LXR linux/arch/m68k/include/asm/mmu

   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