arch/m68k/include/asm/mmu_context.h

   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[];
  24 extern mm_context_t next_mmu_context;
  25
  26 extern atomic_t nr_free_contexts;
  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 {
  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  */
  59 static 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
  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)
 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
 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 {
 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. */
 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 */