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