/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  arch/arm/include/asm/processor.h
 *
 *  Copyright (C) 1995-1999 Russell King
 */

#ifndef __ASM_ARM_PROCESSOR_H
#define __ASM_ARM_PROCESSOR_H

#ifdef __KERNEL__

#include <asm/hw_breakpoint.h>
#include <asm/ptrace.h>
#include <asm/types.h>
#include <asm/unified.h>
#include <asm/vdso/processor.h>

#ifdef __KERNEL__
#define STACK_TOP       ((current->personality & ADDR_LIMIT_32BIT) ? \
                         TASK_SIZE : TASK_SIZE_26)
#define STACK_TOP_MAX   TASK_SIZE
#endif

struct debug_info {
#ifdef CONFIG_HAVE_HW_BREAKPOINT
        struct perf_event       *hbp[ARM_MAX_HBP_SLOTS];
#endif
};

struct thread_struct {
                                                        /* fault info     */
        unsigned long           address;
        unsigned long           trap_no;
        unsigned long           error_code;
                                                        /* debugging      */
        struct debug_info       debug;
};

/*
 * Everything usercopied to/from thread_struct is statically-sized, so
 * no hardened usercopy whitelist is needed.
 */
static inline void arch_thread_struct_whitelist(unsigned long *offset,
                                                unsigned long *size)
{
        *offset = *size = 0;
}

#define INIT_THREAD  {  }

#define start_thread(regs,pc,sp)                                        \
({                                                                      \
        unsigned long r7, r8, r9;                                       \
                                                                        \
        if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {                      \
                r7 = regs->ARM_r7;                                      \
                r8 = regs->ARM_r8;                                      \
                r9 = regs->ARM_r9;                                      \
        }                                                               \
        memset(regs->uregs, 0, sizeof(regs->uregs));                    \
        if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&                      \
            current->personality & FDPIC_FUNCPTRS) {                    \
                regs->ARM_r7 = r7;                                      \
                regs->ARM_r8 = r8;                                      \
                regs->ARM_r9 = r9;                                      \
                regs->ARM_r10 = current->mm->start_data;                \
        } else if (!IS_ENABLED(CONFIG_MMU))                             \
                regs->ARM_r10 = current->mm->start_data;                \
        if (current->personality & ADDR_LIMIT_32BIT)                    \
                regs->ARM_cpsr = USR_MODE;                              \
        else                                                            \
                regs->ARM_cpsr = USR26_MODE;                            \
        if (elf_hwcap & HWCAP_THUMB && pc & 1)                          \
                regs->ARM_cpsr |= PSR_T_BIT;                            \
        if (IS_ENABLED(CONFIG_CPU_ENDIAN_BE8))                          \
                regs->ARM_cpsr |= PSR_E_BIT;                            \
        regs->ARM_pc = pc & ~1;         /* pc */                        \
        regs->ARM_sp = sp;              /* sp */                        \
})

/* Forward declaration, a strange C thing */
struct task_struct;

unsigned long __get_wchan(struct task_struct *p);

#define task_pt_regs(p) \
        ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)

#define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
#define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp

#ifdef CONFIG_SMP
#define __ALT_SMP_ASM(smp, up)                                          \
        "9998:  " smp "\n"                                              \
        "       .pushsection \".alt.smp.init\", \"a\"\n"                \
        "       .align  2\n"                                            \
        "       .long   9998b - .\n"                                    \
        "       " up "\n"                                               \
        "       .popsection\n"
#else
#define __ALT_SMP_ASM(smp, up)  up
#endif

/*
 * Prefetching support - only ARMv5.
 */
#if __LINUX_ARM_ARCH__ >= 5

#define ARCH_HAS_PREFETCH
static inline void prefetch(const void *ptr)
{
        __asm__ __volatile__(
                "pld\t%a0"
                :: "p" (ptr));
}

#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
#define ARCH_HAS_PREFETCHW
static inline void prefetchw(const void *ptr)
{
        __asm__ __volatile__(
                ".arch_extension        mp\n"
                __ALT_SMP_ASM(
                        "pldw\t%a0",
                        "pld\t%a0"
                )
                :: "p" (ptr));
}
#endif
#endif

#endif

#endif /* __ASM_ARM_PROCESSOR_H */