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 static 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 25 extern unsigned long context_map[]; 26 extern mm_context_t next_mmu_context; 27 28 extern atomic_t nr_free_contexts; 29 extern struct mm_struct *context_mm[LAST_CONTEXT+1]; 30 extern void steal_context(void); 31 32 static 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 */ 61 static 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 70 static inline void set_context(mm_context_t context, pgd_t *pgd) 71 { 72 __asm__ __volatile__ ("movec %0,%%asid" : : "d" (context)); 73 } 74 75 static 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 */ 86 static 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 extern void mmu_context_init(void); 96 #define prepare_arch_switch(next) load_ksp_mmu(next) 97 98 static inline void load_ksp_mmu(struct task_struct *task) 99 { 100 unsigned long flags; 101 struct mm_struct *mm; 102 int asid; 103 pgd_t *pgd; 104 pmd_t *pmd; 105 pte_t *pte; 106 unsigned long mmuar; 107 108 local_irq_save(flags); 109 mmuar = task->thread.ksp; 110 111 /* Search for a valid TLB entry, if one is found, don't remap */ 112 mmu_write(MMUAR, mmuar); 113 mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR); 114 if (mmu_read(MMUSR) & MMUSR_HIT) 115 goto end; 116 117 if (mmuar >= PAGE_OFFSET) { 118 mm = &init_mm; 119 } else { 120 pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm); 121 mm = task->mm; 122 } 123 124 if (!mm) 125 goto bug; 126 127 pgd = pgd_offset(mm, mmuar); 128 if (pgd_none(*pgd)) 129 goto bug; 130 131 pmd = pmd_offset(pgd, mmuar); 132 if (pmd_none(*pmd)) 133 goto bug; 134 135 pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar) 136 : pte_offset_map(pmd, mmuar); 137 if (pte_none(*pte) || !pte_present(*pte)) 138 goto bug; 139 140 set_pte(pte, pte_mkyoung(*pte)); 141 asid = mm->context & 0xff; 142 if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET) 143 set_pte(pte, pte_wrprotect(*pte)); 144 145 mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | 146 (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK) 147 >> CF_PAGE_MMUTR_SHIFT) | MMUTR_V); 148 149 mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) | 150 ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X); 151 152 mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA); 153 154 goto end; 155 156 bug: 157 pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar); 158 end: 159 local_irq_restore(flags); 160 } 161 162 #elif defined(CONFIG_SUN3) 163 #include <asm/sun3mmu.h> 164 #include <linux/sched.h> 165 166 extern unsigned long get_free_context(struct mm_struct *mm); 167 extern void clear_context(unsigned long context); 168 169 /* set the context for a new task to unmapped */ 170 static inline int init_new_context(struct task_struct *tsk, 171 struct mm_struct *mm) 172 { 173 mm->context = SUN3_INVALID_CONTEXT; 174 return 0; 175 } 176 177 /* find the context given to this process, and if it hasn't already 178 got one, go get one for it. */ 179 static inline void get_mmu_context(struct mm_struct *mm) 180 { 181 if (mm->context == SUN3_INVALID_CONTEXT) 182 mm->context = get_free_context(mm); 183 } 184 185 /* flush context if allocated... */ 186 static inline void destroy_context(struct mm_struct *mm) 187 { 188 if (mm->context != SUN3_INVALID_CONTEXT) 189 clear_context(mm->context); 190 } 191 192 static inline void activate_context(struct mm_struct *mm) 193 { 194 get_mmu_context(mm); 195 sun3_put_context(mm->context); 196 } 197 198 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 199 struct task_struct *tsk) 200 { 201 activate_context(tsk->mm); 202 } 203 204 #define deactivate_mm(tsk, mm) do { } while (0) 205 206 static inline void activate_mm(struct mm_struct *prev_mm, 207 struct mm_struct *next_mm) 208 { 209 activate_context(next_mm); 210 } 211 212 #else 213 214 #include <asm/setup.h> 215 #include <asm/page.h> 216 #include <asm/pgalloc.h> 217 218 static inline int init_new_context(struct task_struct *tsk, 219 struct mm_struct *mm) 220 { 221 mm->context = virt_to_phys(mm->pgd); 222 return 0; 223 } 224 225 #define destroy_context(mm) do { } while(0) 226 227 static inline void switch_mm_0230(struct mm_struct *mm) 228 { 229 unsigned long crp[2] = { 230 0x80000000 | _PAGE_TABLE, mm->context 231 }; 232 unsigned long tmp; 233 234 asm volatile (".chip 68030"); 235 236 /* flush MC68030/MC68020 caches (they are virtually addressed) */ 237 asm volatile ( 238 "movec %%cacr,%0;" 239 "orw %1,%0; " 240 "movec %0,%%cacr" 241 : "=d" (tmp) : "di" (FLUSH_I_AND_D)); 242 243 /* Switch the root pointer. For a 030-only kernel, 244 * avoid flushing the whole ATC, we only need to 245 * flush the user entries. The 68851 does this by 246 * itself. Avoid a runtime check here. 247 */ 248 asm volatile ( 249 #ifdef CPU_M68030_ONLY 250 "pmovefd %0,%%crp; " 251 "pflush #0,#4" 252 #else 253 "pmove %0,%%crp" 254 #endif 255 : : "m" (crp[0])); 256 257 asm volatile (".chip 68k"); 258 } 259 260 static inline void switch_mm_0460(struct mm_struct *mm) 261 { 262 asm volatile (".chip 68040"); 263 264 /* flush address translation cache (user entries) */ 265 asm volatile ("pflushan"); 266 267 /* switch the root pointer */ 268 asm volatile ("movec %0,%%urp" : : "r" (mm->context)); 269 270 if (CPU_IS_060) { 271 unsigned long tmp; 272 273 /* clear user entries in the branch cache */ 274 asm volatile ( 275 "movec %%cacr,%0; " 276 "orl %1,%0; " 277 "movec %0,%%cacr" 278 : "=d" (tmp): "di" (0x00200000)); 279 } 280 281 asm volatile (".chip 68k"); 282 } 283 284 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) 285 { 286 if (prev != next) { 287 if (CPU_IS_020_OR_030) 288 switch_mm_0230(next); 289 else 290 switch_mm_0460(next); 291 } 292 } 293 294 #define deactivate_mm(tsk,mm) do { } while (0) 295 296 static inline void activate_mm(struct mm_struct *prev_mm, 297 struct mm_struct *next_mm) 298 { 299 next_mm->context = virt_to_phys(next_mm->pgd); 300 301 if (CPU_IS_020_OR_030) 302 switch_mm_0230(next_mm); 303 else 304 switch_mm_0460(next_mm); 305 } 306 307 #endif 308 309 #else /* !CONFIG_MMU */ 310 311 static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) 312 { 313 return 0; 314 } 315 316 317 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) 318 { 319 } 320 321 #define destroy_context(mm) do { } while (0) 322 #define deactivate_mm(tsk,mm) do { } while (0) 323 324 static inline void activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm) 325 { 326 } 327 328 #endif /* CONFIG_MMU */ 329 #endif /* __M68K_MMU_CONTEXT_H */ 330