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mmu_context.h
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1 #ifndef __M68K_MMU_CONTEXT_H
2 #define __M68K_MMU_CONTEXT_H
3 
4 #include <asm-generic/mm_hooks.h>
5 
6 static 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 
23 extern unsigned long context_map[];
25 
27 extern struct mm_struct *context_mm[LAST_CONTEXT+1];
28 extern void steal_context(void);
29 
30 static inline void get_mmu_context(struct mm_struct *mm)
31 {
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)) {
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  */
59 static inline void destroy_context(struct mm_struct *mm)
60 {
61  if (mm->context != NO_CONTEXT) {
63  mm->context = NO_CONTEXT;
64  atomic_inc(&nr_free_contexts);
65  }
66 }
67 
68 static inline void set_context(mm_context_t context, pgd_t *pgd)
69 {
70  __asm__ __volatile__ ("movec %0,%%asid" : : "d" (context));
71 }
72 
73 static 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  */
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 deactivate_mm(tsk, mm) do { } while (0)
92 
93 extern void mmu_context_init(void);
94 #define prepare_arch_switch(next) load_ksp_mmu(next)
95 
96 static 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)
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 
154 bug:
155  pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar);
156 end:
157  local_irq_restore(flags);
158 }
159 
160 #elif defined(CONFIG_SUN3)
161 #include <asm/sun3mmu.h>
162 #include <linux/sched.h>
163 
164 extern unsigned long get_free_context(struct mm_struct *mm);
165 extern void clear_context(unsigned long context);
166 
167 /* set the context for a new task to unmapped */
168 static inline int init_new_context(struct task_struct *tsk,
169  struct mm_struct *mm)
170 {
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. */
177 static 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... */
184 static inline void destroy_context(struct mm_struct *mm)
185 {
186  if (mm->context != SUN3_INVALID_CONTEXT)
187  clear_context(mm->context);
188 }
189 
190 static inline void activate_context(struct mm_struct *mm)
191 {
192  get_mmu_context(mm);
193  sun3_put_context(mm->context);
194 }
195 
196 static 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 
204 static 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 
216 static 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 
225 static 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 
258 static 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 
282 static 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 
294 static 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 
309 static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
310 {
311  return 0;
312 }
313 
314 
315 static 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 
322 static 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 */