1#ifndef __M68K_MMU_CONTEXT_H
2#define __M68K_MMU_CONTEXT_H
3
4#include <asm-generic/mm_hooks.h>
5
6static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
7{
8}
9
10#ifdef CONFIG_MMU
11
12#if defined(CONFIG_COLDFIRE)
13
14#include <asm/atomic.h>
15#include <asm/bitops.h>
16#include <asm/mcfmmu.h>
17#include <asm/mmu.h>
18
19#define NO_CONTEXT		256
20#define LAST_CONTEXT		255
21#define FIRST_CONTEXT		1
22
23extern unsigned long context_map[];
24extern mm_context_t next_mmu_context;
25
26extern atomic_t nr_free_contexts;
27extern struct mm_struct *context_mm[LAST_CONTEXT+1];
28extern void steal_context(void);
29
30static inline void get_mmu_context(struct mm_struct *mm)
31{
32	mm_context_t ctx;
33
34	if (mm->context != NO_CONTEXT)
35		return;
36	while (atomic_dec_and_test_lt(&nr_free_contexts)) {
37		atomic_inc(&nr_free_contexts);
38		steal_context();
39	}
40	ctx = next_mmu_context;
41	while (test_and_set_bit(ctx, context_map)) {
42		ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx);
43		if (ctx > LAST_CONTEXT)
44			ctx = 0;
45	}
46	next_mmu_context = (ctx + 1) & LAST_CONTEXT;
47	mm->context = ctx;
48	context_mm[ctx] = mm;
49}
50
51/*
52 * Set up the context for a new address space.
53 */
54#define init_new_context(tsk, mm)	(((mm)->context = NO_CONTEXT), 0)
55
56/*
57 * We're finished using the context for an address space.
58 */
59static inline void destroy_context(struct mm_struct *mm)
60{
61	if (mm->context != NO_CONTEXT) {
62		clear_bit(mm->context, context_map);
63		mm->context = NO_CONTEXT;
64		atomic_inc(&nr_free_contexts);
65	}
66}
67
68static inline void set_context(mm_context_t context, pgd_t *pgd)
69{
70	__asm__ __volatile__ ("movec %0,%%asid" : : "d" (context));
71}
72
73static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
74	struct task_struct *tsk)
75{
76	get_mmu_context(tsk->mm);
77	set_context(tsk->mm->context, next->pgd);
78}
79
80/*
81 * After we have set current->mm to a new value, this activates
82 * the context for the new mm so we see the new mappings.
83 */
84static inline void activate_mm(struct mm_struct *active_mm,
85	struct mm_struct *mm)
86{
87	get_mmu_context(mm);
88	set_context(mm->context, mm->pgd);
89}
90
91#define deactivate_mm(tsk, mm) do { } while (0)
92
93extern void mmu_context_init(void);
94#define prepare_arch_switch(next) load_ksp_mmu(next)
95
96static inline void load_ksp_mmu(struct task_struct *task)
97{
98	unsigned long flags;
99	struct mm_struct *mm;
100	int asid;
101	pgd_t *pgd;
102	pmd_t *pmd;
103	pte_t *pte;
104	unsigned long mmuar;
105
106	local_irq_save(flags);
107	mmuar = task->thread.ksp;
108
109	/* Search for a valid TLB entry, if one is found, don't remap */
110	mmu_write(MMUAR, mmuar);
111	mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR);
112	if (mmu_read(MMUSR) & MMUSR_HIT)
113		goto end;
114
115	if (mmuar >= PAGE_OFFSET) {
116		mm = &init_mm;
117	} else {
118		pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm);
119		mm = task->mm;
120	}
121
122	if (!mm)
123		goto bug;
124
125	pgd = pgd_offset(mm, mmuar);
126	if (pgd_none(*pgd))
127		goto bug;
128
129	pmd = pmd_offset(pgd, mmuar);
130	if (pmd_none(*pmd))
131		goto bug;
132
133	pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar)
134				     : pte_offset_map(pmd, mmuar);
135	if (pte_none(*pte) || !pte_present(*pte))
136		goto bug;
137
138	set_pte(pte, pte_mkyoung(*pte));
139	asid = mm->context & 0xff;
140	if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET)
141		set_pte(pte, pte_wrprotect(*pte));
142
143	mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) |
144		(((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK)
145		>> CF_PAGE_MMUTR_SHIFT) | MMUTR_V);
146
147	mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
148		((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
149
150	mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
151
152	goto end;
153
154bug:
155	pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar);
156end:
157	local_irq_restore(flags);
158}
159
160#elif defined(CONFIG_SUN3)
161#include <asm/sun3mmu.h>
162#include <linux/sched.h>
163
164extern unsigned long get_free_context(struct mm_struct *mm);
165extern void clear_context(unsigned long context);
166
167/* set the context for a new task to unmapped */
168static inline int init_new_context(struct task_struct *tsk,
169				   struct mm_struct *mm)
170{
171	mm->context = SUN3_INVALID_CONTEXT;
172	return 0;
173}
174
175/* find the context given to this process, and if it hasn't already
176   got one, go get one for it. */
177static inline void get_mmu_context(struct mm_struct *mm)
178{
179	if (mm->context == SUN3_INVALID_CONTEXT)
180		mm->context = get_free_context(mm);
181}
182
183/* flush context if allocated... */
184static inline void destroy_context(struct mm_struct *mm)
185{
186	if (mm->context != SUN3_INVALID_CONTEXT)
187		clear_context(mm->context);
188}
189
190static inline void activate_context(struct mm_struct *mm)
191{
192	get_mmu_context(mm);
193	sun3_put_context(mm->context);
194}
195
196static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
197			     struct task_struct *tsk)
198{
199	activate_context(tsk->mm);
200}
201
202#define deactivate_mm(tsk, mm)	do { } while (0)
203
204static inline void activate_mm(struct mm_struct *prev_mm,
205			       struct mm_struct *next_mm)
206{
207	activate_context(next_mm);
208}
209
210#else
211
212#include <asm/setup.h>
213#include <asm/page.h>
214#include <asm/pgalloc.h>
215
216static inline int init_new_context(struct task_struct *tsk,
217				   struct mm_struct *mm)
218{
219	mm->context = virt_to_phys(mm->pgd);
220	return 0;
221}
222
223#define destroy_context(mm)		do { } while(0)
224
225static inline void switch_mm_0230(struct mm_struct *mm)
226{
227	unsigned long crp[2] = {
228		0x80000000 | _PAGE_TABLE, mm->context
229	};
230	unsigned long tmp;
231
232	asm volatile (".chip 68030");
233
234	/* flush MC68030/MC68020 caches (they are virtually addressed) */
235	asm volatile (
236		"movec %%cacr,%0;"
237		"orw %1,%0; "
238		"movec %0,%%cacr"
239		: "=d" (tmp) : "di" (FLUSH_I_AND_D));
240
241	/* Switch the root pointer. For a 030-only kernel,
242	 * avoid flushing the whole ATC, we only need to
243	 * flush the user entries. The 68851 does this by
244	 * itself. Avoid a runtime check here.
245	 */
246	asm volatile (
247#ifdef CPU_M68030_ONLY
248		"pmovefd %0,%%crp; "
249		"pflush #0,#4"
250#else
251		"pmove %0,%%crp"
252#endif
253		: : "m" (crp[0]));
254
255	asm volatile (".chip 68k");
256}
257
258static inline void switch_mm_0460(struct mm_struct *mm)
259{
260	asm volatile (".chip 68040");
261
262	/* flush address translation cache (user entries) */
263	asm volatile ("pflushan");
264
265	/* switch the root pointer */
266	asm volatile ("movec %0,%%urp" : : "r" (mm->context));
267
268	if (CPU_IS_060) {
269		unsigned long tmp;
270
271		/* clear user entries in the branch cache */
272		asm volatile (
273			"movec %%cacr,%0; "
274		        "orl %1,%0; "
275		        "movec %0,%%cacr"
276			: "=d" (tmp): "di" (0x00200000));
277	}
278
279	asm volatile (".chip 68k");
280}
281
282static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
283{
284	if (prev != next) {
285		if (CPU_IS_020_OR_030)
286			switch_mm_0230(next);
287		else
288			switch_mm_0460(next);
289	}
290}
291
292#define deactivate_mm(tsk,mm)	do { } while (0)
293
294static inline void activate_mm(struct mm_struct *prev_mm,
295			       struct mm_struct *next_mm)
296{
297	next_mm->context = virt_to_phys(next_mm->pgd);
298
299	if (CPU_IS_020_OR_030)
300		switch_mm_0230(next_mm);
301	else
302		switch_mm_0460(next_mm);
303}
304
305#endif
306
307#else /* !CONFIG_MMU */
308
309static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
310{
311	return 0;
312}
313
314
315static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
316{
317}
318
319#define destroy_context(mm)	do { } while (0)
320#define deactivate_mm(tsk,mm)	do { } while (0)
321
322static inline void activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
323{
324}
325
326#endif /* CONFIG_MMU */
327#endif /* __M68K_MMU_CONTEXT_H */
328