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
  24 struct debug_info {
  25 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  26         struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
  27 #endif
  28 };
  29
  30 struct 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  */
  43 static 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 */
  81 struct task_struct;
  82
  83 /* Free all resources held by a thread. */
  84 extern void release_thread(struct task_struct *);
  85
  86 unsigned 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
 121 static 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
 130 static 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 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 144
 145 #endif
 146
 147 #endif /* __ASM_ARM_PROCESSOR_H */