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 /*
  49  * Everything usercopied to/from thread_struct is statically-sized, so
  50  * no hardened usercopy whitelist is needed.
  51  */
  52 static inline void arch_thread_struct_whitelist(unsigned long *offset,
  53                                                 unsigned long *size)
  54 {
  55         *offset = *size = 0;
  56 }
  57
  58 #define INIT_THREAD  {  }
  59
  60 #define start_thread(regs,pc,sp)                                        \
  61 ({                                                                      \
  62         unsigned long r7, r8, r9;                                       \
  63                                                                         \
  64         if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {                      \
  65                 r7 = regs->ARM_r7;                                      \
  66                 r8 = regs->ARM_r8;                                      \
  67                 r9 = regs->ARM_r9;                                      \
  68         }                                                               \
  69         memset(regs->uregs, 0, sizeof(regs->uregs));                    \
  70         if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&                      \
  71             current->personality & FDPIC_FUNCPTRS) {                    \
  72                 regs->ARM_r7 = r7;                                      \
  73                 regs->ARM_r8 = r8;                                      \
  74                 regs->ARM_r9 = r9;                                      \
  75                 regs->ARM_r10 = current->mm->start_data;                \
  76         } else if (!IS_ENABLED(CONFIG_MMU))                             \
  77                 regs->ARM_r10 = current->mm->start_data;                \
  78         if (current->personality & ADDR_LIMIT_32BIT)                    \
  79                 regs->ARM_cpsr = USR_MODE;                              \
  80         else                                                            \
  81                 regs->ARM_cpsr = USR26_MODE;                            \
  82         if (elf_hwcap & HWCAP_THUMB && pc & 1)                          \
  83                 regs->ARM_cpsr |= PSR_T_BIT;                            \
  84         regs->ARM_cpsr |= PSR_ENDSTATE;                                 \
  85         regs->ARM_pc = pc & ~1;         /* pc */                        \
  86         regs->ARM_sp = sp;              /* sp */                        \
  87 })
  88
  89 /* Forward declaration, a strange C thing */
  90 struct task_struct;
  91
  92 /* Free all resources held by a thread. */
  93 extern void release_thread(struct task_struct *);
  94
  95 unsigned long get_wchan(struct task_struct *p);
  96
  97 #if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
  98 #define cpu_relax()                     smp_mb()
  99 #else
 100 #define cpu_relax()                     barrier()
 101 #endif
 102
 103 #define task_pt_regs(p) \
 104         ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
 105
 106 #define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
 107 #define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp
 108
 109 #ifdef CONFIG_SMP
 110 #define __ALT_SMP_ASM(smp, up)                                          \
 111         "9998:  " smp "\n"                                              \
 112         "       .pushsection \".alt.smp.init\", \"a\"\n"                \
 113         "       .long   9998b\n"                                        \
 114         "       " up "\n"                                               \
 115         "       .popsection\n"
 116 #else
 117 #define __ALT_SMP_ASM(smp, up)  up
 118 #endif
 119
 120 /*
 121  * Prefetching support - only ARMv5.
 122  */
 123 #if __LINUX_ARM_ARCH__ >= 5
 124
 125 #define ARCH_HAS_PREFETCH
 126 static inline void prefetch(const void *ptr)
 127 {
 128         __asm__ __volatile__(
 129                 "pld\t%a0"
 130                 :: "p" (ptr));
 131 }
 132
 133 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
 134 #define ARCH_HAS_PREFETCHW
 135 static inline void prefetchw(const void *ptr)
 136 {
 137         __asm__ __volatile__(
 138                 ".arch_extension        mp\n"
 139                 __ALT_SMP_ASM(
 140                         WASM(pldw)              "\t%a0",
 141                         WASM(pld)               "\t%a0"
 142                 )
 143                 :: "p" (ptr));
 144 }
 145 #endif
 146 #endif
 147
 148 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 149
 150 #endif
 151
 152 #endif /* __ASM_ARM_PROCESSOR_H */