kernel/arch/arm/include/asm/processor.h

   1 /*
   2  *  arch/arm/include/asm/processor.h
   3  *
   4  *  Copyright (C) 1995-1999 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #ifndef __ASM_ARM_PROCESSOR_H
  12 #define __ASM_ARM_PROCESSOR_H
  13
  14 /*
  15  * Default implementation of macro that returns current
  16  * instruction pointer ("program counter").
  17  */
  18 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
  19
  20 #ifdef __KERNEL__
  21
  22 #include <asm/hw_breakpoint.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/types.h>
  25 #include <asm/unified.h>
  26
  27 #ifdef __KERNEL__
  28 #define STACK_TOP       ((current->personality & ADDR_LIMIT_32BIT) ? \
  29                          TASK_SIZE : TASK_SIZE_26)
  30 #define STACK_TOP_MAX   TASK_SIZE
  31 #endif
  32
  33 struct debug_info {
  34 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  35         struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  36 #endif
  37 };
  38
  39 struct thread_struct {
  40                                                         /* fault info     */
  41         unsigned long           address;
  42         unsigned long           trap_no;
  43         unsigned long           error_code;
  44                                                         /* debugging      */
  45         struct debug_info       debug;
  46 };
  47
  48 #define INIT_THREAD  {  }
  49
  50 #ifdef CONFIG_MMU
  51 #define nommu_start_thread(regs) do { } while (0)
  52 #else
  53 #define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data
  54 #endif
  55
  56 #define start_thread(regs,pc,sp)                                        \
  57 ({                                                                      \
  58         memset(regs->uregs, 0, sizeof(regs->uregs));                    \
  59         if (current->personality & ADDR_LIMIT_32BIT)                    \
  60                 regs->ARM_cpsr = USR_MODE;                              \
  61         else                                                            \
  62                 regs->ARM_cpsr = USR26_MODE;                            \
  63         if (elf_hwcap & HWCAP_THUMB && pc & 1)                          \
  64                 regs->ARM_cpsr |= PSR_T_BIT;                            \
  65         regs->ARM_cpsr |= PSR_ENDSTATE;                                 \
  66         regs->ARM_pc = pc & ~1;         /* pc */                        \
  67         regs->ARM_sp = sp;              /* sp */                        \
  68         nommu_start_thread(regs);                                       \
  69 })
  70
  71 /* Forward declaration, a strange C thing */
  72 struct task_struct;
  73
  74 /* Free all resources held by a thread. */
  75 extern void release_thread(struct task_struct *);
  76
  77 unsigned long get_wchan(struct task_struct *p);
  78
  79 #if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
  80 #define cpu_relax()                     smp_mb()
  81 #else
  82 #define cpu_relax()                     barrier()
  83 #endif
  84
  85 #define cpu_relax_lowlatency()                cpu_relax()
  86
  87 #define task_pt_regs(p) \
  88         ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
  89
  90 #define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
  91 #define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp
  92
  93 #ifdef CONFIG_SMP
  94 #define __ALT_SMP_ASM(smp, up)                                          \
  95         "9998:  " smp "\n"                                              \
  96         "       .pushsection \".alt.smp.init\", \"a\"\n"                \
  97         "       .long   9998b\n"                                        \
  98         "       " up "\n"                                               \
  99         "       .popsection\n"
 100 #else
 101 #define __ALT_SMP_ASM(smp, up)  up
 102 #endif
 103
 104 /*
 105  * Prefetching support - only ARMv5.
 106  */
 107 #if __LINUX_ARM_ARCH__ >= 5
 108
 109 #define ARCH_HAS_PREFETCH
 110 static inline void prefetch(const void *ptr)
 111 {
 112         __asm__ __volatile__(
 113                 "pld\t%a0"
 114                 :: "p" (ptr));
 115 }
 116
 117 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
 118 #define ARCH_HAS_PREFETCHW
 119 static inline void prefetchw(const void *ptr)
 120 {
 121         __asm__ __volatile__(
 122                 ".arch_extension        mp\n"
 123                 __ALT_SMP_ASM(
 124                         WASM(pldw)              "\t%a0",
 125                         WASM(pld)               "\t%a0"
 126                 )
 127                 :: "p" (ptr));
 128 }
 129 #endif
 130 #endif
 131
 132 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 133
 134 #endif
 135
 136 #endif /* __ASM_ARM_PROCESSOR_H */