LXR linux/arch/parisc/include/asm/mmu

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __PARISC_MMU_CONTEXT_H
   3#define __PARISC_MMU_CONTEXT_H
   4
   5#include <linux/mm.h>
   6#include <linux/sched.h>
   7#include <linux/atomic.h>
   8#include <linux/spinlock.h>
   9#include <asm-generic/mm_hooks.h>
  10
  11/* on PA-RISC, we actually have enough contexts to justify an allocator
  12 * for them.  prumpf */
  13
  14extern unsigned long alloc_sid(void);
  15extern void free_sid(unsigned long);
  16
  17#define init_new_context init_new_context
  18static inline int
  19init_new_context(struct task_struct *tsk, struct mm_struct *mm)
  20{
  21        BUG_ON(atomic_read(&mm->mm_users) != 1);
  22
  23        mm->context = alloc_sid();
  24        return 0;
  25}
  26
  27#define destroy_context destroy_context
  28static inline void
  29destroy_context(struct mm_struct *mm)
  30{
  31        free_sid(mm->context);
  32        mm->context = 0;
  33}
  34
  35static inline unsigned long __space_to_prot(mm_context_t context)
  36{
  37#if SPACEID_SHIFT == 0
  38        return context << 1;
  39#else
  40        return context >> (SPACEID_SHIFT - 1);
  41#endif
  42}
  43
  44static inline void load_context(mm_context_t context)
  45{
  46        mtsp(context, 3);
  47        mtctl(__space_to_prot(context), 8);
  48}
  49
  50static inline void switch_mm_irqs_off(struct mm_struct *prev,
  51                struct mm_struct *next, struct task_struct *tsk)
  52{
  53        if (prev != next) {
  54#ifdef CONFIG_TLB_PTLOCK
  55                /* put physical address of page_table_lock in cr28 (tr4)
  56                   for TLB faults */
  57                spinlock_t *pgd_lock = &next->page_table_lock;
  58                mtctl(__pa(__ldcw_align(&pgd_lock->rlock.raw_lock)), 28);
  59#endif
  60                mtctl(__pa(next->pgd), 25);
  61                load_context(next->context);
  62        }
  63}
  64
  65static inline void switch_mm(struct mm_struct *prev,
  66                struct mm_struct *next, struct task_struct *tsk)
  67{
  68        unsigned long flags;
  69
  70        if (prev == next)
  71                return;
  72
  73        local_irq_save(flags);
  74        switch_mm_irqs_off(prev, next, tsk);
  75        local_irq_restore(flags);
  76}
  77#define switch_mm_irqs_off switch_mm_irqs_off
  78
  79#define activate_mm activate_mm
  80static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  81{
  82        /*
  83         * Activate_mm is our one chance to allocate a space id
  84         * for a new mm created in the exec path. There's also
  85         * some lazy tlb stuff, which is currently dead code, but
  86         * we only allocate a space id if one hasn't been allocated
  87         * already, so we should be OK.
  88         */
  89
  90        BUG_ON(next == &init_mm); /* Should never happen */
  91
  92        if (next->context == 0)
  93            next->context = alloc_sid();
  94
  95        switch_mm(prev,next,current);
  96}
  97
  98#include <asm-generic/mmu_context.h>
  99
 100#endif
 101