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

   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
   8static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
   9{
  10}
  11
  12#ifdef CONFIG_MMU
  13
  14#if defined(CONFIG_COLDFIRE)
  15
  16#include <asm/atomic.h>
  17#include <asm/bitops.h>
  18#include <asm/mcfmmu.h>
  19#include <asm/mmu.h>
  20
  21#define NO_CONTEXT              256
  22#define LAST_CONTEXT            255
  23#define FIRST_CONTEXT           1
  24
  25extern unsigned long context_map[];
  26extern mm_context_t next_mmu_context;
  27
  28extern atomic_t nr_free_contexts;
  29extern struct mm_struct *context_mm[LAST_CONTEXT+1];
  30extern void steal_context(void);
  31
  32static inline void get_mmu_context(struct mm_struct *mm)
  33{
  34        mm_context_t ctx;
  35
  36        if (mm->context != NO_CONTEXT)
  37                return;
  38        while (atomic_dec_and_test_lt(&nr_free_contexts)) {
  39                atomic_inc(&nr_free_contexts);
  40                steal_context();
  41        }
  42        ctx = next_mmu_context;
  43        while (test_and_set_bit(ctx, context_map)) {
  44                ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx);
  45                if (ctx > LAST_CONTEXT)
  46                        ctx = 0;
  47        }
  48        next_mmu_context = (ctx + 1) & LAST_CONTEXT;
  49        mm->context = ctx;
  50        context_mm[ctx] = mm;
  51}
  52
  53/*
  54 * Set up the context for a new address space.
  55 */
  56#define init_new_context(tsk, mm)       (((mm)->context = NO_CONTEXT), 0)
  57
  58/*
  59 * We're finished using the context for an address space.
  60 */
  61static inline void destroy_context(struct mm_struct *mm)
  62{
  63        if (mm->context != NO_CONTEXT) {
  64                clear_bit(mm->context, context_map);
  65                mm->context = NO_CONTEXT;
  66                atomic_inc(&nr_free_contexts);
  67        }
  68}
  69
  70static inline void set_context(mm_context_t context, pgd_t *pgd)
  71{
  72        __asm__ __volatile__ ("movec %0,%%asid" : : "d" (context));
  73}
  74
  75static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  76        struct task_struct *tsk)
  77{
  78        get_mmu_context(tsk->mm);
  79        set_context(tsk->mm->context, next->pgd);
  80}
  81
  82/*
  83 * After we have set current->mm to a new value, this activates
  84 * the context for the new mm so we see the new mappings.
  85 */
  86static inline void activate_mm(struct mm_struct *active_mm,
  87        struct mm_struct *mm)
  88{
  89        get_mmu_context(mm);
  90        set_context(mm->context, mm->pgd);
  91}
  92
  93#define deactivate_mm(tsk, mm) do { } while (0)
  94
  95#define prepare_arch_switch(next) load_ksp_mmu(next)
  96
  97static inline void load_ksp_mmu(struct task_struct *task)
  98{
  99        unsigned long flags;
 100        struct mm_struct *mm;
 101        int asid;
 102        pgd_t *pgd;
 103        p4d_t *p4d;
 104        pud_t *pud;
 105        pmd_t *pmd;
 106        pte_t *pte;
 107        unsigned long mmuar;
 108
 109        local_irq_save(flags);
 110        mmuar = task->thread.ksp;
 111
 112        /* Search for a valid TLB entry, if one is found, don't remap */
 113        mmu_write(MMUAR, mmuar);
 114        mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR);
 115        if (mmu_read(MMUSR) & MMUSR_HIT)
 116                goto end;
 117
 118        if (mmuar >= PAGE_OFFSET) {
 119                mm = &init_mm;
 120        } else {
 121                pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm);
 122                mm = task->mm;
 123        }
 124
 125        if (!mm)
 126                goto bug;
 127
 128        pgd = pgd_offset(mm, mmuar);
 129        if (pgd_none(*pgd))
 130                goto bug;
 131
 132        p4d = p4d_offset(pgd, mmuar);
 133        if (p4d_none(*p4d))
 134                goto bug;
 135
 136        pud = pud_offset(p4d, mmuar);
 137        if (pud_none(*pud))
 138                goto bug;
 139
 140        pmd = pmd_offset(pud, mmuar);
 141        if (pmd_none(*pmd))
 142                goto bug;
 143
 144        pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar)
 145                                     : pte_offset_map(pmd, mmuar);
 146        if (pte_none(*pte) || !pte_present(*pte))
 147                goto bug;
 148
 149        set_pte(pte, pte_mkyoung(*pte));
 150        asid = mm->context & 0xff;
 151        if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET)
 152                set_pte(pte, pte_wrprotect(*pte));
 153
 154        mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) |
 155                (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK)
 156                >> CF_PAGE_MMUTR_SHIFT) | MMUTR_V);
 157
 158        mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
 159                ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
 160
 161        mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
 162
 163        goto end;
 164
 165bug:
 166        pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar);
 167end:
 168        local_irq_restore(flags);
 169}
 170
 171#elif defined(CONFIG_SUN3)
 172#include <asm/sun3mmu.h>
 173#include <linux/sched.h>
 174
 175extern unsigned long get_free_context(struct mm_struct *mm);
 176extern void clear_context(unsigned long context);
 177
 178/* set the context for a new task to unmapped */
 179static inline int init_new_context(struct task_struct *tsk,
 180                                   struct mm_struct *mm)
 181{
 182        mm->context = SUN3_INVALID_CONTEXT;
 183        return 0;
 184}
 185
 186/* find the context given to this process, and if it hasn't already
 187   got one, go get one for it. */
 188static inline void get_mmu_context(struct mm_struct *mm)
 189{
 190        if (mm->context == SUN3_INVALID_CONTEXT)
 191                mm->context = get_free_context(mm);
 192}
 193
 194/* flush context if allocated... */
 195static inline void destroy_context(struct mm_struct *mm)
 196{
 197        if (mm->context != SUN3_INVALID_CONTEXT)
 198                clear_context(mm->context);
 199}
 200
 201static inline void activate_context(struct mm_struct *mm)
 202{
 203        get_mmu_context(mm);
 204        sun3_put_context(mm->context);
 205}
 206
 207static 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 deactivate_mm(tsk, mm)  do { } while (0)
 214
 215static inline void activate_mm(struct mm_struct *prev_mm,
 216                               struct mm_struct *next_mm)
 217{
 218        activate_context(next_mm);
 219}
 220
 221#else
 222
 223#include <asm/setup.h>
 224#include <asm/page.h>
 225#include <asm/pgalloc.h>
 226
 227static 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#define destroy_context(mm)             do { } while(0)
 235
 236static inline void switch_mm_0230(struct mm_struct *mm)
 237{
 238        unsigned long crp[2] = {
 239                0x80000000 | _PAGE_TABLE, mm->context
 240        };
 241        unsigned long tmp;
 242
 243        asm volatile (".chip 68030");
 244
 245        /* flush MC68030/MC68020 caches (they are virtually addressed) */
 246        asm volatile (
 247                "movec %%cacr,%0;"
 248                "orw %1,%0; "
 249                "movec %0,%%cacr"
 250                : "=d" (tmp) : "di" (FLUSH_I_AND_D));
 251
 252        /* Switch the root pointer. For a 030-only kernel,
 253         * avoid flushing the whole ATC, we only need to
 254         * flush the user entries. The 68851 does this by
 255         * itself. Avoid a runtime check here.
 256         */
 257        asm volatile (
 258#ifdef CPU_M68030_ONLY
 259                "pmovefd %0,%%crp; "
 260                "pflush #0,#4"
 261#else
 262                "pmove %0,%%crp"
 263#endif
 264                : : "m" (crp[0]));
 265
 266        asm volatile (".chip 68k");
 267}
 268
 269static inline void switch_mm_0460(struct mm_struct *mm)
 270{
 271        asm volatile (".chip 68040");
 272
 273        /* flush address translation cache (user entries) */
 274        asm volatile ("pflushan");
 275
 276        /* switch the root pointer */
 277        asm volatile ("movec %0,%%urp" : : "r" (mm->context));
 278
 279        if (CPU_IS_060) {
 280                unsigned long tmp;
 281
 282                /* clear user entries in the branch cache */
 283                asm volatile (
 284                        "movec %%cacr,%0; "
 285                        "orl %1,%0; "
 286                        "movec %0,%%cacr"
 287                        : "=d" (tmp): "di" (0x00200000));
 288        }
 289
 290        asm volatile (".chip 68k");
 291}
 292
 293static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
 294{
 295        if (prev != next) {
 296                if (CPU_IS_020_OR_030)
 297                        switch_mm_0230(next);
 298                else
 299                        switch_mm_0460(next);
 300        }
 301}
 302
 303#define deactivate_mm(tsk,mm)   do { } while (0)
 304
 305static inline void activate_mm(struct mm_struct *prev_mm,
 306                               struct mm_struct *next_mm)
 307{
 308        next_mm->context = virt_to_phys(next_mm->pgd);
 309
 310        if (CPU_IS_020_OR_030)
 311                switch_mm_0230(next_mm);
 312        else
 313                switch_mm_0460(next_mm);
 314}
 315
 316#endif
 317
 318#else /* !CONFIG_MMU */
 319
 320static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 321{
 322        return 0;
 323}
 324
 325
 326static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
 327{
 328}
 329
 330#define destroy_context(mm)     do { } while (0)
 331#define deactivate_mm(tsk,mm)   do { } while (0)
 332
 333static inline void activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm)
 334{
 335}
 336
 337#endif /* CONFIG_MMU */
 338#endif /* __M68K_MMU_CONTEXT_H */
 339