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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 | ||
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 | |
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 | |
32 | destroy_context(struct mm_struct *mm) | |
33 | { | |
34 | free_sid(mm->context); | |
35 | mm->context = 0; | |
36 | } | |
37 | ||
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 | ||
47 | static inline void load_context(mm_context_t context) | |
48 | { | |
49 | mtsp(context, 3); | |
50 | mtctl(__space_to_prot(context), 8); | |
51 | } | |
52 | ||
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 | ||
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 | ||
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 |