1#ifndef __ASM_SH64_MMU_CONTEXT_H
2#define __ASM_SH64_MMU_CONTEXT_H
3
4/*
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License.  See the file "COPYING" in the main directory of this archive
7 * for more details.
8 *
9 * include/asm-sh64/mmu_context.h
10 *
11 * Copyright (C) 2000, 2001  Paolo Alberelli
12 * Copyright (C) 2003  Paul Mundt
13 *
14 * ASID handling idea taken from MIPS implementation.
15 *
16 */
17
18#ifndef __ASSEMBLY__
19
20/*
21 * Cache of MMU context last used.
22 *
23 * The MMU "context" consists of two things:
24 *   (a) TLB cache version (or cycle, top 24 bits of mmu_context_cache)
25 *   (b) ASID (Address Space IDentifier, bottom 8 bits of mmu_context_cache)
26 */
27extern unsigned long mmu_context_cache;
28
29#include <asm/page.h>
30#include <asm-generic/mm_hooks.h>
31
32/* Current mm's pgd */
33extern pgd_t *mmu_pdtp_cache;
34
35#define SR_ASID_MASK		0xffffffffff00ffffULL
36#define SR_ASID_SHIFT		16
37
38#define MMU_CONTEXT_ASID_MASK		0x000000ff
39#define MMU_CONTEXT_VERSION_MASK	0xffffff00
40#define MMU_CONTEXT_FIRST_VERSION	0x00000100
41#define NO_CONTEXT			0
42
43/* ASID is 8-bit value, so it can't be 0x100 */
44#define MMU_NO_ASID			0x100
45
46
47/*
48 * Virtual Page Number mask
49 */
50#define MMU_VPN_MASK	0xfffff000
51
52static inline void
53get_new_mmu_context(struct mm_struct *mm)
54{
55	extern void flush_tlb_all(void);
56	extern void flush_cache_all(void);
57
58	unsigned long mc = ++mmu_context_cache;
59
60	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
61		/* We exhaust ASID of this version.
62		   Flush all TLB and start new cycle. */
63		flush_tlb_all();
64		/* We have to flush all caches as ASIDs are
65                   used in cache */
66		flush_cache_all();
67		/* Fix version if needed.
68		   Note that we avoid version #0/asid #0 to distingush NO_CONTEXT. */
69		if (!mc)
70			mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
71	}
72	mm->context = mc;
73}
74
75/*
76 * Get MMU context if needed.
77 */
78static __inline__ void
79get_mmu_context(struct mm_struct *mm)
80{
81	if (mm) {
82		unsigned long mc = mmu_context_cache;
83		/* Check if we have old version of context.
84		   If it's old, we need to get new context with new version. */
85		if ((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK)
86			get_new_mmu_context(mm);
87	}
88}
89
90/*
91 * Initialize the context related info for a new mm_struct
92 * instance.
93 */
94static inline int init_new_context(struct task_struct *tsk,
95					struct mm_struct *mm)
96{
97	mm->context = NO_CONTEXT;
98
99	return 0;
100}
101
102/*
103 * Destroy context related info for an mm_struct that is about
104 * to be put to rest.
105 */
106static inline void destroy_context(struct mm_struct *mm)
107{
108	extern void flush_tlb_mm(struct mm_struct *mm);
109
110	/* Well, at least free TLB entries */
111	flush_tlb_mm(mm);
112}
113
114#endif	/* __ASSEMBLY__ */
115
116/* Common defines */
117#define TLB_STEP	0x00000010
118#define TLB_PTEH	0x00000000
119#define TLB_PTEL	0x00000008
120
121/* PTEH defines */
122#define PTEH_ASID_SHIFT	2
123#define PTEH_VALID	0x0000000000000001
124#define PTEH_SHARED	0x0000000000000002
125#define PTEH_MATCH_ASID	0x00000000000003ff
126
127#ifndef __ASSEMBLY__
128/* This has to be a common function because the next location to fill
129 * information is shared. */
130extern void __do_tlb_refill(unsigned long address, unsigned long long is_text_not_data, pte_t *pte);
131
132/* Profiling counter. */
133#ifdef CONFIG_SH64_PROC_TLB
134extern unsigned long long calls_to_do_fast_page_fault;
135#endif
136
137static inline unsigned long get_asid(void)
138{
139	unsigned long long sr;
140
141	asm volatile ("getcon   " __SR ", %0\n\t"
142		      : "=r" (sr));
143
144	sr = (sr >> SR_ASID_SHIFT) & MMU_CONTEXT_ASID_MASK;
145	return (unsigned long) sr;
146}
147
148/* Set ASID into SR */
149static inline void set_asid(unsigned long asid)
150{
151	unsigned long long sr, pc;
152
153	asm volatile ("getcon	" __SR ", %0" : "=r" (sr));
154
155	sr = (sr & SR_ASID_MASK) | (asid << SR_ASID_SHIFT);
156
157	/*
158	 * It is possible that this function may be inlined and so to avoid
159	 * the assembler reporting duplicate symbols we make use of the gas trick
160	 * of generating symbols using numerics and forward reference.
161	 */
162	asm volatile ("movi	1, %1\n\t"
163		      "shlli	%1, 28, %1\n\t"
164		      "or	%0, %1, %1\n\t"
165		      "putcon	%1, " __SR "\n\t"
166		      "putcon	%0, " __SSR "\n\t"
167		      "movi	1f, %1\n\t"
168		      "ori	%1, 1 , %1\n\t"
169		      "putcon	%1, " __SPC "\n\t"
170		      "rte\n"
171		      "1:\n\t"
172		      : "=r" (sr), "=r" (pc) : "0" (sr));
173}
174
175/*
176 * After we have set current->mm to a new value, this activates
177 * the context for the new mm so we see the new mappings.
178 */
179static __inline__ void activate_context(struct mm_struct *mm)
180{
181	get_mmu_context(mm);
182	set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
183}
184
185
186static __inline__ void switch_mm(struct mm_struct *prev,
187				 struct mm_struct *next,
188				 struct task_struct *tsk)
189{
190	if (prev != next) {
191		mmu_pdtp_cache = next->pgd;
192		activate_context(next);
193	}
194}
195
196#define deactivate_mm(tsk,mm)	do { } while (0)
197
198#define activate_mm(prev, next) \
199	switch_mm((prev),(next),NULL)
200
201static inline void
202enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
203{
204}
205
206#endif	/* __ASSEMBLY__ */
207
208#endif /* __ASM_SH64_MMU_CONTEXT_H */
209