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   1#ifndef __SPARC64_SYSTEM_H
   2#define __SPARC64_SYSTEM_H
   3
   4#include <asm/ptrace.h>
   5#include <asm/processor.h>
   6#include <asm/visasm.h>
   7
   8#ifndef __ASSEMBLY__
   9
  10#include <linux/irqflags.h>
  11#include <asm-generic/cmpxchg-local.h>
  12
  13/*
  14 * Sparc (general) CPU types
  15 */
  16enum 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 :) That's just history. */
  30#define ARCH_SUN4C 0
  31
  32extern const char *sparc_cpu_type;
  33extern const char *sparc_fpu_type;
  34extern const char *sparc_pmu_type;
  35
  36extern char reboot_command[];
  37
  38/* These are here in an effort to more fully work around Spitfire Errata
  39 * #51.  Essentially, if a memory barrier occurs soon after a mispredicted
  40 * branch, the chip can stop executing instructions until a trap occurs.
  41 * Therefore, if interrupts are disabled, the chip can hang forever.
  42 *
  43 * It used to be believed that the memory barrier had to be right in the
  44 * delay slot, but a case has been traced recently wherein the memory barrier
  45 * was one instruction after the branch delay slot and the chip still hung.
  46 * The offending sequence was the following in sym_wakeup_done() of the
  47 * sym53c8xx_2 driver:
  48 *
  49 *      call    sym_ccb_from_dsa, 0
  50 *       movge  %icc, 0, %l0
  51 *      brz,pn  %o0, .LL1303
  52 *       mov    %o0, %l2
  53 *      membar  #LoadLoad
  54 *
  55 * The branch has to be mispredicted for the bug to occur.  Therefore, we put
  56 * the memory barrier explicitly into a "branch always, predicted taken"
  57 * delay slot to avoid the problem case.
  58 */
  59#define membar_safe(type) \
  60do {    __asm__ __volatile__("ba,pt     %%xcc, 1f\n\t" \
  61                             " membar   " type "\n" \
  62                             "1:\n" \
  63                             : : : "memory"); \
  64} while (0)
  65
  66/* The kernel always executes in TSO memory model these days,
  67 * and furthermore most sparc64 chips implement more stringent
  68 * memory ordering than required by the specifications.
  69 */
  70#define mb()    membar_safe("#StoreLoad")
  71#define rmb()   __asm__ __volatile__("":::"memory")
  72#define wmb()   __asm__ __volatile__("":::"memory")
  73
  74#endif
  75
  76#define nop()           __asm__ __volatile__ ("nop")
  77
  78#define read_barrier_depends()          do { } while(0)
  79#define set_mb(__var, __value) \
  80        do { __var = __value; membar_safe("#StoreLoad"); } while(0)
  81
  82#ifdef CONFIG_SMP
  83#define smp_mb()        mb()
  84#define smp_rmb()       rmb()
  85#define smp_wmb()       wmb()
  86#else
  87#define smp_mb()        __asm__ __volatile__("":::"memory")
  88#define smp_rmb()       __asm__ __volatile__("":::"memory")
  89#define smp_wmb()       __asm__ __volatile__("":::"memory")
  90#endif
  91
  92#define smp_read_barrier_depends()      do { } while(0)
  93
  94#define flushi(addr)    __asm__ __volatile__ ("flush %0" : : "r" (addr) : "memory")
  95
  96#define flushw_all()    __asm__ __volatile__("flushw")
  97
  98/* Performance counter register access. */
  99#define read_pcr(__p)  __asm__ __volatile__("rd %%pcr, %0" : "=r" (__p))
 100#define write_pcr(__p) __asm__ __volatile__("wr %0, 0x0, %%pcr" : : "r" (__p))
 101#define read_pic(__p)  __asm__ __volatile__("rd %%pic, %0" : "=r" (__p))
 102
 103/* Blackbird errata workaround.  See commentary in
 104 * arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
 105 * for more information.
 106 */
 107#define write_pic(__p)                                          \
 108        __asm__ __volatile__("ba,pt     %%xcc, 99f\n\t"         \
 109                             ".align    64\n"                   \
 110                          "99:wr        %0, 0x0, %%pic\n\t"     \
 111                             "rd        %%pic, %%g0" : : "r" (__p))
 112#define reset_pic()     write_pic(0)
 113
 114#ifndef __ASSEMBLY__
 115
 116extern void sun_do_break(void);
 117extern int stop_a_enabled;
 118extern int scons_pwroff;
 119
 120extern void fault_in_user_windows(void);
 121extern void synchronize_user_stack(void);
 122
 123extern void __flushw_user(void);
 124#define flushw_user() __flushw_user()
 125
 126#define flush_user_windows flushw_user
 127#define flush_register_windows flushw_all
 128
 129/* Don't hold the runqueue lock over context switch */
 130#define __ARCH_WANT_UNLOCKED_CTXSW
 131#define prepare_arch_switch(next)               \
 132do {                                            \
 133        flushw_all();                           \
 134} while (0)
 135
 136        /* See what happens when you design the chip correctly?
 137         *
 138         * We tell gcc we clobber all non-fixed-usage registers except
 139         * for l0/l1.  It will use one for 'next' and the other to hold
 140         * the output value of 'last'.  'next' is not referenced again
 141         * past the invocation of switch_to in the scheduler, so we need
 142         * not preserve it's value.  Hairy, but it lets us remove 2 loads
 143         * and 2 stores in this critical code path.  -DaveM
 144         */
 145#define switch_to(prev, next, last)                                     \
 146do {    if (test_thread_flag(TIF_PERFCTR)) {                            \
 147                unsigned long __tmp;                                    \
 148                read_pcr(__tmp);                                        \
 149                current_thread_info()->pcr_reg = __tmp;                 \
 150                read_pic(__tmp);                                        \
 151                current_thread_info()->kernel_cntd0 += (unsigned int)(__tmp);\
 152                current_thread_info()->kernel_cntd1 += ((__tmp) >> 32); \
 153        }                                                               \
 154        flush_tlb_pending();                                            \
 155        save_and_clear_fpu();                                           \
 156        /* If you are tempted to conditionalize the following */        \
 157        /* so that ASI is only written if it changes, think again. */   \
 158        __asm__ __volatile__("wr %%g0, %0, %%asi"                       \
 159        : : "r" (__thread_flag_byte_ptr(task_thread_info(next))[TI_FLAG_BYTE_CURRENT_DS]));\
 160        trap_block[current_thread_info()->cpu].thread =                 \
 161                task_thread_info(next);                                 \
 162        __asm__ __volatile__(                                           \
 163        "mov    %%g4, %%g7\n\t"                                         \
 164        "stx    %%i6, [%%sp + 2047 + 0x70]\n\t"                         \
 165        "stx    %%i7, [%%sp + 2047 + 0x78]\n\t"                         \
 166        "rdpr   %%wstate, %%o5\n\t"                                     \
 167        "stx    %%o6, [%%g6 + %6]\n\t"                                  \
 168        "stb    %%o5, [%%g6 + %5]\n\t"                                  \
 169        "rdpr   %%cwp, %%o5\n\t"                                        \
 170        "stb    %%o5, [%%g6 + %8]\n\t"                                  \
 171        "wrpr   %%g0, 15, %%pil\n\t"                                    \
 172        "mov    %4, %%g6\n\t"                                           \
 173        "ldub   [%4 + %8], %%g1\n\t"                                    \
 174        "wrpr   %%g1, %%cwp\n\t"                                        \
 175        "ldx    [%%g6 + %6], %%o6\n\t"                                  \
 176        "ldub   [%%g6 + %5], %%o5\n\t"                                  \
 177        "ldub   [%%g6 + %7], %%o7\n\t"                                  \
 178        "wrpr   %%o5, 0x0, %%wstate\n\t"                                \
 179        "ldx    [%%sp + 2047 + 0x70], %%i6\n\t"                         \
 180        "ldx    [%%sp + 2047 + 0x78], %%i7\n\t"                         \
 181        "ldx    [%%g6 + %9], %%g4\n\t"                                  \
 182        "wrpr   %%g0, 14, %%pil\n\t"                                    \
 183        "brz,pt %%o7, switch_to_pc\n\t"                                 \
 184        " mov   %%g7, %0\n\t"                                           \
 185        "sethi  %%hi(ret_from_syscall), %%g1\n\t"                       \
 186        "jmpl   %%g1 + %%lo(ret_from_syscall), %%g0\n\t"                \
 187        " nop\n\t"                                                      \
 188        ".globl switch_to_pc\n\t"                                       \
 189        "switch_to_pc:\n\t"                                             \
 190        : "=&r" (last), "=r" (current), "=r" (current_thread_info_reg), \
 191          "=r" (__local_per_cpu_offset)                                 \
 192        : "0" (task_thread_info(next)),                                 \
 193          "i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD),            \
 194          "i" (TI_CWP), "i" (TI_TASK)                                   \
 195        : "cc",                                                         \
 196                "g1", "g2", "g3",                   "g7",               \
 197                "l1", "l2", "l3", "l4", "l5", "l6", "l7",               \
 198          "i0", "i1", "i2", "i3", "i4", "i5",                           \
 199          "o0", "o1", "o2", "o3", "o4", "o5",       "o7");              \
 200        /* If you fuck with this, update ret_from_syscall code too. */  \
 201        if (test_thread_flag(TIF_PERFCTR)) {                            \
 202                write_pcr(current_thread_info()->pcr_reg);              \
 203                reset_pic();                                            \
 204        }                                                               \
 205} while(0)
 206
 207static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
 208{
 209        unsigned long tmp1, tmp2;
 210
 211        __asm__ __volatile__(
 212"       mov             %0, %1\n"
 213"1:     lduw            [%4], %2\n"
 214"       cas             [%4], %2, %0\n"
 215"       cmp             %2, %0\n"
 216"       bne,a,pn        %%icc, 1b\n"
 217"        mov            %1, %0\n"
 218        : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
 219        : "0" (val), "r" (m)
 220        : "cc", "memory");
 221        return val;
 222}
 223
 224static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
 225{
 226        unsigned long tmp1, tmp2;
 227
 228        __asm__ __volatile__(
 229"       mov             %0, %1\n"
 230"1:     ldx             [%4], %2\n"
 231"       casx            [%4], %2, %0\n"
 232"       cmp             %2, %0\n"
 233"       bne,a,pn        %%xcc, 1b\n"
 234"        mov            %1, %0\n"
 235        : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
 236        : "0" (val), "r" (m)
 237        : "cc", "memory");
 238        return val;
 239}
 240
 241#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 242
 243extern void __xchg_called_with_bad_pointer(void);
 244
 245static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
 246                                       int size)
 247{
 248        switch (size) {
 249        case 4:
 250                return xchg32(ptr, x);
 251        case 8:
 252                return xchg64(ptr, x);
 253        };
 254        __xchg_called_with_bad_pointer();
 255        return x;
 256}
 257
 258extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
 259
 260/*
 261 * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 262 * store NEW in MEM.  Return the initial value in MEM.  Success is
 263 * indicated by comparing RETURN with OLD.
 264 */
 265
 266#define __HAVE_ARCH_CMPXCHG 1
 267
 268static inline unsigned long
 269__cmpxchg_u32(volatile int *m, int old, int new)
 270{
 271        __asm__ __volatile__("cas [%2], %3, %0"
 272                             : "=&r" (new)
 273                             : "0" (new), "r" (m), "r" (old)
 274                             : "memory");
 275
 276        return new;
 277}
 278
 279static inline unsigned long
 280__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
 281{
 282        __asm__ __volatile__("casx [%2], %3, %0"
 283                             : "=&r" (new)
 284                             : "0" (new), "r" (m), "r" (old)
 285                             : "memory");
 286
 287        return new;
 288}
 289
 290/* This function doesn't exist, so you'll get a linker error
 291   if something tries to do an invalid cmpxchg().  */
 292extern void __cmpxchg_called_with_bad_pointer(void);
 293
 294static inline unsigned long
 295__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 296{
 297        switch (size) {
 298                case 4:
 299                        return __cmpxchg_u32(ptr, old, new);
 300                case 8:
 301                        return __cmpxchg_u64(ptr, old, new);
 302        }
 303        __cmpxchg_called_with_bad_pointer();
 304        return old;
 305}
 306
 307#define cmpxchg(ptr,o,n)                                                 \
 308  ({                                                                     \
 309     __typeof__(*(ptr)) _o_ = (o);                                       \
 310     __typeof__(*(ptr)) _n_ = (n);                                       \
 311     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 312                                    (unsigned long)_n_, sizeof(*(ptr))); \
 313  })
 314
 315/*
 316 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
 317 * them available.
 318 */
 319
 320static inline unsigned long __cmpxchg_local(volatile void *ptr,
 321                                      unsigned long old,
 322                                      unsigned long new, int size)
 323{
 324        switch (size) {
 325        case 4:
 326        case 8: return __cmpxchg(ptr, old, new, size);
 327        default:
 328                return __cmpxchg_local_generic(ptr, old, new, size);
 329        }
 330
 331        return old;
 332}
 333
 334#define cmpxchg_local(ptr, o, n)                                        \
 335        ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
 336                        (unsigned long)(n), sizeof(*(ptr))))
 337#define cmpxchg64_local(ptr, o, n)                                      \
 338  ({                                                                    \
 339        BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
 340        cmpxchg_local((ptr), (o), (n));                                 \
 341  })
 342
 343#endif /* !(__ASSEMBLY__) */
 344
 345#define arch_align_stack(x) (x)
 346
 347#endif /* !(__SPARC64_SYSTEM_H) */
 348