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