/* 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 <linux/spinlock.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.space_id = alloc_sid();
return 0;
}
#define destroy_context destroy_context
static inline void
destroy_context(
struct mm_struct *mm)
{
free_sid(mm->context.space_id);
mm->context.space_id = 0;
}
static inline unsigned long __space_to_prot(mm_context_t context)
{
#if SPACEID_SHIFT == 0
return context.space_id << 1;
#else
return context.space_id >> (SPACEID_SHIFT - 1);
#endif
}
static inline void load_context(mm_context_t context)
{
mtsp(context.space_id, SR_USER);
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) {
#ifdef CONFIG_TLB_PTLOCK
/* put physical address of page_table_lock in cr28 (tr4)
for TLB faults */
spinlock_t *pgd_lock = &next->page_table_lock;
mtctl(__pa(__ldcw_align(&pgd_lock->rlock.raw_lock)), 28);
#endif
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.space_id == 0)
next->context.space_id = alloc_sid();
switch_mm(prev,next,current);
}
#include <asm-generic/mmu_context.h>
#endif
