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