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
enter_lazy_tlb(struct mm_struct * mm,struct task_struct * tsk)11 static 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
18 extern unsigned long alloc_sid(void);
19 extern void free_sid(unsigned long);
20
21 static inline int
init_new_context(struct task_struct * tsk,struct mm_struct * mm)22 init_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
30 static inline void
destroy_context(struct mm_struct * mm)31 destroy_context(struct mm_struct *mm)
32 {
33 free_sid(mm->context);
34 mm->context = 0;
35 }
36
__space_to_prot(mm_context_t context)37 static inline unsigned long __space_to_prot(mm_context_t context)
38 {
39 #if SPACEID_SHIFT == 0
40 return context << 1;
41 #else
42 return context >> (SPACEID_SHIFT - 1);
43 #endif
44 }
45
load_context(mm_context_t context)46 static inline void load_context(mm_context_t context)
47 {
48 mtsp(context, 3);
49 mtctl(__space_to_prot(context), 8);
50 }
51
switch_mm_irqs_off(struct mm_struct * prev,struct mm_struct * next,struct task_struct * tsk)52 static inline void switch_mm_irqs_off(struct mm_struct *prev,
53 struct mm_struct *next, struct task_struct *tsk)
54 {
55 if (prev != next) {
56 #ifdef CONFIG_TLB_PTLOCK
57 /* put physical address of page_table_lock in cr28 (tr4)
58 for TLB faults */
59 spinlock_t *pgd_lock = &next->page_table_lock;
60 mtctl(__pa(__ldcw_align(&pgd_lock->rlock.raw_lock)), 28);
61 #endif
62 mtctl(__pa(next->pgd), 25);
63 load_context(next->context);
64 }
65 }
66
switch_mm(struct mm_struct * prev,struct mm_struct * next,struct task_struct * tsk)67 static inline void switch_mm(struct mm_struct *prev,
68 struct mm_struct *next, struct task_struct *tsk)
69 {
70 unsigned long flags;
71
72 if (prev == next)
73 return;
74
75 local_irq_save(flags);
76 switch_mm_irqs_off(prev, next, tsk);
77 local_irq_restore(flags);
78 }
79 #define switch_mm_irqs_off switch_mm_irqs_off
80
81 #define deactivate_mm(tsk,mm) do { } while (0)
82
activate_mm(struct mm_struct * prev,struct mm_struct * next)83 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
84 {
85 /*
86 * Activate_mm is our one chance to allocate a space id
87 * for a new mm created in the exec path. There's also
88 * some lazy tlb stuff, which is currently dead code, but
89 * we only allocate a space id if one hasn't been allocated
90 * already, so we should be OK.
91 */
92
93 BUG_ON(next == &init_mm); /* Should never happen */
94
95 if (next->context == 0)
96 next->context = alloc_sid();
97
98 switch_mm(prev,next,current);
99 }
100 #endif
101