include/asm-mips/system.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
   7  * Copyright (C) 1996 by Paul M. Antoine
   8  * Copyright (C) 1999 Silicon Graphics
   9  * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 2000 MIPS Technologies, Inc.
  11  */
  12 #ifndef _ASM_SYSTEM_H
  13 #define _ASM_SYSTEM_H
  14
  15 #include <linux/types.h>
  16 #include <linux/irqflags.h>
  17
  18 #include <asm/addrspace.h>
  19 #include <asm/barrier.h>
  20 #include <asm/cpu-features.h>
  21 #include <asm/dsp.h>
  22 #include <asm/war.h>
  23
  24
  25 /*
  26  * switch_to(n) should switch tasks to task nr n, first
  27  * checking that n isn't the current task, in which case it does nothing.
  28  */
  29 extern asmlinkage void *resume(void *last, void *next, void *next_ti);
  30
  31 struct task_struct;
  32
  33 #ifdef CONFIG_MIPS_MT_FPAFF
  34
  35 /*
  36  * Handle the scheduler resume end of FPU affinity management.  We do this
  37  * inline to try to keep the overhead down. If we have been forced to run on
  38  * a "CPU" with an FPU because of a previous high level of FP computation,
  39  * but did not actually use the FPU during the most recent time-slice (CU1
  40  * isn't set), we undo the restriction on cpus_allowed.
  41  *
  42  * We're not calling set_cpus_allowed() here, because we have no need to
  43  * force prompt migration - we're already switching the current CPU to a
  44  * different thread.
  45  */
  46
  47 #define __mips_mt_fpaff_switch_to(prev)                                 \
  48 do {                                                                    \
  49         if (cpu_has_fpu &&                                              \
  50             (prev->thread.mflags & MF_FPUBOUND) &&                      \
  51              (!(KSTK_STATUS(prev) & ST0_CU1))) {                        \
  52                 prev->thread.mflags &= ~MF_FPUBOUND;                    \
  53                 prev->cpus_allowed = prev->thread.user_cpus_allowed;    \
  54         }                                                               \
  55         next->thread.emulated_fp = 0;                                   \
  56 } while(0)
  57
  58 #else
  59 #define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0)
  60 #endif
  61
  62 #define switch_to(prev,next,last)                                       \
  63 do {                                                                    \
  64         __mips_mt_fpaff_switch_to(prev);                                \
  65         if (cpu_has_dsp)                                                \
  66                 __save_dsp(prev);                                       \
  67         (last) = resume(prev, next, task_thread_info(next));            \
  68         if (cpu_has_dsp)                                                \
  69                 __restore_dsp(current);                                 \
  70         if (cpu_has_userlocal)                                          \
  71                 write_c0_userlocal(task_thread_info(current)->tp_value);\
  72 } while(0)
  73
  74 static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
  75 {
  76         __u32 retval;
  77
  78         if (cpu_has_llsc && R10000_LLSC_WAR) {
  79                 unsigned long dummy;
  80
  81                 __asm__ __volatile__(
  82                 "       .set    mips3                                   \n"
  83                 "1:     ll      %0, %3                  # xchg_u32      \n"
  84                 "       .set    mips0                                   \n"
  85                 "       move    %2, %z4                                 \n"
  86                 "       .set    mips3                                   \n"
  87                 "       sc      %2, %1                                  \n"
  88                 "       beqzl   %2, 1b                                  \n"
  89                 "       .set    mips0                                   \n"
  90                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
  91                 : "R" (*m), "Jr" (val)
  92                 : "memory");
  93         } else if (cpu_has_llsc) {
  94                 unsigned long dummy;
  95
  96                 __asm__ __volatile__(
  97                 "       .set    mips3                                   \n"
  98                 "1:     ll      %0, %3                  # xchg_u32      \n"
  99                 "       .set    mips0                                   \n"
 100                 "       move    %2, %z4                                 \n"
 101                 "       .set    mips3                                   \n"
 102                 "       sc      %2, %1                                  \n"
 103                 "       beqz    %2, 2f                                  \n"
 104                 "       .subsection 2                                   \n"
 105                 "2:     b       1b                                      \n"
 106                 "       .previous                                       \n"
 107                 "       .set    mips0                                   \n"
 108                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 109                 : "R" (*m), "Jr" (val)
 110                 : "memory");
 111         } else {
 112                 unsigned long flags;
 113
 114                 raw_local_irq_save(flags);
 115                 retval = *m;
 116                 *m = val;
 117                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 118         }
 119
 120         smp_llsc_mb();
 121
 122         return retval;
 123 }
 124
 125 #ifdef CONFIG_64BIT
 126 static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
 127 {
 128         __u64 retval;
 129
 130         if (cpu_has_llsc && R10000_LLSC_WAR) {
 131                 unsigned long dummy;
 132
 133                 __asm__ __volatile__(
 134                 "       .set    mips3                                   \n"
 135                 "1:     lld     %0, %3                  # xchg_u64      \n"
 136                 "       move    %2, %z4                                 \n"
 137                 "       scd     %2, %1                                  \n"
 138                 "       beqzl   %2, 1b                                  \n"
 139                 "       .set    mips0                                   \n"
 140                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 141                 : "R" (*m), "Jr" (val)
 142                 : "memory");
 143         } else if (cpu_has_llsc) {
 144                 unsigned long dummy;
 145
 146                 __asm__ __volatile__(
 147                 "       .set    mips3                                   \n"
 148                 "1:     lld     %0, %3                  # xchg_u64      \n"
 149                 "       move    %2, %z4                                 \n"
 150                 "       scd     %2, %1                                  \n"
 151                 "       beqz    %2, 2f                                  \n"
 152                 "       .subsection 2                                   \n"
 153                 "2:     b       1b                                      \n"
 154                 "       .previous                                       \n"
 155                 "       .set    mips0                                   \n"
 156                 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
 157                 : "R" (*m), "Jr" (val)
 158                 : "memory");
 159         } else {
 160                 unsigned long flags;
 161
 162                 raw_local_irq_save(flags);
 163                 retval = *m;
 164                 *m = val;
 165                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 166         }
 167
 168         smp_llsc_mb();
 169
 170         return retval;
 171 }
 172 #else
 173 extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
 174 #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
 175 #endif
 176
 177 /* This function doesn't exist, so you'll get a linker error
 178    if something tries to do an invalid xchg().  */
 179 extern void __xchg_called_with_bad_pointer(void);
 180
 181 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
 182 {
 183         switch (size) {
 184         case 4:
 185                 return __xchg_u32(ptr, x);
 186         case 8:
 187                 return __xchg_u64(ptr, x);
 188         }
 189         __xchg_called_with_bad_pointer();
 190         return x;
 191 }
 192
 193 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 194
 195 #define __HAVE_ARCH_CMPXCHG 1
 196
 197 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 198         unsigned long new)
 199 {
 200         __u32 retval;
 201
 202         if (cpu_has_llsc && R10000_LLSC_WAR) {
 203                 __asm__ __volatile__(
 204                 "       .set    push                                    \n"
 205                 "       .set    noat                                    \n"
 206                 "       .set    mips3                                   \n"
 207                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 208                 "       bne     %0, %z3, 2f                             \n"
 209                 "       .set    mips0                                   \n"
 210                 "       move    $1, %z4                                 \n"
 211                 "       .set    mips3                                   \n"
 212                 "       sc      $1, %1                                  \n"
 213                 "       beqzl   $1, 1b                                  \n"
 214                 "2:                                                     \n"
 215                 "       .set    pop                                     \n"
 216                 : "=&r" (retval), "=R" (*m)
 217                 : "R" (*m), "Jr" (old), "Jr" (new)
 218                 : "memory");
 219         } else if (cpu_has_llsc) {
 220                 __asm__ __volatile__(
 221                 "       .set    push                                    \n"
 222                 "       .set    noat                                    \n"
 223                 "       .set    mips3                                   \n"
 224                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 225                 "       bne     %0, %z3, 2f                             \n"
 226                 "       .set    mips0                                   \n"
 227                 "       move    $1, %z4                                 \n"
 228                 "       .set    mips3                                   \n"
 229                 "       sc      $1, %1                                  \n"
 230                 "       beqz    $1, 3f                                  \n"
 231                 "2:                                                     \n"
 232                 "       .subsection 2                                   \n"
 233                 "3:     b       1b                                      \n"
 234                 "       .previous                                       \n"
 235                 "       .set    pop                                     \n"
 236                 : "=&r" (retval), "=R" (*m)
 237                 : "R" (*m), "Jr" (old), "Jr" (new)
 238                 : "memory");
 239         } else {
 240                 unsigned long flags;
 241
 242                 raw_local_irq_save(flags);
 243                 retval = *m;
 244                 if (retval == old)
 245                         *m = new;
 246                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 247         }
 248
 249         smp_llsc_mb();
 250
 251         return retval;
 252 }
 253
 254 static inline unsigned long __cmpxchg_u32_local(volatile int * m,
 255         unsigned long old, unsigned long new)
 256 {
 257         __u32 retval;
 258
 259         if (cpu_has_llsc && R10000_LLSC_WAR) {
 260                 __asm__ __volatile__(
 261                 "       .set    push                                    \n"
 262                 "       .set    noat                                    \n"
 263                 "       .set    mips3                                   \n"
 264                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 265                 "       bne     %0, %z3, 2f                             \n"
 266                 "       .set    mips0                                   \n"
 267                 "       move    $1, %z4                                 \n"
 268                 "       .set    mips3                                   \n"
 269                 "       sc      $1, %1                                  \n"
 270                 "       beqzl   $1, 1b                                  \n"
 271                 "2:                                                     \n"
 272                 "       .set    pop                                     \n"
 273                 : "=&r" (retval), "=R" (*m)
 274                 : "R" (*m), "Jr" (old), "Jr" (new)
 275                 : "memory");
 276         } else if (cpu_has_llsc) {
 277                 __asm__ __volatile__(
 278                 "       .set    push                                    \n"
 279                 "       .set    noat                                    \n"
 280                 "       .set    mips3                                   \n"
 281                 "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
 282                 "       bne     %0, %z3, 2f                             \n"
 283                 "       .set    mips0                                   \n"
 284                 "       move    $1, %z4                                 \n"
 285                 "       .set    mips3                                   \n"
 286                 "       sc      $1, %1                                  \n"
 287                 "       beqz    $1, 1b                                  \n"
 288                 "2:                                                     \n"
 289                 "       .set    pop                                     \n"
 290                 : "=&r" (retval), "=R" (*m)
 291                 : "R" (*m), "Jr" (old), "Jr" (new)
 292                 : "memory");
 293         } else {
 294                 unsigned long flags;
 295
 296                 local_irq_save(flags);
 297                 retval = *m;
 298                 if (retval == old)
 299                         *m = new;
 300                 local_irq_restore(flags);       /* implies memory barrier  */
 301         }
 302
 303         return retval;
 304 }
 305
 306 #ifdef CONFIG_64BIT
 307 static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
 308         unsigned long new)
 309 {
 310         __u64 retval;
 311
 312         if (cpu_has_llsc && R10000_LLSC_WAR) {
 313                 __asm__ __volatile__(
 314                 "       .set    push                                    \n"
 315                 "       .set    noat                                    \n"
 316                 "       .set    mips3                                   \n"
 317                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 318                 "       bne     %0, %z3, 2f                             \n"
 319                 "       move    $1, %z4                                 \n"
 320                 "       scd     $1, %1                                  \n"
 321                 "       beqzl   $1, 1b                                  \n"
 322                 "2:                                                     \n"
 323                 "       .set    pop                                     \n"
 324                 : "=&r" (retval), "=R" (*m)
 325                 : "R" (*m), "Jr" (old), "Jr" (new)
 326                 : "memory");
 327         } else if (cpu_has_llsc) {
 328                 __asm__ __volatile__(
 329                 "       .set    push                                    \n"
 330                 "       .set    noat                                    \n"
 331                 "       .set    mips3                                   \n"
 332                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 333                 "       bne     %0, %z3, 2f                             \n"
 334                 "       move    $1, %z4                                 \n"
 335                 "       scd     $1, %1                                  \n"
 336                 "       beqz    $1, 3f                                  \n"
 337                 "2:                                                     \n"
 338                 "       .subsection 2                                   \n"
 339                 "3:     b       1b                                      \n"
 340                 "       .previous                                       \n"
 341                 "       .set    pop                                     \n"
 342                 : "=&r" (retval), "=R" (*m)
 343                 : "R" (*m), "Jr" (old), "Jr" (new)
 344                 : "memory");
 345         } else {
 346                 unsigned long flags;
 347
 348                 raw_local_irq_save(flags);
 349                 retval = *m;
 350                 if (retval == old)
 351                         *m = new;
 352                 raw_local_irq_restore(flags);   /* implies memory barrier  */
 353         }
 354
 355         smp_llsc_mb();
 356
 357         return retval;
 358 }
 359
 360 static inline unsigned long __cmpxchg_u64_local(volatile int * m,
 361         unsigned long old, unsigned long new)
 362 {
 363         __u64 retval;
 364
 365         if (cpu_has_llsc && R10000_LLSC_WAR) {
 366                 __asm__ __volatile__(
 367                 "       .set    push                                    \n"
 368                 "       .set    noat                                    \n"
 369                 "       .set    mips3                                   \n"
 370                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 371                 "       bne     %0, %z3, 2f                             \n"
 372                 "       move    $1, %z4                                 \n"
 373                 "       scd     $1, %1                                  \n"
 374                 "       beqzl   $1, 1b                                  \n"
 375                 "2:                                                     \n"
 376                 "       .set    pop                                     \n"
 377                 : "=&r" (retval), "=R" (*m)
 378                 : "R" (*m), "Jr" (old), "Jr" (new)
 379                 : "memory");
 380         } else if (cpu_has_llsc) {
 381                 __asm__ __volatile__(
 382                 "       .set    push                                    \n"
 383                 "       .set    noat                                    \n"
 384                 "       .set    mips3                                   \n"
 385                 "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
 386                 "       bne     %0, %z3, 2f                             \n"
 387                 "       move    $1, %z4                                 \n"
 388                 "       scd     $1, %1                                  \n"
 389                 "       beqz    $1, 1b                                  \n"
 390                 "2:                                                     \n"
 391                 "       .set    pop                                     \n"
 392                 : "=&r" (retval), "=R" (*m)
 393                 : "R" (*m), "Jr" (old), "Jr" (new)
 394                 : "memory");
 395         } else {
 396                 unsigned long flags;
 397
 398                 local_irq_save(flags);
 399                 retval = *m;
 400                 if (retval == old)
 401                         *m = new;
 402                 local_irq_restore(flags);       /* implies memory barrier  */
 403         }
 404
 405         return retval;
 406 }
 407
 408 #else
 409 extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
 410         volatile int * m, unsigned long old, unsigned long new);
 411 #define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
 412 extern unsigned long __cmpxchg_u64_local_unsupported_on_32bit_kernels(
 413         volatile int * m, unsigned long old, unsigned long new);
 414 #define __cmpxchg_u64_local __cmpxchg_u64_local_unsupported_on_32bit_kernels
 415 #endif
 416
 417 /* This function doesn't exist, so you'll get a linker error
 418    if something tries to do an invalid cmpxchg().  */
 419 extern void __cmpxchg_called_with_bad_pointer(void);
 420
 421 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 422         unsigned long new, int size)
 423 {
 424         switch (size) {
 425         case 4:
 426                 return __cmpxchg_u32(ptr, old, new);
 427         case 8:
 428                 return __cmpxchg_u64(ptr, old, new);
 429         }
 430         __cmpxchg_called_with_bad_pointer();
 431         return old;
 432 }
 433
 434 static inline unsigned long __cmpxchg_local(volatile void * ptr,
 435         unsigned long old, unsigned long new, int size)
 436 {
 437         switch (size) {
 438         case 4:
 439                 return __cmpxchg_u32_local(ptr, old, new);
 440         case 8:
 441                 return __cmpxchg_u64_local(ptr, old, new);
 442         }
 443         __cmpxchg_called_with_bad_pointer();
 444         return old;
 445 }
 446
 447 #define cmpxchg(ptr,old,new) \
 448         ((__typeof__(*(ptr)))__cmpxchg((ptr), \
 449                 (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
 450
 451 #define cmpxchg_local(ptr,old,new) \
 452         ((__typeof__(*(ptr)))__cmpxchg_local((ptr), \
 453                 (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
 454
 455 extern void set_handler (unsigned long offset, void *addr, unsigned long len);
 456 extern void set_uncached_handler (unsigned long offset, void *addr, unsigned long len);
 457
 458 typedef void (*vi_handler_t)(void);
 459 extern void *set_vi_handler (int n, vi_handler_t addr);
 460
 461 extern void *set_except_vector(int n, void *addr);
 462 extern unsigned long ebase;
 463 extern void per_cpu_trap_init(void);
 464
 465 extern int stop_a_enabled;
 466
 467 /*
 468  * See include/asm-ia64/system.h; prevents deadlock on SMP
 469  * systems.
 470  */
 471 #define __ARCH_WANT_UNLOCKED_CTXSW
 472
 473 #define arch_align_stack(x) (x)
 474
 475 #endif /* _ASM_SYSTEM_H */