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1#ifndef _ASM_SCORE_MMU_CONTEXT_H
2#define _ASM_SCORE_MMU_CONTEXT_H
3
4#include <linux/errno.h>
5#include <linux/sched.h>
6#include <linux/mm_types.h>
7#include <linux/slab.h>
8
9#include <asm-generic/mm_hooks.h>
10
11#include <asm/cacheflush.h>
12#include <asm/tlbflush.h>
13#include <asm/scoreregs.h>
14
15/*
16 * For the fast tlb miss handlers, we keep a per cpu array of pointers
17 * to the current pgd for each processor. Also, the proc. id is stuffed
18 * into the context register.
19 */
20extern unsigned long asid_cache;
21extern unsigned long pgd_current;
22
23#define TLBMISS_HANDLER_SETUP_PGD(pgd) (pgd_current = (unsigned long)(pgd))
24
25#define TLBMISS_HANDLER_SETUP() \
26do { \
27 write_c0_context(0); \
28 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) \
29} while (0)
30
31/*
32 * All unused by hardware upper bits will be considered
33 * as a software asid extension.
34 */
35#define ASID_VERSION_MASK 0xfffff000
36#define ASID_FIRST_VERSION 0x1000
37
38/* PEVN --------- VPN ---------- --ASID--- -NA- */
39/* binary: 0000 0000 0000 0000 0000 0000 0001 0000 */
40/* binary: 0000 0000 0000 0000 0000 1111 1111 0000 */
41#define ASID_INC 0x10
42#define ASID_MASK 0xff0
43
44static inline void enter_lazy_tlb(struct mm_struct *mm,
45 struct task_struct *tsk)
46{}
47
48static inline void
49get_new_mmu_context(struct mm_struct *mm)
50{
51 unsigned long asid = asid_cache + ASID_INC;
52
53 if (!(asid & ASID_MASK)) {
54 local_flush_tlb_all(); /* start new asid cycle */
55 if (!asid) /* fix version if needed */
56 asid = ASID_FIRST_VERSION;
57 }
58
59 mm->context = asid;
60 asid_cache = asid;
61}
62
63/*
64 * Initialize the context related info for a new mm_struct
65 * instance.
66 */
67static inline int
68init_new_context(struct task_struct *tsk, struct mm_struct *mm)
69{
70 mm->context = 0;
71 return 0;
72}
73
74static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
75 struct task_struct *tsk)
76{
77 unsigned long flags;
78
79 local_irq_save(flags);
80 if ((next->context ^ asid_cache) & ASID_VERSION_MASK)
81 get_new_mmu_context(next);
82
83 pevn_set(next->context);
84 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
85 local_irq_restore(flags);
86}
87
88/*
89 * Destroy context related info for an mm_struct that is about
90 * to be put to rest.
91 */
92static inline void destroy_context(struct mm_struct *mm)
93{}
94
95static inline void
96deactivate_mm(struct task_struct *task, struct mm_struct *mm)
97{}
98
99/*
100 * After we have set current->mm to a new value, this activates
101 * the context for the new mm so we see the new mappings.
102 */
103static inline void
104activate_mm(struct mm_struct *prev, struct mm_struct *next)
105{
106 unsigned long flags;
107
108 local_irq_save(flags);
109 get_new_mmu_context(next);
110 pevn_set(next->context);
111 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
112 local_irq_restore(flags);
113}
114
115#endif /* _ASM_SCORE_MMU_CONTEXT_H */