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 #ifdef __KERNEL__
  15
  16 #include <asm/hw_breakpoint.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/types.h>
  19 #include <asm/unified.h>
  20
  21 #ifdef __KERNEL__
  22 #define STACK_TOP       ((current->personality & ADDR_LIMIT_32BIT) ? \
  23                          TASK_SIZE : TASK_SIZE_26)
  24 #define STACK_TOP_MAX   TASK_SIZE
  25 #endif
  26
  27 struct debug_info {
  28 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  29         struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  30 #endif
  31 };
  32
  33 struct thread_struct {
  34                                                         /* fault info     */
  35         unsigned long           address;
  36         unsigned long           trap_no;
  37         unsigned long           error_code;
  38                                                         /* debugging      */
  39         struct debug_info       debug;
  40 };
  41
  42 /*
  43  * Everything usercopied to/from thread_struct is statically-sized, so
  44  * no hardened usercopy whitelist is needed.
  45  */
  46 static inline void arch_thread_struct_whitelist(unsigned long *offset,
  47                                                 unsigned long *size)
  48 {
  49         *offset = *size = 0;
  50 }
  51
  52 #define INIT_THREAD  {  }
  53
  54 #define start_thread(regs,pc,sp)                                        \
  55 ({                                                                      \
  56         unsigned long r7, r8, r9;                                       \
  57                                                                         \
  58         if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {                      \
  59                 r7 = regs->ARM_r7;                                      \
  60                 r8 = regs->ARM_r8;                                      \
  61                 r9 = regs->ARM_r9;                                      \
  62         }                                                               \
  63         memset(regs->uregs, 0, sizeof(regs->uregs));                    \
  64         if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&                      \
  65             current->personality & FDPIC_FUNCPTRS) {                    \
  66                 regs->ARM_r7 = r7;                                      \
  67                 regs->ARM_r8 = r8;                                      \
  68                 regs->ARM_r9 = r9;                                      \
  69                 regs->ARM_r10 = current->mm->start_data;                \
  70         } else if (!IS_ENABLED(CONFIG_MMU))                             \
  71                 regs->ARM_r10 = current->mm->start_data;                \
  72         if (current->personality & ADDR_LIMIT_32BIT)                    \
  73                 regs->ARM_cpsr = USR_MODE;                              \
  74         else                                                            \
  75                 regs->ARM_cpsr = USR26_MODE;                            \
  76         if (elf_hwcap & HWCAP_THUMB && pc & 1)                          \
  77                 regs->ARM_cpsr |= PSR_T_BIT;                            \
  78         regs->ARM_cpsr |= PSR_ENDSTATE;                                 \
  79         regs->ARM_pc = pc & ~1;         /* pc */                        \
  80         regs->ARM_sp = sp;              /* sp */                        \
  81 })
  82
  83 /* Forward declaration, a strange C thing */
  84 struct task_struct;
  85
  86 /* Free all resources held by a thread. */
  87 extern void release_thread(struct task_struct *);
  88
  89 unsigned long get_wchan(struct task_struct *p);
  90
  91 #if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
  92 #define cpu_relax()                     smp_mb()
  93 #else
  94 #define cpu_relax()                     barrier()
  95 #endif
  96
  97 #define task_pt_regs(p) \
  98         ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
  99
 100 #define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
 101 #define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp
 102
 103 #ifdef CONFIG_SMP
 104 #define __ALT_SMP_ASM(smp, up)                                          \
 105         "9998:  " smp "\n"                                              \
 106         "       .pushsection \".alt.smp.init\", \"a\"\n"                \
 107         "       .long   9998b\n"                                        \
 108         "       " up "\n"                                               \
 109         "       .popsection\n"
 110 #else
 111 #define __ALT_SMP_ASM(smp, up)  up
 112 #endif
 113
 114 /*
 115  * Prefetching support - only ARMv5.
 116  */
 117 #if __LINUX_ARM_ARCH__ >= 5
 118
 119 #define ARCH_HAS_PREFETCH
 120 static inline void prefetch(const void *ptr)
 121 {
 122         __asm__ __volatile__(
 123                 "pld\t%a0"
 124                 :: "p" (ptr));
 125 }
 126
 127 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
 128 #define ARCH_HAS_PREFETCHW
 129 static inline void prefetchw(const void *ptr)
 130 {
 131         __asm__ __volatile__(
 132                 ".arch_extension        mp\n"
 133                 __ALT_SMP_ASM(
 134                         WASM(pldw)              "\t%a0",
 135                         WASM(pld)               "\t%a0"
 136                 )
 137                 :: "p" (ptr));
 138 }
 139 #endif
 140 #endif
 141
 142 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 143
 144 #endif
 145
 146 #endif /* __ASM_ARM_PROCESSOR_H */