summaryrefslogtreecommitdiffstats
path: root/arch/m68k/include/asm/mmu_context.h
blob: 993fd7e37069fda5ff93bdccefd37f8d6762da5d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __M68K_MMU_CONTEXT_H
#define __M68K_MMU_CONTEXT_H

#include <asm-generic/mm_hooks.h>
#include <linux/mm_types.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}

#ifdef CONFIG_MMU

#if defined(CONFIG_COLDFIRE)

#include <asm/atomic.h>
#include <asm/bitops.h>
#include <asm/mcfmmu.h>
#include <asm/mmu.h>

#define NO_CONTEXT		256
#define LAST_CONTEXT		255
#define FIRST_CONTEXT		1

extern unsigned long context_map[];
extern mm_context_t next_mmu_context;

extern atomic_t nr_free_contexts;
extern struct mm_struct *context_mm[LAST_CONTEXT+1];
extern void steal_context(void);

static inline void get_mmu_context(struct mm_struct *mm)
{
	mm_context_t ctx;

	if (mm->context != NO_CONTEXT)
		return;
	while (atomic_dec_and_test_lt(&nr_free_contexts)) {
		atomic_inc(&nr_free_contexts);
		steal_context();
	}
	ctx = next_mmu_context;
	while (test_and_set_bit(ctx, context_map)) {
		ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx);
		if (ctx > LAST_CONTEXT)
			ctx = 0;
	}
	next_mmu_context = (ctx + 1) & LAST_CONTEXT;
	mm->context = ctx;
	context_mm[ctx] = mm;
}

/*
 * Set up the context for a new address space.
 */
#define init_new_context(tsk, mm)	(((mm)->context = NO_CONTEXT), 0)

/*
 * We're finished using the context for an address space.
 */
static inline void destroy_context(struct mm_struct *mm)
{
	if (mm->context != NO_CONTEXT) {
		clear_bit(mm->context, context_map);
		mm->context = NO_CONTEXT;
		atomic_inc(&nr_free_contexts);
	}
}

static inline void set_context(mm_context_t context, pgd_t *pgd)
{
	__asm__ __volatile__ ("movec %0,%%asid" : : "d" (context));
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
	struct task_struct *tsk)
{
	get_mmu_context(tsk->mm);
	set_context(tsk->mm->context, next->pgd);
}

/*
 * After we have set current->mm to a new value, this activates
 * the context for the new mm so we see the new mappings.
 */
static inline void activate_mm(struct mm_struct *active_mm,
	struct mm_struct *mm)
{
	get_mmu_context(mm);
	set_context(mm->context, mm->pgd);
}

#define deactivate_mm(tsk, mm) do { } while (0)

#define prepare_arch_switch(next) load_ksp_mmu(next)

static inline void load_ksp_mmu(struct task_struct *task)
{
	unsigned long flags;
	struct mm_struct *mm;
	int asid;
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	unsigned long mmuar;

	local_irq_save(flags);
	mmuar = task->thread.ksp;

	/* Search for a valid TLB entry, if one is found, don't remap */
	mmu_write(MMUAR, mmuar);
	mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR);
	if (mmu_read(MMUSR) & MMUSR_HIT)
		goto end;

	if (mmuar >= PAGE_OFFSET) {
		mm = &init_mm;
	} else {
		pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm);
		mm = task->mm;
	}

	if (!mm)
		goto bug;

	pgd = pgd_offset(mm, mmuar);
	if (pgd_none(*pgd))
		goto bug;

	p4d = p4d_offset(pgd, mmuar);
	if (p4d_none(*p4d))
		goto bug;

	pud = pud_offset(p4d, mmuar);
	if (pud_none(*pud))
		goto bug;

	pmd = pmd_offset(pud, mmuar);
	if (pmd_none(*pmd))
		goto bug;

	pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar)
				     : pte_offset_map(pmd, mmuar);
	if (pte_none(*pte) || !pte_present(*pte))
		goto bug;

	set_pte(pte, pte_mkyoung(*pte));
	asid = mm->context & 0xff;
	if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET)
		set_pte(pte, pte_wrprotect(*pte));

	mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) |
		(((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK)
		>> CF_PAGE_MMUTR_SHIFT) | MMUTR_V);

	mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
		((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);

	mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);

	goto end;

bug:
	pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar);
end:
	local_irq_restore(flags);
}

#elif defined(CONFIG_SUN3)
#include <asm/sun3mmu.h>
#include <linux/sched.h>

extern unsigned long get_free_context(struct mm_struct *mm);
extern void clear_context(unsigned long context);

/* set the context for a new task to unmapped */
static inline int init_new_context(struct task_struct *tsk,
				   struct mm_struct *mm)
{
	mm->context = SUN3_INVALID_CONTEXT;
	return 0;
}

/* find the context given to this process, and if it hasn't already
   got one, go get one for it. */
static inline void get_mmu_context(struct mm_struct *mm)
{
	if (mm->context == SUN3_INVALID_CONTEXT)
		mm->context = get_free_context(mm);
}

/* flush context if allocated... */
static inline void destroy_context(struct mm_struct *mm)
{
	if (mm->context != SUN3_INVALID_CONTEXT)
		clear_context(mm->context);
}

static inline void activate_context(struct mm_struct *mm)
{
	get_mmu_context(mm);
	sun3_put_context(mm->context);
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
			     struct task_struct *tsk)
{
	activate_context(tsk->mm);
}

#define deactivate_mm(tsk, mm)	do { } while (0)

static inline void activate_mm(struct mm_struct *prev_mm,
			       struct mm_struct *next_mm)
{
	activate_context(next_mm);
}

#else

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/cacheflush.h>

static inline int init_new_context(struct task_struct *tsk,
				   struct mm_struct *mm)
{
	mm->context = virt_to_phys(mm->pgd);
	return 0;
}

#define destroy_context(mm)		do { } while(0)

static inline void switch_mm_0230(struct mm_struct *mm)
{
	unsigned long crp[2] = {
		0x80000000 | _PAGE_TABLE, mm->context
	};
	unsigned long tmp;

	asm volatile (".chip 68030");

	/* flush MC68030/MC68020 caches (they are virtually addressed) */
	asm volatile (
		"movec %%cacr,%0;"
		"orw %1,%0; "
		"movec %0,%%cacr"
		: "=d" (tmp) : "di" (FLUSH_I_AND_D));

	/* Switch the root pointer. For a 030-only kernel,
	 * avoid flushing the whole ATC, we only need to
	 * flush the user entries. The 68851 does this by
	 * itself. Avoid a runtime check here.
	 */
	asm volatile (
#ifdef CPU_M68030_ONLY
		"pmovefd %0,%%crp; "
		"pflush #0,#4"
#else
		"pmove %0,%%crp"
#endif
		: : "m" (crp[0]));

	asm volatile (".chip 68k");
}

static inline void switch_mm_0460(struct mm_struct *mm)
{
	asm volatile (".chip 68040");

	/* flush address translation cache (user entries) */
	asm volatile ("pflushan");

	/* switch the root pointer */
	asm volatile ("movec %0,%%urp" : : "r" (mm->context));

	if (CPU_IS_060) {
		unsigned long tmp;

		/* clear user entries in the branch cache */
		asm volatile (
			"movec %%cacr,%0; "
		        "orl %1,%0; "
		        "movec %0,%%cacr"
			: "=d" (tmp): "di" (0x00200000));
	}

	asm volatile (".chip 68k");
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
{
	if (prev != next) {
		if (CPU_IS_020_OR_030)
			switch_mm_0230(next);
		else
			switch_mm_0460(next);
	}
}

#define deactivate_mm(tsk,mm)	do { } while (0)

static inline void activate_mm(struct mm_struct *prev_mm,
			       struct mm_struct *next_mm)
{
	next_mm->context = virt_to_phys(next_mm->pgd);

	if (CPU_IS_020_OR_030)
		switch_mm_0230(next_mm);
	else
		switch_mm_0460(next_mm);
}

#endif

#else /* !CONFIG_MMU */

static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
	return 0;
}


static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
{
}

#define destroy_context(mm)	do { } while (0)
#define deactivate_mm(tsk,mm)	do { } while (0)

static inline void activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
{
}

#endif /* CONFIG_MMU */
#endif /* __M68K_MMU_CONTEXT_H */