processor_32.h

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/*
 * include/asm-sh/processor.h
 *
 * Copyright (C) 1999, 2000  Niibe Yutaka
 * Copyright (C) 2002, 2003  Paul Mundt
 */

#ifndef __ASM_SH_PROCESSOR_32_H
#define __ASM_SH_PROCESSOR_32_H
#ifdef __KERNEL__

#include <linux/compiler.h>
#include <linux/linkage.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/hw_breakpoint.h>

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */
#define current_text_addr() ({ void *pc; __asm__("mova  1f, %0\n.align 2\n1:":"=z" (pc)); pc; })

/* Core Processor Version Register */
#define CCN_PVR     0xff000030
#define CCN_CVR     0xff000040
#define CCN_PRR     0xff000044

/*
 * User space process size: 2GB.
 *
 * Since SH7709 and SH7750 have "area 7", we can't use 0x7c000000--0x7fffffff
 */
#define TASK_SIZE   0x7c000000UL

#define STACK_TOP   TASK_SIZE
#define STACK_TOP_MAX   STACK_TOP

/* This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */
#define TASK_UNMAPPED_BASE  (TASK_SIZE / 3)

/*
 * Bit of SR register
 *
 * FD-bit:
 *     When it's set, it means the processor doesn't have right to use FPU,
 *     and it results exception when the floating operation is executed.
 *
 * IMASK-bit:
 *     Interrupt level mask
 */
#define SR_DSP      0x00001000
#define SR_IMASK    0x000000f0
#define SR_FD       0x00008000
#define SR_MD       0x40000000

/*
 * DSP structure and data
 */
struct sh_dsp_struct {
    unsigned long dsp_regs[14];
    long status;
};

/*
 * FPU structure and data
 */

struct sh_fpu_hard_struct {
    unsigned long fp_regs[16];
    unsigned long xfp_regs[16];
    unsigned long fpscr;
    unsigned long fpul;

    long status; /* software status information */
};

/* Dummy fpu emulator  */
struct sh_fpu_soft_struct {
    unsigned long fp_regs[16];
    unsigned long xfp_regs[16];
    unsigned long fpscr;
    unsigned long fpul;

    unsigned char lookahead;
    unsigned long entry_pc;
};

union thread_xstate {
    struct sh_fpu_hard_struct hardfpu;
    struct sh_fpu_soft_struct softfpu;
};

struct thread_struct {
    /* Saved registers when thread is descheduled */
    unsigned long sp;
    unsigned long pc;

    /* Various thread flags, see SH_THREAD_xxx */
    unsigned long flags;

    /* Save middle states of ptrace breakpoints */
    struct perf_event *ptrace_bps[HBP_NUM];

#ifdef CONFIG_SH_DSP
    /* Dsp status information */
    struct sh_dsp_struct dsp_status;
#endif

    /* Extended processor state */
    union thread_xstate *xstate;
};

#define INIT_THREAD  {                      \
    .sp = sizeof(init_stack) + (long) &init_stack,      \
    .flags = 0,                     \
}

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

extern void start_thread(struct pt_regs *regs, unsigned long new_pc, unsigned long new_sp);

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

/*
 * create a kernel thread without removing it from tasklists
 */
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);

/* Copy and release all segment info associated with a VM */
#define copy_segments(p, mm)    do { } while(0)
#define release_segments(mm)    do { } while(0)

/*
 * FPU lazy state save handling.
 */

static __inline__ void disable_fpu(void)
{
    unsigned long __dummy;

    /* Set FD flag in SR */
    __asm__ __volatile__("stc   sr, %0\n\t"
                 "or    %1, %0\n\t"
                 "ldc   %0, sr"
                 : "=&r" (__dummy)
                 : "r" (SR_FD));
}

static __inline__ void enable_fpu(void)
{
    unsigned long __dummy;

    /* Clear out FD flag in SR */
    __asm__ __volatile__("stc   sr, %0\n\t"
                 "and   %1, %0\n\t"
                 "ldc   %0, sr"
                 : "=&r" (__dummy)
                 : "r" (~SR_FD));
}

/* Double presision, NANS as NANS, rounding to nearest, no exceptions */
#define FPSCR_INIT  0x00080000

#define FPSCR_CAUSE_MASK    0x0001f000  /* Cause bits */
#define FPSCR_FLAG_MASK     0x0000007c  /* Flag bits */

/*
 * Return saved PC of a blocked thread.
 */
#define thread_saved_pc(tsk)    (tsk->thread.pc)

void show_trace(struct task_struct *tsk, unsigned long *sp,
        struct pt_regs *regs);

#ifdef CONFIG_DUMP_CODE
void show_code(struct pt_regs *regs);
#else
static inline void show_code(struct pt_regs *regs)
{
}
#endif

extern unsigned long get_wchan(struct task_struct *p);

#define KSTK_EIP(tsk)  (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk)  (task_pt_regs(tsk)->regs[15])

#if defined(CONFIG_CPU_SH2A) || defined(CONFIG_CPU_SH4)

#define PREFETCH_STRIDE     L1_CACHE_BYTES
#define ARCH_HAS_PREFETCH
#define ARCH_HAS_PREFETCHW

static inline void prefetch(const void *x)
{
    __builtin_prefetch(x, 0, 3);
}

static inline void prefetchw(const void *x)
{
    __builtin_prefetch(x, 1, 3);
}
#endif

#endif /* __KERNEL__ */
#endif /* __ASM_SH_PROCESSOR_32_H */