processor.h

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/*
 * Based on arch/arm/include/asm/processor.h
 *
 * Copyright (C) 1995-1999 Russell King
 * Copyright (C) 2012 ARM Ltd.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_PROCESSOR_H
#define __ASM_PROCESSOR_H

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

#ifdef __KERNEL__

#include <linux/string.h>

#include <asm/fpsimd.h>
#include <asm/hw_breakpoint.h>
#include <asm/ptrace.h>
#include <asm/types.h>

#ifdef __KERNEL__
#define STACK_TOP_MAX       TASK_SIZE_64
#ifdef CONFIG_COMPAT
#define AARCH32_VECTORS_BASE    0xffff0000
#define STACK_TOP       (test_thread_flag(TIF_32BIT) ? \
                AARCH32_VECTORS_BASE : STACK_TOP_MAX)
#else
#define STACK_TOP       STACK_TOP_MAX
#endif /* CONFIG_COMPAT */

#define ARCH_LOW_ADDRESS_LIMIT  PHYS_MASK
#endif /* __KERNEL__ */

struct debug_info {
    /* Have we suspended stepping by a debugger? */
    int         suspended_step;
    /* Allow breakpoints and watchpoints to be disabled for this thread. */
    int         bps_disabled;
    int         wps_disabled;
    /* Hardware breakpoints pinned to this task. */
    struct perf_event   *hbp_break[ARM_MAX_BRP];
    struct perf_event   *hbp_watch[ARM_MAX_WRP];
};

struct cpu_context {
    unsigned long x19;
    unsigned long x20;
    unsigned long x21;
    unsigned long x22;
    unsigned long x23;
    unsigned long x24;
    unsigned long x25;
    unsigned long x26;
    unsigned long x27;
    unsigned long x28;
    unsigned long fp;
    unsigned long sp;
    unsigned long pc;
};

struct thread_struct {
    struct cpu_context  cpu_context;    /* cpu context */
    unsigned long       tp_value;
    struct fpsimd_state fpsimd_state;
    unsigned long       fault_address;  /* fault info */
    struct debug_info   debug;      /* debugging */
};

#define INIT_THREAD  {  }

static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
{
    memset(regs, 0, sizeof(*regs));
    regs->syscallno = ~0UL;
    regs->pc = pc;
}

static inline void start_thread(struct pt_regs *regs, unsigned long pc,
                unsigned long sp)
{
    start_thread_common(regs, pc);
    regs->pstate = PSR_MODE_EL0t;
    regs->sp = sp;
}

#ifdef CONFIG_COMPAT
static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
                       unsigned long sp)
{
    start_thread_common(regs, pc);
    regs->pstate = COMPAT_PSR_MODE_USR;
    if (pc & 1)
        regs->pstate |= COMPAT_PSR_T_BIT;
    regs->compat_sp = sp;
}
#endif

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

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

/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk)    do { } while (0)

unsigned long get_wchan(struct task_struct *p);

#define cpu_relax()         barrier()

/* Thread switching */
extern struct task_struct *cpu_switch_to(struct task_struct *prev,
                     struct task_struct *next);

/*
 * Create a new kernel thread
 */
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);

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

#define KSTK_EIP(tsk)   task_pt_regs(tsk)->pc
#define KSTK_ESP(tsk)   task_pt_regs(tsk)->sp

/*
 * Prefetching support
 */
#define ARCH_HAS_PREFETCH
static inline void prefetch(const void *ptr)
{
    asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
}

#define ARCH_HAS_PREFETCHW
static inline void prefetchw(const void *ptr)
{
    asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
}

#define ARCH_HAS_SPINLOCK_PREFETCH
static inline void spin_lock_prefetch(const void *x)
{
    prefetchw(x);
}

#define HAVE_ARCH_PICK_MMAP_LAYOUT

#endif

#endif /* __ASM_PROCESSOR_H */