1 /* 2 * arch/sh/mm/cache-sh4.c 3 * 4 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka 5 * Copyright (C) 2001 - 2009 Paul Mundt 6 * Copyright (C) 2003 Richard Curnow 7 * Copyright (c) 2007 STMicroelectronics (R&D) Ltd. 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file "COPYING" in the main directory of this archive 11 * for more details. 12 */ 13 #include <linux/init.h> 14 #include <linux/mm.h> 15 #include <linux/io.h> 16 #include <linux/mutex.h> 17 #include <linux/fs.h> 18 #include <linux/highmem.h> 19 #include <linux/pagemap.h> 20 #include <asm/mmu_context.h> 21 #include <asm/cache_insns.h> 22 #include <asm/cacheflush.h> 23 24 /* 25 * The maximum number of pages we support up to when doing ranged dcache 26 * flushing. Anything exceeding this will simply flush the dcache in its 27 * entirety. 28 */ 29 #define MAX_ICACHE_PAGES 32 30 31 static void __flush_cache_one(unsigned long addr, unsigned long phys, 32 unsigned long exec_offset); 33 34 /* 35 * Write back the range of D-cache, and purge the I-cache. 36 * 37 * Called from kernel/module.c:sys_init_module and routine for a.out format, 38 * signal handler code and kprobes code 39 */ 40 static void sh4_flush_icache_range(void *args) 41 { 42 struct flusher_data *data = args; 43 unsigned long start, end; 44 unsigned long flags, v; 45 int i; 46 47 start = data->addr1; 48 end = data->addr2; 49 50 /* If there are too many pages then just blow away the caches */ 51 if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) { 52 local_flush_cache_all(NULL); 53 return; 54 } 55 56 /* 57 * Selectively flush d-cache then invalidate the i-cache. 58 * This is inefficient, so only use this for small ranges. 59 */ 60 start &= ~(L1_CACHE_BYTES-1); 61 end += L1_CACHE_BYTES-1; 62 end &= ~(L1_CACHE_BYTES-1); 63 64 local_irq_save(flags); 65 jump_to_uncached(); 66 67 for (v = start; v < end; v += L1_CACHE_BYTES) { 68 unsigned long icacheaddr; 69 int j, n; 70 71 __ocbwb(v); 72 73 icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v & 74 cpu_data->icache.entry_mask); 75 76 /* Clear i-cache line valid-bit */ 77 n = boot_cpu_data.icache.n_aliases; 78 for (i = 0; i < cpu_data->icache.ways; i++) { 79 for (j = 0; j < n; j++) 80 __raw_writel(0, icacheaddr + (j * PAGE_SIZE)); 81 icacheaddr += cpu_data->icache.way_incr; 82 } 83 } 84 85 back_to_cached(); 86 local_irq_restore(flags); 87 } 88 89 static inline void flush_cache_one(unsigned long start, unsigned long phys) 90 { 91 unsigned long flags, exec_offset = 0; 92 93 /* 94 * All types of SH-4 require PC to be uncached to operate on the I-cache. 95 * Some types of SH-4 require PC to be uncached to operate on the D-cache. 96 */ 97 if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) || 98 (start < CACHE_OC_ADDRESS_ARRAY)) 99 exec_offset = cached_to_uncached; 100 101 local_irq_save(flags); 102 __flush_cache_one(start, phys, exec_offset); 103 local_irq_restore(flags); 104 } 105 106 /* 107 * Write back & invalidate the D-cache of the page. 108 * (To avoid "alias" issues) 109 */ 110 static void sh4_flush_dcache_folio(void *arg) 111 { 112 struct folio *folio = arg; 113 #ifndef CONFIG_SMP 114 struct address_space *mapping = folio_flush_mapping(folio); 115 116 if (mapping && !mapping_mapped(mapping)) 117 clear_bit(PG_dcache_clean, &folio->flags); 118 else 119 #endif 120 { 121 unsigned long pfn = folio_pfn(folio); 122 unsigned long addr = (unsigned long)folio_address(folio); 123 unsigned int i, nr = folio_nr_pages(folio); 124 125 for (i = 0; i < nr; i++) { 126 flush_cache_one(CACHE_OC_ADDRESS_ARRAY | 127 (addr & shm_align_mask), 128 pfn * PAGE_SIZE); 129 addr += PAGE_SIZE; 130 pfn++; 131 } 132 } 133 134 wmb(); 135 } 136 137 /* TODO: Selective icache invalidation through IC address array.. */ 138 static void flush_icache_all(void) 139 { 140 unsigned long flags, ccr; 141 142 local_irq_save(flags); 143 jump_to_uncached(); 144 145 /* Flush I-cache */ 146 ccr = __raw_readl(SH_CCR); 147 ccr |= CCR_CACHE_ICI; 148 __raw_writel(ccr, SH_CCR); 149 150 /* 151 * back_to_cached() will take care of the barrier for us, don't add 152 * another one! 153 */ 154 155 back_to_cached(); 156 local_irq_restore(flags); 157 } 158 159 static void flush_dcache_all(void) 160 { 161 unsigned long addr, end_addr, entry_offset; 162 163 end_addr = CACHE_OC_ADDRESS_ARRAY + 164 (current_cpu_data.dcache.sets << 165 current_cpu_data.dcache.entry_shift) * 166 current_cpu_data.dcache.ways; 167 168 entry_offset = 1 << current_cpu_data.dcache.entry_shift; 169 170 for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) { 171 __raw_writel(0, addr); addr += entry_offset; 172 __raw_writel(0, addr); addr += entry_offset; 173 __raw_writel(0, addr); addr += entry_offset; 174 __raw_writel(0, addr); addr += entry_offset; 175 __raw_writel(0, addr); addr += entry_offset; 176 __raw_writel(0, addr); addr += entry_offset; 177 __raw_writel(0, addr); addr += entry_offset; 178 __raw_writel(0, addr); addr += entry_offset; 179 } 180 } 181 182 static void sh4_flush_cache_all(void *unused) 183 { 184 flush_dcache_all(); 185 flush_icache_all(); 186 } 187 188 /* 189 * Note : (RPC) since the caches are physically tagged, the only point 190 * of flush_cache_mm for SH-4 is to get rid of aliases from the 191 * D-cache. The assumption elsewhere, e.g. flush_cache_range, is that 192 * lines can stay resident so long as the virtual address they were 193 * accessed with (hence cache set) is in accord with the physical 194 * address (i.e. tag). It's no different here. 195 * 196 * Caller takes mm->mmap_lock. 197 */ 198 static void sh4_flush_cache_mm(void *arg) 199 { 200 struct mm_struct *mm = arg; 201 202 if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT) 203 return; 204 205 flush_dcache_all(); 206 } 207 208 /* 209 * Write back and invalidate I/D-caches for the page. 210 * 211 * ADDR: Virtual Address (U0 address) 212 * PFN: Physical page number 213 */ 214 static void sh4_flush_cache_page(void *args) 215 { 216 struct flusher_data *data = args; 217 struct vm_area_struct *vma; 218 struct page *page; 219 unsigned long address, pfn, phys; 220 int map_coherent = 0; 221 pmd_t *pmd; 222 pte_t *pte; 223 void *vaddr; 224 225 vma = data->vma; 226 address = data->addr1 & PAGE_MASK; 227 pfn = data->addr2; 228 phys = pfn << PAGE_SHIFT; 229 page = pfn_to_page(pfn); 230 231 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT) 232 return; 233 234 pmd = pmd_off(vma->vm_mm, address); 235 pte = pte_offset_kernel(pmd, address); 236 237 /* If the page isn't present, there is nothing to do here. */ 238 if (!(pte_val(*pte) & _PAGE_PRESENT)) 239 return; 240 241 if ((vma->vm_mm == current->active_mm)) 242 vaddr = NULL; 243 else { 244 /* 245 * Use kmap_coherent or kmap_atomic to do flushes for 246 * another ASID than the current one. 247 */ 248 map_coherent = (current_cpu_data.dcache.n_aliases && 249 test_bit(PG_dcache_clean, &page->flags) && 250 page_mapcount(page)); 251 if (map_coherent) 252 vaddr = kmap_coherent(page, address); 253 else 254 vaddr = kmap_atomic(page); 255 256 address = (unsigned long)vaddr; 257 } 258 259 flush_cache_one(CACHE_OC_ADDRESS_ARRAY | 260 (address & shm_align_mask), phys); 261 262 if (vma->vm_flags & VM_EXEC) 263 flush_icache_all(); 264 265 if (vaddr) { 266 if (map_coherent) 267 kunmap_coherent(vaddr); 268 else 269 kunmap_atomic(vaddr); 270 } 271 } 272 273 /* 274 * Write back and invalidate D-caches. 275 * 276 * START, END: Virtual Address (U0 address) 277 * 278 * NOTE: We need to flush the _physical_ page entry. 279 * Flushing the cache lines for U0 only isn't enough. 280 * We need to flush for P1 too, which may contain aliases. 281 */ 282 static void sh4_flush_cache_range(void *args) 283 { 284 struct flusher_data *data = args; 285 struct vm_area_struct *vma; 286 unsigned long start, end; 287 288 vma = data->vma; 289 start = data->addr1; 290 end = data->addr2; 291 292 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT) 293 return; 294 295 /* 296 * If cache is only 4k-per-way, there are never any 'aliases'. Since 297 * the cache is physically tagged, the data can just be left in there. 298 */ 299 if (boot_cpu_data.dcache.n_aliases == 0) 300 return; 301 302 flush_dcache_all(); 303 304 if (vma->vm_flags & VM_EXEC) 305 flush_icache_all(); 306 } 307 308 /** 309 * __flush_cache_one 310 * 311 * @addr: address in memory mapped cache array 312 * @phys: P1 address to flush (has to match tags if addr has 'A' bit 313 * set i.e. associative write) 314 * @exec_offset: set to 0x20000000 if flush has to be executed from P2 315 * region else 0x0 316 * 317 * The offset into the cache array implied by 'addr' selects the 318 * 'colour' of the virtual address range that will be flushed. The 319 * operation (purge/write-back) is selected by the lower 2 bits of 320 * 'phys'. 321 */ 322 static void __flush_cache_one(unsigned long addr, unsigned long phys, 323 unsigned long exec_offset) 324 { 325 int way_count; 326 unsigned long base_addr = addr; 327 struct cache_info *dcache; 328 unsigned long way_incr; 329 unsigned long a, ea, p; 330 unsigned long temp_pc; 331 332 dcache = &boot_cpu_data.dcache; 333 /* Write this way for better assembly. */ 334 way_count = dcache->ways; 335 way_incr = dcache->way_incr; 336 337 /* 338 * Apply exec_offset (i.e. branch to P2 if required.). 339 * 340 * FIXME: 341 * 342 * If I write "=r" for the (temp_pc), it puts this in r6 hence 343 * trashing exec_offset before it's been added on - why? Hence 344 * "=&r" as a 'workaround' 345 */ 346 asm volatile("mov.l 1f, %0\n\t" 347 "add %1, %0\n\t" 348 "jmp @%0\n\t" 349 "nop\n\t" 350 ".balign 4\n\t" 351 "1: .long 2f\n\t" 352 "2:\n" : "=&r" (temp_pc) : "r" (exec_offset)); 353 354 /* 355 * We know there will be >=1 iteration, so write as do-while to avoid 356 * pointless nead-of-loop check for 0 iterations. 357 */ 358 do { 359 ea = base_addr + PAGE_SIZE; 360 a = base_addr; 361 p = phys; 362 363 do { 364 *(volatile unsigned long *)a = p; 365 /* 366 * Next line: intentionally not p+32, saves an add, p 367 * will do since only the cache tag bits need to 368 * match. 369 */ 370 *(volatile unsigned long *)(a+32) = p; 371 a += 64; 372 p += 64; 373 } while (a < ea); 374 375 base_addr += way_incr; 376 } while (--way_count != 0); 377 } 378 379 extern void __weak sh4__flush_region_init(void); 380 381 /* 382 * SH-4 has virtually indexed and physically tagged cache. 383 */ 384 void __init sh4_cache_init(void) 385 { 386 printk("PVR=%08x CVR=%08x PRR=%08x\n", 387 __raw_readl(CCN_PVR), 388 __raw_readl(CCN_CVR), 389 __raw_readl(CCN_PRR)); 390 391 local_flush_icache_range = sh4_flush_icache_range; 392 local_flush_dcache_folio = sh4_flush_dcache_folio; 393 local_flush_cache_all = sh4_flush_cache_all; 394 local_flush_cache_mm = sh4_flush_cache_mm; 395 local_flush_cache_dup_mm = sh4_flush_cache_mm; 396 local_flush_cache_page = sh4_flush_cache_page; 397 local_flush_cache_range = sh4_flush_cache_range; 398 399 sh4__flush_region_init(); 400 } 401