1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __M68K_MMU_CONTEXT_H
3 #define __M68K_MMU_CONTEXT_H
4
5 #include <asm-generic/mm_hooks.h>
6 #include <linux/mm_types.h>
7
8 #ifdef CONFIG_MMU
9
10 #if defined(CONFIG_COLDFIRE)
11
12 #include <asm/atomic.h>
13 #include <asm/bitops.h>
14 #include <asm/mcfmmu.h>
15 #include <asm/mmu.h>
16
17 #define NO_CONTEXT 256
18 #define LAST_CONTEXT 255
19 #define FIRST_CONTEXT 1
20
21 extern unsigned long context_map[];
22 extern mm_context_t next_mmu_context;
23
24 extern atomic_t nr_free_contexts;
25 extern struct mm_struct *context_mm[LAST_CONTEXT+1];
26 extern void steal_context(void);
27
28 static inline void get_mmu_context(struct mm_struct *mm)
29 {
30 mm_context_t ctx;
31
32 if (mm->context != NO_CONTEXT)
33 return;
34 while (arch_atomic_dec_and_test_lt(&nr_free_contexts)) {
35 atomic_inc(&nr_free_contexts);
36 steal_context();
37 }
38 ctx = next_mmu_context;
39 while (test_and_set_bit(ctx, context_map)) {
40 ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx);
41 if (ctx > LAST_CONTEXT)
42 ctx = 0;
43 }
44 next_mmu_context = (ctx + 1) & LAST_CONTEXT;
45 mm->context = ctx;
46 context_mm[ctx] = mm;
47 }
48
49 /*
50 * Set up the context for a new address space.
51 */
52 #define init_new_context(tsk, mm) (((mm)->context = NO_CONTEXT), 0)
53
54 /*
55 * We're finished using the context for an address space.
56 */
57 #define destroy_context destroy_context
58 static inline void destroy_context(struct mm_struct *mm)
59 {
60 if (mm->context != NO_CONTEXT) {
61 clear_bit(mm->context, context_map);
62 mm->context = NO_CONTEXT;
63 atomic_inc(&nr_free_contexts);
64 }
65 }
66
67 static inline void set_context(mm_context_t context, pgd_t *pgd)
68 {
69 __asm__ __volatile__ ("movec %0,%%asid" : : "d" (context));
70 }
71
72 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
73 struct task_struct *tsk)
74 {
75 get_mmu_context(tsk->mm);
76 set_context(tsk->mm->context, next->pgd);
77 }
78
79 /*
80 * After we have set current->mm to a new value, this activates
81 * the context for the new mm so we see the new mappings.
82 */
83 #define activate_mm activate_mm
84 static 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 prepare_arch_switch(next) load_ksp_mmu(next)
92
93 static inline void load_ksp_mmu(struct task_struct *task)
94 {
95 unsigned long flags;
96 struct mm_struct *mm;
97 int asid;
98 pgd_t *pgd;
99 p4d_t *p4d;
100 pud_t *pud;
101 pmd_t *pmd;
102 pte_t *pte = NULL;
103 unsigned long mmuar;
104
105 local_irq_save(flags);
106 mmuar = task->thread.ksp;
107
108 /* Search for a valid TLB entry, if one is found, don't remap */
109 mmu_write(MMUAR, mmuar);
110 mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR);
111 if (mmu_read(MMUSR) & MMUSR_HIT)
112 goto end;
113
114 if (mmuar >= PAGE_OFFSET) {
115 mm = &init_mm;
116 } else {
117 pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm);
118 mm = task->mm;
119 }
120
121 if (!mm)
122 goto bug;
123
124 pgd = pgd_offset(mm, mmuar);
125 if (pgd_none(*pgd))
126 goto bug;
127
128 p4d = p4d_offset(pgd, mmuar);
129 if (p4d_none(*p4d))
130 goto bug;
131
132 pud = pud_offset(p4d, mmuar);
133 if (pud_none(*pud))
134 goto bug;
135
136 pmd = pmd_offset(pud, mmuar);
137 if (pmd_none(*pmd))
138 goto bug;
139
140 pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar)
141 : pte_offset_map(pmd, mmuar);
142 if (!pte || pte_none(*pte) || !pte_present(*pte))
143 goto bug;
144
145 set_pte(pte, pte_mkyoung(*pte));
146 asid = mm->context & 0xff;
147 if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET)
148 set_pte(pte, pte_wrprotect(*pte));
149
150 mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) |
151 (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK)
152 >> CF_PAGE_MMUTR_SHIFT) | MMUTR_V);
153
154 mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
155 ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
156
157 mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
158
159 goto end;
160
161 bug:
162 pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar);
163 end:
164 if (pte && mmuar < PAGE_OFFSET)
165 pte_unmap(pte);
166 local_irq_restore(flags);
167 }
168
169 #elif defined(CONFIG_SUN3)
170 #include <asm/sun3mmu.h>
171 #include <linux/sched.h>
172
173 extern unsigned long get_free_context(struct mm_struct *mm);
174 extern void clear_context(unsigned long context);
175
176 /* set the context for a new task to unmapped */
177 #define init_new_context init_new_context
178 static inline int init_new_context(struct task_struct *tsk,
179 struct mm_struct *mm)
180 {
181 mm->context = SUN3_INVALID_CONTEXT;
182 return 0;
183 }
184
185 /* find the context given to this process, and if it hasn't already
186 got one, go get one for it. */
187 static inline void get_mmu_context(struct mm_struct *mm)
188 {
189 if (mm->context == SUN3_INVALID_CONTEXT)
190 mm->context = get_free_context(mm);
191 }
192
193 /* flush context if allocated... */
194 #define destroy_context destroy_context
195 static inline void destroy_context(struct mm_struct *mm)
196 {
197 if (mm->context != SUN3_INVALID_CONTEXT)
198 clear_context(mm->context);
199 }
200
201 static inline void activate_context(struct mm_struct *mm)
202 {
203 get_mmu_context(mm);
204 sun3_put_context(mm->context);
205 }
206
207 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
208 struct task_struct *tsk)
209 {
210 activate_context(tsk->mm);
211 }
212
213 #define activate_mm activate_mm
214 static inline void activate_mm(struct mm_struct *prev_mm,
215 struct mm_struct *next_mm)
216 {
217 activate_context(next_mm);
218 }
219
220 #else
221
222 #include <asm/setup.h>
223 #include <asm/page.h>
224 #include <asm/cacheflush.h>
225
226 #define init_new_context init_new_context
227 static inline int init_new_context(struct task_struct *tsk,
228 struct mm_struct *mm)
229 {
230 mm->context = virt_to_phys(mm->pgd);
231 return 0;
232 }
233
234 static inline void switch_mm_0230(struct mm_struct *mm)
235 {
236 unsigned long crp[2] = {
237 0x80000000 | _PAGE_TABLE, mm->context
238 };
239 unsigned long tmp;
240
241 asm volatile (".chip 68030");
242
243 /* flush MC68030/MC68020 caches (they are virtually addressed) */
244 asm volatile (
245 "movec %%cacr,%0;"
246 "orw %1,%0; "
247 "movec %0,%%cacr"
248 : "=d" (tmp) : "di" (FLUSH_I_AND_D));
249
250 /* Switch the root pointer. For a 030-only kernel,
251 * avoid flushing the whole ATC, we only need to
252 * flush the user entries. The 68851 does this by
253 * itself. Avoid a runtime check here.
254 */
255 asm volatile (
256 #ifdef CPU_M68030_ONLY
257 "pmovefd %0,%%crp; "
258 "pflush #0,#4"
259 #else
260 "pmove %0,%%crp"
261 #endif
262 : : "m" (crp[0]));
263
264 asm volatile (".chip 68k");
265 }
266
267 static inline void switch_mm_0460(struct mm_struct *mm)
268 {
269 asm volatile (".chip 68040");
270
271 /* flush address translation cache (user entries) */
272 asm volatile ("pflushan");
273
274 /* switch the root pointer */
275 asm volatile ("movec %0,%%urp" : : "r" (mm->context));
276
277 if (CPU_IS_060) {
278 unsigned long tmp;
279
280 /* clear user entries in the branch cache */
281 asm volatile (
282 "movec %%cacr,%0; "
283 "orl %1,%0; "
284 "movec %0,%%cacr"
285 : "=d" (tmp): "di" (0x00200000));
286 }
287
288 asm volatile (".chip 68k");
289 }
290
291 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
292 {
293 if (prev != next) {
294 if (CPU_IS_020_OR_030)
295 switch_mm_0230(next);
296 else
297 switch_mm_0460(next);
298 }
299 }
300
301 #define activate_mm activate_mm
302 static inline void activate_mm(struct mm_struct *prev_mm,
303 struct mm_struct *next_mm)
304 {
305 next_mm->context = virt_to_phys(next_mm->pgd);
306
307 if (CPU_IS_020_OR_030)
308 switch_mm_0230(next_mm);
309 else
310 switch_mm_0460(next_mm);
311 }
312
313 #endif
314
315 #include <asm-generic/mmu_context.h>
316
317 #else /* !CONFIG_MMU */
318
319 #include <asm-generic/nommu_context.h>
320
321 #endif /* CONFIG_MMU */
322 #endif /* __M68K_MMU_CONTEXT_H */
323
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