LXR linux/arch/arm/include/asm/processor.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 *  arch/arm/include/asm/processor.h
   4 *
   5 *  Copyright (C) 1995-1999 Russell King
   6 */
   7
   8#ifndef __ASM_ARM_PROCESSOR_H
   9#define __ASM_ARM_PROCESSOR_H
  10
  11#ifdef __KERNEL__
  12
  13#include <asm/hw_breakpoint.h>
  14#include <asm/ptrace.h>
  15#include <asm/types.h>
  16#include <asm/unified.h>
  17
  18#ifdef __KERNEL__
  19#define STACK_TOP       ((current->personality & ADDR_LIMIT_32BIT) ? \
  20                         TASK_SIZE : TASK_SIZE_26)
  21#define STACK_TOP_MAX   TASK_SIZE
  22#endif
  23
  24struct debug_info {
  25#ifdef CONFIG_HAVE_HW_BREAKPOINT
  26        struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  27#endif
  28};
  29
  30struct thread_struct {
  31                                                        /* fault info     */
  32        unsigned long           address;
  33        unsigned long           trap_no;
  34        unsigned long           error_code;
  35                                                        /* debugging      */
  36        struct debug_info       debug;
  37};
  38
  39/*
  40 * Everything usercopied to/from thread_struct is statically-sized, so
  41 * no hardened usercopy whitelist is needed.
  42 */
  43static inline void arch_thread_struct_whitelist(unsigned long *offset,
  44                                                unsigned long *size)
  45{
  46        *offset = *size = 0;
  47}
  48
  49#define INIT_THREAD  {  }
  50
  51#define start_thread(regs,pc,sp)                                        \
  52({                                                                      \
  53        unsigned long r7, r8, r9;                                       \
  54                                                                        \
  55        if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {                      \
  56                r7 = regs->ARM_r7;                                      \
  57                r8 = regs->ARM_r8;                                      \
  58                r9 = regs->ARM_r9;                                      \
  59        }                                                               \
  60        memset(regs->uregs, 0, sizeof(regs->uregs));                    \
  61        if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&                      \
  62            current->personality & FDPIC_FUNCPTRS) {                    \
  63                regs->ARM_r7 = r7;                                      \
  64                regs->ARM_r8 = r8;                                      \
  65                regs->ARM_r9 = r9;                                      \
  66                regs->ARM_r10 = current->mm->start_data;                \
  67        } else if (!IS_ENABLED(CONFIG_MMU))                             \
  68                regs->ARM_r10 = current->mm->start_data;                \
  69        if (current->personality & ADDR_LIMIT_32BIT)                    \
  70                regs->ARM_cpsr = USR_MODE;                              \
  71        else                                                            \
  72                regs->ARM_cpsr = USR26_MODE;                            \
  73        if (elf_hwcap & HWCAP_THUMB && pc & 1)                          \
  74                regs->ARM_cpsr |= PSR_T_BIT;                            \
  75        regs->ARM_cpsr |= PSR_ENDSTATE;                                 \
  76        regs->ARM_pc = pc & ~1;         /* pc */                        \
  77        regs->ARM_sp = sp;              /* sp */                        \
  78})
  79
  80/* Forward declaration, a strange C thing */
  81struct task_struct;
  82
  83/* Free all resources held by a thread. */
  84extern void release_thread(struct task_struct *);
  85
  86unsigned long get_wchan(struct task_struct *p);
  87
  88#if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
  89#define cpu_relax()                                             \
  90        do {                                                    \
  91                smp_mb();                                       \
  92                __asm__ __volatile__("nop; nop; nop; nop; nop; nop; nop; nop; nop; nop;");      \
  93        } while (0)
  94#else
  95#define cpu_relax()                     barrier()
  96#endif
  97
  98#define task_pt_regs(p) \
  99        ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
 100
 101#define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
 102#define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp
 103
 104#ifdef CONFIG_SMP
 105#define __ALT_SMP_ASM(smp, up)                                          \
 106        "9998:  " smp "\n"                                              \
 107        "       .pushsection \".alt.smp.init\", \"a\"\n"                \
 108        "       .long   9998b\n"                                        \
 109        "       " up "\n"                                               \
 110        "       .popsection\n"
 111#else
 112#define __ALT_SMP_ASM(smp, up)  up
 113#endif
 114
 115/*
 116 * Prefetching support - only ARMv5.
 117 */
 118#if __LINUX_ARM_ARCH__ >= 5
 119
 120#define ARCH_HAS_PREFETCH
 121static inline void prefetch(const void *ptr)
 122{
 123        __asm__ __volatile__(
 124                "pld\t%a0"
 125                :: "p" (ptr));
 126}
 127
 128#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
 129#define ARCH_HAS_PREFETCHW
 130static inline void prefetchw(const void *ptr)
 131{
 132        __asm__ __volatile__(
 133                ".arch_extension        mp\n"
 134                __ALT_SMP_ASM(
 135                        "pldw\t%a0",
 136                        "pld\t%a0"
 137                )
 138                :: "p" (ptr));
 139}
 140#endif
 141#endif
 142
 143#endif
 144
 145#endif /* __ASM_ARM_PROCESSOR_H */
 146