1#ifndef __PARISC_MMU_CONTEXT_H
2#define __PARISC_MMU_CONTEXT_H
3
4#include <linux/mm.h>
5#include <linux/sched.h>
6#include <asm/atomic.h>
7#include <asm/pgalloc.h>
8#include <asm/pgtable.h>
9#include <asm-generic/mm_hooks.h>
10
11static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
12{
13}
14
15/* on PA-RISC, we actually have enough contexts to justify an allocator
16 * for them.  prumpf */
17
18extern unsigned long alloc_sid(void);
19extern void free_sid(unsigned long);
20
21static inline int
22init_new_context(struct task_struct *tsk, struct mm_struct *mm)
23{
24	BUG_ON(atomic_read(&mm->mm_users) != 1);
25
26	mm->context = alloc_sid();
27	return 0;
28}
29
30static inline void
31destroy_context(struct mm_struct *mm)
32{
33	free_sid(mm->context);
34	mm->context = 0;
35}
36
37static inline void load_context(mm_context_t context)
38{
39	mtsp(context, 3);
40#if SPACEID_SHIFT == 0
41	mtctl(context << 1,8);
42#else
43	mtctl(context >> (SPACEID_SHIFT - 1),8);
44#endif
45}
46
47static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
48{
49
50	if (prev != next) {
51		mtctl(__pa(next->pgd), 25);
52		load_context(next->context);
53	}
54}
55
56#define deactivate_mm(tsk,mm)	do { } while (0)
57
58static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
59{
60	/*
61	 * Activate_mm is our one chance to allocate a space id
62	 * for a new mm created in the exec path. There's also
63	 * some lazy tlb stuff, which is currently dead code, but
64	 * we only allocate a space id if one hasn't been allocated
65	 * already, so we should be OK.
66	 */
67
68	BUG_ON(next == &init_mm); /* Should never happen */
69
70	if (next->context == 0)
71	    next->context = alloc_sid();
72
73	switch_mm(prev,next,current);
74}
75#endif
76