LXR linux/arch/arm/include/asm/system.h

   1#ifndef __ASM_ARM_SYSTEM_H
   2#define __ASM_ARM_SYSTEM_H
   3
   4#ifdef __KERNEL__
   5
   6#define CPU_ARCH_UNKNOWN        0
   7#define CPU_ARCH_ARMv3          1
   8#define CPU_ARCH_ARMv4          2
   9#define CPU_ARCH_ARMv4T         3
  10#define CPU_ARCH_ARMv5          4
  11#define CPU_ARCH_ARMv5T         5
  12#define CPU_ARCH_ARMv5TE        6
  13#define CPU_ARCH_ARMv5TEJ       7
  14#define CPU_ARCH_ARMv6          8
  15#define CPU_ARCH_ARMv7          9
  16
  17/*
  18 * CR1 bits (CP#15 CR1)
  19 */
  20#define CR_M    (1 << 0)        /* MMU enable                           */
  21#define CR_A    (1 << 1)        /* Alignment abort enable               */
  22#define CR_C    (1 << 2)        /* Dcache enable                        */
  23#define CR_W    (1 << 3)        /* Write buffer enable                  */
  24#define CR_P    (1 << 4)        /* 32-bit exception handler             */
  25#define CR_D    (1 << 5)        /* 32-bit data address range            */
  26#define CR_L    (1 << 6)        /* Implementation defined               */
  27#define CR_B    (1 << 7)        /* Big endian                           */
  28#define CR_S    (1 << 8)        /* System MMU protection                */
  29#define CR_R    (1 << 9)        /* ROM MMU protection                   */
  30#define CR_F    (1 << 10)       /* Implementation defined               */
  31#define CR_Z    (1 << 11)       /* Implementation defined               */
  32#define CR_I    (1 << 12)       /* Icache enable                        */
  33#define CR_V    (1 << 13)       /* Vectors relocated to 0xffff0000      */
  34#define CR_RR   (1 << 14)       /* Round Robin cache replacement        */
  35#define CR_L4   (1 << 15)       /* LDR pc can set T bit                 */
  36#define CR_DT   (1 << 16)
  37#define CR_IT   (1 << 18)
  38#define CR_ST   (1 << 19)
  39#define CR_FI   (1 << 21)       /* Fast interrupt (lower latency mode)  */
  40#define CR_U    (1 << 22)       /* Unaligned access operation           */
  41#define CR_XP   (1 << 23)       /* Extended page tables                 */
  42#define CR_VE   (1 << 24)       /* Vectored interrupts                  */
  43#define CR_EE   (1 << 25)       /* Exception (Big) Endian               */
  44#define CR_TRE  (1 << 28)       /* TEX remap enable                     */
  45#define CR_AFE  (1 << 29)       /* Access flag enable                   */
  46#define CR_TE   (1 << 30)       /* Thumb exception enable               */
  47
  48/*
  49 * This is used to ensure the compiler did actually allocate the register we
  50 * asked it for some inline assembly sequences.  Apparently we can't trust
  51 * the compiler from one version to another so a bit of paranoia won't hurt.
  52 * This string is meant to be concatenated with the inline asm string and
  53 * will cause compilation to stop on mismatch.
  54 * (for details, see gcc PR 15089)
  55 */
  56#define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"
  57
  58#ifndef __ASSEMBLY__
  59
  60#include <linux/linkage.h>
  61#include <linux/irqflags.h>
  62
  63#include <asm/outercache.h>
  64
  65#define __exception     __attribute__((section(".exception.text")))
  66#ifdef CONFIG_FUNCTION_GRAPH_TRACER
  67#define __exception_irq_entry   __irq_entry
  68#else
  69#define __exception_irq_entry   __exception
  70#endif
  71
  72struct thread_info;
  73struct task_struct;
  74
  75/* information about the system we're running on */
  76extern unsigned int system_rev;
  77extern unsigned int system_serial_low;
  78extern unsigned int system_serial_high;
  79extern unsigned int mem_fclk_21285;
  80
  81struct pt_regs;
  82
  83void die(const char *msg, struct pt_regs *regs, int err);
  84
  85struct siginfo;
  86void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info,
  87                unsigned long err, unsigned long trap);
  88
  89void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
  90                                       struct pt_regs *),
  91                     int sig, int code, const char *name);
  92
  93void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
  94                                       struct pt_regs *),
  95                     int sig, int code, const char *name);
  96
  97#define xchg(ptr,x) \
  98        ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
  99
 100extern asmlinkage void __backtrace(void);
 101extern asmlinkage void c_backtrace(unsigned long fp, int pmode);
 102
 103struct mm_struct;
 104extern void show_pte(struct mm_struct *mm, unsigned long addr);
 105extern void __show_regs(struct pt_regs *);
 106
 107extern int cpu_architecture(void);
 108extern void cpu_init(void);
 109
 110void arm_machine_restart(char mode, const char *cmd);
 111extern void (*arm_pm_restart)(char str, const char *cmd);
 112
 113#define UDBG_UNDEFINED  (1 << 0)
 114#define UDBG_SYSCALL    (1 << 1)
 115#define UDBG_BADABORT   (1 << 2)
 116#define UDBG_SEGV       (1 << 3)
 117#define UDBG_BUS        (1 << 4)
 118
 119extern unsigned int user_debug;
 120
 121#if __LINUX_ARM_ARCH__ >= 4
 122#define vectors_high()  (cr_alignment & CR_V)
 123#else
 124#define vectors_high()  (0)
 125#endif
 126
 127#if __LINUX_ARM_ARCH__ >= 7 ||          \
 128        (__LINUX_ARM_ARCH__ == 6 && defined(CONFIG_CPU_32v6K))
 129#define sev()   __asm__ __volatile__ ("sev" : : : "memory")
 130#define wfe()   __asm__ __volatile__ ("wfe" : : : "memory")
 131#define wfi()   __asm__ __volatile__ ("wfi" : : : "memory")
 132#endif
 133
 134#if __LINUX_ARM_ARCH__ >= 7
 135#define isb() __asm__ __volatile__ ("isb" : : : "memory")
 136#define dsb() __asm__ __volatile__ ("dsb" : : : "memory")
 137#define dmb() __asm__ __volatile__ ("dmb" : : : "memory")
 138#elif defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ == 6
 139#define isb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
 140                                    : : "r" (0) : "memory")
 141#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
 142                                    : : "r" (0) : "memory")
 143#define dmb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
 144                                    : : "r" (0) : "memory")
 145#elif defined(CONFIG_CPU_FA526)
 146#define isb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
 147                                    : : "r" (0) : "memory")
 148#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
 149                                    : : "r" (0) : "memory")
 150#define dmb() __asm__ __volatile__ ("" : : : "memory")
 151#else
 152#define isb() __asm__ __volatile__ ("" : : : "memory")
 153#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
 154                                    : : "r" (0) : "memory")
 155#define dmb() __asm__ __volatile__ ("" : : : "memory")
 156#endif
 157
 158#ifdef CONFIG_ARCH_HAS_BARRIERS
 159#include <mach/barriers.h>
 160#elif defined(CONFIG_ARM_DMA_MEM_BUFFERABLE) || defined(CONFIG_SMP)
 161#define mb()            do { dsb(); outer_sync(); } while (0)
 162#define rmb()           dmb()
 163#define wmb()           mb()
 164#else
 165#include <asm/memory.h>
 166#define mb()    do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
 167#define rmb()   do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
 168#define wmb()   do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
 169#endif
 170
 171#ifndef CONFIG_SMP
 172#define smp_mb()        barrier()
 173#define smp_rmb()       barrier()
 174#define smp_wmb()       barrier()
 175#else
 176#define smp_mb()        dmb()
 177#define smp_rmb()       dmb()
 178#define smp_wmb()       dmb()
 179#endif
 180
 181#define read_barrier_depends()          do { } while(0)
 182#define smp_read_barrier_depends()      do { } while(0)
 183
 184#define set_mb(var, value)      do { var = value; smp_mb(); } while (0)
 185#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
 186
 187extern unsigned long cr_no_alignment;   /* defined in entry-armv.S */
 188extern unsigned long cr_alignment;      /* defined in entry-armv.S */
 189
 190static inline unsigned int get_cr(void)
 191{
 192        unsigned int val;
 193        asm("mrc p15, 0, %0, c1, c0, 0  @ get CR" : "=r" (val) : : "cc");
 194        return val;
 195}
 196
 197static inline void set_cr(unsigned int val)
 198{
 199        asm volatile("mcr p15, 0, %0, c1, c0, 0 @ set CR"
 200          : : "r" (val) : "cc");
 201        isb();
 202}
 203
 204#ifndef CONFIG_SMP
 205extern void adjust_cr(unsigned long mask, unsigned long set);
 206#endif
 207
 208#define CPACC_FULL(n)           (3 << (n * 2))
 209#define CPACC_SVC(n)            (1 << (n * 2))
 210#define CPACC_DISABLE(n)        (0 << (n * 2))
 211
 212static inline unsigned int get_copro_access(void)
 213{
 214        unsigned int val;
 215        asm("mrc p15, 0, %0, c1, c0, 2 @ get copro access"
 216          : "=r" (val) : : "cc");
 217        return val;
 218}
 219
 220static inline void set_copro_access(unsigned int val)
 221{
 222        asm volatile("mcr p15, 0, %0, c1, c0, 2 @ set copro access"
 223          : : "r" (val) : "cc");
 224        isb();
 225}
 226
 227/*
 228 * switch_mm() may do a full cache flush over the context switch,
 229 * so enable interrupts over the context switch to avoid high
 230 * latency.
 231 */
 232#define __ARCH_WANT_INTERRUPTS_ON_CTXSW
 233
 234/*
 235 * switch_to(prev, next) should switch from task `prev' to `next'
 236 * `prev' will never be the same as `next'.  schedule() itself
 237 * contains the memory barrier to tell GCC not to cache `current'.
 238 */
 239extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
 240
 241#define switch_to(prev,next,last)                                       \
 242do {                                                                    \
 243        last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));        \
 244} while (0)
 245
 246#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
 247/*
 248 * On the StrongARM, "swp" is terminally broken since it bypasses the
 249 * cache totally.  This means that the cache becomes inconsistent, and,
 250 * since we use normal loads/stores as well, this is really bad.
 251 * Typically, this causes oopsen in filp_close, but could have other,
 252 * more disasterous effects.  There are two work-arounds:
 253 *  1. Disable interrupts and emulate the atomic swap
 254 *  2. Clean the cache, perform atomic swap, flush the cache
 255 *
 256 * We choose (1) since its the "easiest" to achieve here and is not
 257 * dependent on the processor type.
 258 *
 259 * NOTE that this solution won't work on an SMP system, so explcitly
 260 * forbid it here.
 261 */
 262#define swp_is_buggy
 263#endif
 264
 265static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
 266{
 267        extern void __bad_xchg(volatile void *, int);
 268        unsigned long ret;
 269#ifdef swp_is_buggy
 270        unsigned long flags;
 271#endif
 272#if __LINUX_ARM_ARCH__ >= 6
 273        unsigned int tmp;
 274#endif
 275
 276        smp_mb();
 277
 278        switch (size) {
 279#if __LINUX_ARM_ARCH__ >= 6
 280        case 1:
 281                asm volatile("@ __xchg1\n"
 282                "1:     ldrexb  %0, [%3]\n"
 283                "       strexb  %1, %2, [%3]\n"
 284                "       teq     %1, #0\n"
 285                "       bne     1b"
 286                        : "=&r" (ret), "=&r" (tmp)
 287                        : "r" (x), "r" (ptr)
 288                        : "memory", "cc");
 289                break;
 290        case 4:
 291                asm volatile("@ __xchg4\n"
 292                "1:     ldrex   %0, [%3]\n"
 293                "       strex   %1, %2, [%3]\n"
 294                "       teq     %1, #0\n"
 295                "       bne     1b"
 296                        : "=&r" (ret), "=&r" (tmp)
 297                        : "r" (x), "r" (ptr)
 298                        : "memory", "cc");
 299                break;
 300#elif defined(swp_is_buggy)
 301#ifdef CONFIG_SMP
 302#error SMP is not supported on this platform
 303#endif
 304        case 1:
 305                raw_local_irq_save(flags);
 306                ret = *(volatile unsigned char *)ptr;
 307                *(volatile unsigned char *)ptr = x;
 308                raw_local_irq_restore(flags);
 309                break;
 310
 311        case 4:
 312                raw_local_irq_save(flags);
 313                ret = *(volatile unsigned long *)ptr;
 314                *(volatile unsigned long *)ptr = x;
 315                raw_local_irq_restore(flags);
 316                break;
 317#else
 318        case 1:
 319                asm volatile("@ __xchg1\n"
 320                "       swpb    %0, %1, [%2]"
 321                        : "=&r" (ret)
 322                        : "r" (x), "r" (ptr)
 323                        : "memory", "cc");
 324                break;
 325        case 4:
 326                asm volatile("@ __xchg4\n"
 327                "       swp     %0, %1, [%2]"
 328                        : "=&r" (ret)
 329                        : "r" (x), "r" (ptr)
 330                        : "memory", "cc");
 331                break;
 332#endif
 333        default:
 334                __bad_xchg(ptr, size), ret = 0;
 335                break;
 336        }
 337        smp_mb();
 338
 339        return ret;
 340}
 341
 342extern void disable_hlt(void);
 343extern void enable_hlt(void);
 344
 345void cpu_idle_wait(void);
 346
 347#include <asm-generic/cmpxchg-local.h>
 348
 349#if __LINUX_ARM_ARCH__ < 6
 350
 351#ifdef CONFIG_SMP
 352#error "SMP is not supported on this platform"
 353#endif
 354
 355/*
 356 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
 357 * them available.
 358 */
 359#define cmpxchg_local(ptr, o, n)                                               \
 360        ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
 361                        (unsigned long)(n), sizeof(*(ptr))))
 362#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
 363
 364#ifndef CONFIG_SMP
 365#include <asm-generic/cmpxchg.h>
 366#endif
 367
 368#else   /* __LINUX_ARM_ARCH__ >= 6 */
 369
 370extern void __bad_cmpxchg(volatile void *ptr, int size);
 371
 372/*
 373 * cmpxchg only support 32-bits operands on ARMv6.
 374 */
 375
 376static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 377                                      unsigned long new, int size)
 378{
 379        unsigned long oldval, res;
 380
 381        switch (size) {
 382#ifdef CONFIG_CPU_32v6K
 383        case 1:
 384                do {
 385                        asm volatile("@ __cmpxchg1\n"
 386                        "       ldrexb  %1, [%2]\n"
 387                        "       mov     %0, #0\n"
 388                        "       teq     %1, %3\n"
 389                        "       strexbeq %0, %4, [%2]\n"
 390                                : "=&r" (res), "=&r" (oldval)
 391                                : "r" (ptr), "Ir" (old), "r" (new)
 392                                : "memory", "cc");
 393                } while (res);
 394                break;
 395        case 2:
 396                do {
 397                        asm volatile("@ __cmpxchg1\n"
 398                        "       ldrexh  %1, [%2]\n"
 399                        "       mov     %0, #0\n"
 400                        "       teq     %1, %3\n"
 401                        "       strexheq %0, %4, [%2]\n"
 402                                : "=&r" (res), "=&r" (oldval)
 403                                : "r" (ptr), "Ir" (old), "r" (new)
 404                                : "memory", "cc");
 405                } while (res);
 406                break;
 407#endif /* CONFIG_CPU_32v6K */
 408        case 4:
 409                do {
 410                        asm volatile("@ __cmpxchg4\n"
 411                        "       ldrex   %1, [%2]\n"
 412                        "       mov     %0, #0\n"
 413                        "       teq     %1, %3\n"
 414                        "       strexeq %0, %4, [%2]\n"
 415                                : "=&r" (res), "=&r" (oldval)
 416                                : "r" (ptr), "Ir" (old), "r" (new)
 417                                : "memory", "cc");
 418                } while (res);
 419                break;
 420        default:
 421                __bad_cmpxchg(ptr, size);
 422                oldval = 0;
 423        }
 424
 425        return oldval;
 426}
 427
 428static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
 429                                         unsigned long new, int size)
 430{
 431        unsigned long ret;
 432
 433        smp_mb();
 434        ret = __cmpxchg(ptr, old, new, size);
 435        smp_mb();
 436
 437        return ret;
 438}
 439
 440#define cmpxchg(ptr,o,n)                                                \
 441        ((__typeof__(*(ptr)))__cmpxchg_mb((ptr),                        \
 442                                          (unsigned long)(o),           \
 443                                          (unsigned long)(n),           \
 444                                          sizeof(*(ptr))))
 445
 446static inline unsigned long __cmpxchg_local(volatile void *ptr,
 447                                            unsigned long old,
 448                                            unsigned long new, int size)
 449{
 450        unsigned long ret;
 451
 452        switch (size) {
 453#ifndef CONFIG_CPU_32v6K
 454        case 1:
 455        case 2:
 456                ret = __cmpxchg_local_generic(ptr, old, new, size);
 457                break;
 458#endif  /* !CONFIG_CPU_32v6K */
 459        default:
 460                ret = __cmpxchg(ptr, old, new, size);
 461        }
 462
 463        return ret;
 464}
 465
 466#define cmpxchg_local(ptr,o,n)                                          \
 467        ((__typeof__(*(ptr)))__cmpxchg_local((ptr),                     \
 468                                       (unsigned long)(o),              \
 469                                       (unsigned long)(n),              \
 470                                       sizeof(*(ptr))))
 471
 472#ifdef CONFIG_CPU_32v6K
 473
 474/*
 475 * Note : ARMv7-M (currently unsupported by Linux) does not support
 476 * ldrexd/strexd. If ARMv7-M is ever supported by the Linux kernel, it should
 477 * not be allowed to use __cmpxchg64.
 478 */
 479static inline unsigned long long __cmpxchg64(volatile void *ptr,
 480                                             unsigned long long old,
 481                                             unsigned long long new)
 482{
 483        register unsigned long long oldval asm("r0");
 484        register unsigned long long __old asm("r2") = old;
 485        register unsigned long long __new asm("r4") = new;
 486        unsigned long res;
 487
 488        do {
 489                asm volatile(
 490                "       @ __cmpxchg8\n"
 491                "       ldrexd  %1, %H1, [%2]\n"
 492                "       mov     %0, #0\n"
 493                "       teq     %1, %3\n"
 494                "       teqeq   %H1, %H3\n"
 495                "       strexdeq %0, %4, %H4, [%2]\n"
 496                        : "=&r" (res), "=&r" (oldval)
 497                        : "r" (ptr), "Ir" (__old), "r" (__new)
 498                        : "memory", "cc");
 499        } while (res);
 500
 501        return oldval;
 502}
 503
 504static inline unsigned long long __cmpxchg64_mb(volatile void *ptr,
 505                                                unsigned long long old,
 506                                                unsigned long long new)
 507{
 508        unsigned long long ret;
 509
 510        smp_mb();
 511        ret = __cmpxchg64(ptr, old, new);
 512        smp_mb();
 513
 514        return ret;
 515}
 516
 517#define cmpxchg64(ptr,o,n)                                              \
 518        ((__typeof__(*(ptr)))__cmpxchg64_mb((ptr),                      \
 519                                            (unsigned long long)(o),    \
 520                                            (unsigned long long)(n)))
 521
 522#define cmpxchg64_local(ptr,o,n)                                        \
 523        ((__typeof__(*(ptr)))__cmpxchg64((ptr),                         \
 524                                         (unsigned long long)(o),       \
 525                                         (unsigned long long)(n)))
 526
 527#else   /* !CONFIG_CPU_32v6K */
 528
 529#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
 530
 531#endif  /* CONFIG_CPU_32v6K */
 532
 533#endif  /* __LINUX_ARM_ARCH__ >= 6 */
 534
 535#endif /* __ASSEMBLY__ */
 536
 537#define arch_align_stack(x) (x)
 538
 539#endif /* __KERNEL__ */
 540
 541#endif
 542