root/include/asm-parisc/mmu_context.h

INCLUDED FROM

DEFINITIONS

1. enter_lazy_tlb
2. init_new_context
3. destroy_context
4. load_context
5. switch_mm
6. activate_mm

#ifndef __PARISC_MMU_CONTEXT_H
#define __PARISC_MMU_CONTEXT_H

#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}

/* on PA-RISC, we actually have enough contexts to justify an allocator
 * for them.  prumpf */

extern unsigned long alloc_sid(void);
extern void free_sid(unsigned long);

static inline int
init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
        BUG_ON(atomic_read(&mm->mm_users) != 1);

        mm->context = alloc_sid();
        return 0;
}

static inline void
destroy_context(struct mm_struct *mm)
{
        free_sid(mm->context);
        mm->context = 0;
}

static inline void load_context(mm_context_t context)
{
        mtsp(context, 3);
#if SPACEID_SHIFT == 0
        mtctl(context << 1,8);
#else
        mtctl(context >> (SPACEID_SHIFT - 1),8);
#endif
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
{

        if (prev != next) {
                mtctl(__pa(next->pgd), 25);
                load_context(next->context);
        }
}

#define deactivate_mm(tsk,mm)   do { } while (0)

static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
        /*
         * Activate_mm is our one chance to allocate a space id
         * for a new mm created in the exec path. There's also
         * some lazy tlb stuff, which is currently dead code, but
         * we only allocate a space id if one hasn't been allocated
         * already, so we should be OK.
         */

        BUG_ON(next == &init_mm); /* Should never happen */

        if (next->context == 0)
            next->context = alloc_sid();

        switch_mm(prev,next,current);
}
#endif