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#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
  27struct debug_info {
  28#ifdef CONFIG_HAVE_HW_BREAKPOINT
  29        struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  30#endif
  31};
  32
  33struct 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 */
  46static 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 */
  84struct task_struct;
  85
  86/* Free all resources held by a thread. */
  87extern void release_thread(struct task_struct *);
  88
  89unsigned 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
 120static 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
 129static 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 */
 147