/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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

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

/* 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      PAGE_ALIGN(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

#define SR_USER_MASK    0x00000303      // M, Q, S, T bits
/*
 * 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;

        /*
         * fpu_counter contains the number of consecutive context switches
         * that the FPU is used. If this is over a threshold, the lazy fpu
         * saving becomes unlazy to save the trap. This is an unsigned char
         * so that after 256 times the counter wraps and the behavior turns
         * lazy again; this to deal with bursty apps that only use FPU for
         * a short time
         */
        unsigned char fpu_counter;
};

#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);

/*
 * 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, const char *loglvl);

#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 /* __ASM_SH_PROCESSOR_32_H */