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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PARISC_MMU_CONTEXT_H
#define __PARISC_MMU_CONTEXT_H
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/atomic.h>
#include <asm-generic/mm_hooks.h>
/* 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);
#define init_new_context init_new_context
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;
}
#define destroy_context destroy_context
static inline void
destroy_context(struct mm_struct *mm)
{
free_sid(mm->context);
mm->context = 0;
}
static inline unsigned long __space_to_prot(mm_context_t context)
{
#if SPACEID_SHIFT == 0
return context << 1;
#else
return context >> (SPACEID_SHIFT - 1);
#endif
}
static inline void load_context(mm_context_t context)
{
mtsp(context, 3);
mtctl(__space_to_prot(context), 8);
}
static inline void switch_mm_irqs_off(struct mm_struct *prev,
struct mm_struct *next, struct task_struct *tsk)
{
if (prev != next) {
mtctl(__pa(next->pgd), 25);
load_context(next->context);
}
}
static inline void switch_mm(struct mm_struct *prev,
struct mm_struct *next, struct task_struct *tsk)
{
unsigned long flags;
if (prev == next)
return;
local_irq_save(flags);
switch_mm_irqs_off(prev, next, tsk);
local_irq_restore(flags);
}
#define switch_mm_irqs_off switch_mm_irqs_off
#define activate_mm activate_mm
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);
}
#include <asm-generic/mmu_context.h>
#endif
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