#ifndef __ASM_SH64_MMU_CONTEXT_H
#define __ASM_SH64_MMU_CONTEXT_H

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * include/asm-sh64/mmu_context.h
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003  Richard Curnow
 *
 * ASID handling idea taken from MIPS implementation.
 *
 */

#ifndef __ASSEMBLY__

/*
 * Cache of MMU context last used.
 *
 * The MMU "context" consists of two things:
 *   (a) TLB cache version (or cycle, top 24 bits of mmu_context_cache)
 *   (b) ASID (Address Space IDentifier, bottom 8 bits of mmu_context_cache)
 */
extern unsigned long mmu_context_cache;

#include <linux/config.h>
#include <asm/page.h>


/* Current mm's pgd */
extern pgd_t *mmu_pdtp_cache;

#define SR_ASID_MASK            0xffffffffff00ffff
#define SR_ASID_SHIFT           16

#define MMU_CONTEXT_ASID_MASK           0x000000ff
#define MMU_CONTEXT_VERSION_MASK        0xffffff00
#define MMU_CONTEXT_FIRST_VERSION       0x00000100
#define NO_CONTEXT                      0

/* ASID is 8-bit value, so it can't be 0x100 */
#define MMU_NO_ASID                     0x100


/*
 * Virtual Page Number mask
 */
#define MMU_VPN_MASK    0xfffff000

extern __inline__ void
get_new_mmu_context(struct mm_struct *mm)
{
        extern void flush_tlb_all(void);
        extern void flush_cache_all(void);

        unsigned long mc = ++mmu_context_cache;

        if (!(mc & MMU_CONTEXT_ASID_MASK)) {
                /* We exhaust ASID of this version.
                   Flush all TLB and start new cycle. */
                flush_tlb_all();
                /* We have to flush all caches as ASIDs are
                   used in cache */
                flush_cache_all();
                /* Fix version if needed.
                   Note that we avoid version #0/asid #0 to distingush NO_CONTEXT. */
                if (!mc)
                        mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
        }
        mm->context = mc;
}

/*
 * Get MMU context if needed.
 */
static __inline__ void
get_mmu_context(struct mm_struct *mm)
{
        if (mm) {
                unsigned long mc = mmu_context_cache;
                /* Check if we have old version of context.
                   If it's old, we need to get new context with new version. */
                if ((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK)
                        get_new_mmu_context(mm);
        }
}

/*
 * Initialize the context related info for a new mm_struct
 * instance.
 */
static __inline__ int init_new_context(struct task_struct *tsk,
                                        struct mm_struct *mm)
{
        mm->context = NO_CONTEXT;
        return 0;
}

/*
 * Destroy context related info for an mm_struct that is about
 * to be put to rest.
 */
static __inline__ void destroy_context(struct mm_struct *mm)
{
        extern void flush_tlb_mm(struct mm_struct *mm);

        /* Well, at least free TLB entries */
        flush_tlb_mm(mm);
}

#endif  /* __ASSEMBLY__ */

/* Common defines */
#define TLB_STEP        0x00000010
#define TLB_PTEH        0x00000000
#define TLB_PTEL        0x00000008

/* PTEH defines */
#define PTEH_ASID_SHIFT 2
#define PTEH_VALID      0x0000000000000001
#define PTEH_SHARED     0x0000000000000002
#define PTEH_MATCH_ASID 0x00000000000003ff

#ifndef __ASSEMBLY__
/* This has to be a common function because the next location to fill
 * information is shared. */
extern void __do_tlb_refill(unsigned long address, unsigned long long is_text_not_data, pte_t *pte);

/* Profiling counter. */
#if (CONFIG_SH64_PROC_TLB)
extern unsigned long long calls_to_do_fast_page_fault;
#endif

static inline unsigned long get_asid(void)
{
        unsigned long long sr;

        asm volatile ("getcon   " __c0 ", %0\n\t"
                      : "=r" (sr));

        sr = (sr >> SR_ASID_SHIFT) & MMU_CONTEXT_ASID_MASK;
        return (unsigned long) sr;
}

/* Set ASID into SR */
static inline void set_asid(unsigned long asid)
{
        unsigned long long sr, pc;

        asm volatile ("getcon   " __c0 ", %0" : "=r" (sr));

        sr = (sr & SR_ASID_MASK) | (asid << SR_ASID_SHIFT);

        /*
         * It is possible that this function may be inlined and so to avoid
         * the assembler reporting duplicate symbols we make use of the gas trick
         * of generating symbols using numerics and forward reference.
         */
        asm volatile ("movi     1, %1\n\t"
                      "shlli    %1, 28, %1\n\t"
                      "or       %0, %1, %1\n\t"
                      "putcon   %1, " __c0 "\n\t"
                      "putcon   %0, " __c1 "\n\t"
                      "_loada   1f, %1\n\t"
                      "ori      %1, 1 , %1\n\t"
                      "putcon   %1, " __c8 "\n\t"
                      "rte\n"
                      "1:\n\t"
                      : "=r" (sr), "=r" (pc) : "0" (sr));
}

/*
 * After we have set current->mm to a new value, this activates
 * the context for the new mm so we see the new mappings.
 */
static __inline__ void activate_context(struct mm_struct *mm)
{
        get_mmu_context(mm);
        set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
}


static __inline__ void switch_mm(struct mm_struct *prev,
                                 struct mm_struct *next,
                                 struct task_struct *tsk, unsigned int cpu)
{
        set_bit(cpu, &next->cpu_vm_mask);

        if (prev != next) {
                mmu_pdtp_cache = next->pgd;
                activate_context(next);
                clear_bit(cpu, &prev->cpu_vm_mask);
        }
}

#define activate_mm(prev, next) \
        switch_mm((prev),(next),NULL,smp_processor_id())

static __inline__ void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk, unsigned cpu)
{
}

#endif  /* __ASSEMBLY__ */

#endif /* __ASM_SH64_MMU_CONTEXT_H */