arch/s390/include/asm/system.h

   1 /*
   2  * Copyright IBM Corp. 1999, 2009
   3  *
   4  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   5  */
   6
   7 #ifndef __ASM_SYSTEM_H
   8 #define __ASM_SYSTEM_H
   9
  10 #include <linux/kernel.h>
  11 #include <linux/errno.h>
  12 #include <asm/types.h>
  13 #include <asm/ptrace.h>
  14 #include <asm/setup.h>
  15 #include <asm/processor.h>
  16 #include <asm/lowcore.h>
  17
  18 #ifdef __KERNEL__
  19
  20 struct task_struct;
  21
  22 extern struct task_struct *__switch_to(void *, void *);
  23 extern void update_per_regs(struct task_struct *task);
  24
  25 static inline void save_fp_regs(s390_fp_regs *fpregs)
  26 {
  27         asm volatile(
  28                 "       std     0,%O0+8(%R0)\n"
  29                 "       std     2,%O0+24(%R0)\n"
  30                 "       std     4,%O0+40(%R0)\n"
  31                 "       std     6,%O0+56(%R0)"
  32                 : "=Q" (*fpregs) : "Q" (*fpregs));
  33         if (!MACHINE_HAS_IEEE)
  34                 return;
  35         asm volatile(
  36                 "       stfpc   %0\n"
  37                 "       std     1,%O0+16(%R0)\n"
  38                 "       std     3,%O0+32(%R0)\n"
  39                 "       std     5,%O0+48(%R0)\n"
  40                 "       std     7,%O0+64(%R0)\n"
  41                 "       std     8,%O0+72(%R0)\n"
  42                 "       std     9,%O0+80(%R0)\n"
  43                 "       std     10,%O0+88(%R0)\n"
  44                 "       std     11,%O0+96(%R0)\n"
  45                 "       std     12,%O0+104(%R0)\n"
  46                 "       std     13,%O0+112(%R0)\n"
  47                 "       std     14,%O0+120(%R0)\n"
  48                 "       std     15,%O0+128(%R0)\n"
  49                 : "=Q" (*fpregs) : "Q" (*fpregs));
  50 }
  51
  52 static inline void restore_fp_regs(s390_fp_regs *fpregs)
  53 {
  54         asm volatile(
  55                 "       ld      0,%O0+8(%R0)\n"
  56                 "       ld      2,%O0+24(%R0)\n"
  57                 "       ld      4,%O0+40(%R0)\n"
  58                 "       ld      6,%O0+56(%R0)"
  59                 : : "Q" (*fpregs));
  60         if (!MACHINE_HAS_IEEE)
  61                 return;
  62         asm volatile(
  63                 "       lfpc    %0\n"
  64                 "       ld      1,%O0+16(%R0)\n"
  65                 "       ld      3,%O0+32(%R0)\n"
  66                 "       ld      5,%O0+48(%R0)\n"
  67                 "       ld      7,%O0+64(%R0)\n"
  68                 "       ld      8,%O0+72(%R0)\n"
  69                 "       ld      9,%O0+80(%R0)\n"
  70                 "       ld      10,%O0+88(%R0)\n"
  71                 "       ld      11,%O0+96(%R0)\n"
  72                 "       ld      12,%O0+104(%R0)\n"
  73                 "       ld      13,%O0+112(%R0)\n"
  74                 "       ld      14,%O0+120(%R0)\n"
  75                 "       ld      15,%O0+128(%R0)\n"
  76                 : : "Q" (*fpregs));
  77 }
  78
  79 static inline void save_access_regs(unsigned int *acrs)
  80 {
  81         asm volatile("stam 0,15,%0" : "=Q" (*acrs));
  82 }
  83
  84 static inline void restore_access_regs(unsigned int *acrs)
  85 {
  86         asm volatile("lam 0,15,%0" : : "Q" (*acrs));
  87 }
  88
  89 #define switch_to(prev,next,last) do {                                  \
  90         if (prev->mm) {                                                 \
  91                 save_fp_regs(&prev->thread.fp_regs);                    \
  92                 save_access_regs(&prev->thread.acrs[0]);                \
  93         }                                                               \
  94         if (next->mm) {                                                 \
  95                 restore_fp_regs(&next->thread.fp_regs);                 \
  96                 restore_access_regs(&next->thread.acrs[0]);             \
  97                 update_per_regs(next);                                  \
  98         }                                                               \
  99         prev = __switch_to(prev,next);                                  \
 100 } while (0)
 101
 102 extern void account_vtime(struct task_struct *, struct task_struct *);
 103 extern void account_tick_vtime(struct task_struct *);
 104
 105 #ifdef CONFIG_PFAULT
 106 extern int pfault_init(void);
 107 extern void pfault_fini(void);
 108 #else /* CONFIG_PFAULT */
 109 #define pfault_init()           ({-1;})
 110 #define pfault_fini()           do { } while (0)
 111 #endif /* CONFIG_PFAULT */
 112
 113 extern void cmma_init(void);
 114 extern int memcpy_real(void *, void *, size_t);
 115
 116 #define finish_arch_switch(prev) do {                                        \
 117         set_fs(current->thread.mm_segment);                                  \
 118         account_vtime(prev, current);                                        \
 119 } while (0)
 120
 121 #define nop() asm volatile("nop")
 122
 123 #define xchg(ptr,x)                                                       \
 124 ({                                                                        \
 125         __typeof__(*(ptr)) __ret;                                         \
 126         __ret = (__typeof__(*(ptr)))                                      \
 127                 __xchg((unsigned long)(x), (void *)(ptr),sizeof(*(ptr))); \
 128         __ret;                                                            \
 129 })
 130
 131 extern void __xchg_called_with_bad_pointer(void);
 132
 133 static inline unsigned long __xchg(unsigned long x, void * ptr, int size)
 134 {
 135         unsigned long addr, old;
 136         int shift;
 137
 138         switch (size) {
 139         case 1:
 140                 addr = (unsigned long) ptr;
 141                 shift = (3 ^ (addr & 3)) << 3;
 142                 addr ^= addr & 3;
 143                 asm volatile(
 144                         "       l       %0,%4\n"
 145                         "0:     lr      0,%0\n"
 146                         "       nr      0,%3\n"
 147                         "       or      0,%2\n"
 148                         "       cs      %0,0,%4\n"
 149                         "       jl      0b\n"
 150                         : "=&d" (old), "=Q" (*(int *) addr)
 151                         : "d" (x << shift), "d" (~(255 << shift)),
 152                           "Q" (*(int *) addr) : "memory", "cc", "0");
 153                 return old >> shift;
 154         case 2:
 155                 addr = (unsigned long) ptr;
 156                 shift = (2 ^ (addr & 2)) << 3;
 157                 addr ^= addr & 2;
 158                 asm volatile(
 159                         "       l       %0,%4\n"
 160                         "0:     lr      0,%0\n"
 161                         "       nr      0,%3\n"
 162                         "       or      0,%2\n"
 163                         "       cs      %0,0,%4\n"
 164                         "       jl      0b\n"
 165                         : "=&d" (old), "=Q" (*(int *) addr)
 166                         : "d" (x << shift), "d" (~(65535 << shift)),
 167                           "Q" (*(int *) addr) : "memory", "cc", "0");
 168                 return old >> shift;
 169         case 4:
 170                 asm volatile(
 171                         "       l       %0,%3\n"
 172                         "0:     cs      %0,%2,%3\n"
 173                         "       jl      0b\n"
 174                         : "=&d" (old), "=Q" (*(int *) ptr)
 175                         : "d" (x), "Q" (*(int *) ptr)
 176                         : "memory", "cc");
 177                 return old;
 178 #ifdef __s390x__
 179         case 8:
 180                 asm volatile(
 181                         "       lg      %0,%3\n"
 182                         "0:     csg     %0,%2,%3\n"
 183                         "       jl      0b\n"
 184                         : "=&d" (old), "=m" (*(long *) ptr)
 185                         : "d" (x), "Q" (*(long *) ptr)
 186                         : "memory", "cc");
 187                 return old;
 188 #endif /* __s390x__ */
 189         }
 190         __xchg_called_with_bad_pointer();
 191         return x;
 192 }
 193
 194 /*
 195  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 196  * store NEW in MEM.  Return the initial value in MEM.  Success is
 197  * indicated by comparing RETURN with OLD.
 198  */
 199
 200 #define __HAVE_ARCH_CMPXCHG 1
 201
 202 #define cmpxchg(ptr, o, n)                                              \
 203         ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),       \
 204                                         (unsigned long)(n), sizeof(*(ptr))))
 205
 206 extern void __cmpxchg_called_with_bad_pointer(void);
 207
 208 static inline unsigned long
 209 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 210 {
 211         unsigned long addr, prev, tmp;
 212         int shift;
 213
 214         switch (size) {
 215         case 1:
 216                 addr = (unsigned long) ptr;
 217                 shift = (3 ^ (addr & 3)) << 3;
 218                 addr ^= addr & 3;
 219                 asm volatile(
 220                         "       l       %0,%2\n"
 221                         "0:     nr      %0,%5\n"
 222                         "       lr      %1,%0\n"
 223                         "       or      %0,%3\n"
 224                         "       or      %1,%4\n"
 225                         "       cs      %0,%1,%2\n"
 226                         "       jnl     1f\n"
 227                         "       xr      %1,%0\n"
 228                         "       nr      %1,%5\n"
 229                         "       jnz     0b\n"
 230                         "1:"
 231                         : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
 232                         : "d" (old << shift), "d" (new << shift),
 233                           "d" (~(255 << shift)), "Q" (*(int *) ptr)
 234                         : "memory", "cc");
 235                 return prev >> shift;
 236         case 2:
 237                 addr = (unsigned long) ptr;
 238                 shift = (2 ^ (addr & 2)) << 3;
 239                 addr ^= addr & 2;
 240                 asm volatile(
 241                         "       l       %0,%2\n"
 242                         "0:     nr      %0,%5\n"
 243                         "       lr      %1,%0\n"
 244                         "       or      %0,%3\n"
 245                         "       or      %1,%4\n"
 246                         "       cs      %0,%1,%2\n"
 247                         "       jnl     1f\n"
 248                         "       xr      %1,%0\n"
 249                         "       nr      %1,%5\n"
 250                         "       jnz     0b\n"
 251                         "1:"
 252                         : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
 253                         : "d" (old << shift), "d" (new << shift),
 254                           "d" (~(65535 << shift)), "Q" (*(int *) ptr)
 255                         : "memory", "cc");
 256                 return prev >> shift;
 257         case 4:
 258                 asm volatile(
 259                         "       cs      %0,%3,%1\n"
 260                         : "=&d" (prev), "=Q" (*(int *) ptr)
 261                         : "0" (old), "d" (new), "Q" (*(int *) ptr)
 262                         : "memory", "cc");
 263                 return prev;
 264 #ifdef __s390x__
 265         case 8:
 266                 asm volatile(
 267                         "       csg     %0,%3,%1\n"
 268                         : "=&d" (prev), "=Q" (*(long *) ptr)
 269                         : "0" (old), "d" (new), "Q" (*(long *) ptr)
 270                         : "memory", "cc");
 271                 return prev;
 272 #endif /* __s390x__ */
 273         }
 274         __cmpxchg_called_with_bad_pointer();
 275         return old;
 276 }
 277
 278 /*
 279  * Force strict CPU ordering.
 280  * And yes, this is required on UP too when we're talking
 281  * to devices.
 282  *
 283  * This is very similar to the ppc eieio/sync instruction in that is
 284  * does a checkpoint syncronisation & makes sure that
 285  * all memory ops have completed wrt other CPU's ( see 7-15 POP  DJB ).
 286  */
 287
 288 #define eieio() asm volatile("bcr 15,0" : : : "memory")
 289 #define SYNC_OTHER_CORES(x)   eieio()
 290 #define mb()    eieio()
 291 #define rmb()   eieio()
 292 #define wmb()   eieio()
 293 #define read_barrier_depends() do { } while(0)
 294 #define smp_mb()       mb()
 295 #define smp_rmb()      rmb()
 296 #define smp_wmb()      wmb()
 297 #define smp_read_barrier_depends()    read_barrier_depends()
 298 #define smp_mb__before_clear_bit()     smp_mb()
 299 #define smp_mb__after_clear_bit()      smp_mb()
 300
 301
 302 #define set_mb(var, value)      do { var = value; mb(); } while (0)
 303
 304 #ifdef __s390x__
 305
 306 #define __ctl_load(array, low, high) ({                         \
 307         typedef struct { char _[sizeof(array)]; } addrtype;     \
 308         asm volatile(                                           \
 309                 "       lctlg   %1,%2,%0\n"                     \
 310                 : : "Q" (*(addrtype *)(&array)),                \
 311                     "i" (low), "i" (high));                     \
 312         })
 313
 314 #define __ctl_store(array, low, high) ({                        \
 315         typedef struct { char _[sizeof(array)]; } addrtype;     \
 316         asm volatile(                                           \
 317                 "       stctg   %1,%2,%0\n"                     \
 318                 : "=Q" (*(addrtype *)(&array))                  \
 319                 : "i" (low), "i" (high));                       \
 320         })
 321
 322 #else /* __s390x__ */
 323
 324 #define __ctl_load(array, low, high) ({                         \
 325         typedef struct { char _[sizeof(array)]; } addrtype;     \
 326         asm volatile(                                           \
 327                 "       lctl    %1,%2,%0\n"                     \
 328                 : : "Q" (*(addrtype *)(&array)),                \
 329                     "i" (low), "i" (high));                     \
 330 })
 331
 332 #define __ctl_store(array, low, high) ({                        \
 333         typedef struct { char _[sizeof(array)]; } addrtype;     \
 334         asm volatile(                                           \
 335                 "       stctl   %1,%2,%0\n"                     \
 336                 : "=Q" (*(addrtype *)(&array))                  \
 337                 : "i" (low), "i" (high));                       \
 338         })
 339
 340 #endif /* __s390x__ */
 341
 342 #define __ctl_set_bit(cr, bit) ({       \
 343         unsigned long __dummy;          \
 344         __ctl_store(__dummy, cr, cr);   \
 345         __dummy |= 1UL << (bit);        \
 346         __ctl_load(__dummy, cr, cr);    \
 347 })
 348
 349 #define __ctl_clear_bit(cr, bit) ({     \
 350         unsigned long __dummy;          \
 351         __ctl_store(__dummy, cr, cr);   \
 352         __dummy &= ~(1UL << (bit));     \
 353         __ctl_load(__dummy, cr, cr);    \
 354 })
 355
 356 #include <linux/irqflags.h>
 357
 358 #include <asm-generic/cmpxchg-local.h>
 359
 360 static inline unsigned long __cmpxchg_local(volatile void *ptr,
 361                                       unsigned long old,
 362                                       unsigned long new, int size)
 363 {
 364         switch (size) {
 365         case 1:
 366         case 2:
 367         case 4:
 368 #ifdef __s390x__
 369         case 8:
 370 #endif
 371                 return __cmpxchg(ptr, old, new, size);
 372         default:
 373                 return __cmpxchg_local_generic(ptr, old, new, size);
 374         }
 375
 376         return old;
 377 }
 378
 379 /*
 380  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
 381  * them available.
 382  */
 383 #define cmpxchg_local(ptr, o, n)                                        \
 384         ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
 385                         (unsigned long)(n), sizeof(*(ptr))))
 386 #ifdef __s390x__
 387 #define cmpxchg64_local(ptr, o, n)                                      \
 388   ({                                                                    \
 389         BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
 390         cmpxchg_local((ptr), (o), (n));                                 \
 391   })
 392 #else
 393 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
 394 #endif
 395
 396 /*
 397  * Use to set psw mask except for the first byte which
 398  * won't be changed by this function.
 399  */
 400 static inline void
 401 __set_psw_mask(unsigned long mask)
 402 {
 403         __load_psw_mask(mask | (arch_local_save_flags() & ~(-1UL >> 8)));
 404 }
 405
 406 #define local_mcck_enable()  __set_psw_mask(psw_kernel_bits)
 407 #define local_mcck_disable() __set_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK)
 408
 409 #ifdef CONFIG_SMP
 410
 411 extern void smp_ctl_set_bit(int cr, int bit);
 412 extern void smp_ctl_clear_bit(int cr, int bit);
 413 #define ctl_set_bit(cr, bit) smp_ctl_set_bit(cr, bit)
 414 #define ctl_clear_bit(cr, bit) smp_ctl_clear_bit(cr, bit)
 415
 416 #else
 417
 418 #define ctl_set_bit(cr, bit) __ctl_set_bit(cr, bit)
 419 #define ctl_clear_bit(cr, bit) __ctl_clear_bit(cr, bit)
 420
 421 #endif /* CONFIG_SMP */
 422
 423 #define MAX_FACILITY_BIT (256*8)        /* stfle_fac_list has 256 bytes */
 424
 425 /*
 426  * The test_facility function uses the bit odering where the MSB is bit 0.
 427  * That makes it easier to query facility bits with the bit number as
 428  * documented in the Principles of Operation.
 429  */
 430 static inline int test_facility(unsigned long nr)
 431 {
 432         unsigned char *ptr;
 433
 434         if (nr >= MAX_FACILITY_BIT)
 435                 return 0;
 436         ptr = (unsigned char *) &S390_lowcore.stfle_fac_list + (nr >> 3);
 437         return (*ptr & (0x80 >> (nr & 7))) != 0;
 438 }
 439
 440 static inline unsigned short stap(void)
 441 {
 442         unsigned short cpu_address;
 443
 444         asm volatile("stap %0" : "=m" (cpu_address));
 445         return cpu_address;
 446 }
 447
 448 extern void (*_machine_restart)(char *command);
 449 extern void (*_machine_halt)(void);
 450 extern void (*_machine_power_off)(void);
 451
 452 #define arch_align_stack(x) (x)
 453
 454 static inline int tprot(unsigned long addr)
 455 {
 456         int rc = -EFAULT;
 457
 458         asm volatile(
 459                 "       tprot   0(%1),0\n"
 460                 "0:     ipm     %0\n"
 461                 "       srl     %0,28\n"
 462                 "1:\n"
 463                 EX_TABLE(0b,1b)
 464                 : "+d" (rc) : "a" (addr) : "cc");
 465         return rc;
 466 }
 467
 468 #endif /* __KERNEL__ */
 469
 470 #endif