LXR linux/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
  33struct debug_info {
  34#ifdef CONFIG_HAVE_HW_BREAKPOINT
  35        struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  36#endif
  37};
  38
  39struct 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 */
  52static 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 */
  90struct task_struct;
  91
  92/* Free all resources held by a thread. */
  93extern void release_thread(struct task_struct *);
  94
  95unsigned 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
 126static 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
 135static 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 */
 153