1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * r2300.c: R2000 and R3000 specific mmu/cache code. 4 * 5 * Copyright (C) 1996 David S. Miller (davem@davemloft.net) 6 * 7 * with a lot of changes to make this thing work for R3000s 8 * Tx39XX R4k style caches added. HK 9 * Copyright (C) 1998, 1999, 2000 Harald Koerfgen 10 * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov 11 * Copyright (C) 2001, 2004, 2007 Maciej W. Rozycki 12 */ 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/smp.h> 16 #include <linux/mm.h> 17 18 #include <asm/page.h> 19 #include <asm/pgtable.h> 20 #include <asm/mmu_context.h> 21 #include <asm/isadep.h> 22 #include <asm/io.h> 23 #include <asm/bootinfo.h> 24 #include <asm/cpu.h> 25 26 static unsigned long icache_size, dcache_size; /* Size in bytes */ 27 static unsigned long icache_lsize, dcache_lsize; /* Size in bytes */ 28 29 unsigned long r3k_cache_size(unsigned long ca_flags) 30 { 31 unsigned long flags, status, dummy, size; 32 volatile unsigned long *p; 33 34 p = (volatile unsigned long *) KSEG0; 35 36 flags = read_c0_status(); 37 38 /* isolate cache space */ 39 write_c0_status((ca_flags|flags)&~ST0_IEC); 40 41 *p = 0xa5a55a5a; 42 dummy = *p; 43 status = read_c0_status(); 44 45 if (dummy != 0xa5a55a5a || (status & ST0_CM)) { 46 size = 0; 47 } else { 48 for (size = 128; size <= 0x40000; size <<= 1) 49 *(p + size) = 0; 50 *p = -1; 51 for (size = 128; 52 (size <= 0x40000) && (*(p + size) == 0); 53 size <<= 1) 54 ; 55 if (size > 0x40000) 56 size = 0; 57 } 58 59 write_c0_status(flags); 60 61 return size * sizeof(*p); 62 } 63 64 unsigned long r3k_cache_lsize(unsigned long ca_flags) 65 { 66 unsigned long flags, status, lsize, i; 67 volatile unsigned long *p; 68 69 p = (volatile unsigned long *) KSEG0; 70 71 flags = read_c0_status(); 72 73 /* isolate cache space */ 74 write_c0_status((ca_flags|flags)&~ST0_IEC); 75 76 for (i = 0; i < 128; i++) 77 *(p + i) = 0; 78 *(volatile unsigned char *)p = 0; 79 for (lsize = 1; lsize < 128; lsize <<= 1) { 80 *(p + lsize); 81 status = read_c0_status(); 82 if (!(status & ST0_CM)) 83 break; 84 } 85 for (i = 0; i < 128; i += lsize) 86 *(volatile unsigned char *)(p + i) = 0; 87 88 write_c0_status(flags); 89 90 return lsize * sizeof(*p); 91 } 92 93 static void r3k_probe_cache(void) 94 { 95 dcache_size = r3k_cache_size(ST0_ISC); 96 if (dcache_size) 97 dcache_lsize = r3k_cache_lsize(ST0_ISC); 98 99 icache_size = r3k_cache_size(ST0_ISC|ST0_SWC); 100 if (icache_size) 101 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC); 102 } 103 104 static void r3k_flush_icache_range(unsigned long start, unsigned long end) 105 { 106 unsigned long size, i, flags; 107 volatile unsigned char *p; 108 109 size = end - start; 110 if (size > icache_size || KSEGX(start) != KSEG0) { 111 start = KSEG0; 112 size = icache_size; 113 } 114 p = (char *)start; 115 116 flags = read_c0_status(); 117 118 /* isolate cache space */ 119 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC); 120 121 for (i = 0; i < size; i += 0x080) { 122 asm( "sb\t$0, 0x000(%0)\n\t" 123 "sb\t$0, 0x004(%0)\n\t" 124 "sb\t$0, 0x008(%0)\n\t" 125 "sb\t$0, 0x00c(%0)\n\t" 126 "sb\t$0, 0x010(%0)\n\t" 127 "sb\t$0, 0x014(%0)\n\t" 128 "sb\t$0, 0x018(%0)\n\t" 129 "sb\t$0, 0x01c(%0)\n\t" 130 "sb\t$0, 0x020(%0)\n\t" 131 "sb\t$0, 0x024(%0)\n\t" 132 "sb\t$0, 0x028(%0)\n\t" 133 "sb\t$0, 0x02c(%0)\n\t" 134 "sb\t$0, 0x030(%0)\n\t" 135 "sb\t$0, 0x034(%0)\n\t" 136 "sb\t$0, 0x038(%0)\n\t" 137 "sb\t$0, 0x03c(%0)\n\t" 138 "sb\t$0, 0x040(%0)\n\t" 139 "sb\t$0, 0x044(%0)\n\t" 140 "sb\t$0, 0x048(%0)\n\t" 141 "sb\t$0, 0x04c(%0)\n\t" 142 "sb\t$0, 0x050(%0)\n\t" 143 "sb\t$0, 0x054(%0)\n\t" 144 "sb\t$0, 0x058(%0)\n\t" 145 "sb\t$0, 0x05c(%0)\n\t" 146 "sb\t$0, 0x060(%0)\n\t" 147 "sb\t$0, 0x064(%0)\n\t" 148 "sb\t$0, 0x068(%0)\n\t" 149 "sb\t$0, 0x06c(%0)\n\t" 150 "sb\t$0, 0x070(%0)\n\t" 151 "sb\t$0, 0x074(%0)\n\t" 152 "sb\t$0, 0x078(%0)\n\t" 153 "sb\t$0, 0x07c(%0)\n\t" 154 : : "r" (p) ); 155 p += 0x080; 156 } 157 158 write_c0_status(flags); 159 } 160 161 static void r3k_flush_dcache_range(unsigned long start, unsigned long end) 162 { 163 unsigned long size, i, flags; 164 volatile unsigned char *p; 165 166 size = end - start; 167 if (size > dcache_size || KSEGX(start) != KSEG0) { 168 start = KSEG0; 169 size = dcache_size; 170 } 171 p = (char *)start; 172 173 flags = read_c0_status(); 174 175 /* isolate cache space */ 176 write_c0_status((ST0_ISC|flags)&~ST0_IEC); 177 178 for (i = 0; i < size; i += 0x080) { 179 asm( "sb\t$0, 0x000(%0)\n\t" 180 "sb\t$0, 0x004(%0)\n\t" 181 "sb\t$0, 0x008(%0)\n\t" 182 "sb\t$0, 0x00c(%0)\n\t" 183 "sb\t$0, 0x010(%0)\n\t" 184 "sb\t$0, 0x014(%0)\n\t" 185 "sb\t$0, 0x018(%0)\n\t" 186 "sb\t$0, 0x01c(%0)\n\t" 187 "sb\t$0, 0x020(%0)\n\t" 188 "sb\t$0, 0x024(%0)\n\t" 189 "sb\t$0, 0x028(%0)\n\t" 190 "sb\t$0, 0x02c(%0)\n\t" 191 "sb\t$0, 0x030(%0)\n\t" 192 "sb\t$0, 0x034(%0)\n\t" 193 "sb\t$0, 0x038(%0)\n\t" 194 "sb\t$0, 0x03c(%0)\n\t" 195 "sb\t$0, 0x040(%0)\n\t" 196 "sb\t$0, 0x044(%0)\n\t" 197 "sb\t$0, 0x048(%0)\n\t" 198 "sb\t$0, 0x04c(%0)\n\t" 199 "sb\t$0, 0x050(%0)\n\t" 200 "sb\t$0, 0x054(%0)\n\t" 201 "sb\t$0, 0x058(%0)\n\t" 202 "sb\t$0, 0x05c(%0)\n\t" 203 "sb\t$0, 0x060(%0)\n\t" 204 "sb\t$0, 0x064(%0)\n\t" 205 "sb\t$0, 0x068(%0)\n\t" 206 "sb\t$0, 0x06c(%0)\n\t" 207 "sb\t$0, 0x070(%0)\n\t" 208 "sb\t$0, 0x074(%0)\n\t" 209 "sb\t$0, 0x078(%0)\n\t" 210 "sb\t$0, 0x07c(%0)\n\t" 211 : : "r" (p) ); 212 p += 0x080; 213 } 214 215 write_c0_status(flags); 216 } 217 218 static inline void r3k_flush_cache_all(void) 219 { 220 } 221 222 static inline void r3k___flush_cache_all(void) 223 { 224 r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size); 225 r3k_flush_icache_range(KSEG0, KSEG0 + icache_size); 226 } 227 228 static void r3k_flush_cache_mm(struct mm_struct *mm) 229 { 230 } 231 232 static void r3k_flush_cache_range(struct vm_area_struct *vma, 233 unsigned long start, unsigned long end) 234 { 235 } 236 237 static void r3k_flush_cache_page(struct vm_area_struct *vma, 238 unsigned long addr, unsigned long pfn) 239 { 240 unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT); 241 int exec = vma->vm_flags & VM_EXEC; 242 struct mm_struct *mm = vma->vm_mm; 243 pgd_t *pgdp; 244 pud_t *pudp; 245 pmd_t *pmdp; 246 pte_t *ptep; 247 248 pr_debug("cpage[%08lx,%08lx]\n", 249 cpu_context(smp_processor_id(), mm), addr); 250 251 /* No ASID => no such page in the cache. */ 252 if (cpu_context(smp_processor_id(), mm) == 0) 253 return; 254 255 pgdp = pgd_offset(mm, addr); 256 pudp = pud_offset(pgdp, addr); 257 pmdp = pmd_offset(pudp, addr); 258 ptep = pte_offset(pmdp, addr); 259 260 /* Invalid => no such page in the cache. */ 261 if (!(pte_val(*ptep) & _PAGE_PRESENT)) 262 return; 263 264 r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE); 265 if (exec) 266 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE); 267 } 268 269 static void local_r3k_flush_data_cache_page(void *addr) 270 { 271 } 272 273 static void r3k_flush_data_cache_page(unsigned long addr) 274 { 275 } 276 277 static void r3k_flush_cache_sigtramp(unsigned long addr) 278 { 279 unsigned long flags; 280 281 pr_debug("csigtramp[%08lx]\n", addr); 282 283 flags = read_c0_status(); 284 285 write_c0_status(flags&~ST0_IEC); 286 287 /* Fill the TLB to avoid an exception with caches isolated. */ 288 asm( "lw\t$0, 0x000(%0)\n\t" 289 "lw\t$0, 0x004(%0)\n\t" 290 : : "r" (addr) ); 291 292 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC); 293 294 asm( "sb\t$0, 0x000(%0)\n\t" 295 "sb\t$0, 0x004(%0)\n\t" 296 : : "r" (addr) ); 297 298 write_c0_status(flags); 299 } 300 301 static void r3k_flush_kernel_vmap_range(unsigned long vaddr, int size) 302 { 303 BUG(); 304 } 305 306 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size) 307 { 308 /* Catch bad driver code */ 309 BUG_ON(size == 0); 310 311 iob(); 312 r3k_flush_dcache_range(start, start + size); 313 } 314 315 void r3k_cache_init(void) 316 { 317 extern void build_clear_page(void); 318 extern void build_copy_page(void); 319 320 r3k_probe_cache(); 321 322 flush_cache_all = r3k_flush_cache_all; 323 __flush_cache_all = r3k___flush_cache_all; 324 flush_cache_mm = r3k_flush_cache_mm; 325 flush_cache_range = r3k_flush_cache_range; 326 flush_cache_page = r3k_flush_cache_page; 327 flush_icache_range = r3k_flush_icache_range; 328 local_flush_icache_range = r3k_flush_icache_range; 329 __flush_icache_user_range = r3k_flush_icache_range; 330 __local_flush_icache_user_range = r3k_flush_icache_range; 331 332 __flush_kernel_vmap_range = r3k_flush_kernel_vmap_range; 333 334 flush_cache_sigtramp = r3k_flush_cache_sigtramp; 335 local_flush_data_cache_page = local_r3k_flush_data_cache_page; 336 flush_data_cache_page = r3k_flush_data_cache_page; 337 338 _dma_cache_wback_inv = r3k_dma_cache_wback_inv; 339 _dma_cache_wback = r3k_dma_cache_wback_inv; 340 _dma_cache_inv = r3k_dma_cache_wback_inv; 341 342 printk("Primary instruction cache %ldkB, linesize %ld bytes.\n", 343 icache_size >> 10, icache_lsize); 344 printk("Primary data cache %ldkB, linesize %ld bytes.\n", 345 dcache_size >> 10, dcache_lsize); 346 347 build_clear_page(); 348 build_copy_page(); 349 } 350