processor.h

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/*
 *  arch/arm/include/asm/processor.h
 *
 *  Copyright (C) 1995-1999 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef __ASM_ARM_PROCESSOR_H
#define __ASM_ARM_PROCESSOR_H

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */
#define current_text_addr() ({ __label__ _l; _l: &&_l;})

#ifdef __KERNEL__

#include <asm/hw_breakpoint.h>
#include <asm/ptrace.h>
#include <asm/types.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;
};

#define INIT_THREAD  {  }

#ifdef CONFIG_MMU
#define nommu_start_thread(regs) do { } while (0)
#else
#define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data
#endif

#define start_thread(regs,pc,sp)                    \
({                                  \
    unsigned long *stack = (unsigned long *)sp;         \
    memset(regs->uregs, 0, sizeof(regs->uregs));            \
    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;                \
    regs->ARM_cpsr |= PSR_ENDSTATE;                 \
    regs->ARM_pc = pc & ~1;     /* pc */            \
    regs->ARM_sp = sp;      /* sp */            \
    regs->ARM_r2 = stack[2];    /* r2 (envp) */         \
    regs->ARM_r1 = stack[1];    /* r1 (argv) */         \
    regs->ARM_r0 = stack[0];    /* r0 (argc) */         \
    nommu_start_thread(regs);                   \
})

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

/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);

unsigned long get_wchan(struct task_struct *p);

#if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
#define cpu_relax()         smp_mb()
#else
#define cpu_relax()         barrier()
#endif

#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

/*
 * 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)
        : "cc");
}

#define ARCH_HAS_PREFETCHW
#define prefetchw(ptr)  prefetch(ptr)

#define ARCH_HAS_SPINLOCK_PREFETCH
#define spin_lock_prefetch(x) do { } while (0)

#endif

#define HAVE_ARCH_PICK_MMAP_LAYOUT

#endif

#endif /* __ASM_ARM_PROCESSOR_H */