1 /* 2 * Copyright IBM Corp. 2011 3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> 4 */ 5 #include <linux/hugetlb.h> 6 #include <linux/module.h> 7 #include <linux/mm.h> 8 #include <asm/cacheflush.h> 9 #include <asm/facility.h> 10 #include <asm/pgtable.h> 11 #include <asm/page.h> 12 13 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) 14 { 15 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0" 16 : [addr] "+a" (addr) : [skey] "d" (skey)); 17 return addr; 18 } 19 20 void __storage_key_init_range(unsigned long start, unsigned long end) 21 { 22 unsigned long boundary, size; 23 24 if (!PAGE_DEFAULT_KEY) 25 return; 26 while (start < end) { 27 if (MACHINE_HAS_EDAT1) { 28 /* set storage keys for a 1MB frame */ 29 size = 1UL << 20; 30 boundary = (start + size) & ~(size - 1); 31 if (boundary <= end) { 32 do { 33 start = sske_frame(start, PAGE_DEFAULT_KEY); 34 } while (start < boundary); 35 continue; 36 } 37 } 38 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0); 39 start += PAGE_SIZE; 40 } 41 } 42 43 #ifdef CONFIG_PROC_FS 44 atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX]; 45 46 void arch_report_meminfo(struct seq_file *m) 47 { 48 seq_printf(m, "DirectMap4k: %8lu kB\n", 49 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2); 50 seq_printf(m, "DirectMap1M: %8lu kB\n", 51 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10); 52 seq_printf(m, "DirectMap2G: %8lu kB\n", 53 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21); 54 } 55 #endif /* CONFIG_PROC_FS */ 56 57 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr, 58 unsigned long dtt) 59 { 60 unsigned long table, mask; 61 62 mask = 0; 63 if (MACHINE_HAS_EDAT2) { 64 switch (dtt) { 65 case CRDTE_DTT_REGION3: 66 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1); 67 break; 68 case CRDTE_DTT_SEGMENT: 69 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); 70 break; 71 case CRDTE_DTT_PAGE: 72 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1); 73 break; 74 } 75 table = (unsigned long)old & mask; 76 crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce); 77 } else if (MACHINE_HAS_IDTE) { 78 cspg(old, *old, new); 79 } else { 80 csp((unsigned int *)old + 1, *old, new); 81 } 82 } 83 84 struct cpa { 85 unsigned int set_ro : 1; 86 unsigned int clear_ro : 1; 87 }; 88 89 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 90 struct cpa cpa) 91 { 92 pte_t *ptep, new; 93 94 ptep = pte_offset(pmdp, addr); 95 do { 96 if (pte_none(*ptep)) 97 return -EINVAL; 98 if (cpa.set_ro) 99 new = pte_wrprotect(*ptep); 100 else if (cpa.clear_ro) 101 new = pte_mkwrite(pte_mkdirty(*ptep)); 102 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); 103 ptep++; 104 addr += PAGE_SIZE; 105 cond_resched(); 106 } while (addr < end); 107 return 0; 108 } 109 110 static int split_pmd_page(pmd_t *pmdp, unsigned long addr) 111 { 112 unsigned long pte_addr, prot; 113 pte_t *pt_dir, *ptep; 114 pmd_t new; 115 int i, ro; 116 117 pt_dir = vmem_pte_alloc(); 118 if (!pt_dir) 119 return -ENOMEM; 120 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT; 121 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT); 122 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); 123 ptep = pt_dir; 124 for (i = 0; i < PTRS_PER_PTE; i++) { 125 pte_val(*ptep) = pte_addr | prot; 126 pte_addr += PAGE_SIZE; 127 ptep++; 128 } 129 pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY; 130 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 131 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); 132 update_page_count(PG_DIRECT_MAP_1M, -1); 133 return 0; 134 } 135 136 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, struct cpa cpa) 137 { 138 pmd_t new; 139 140 if (cpa.set_ro) 141 new = pmd_wrprotect(*pmdp); 142 else if (cpa.clear_ro) 143 new = pmd_mkwrite(pmd_mkdirty(*pmdp)); 144 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 145 } 146 147 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 148 struct cpa cpa) 149 { 150 unsigned long next; 151 pmd_t *pmdp; 152 int rc = 0; 153 154 pmdp = pmd_offset(pudp, addr); 155 do { 156 if (pmd_none(*pmdp)) 157 return -EINVAL; 158 next = pmd_addr_end(addr, end); 159 if (pmd_large(*pmdp)) { 160 if (addr & ~PMD_MASK || addr + PMD_SIZE > next) { 161 rc = split_pmd_page(pmdp, addr); 162 if (rc) 163 return rc; 164 continue; 165 } 166 modify_pmd_page(pmdp, addr, cpa); 167 } else { 168 rc = walk_pte_level(pmdp, addr, next, cpa); 169 if (rc) 170 return rc; 171 } 172 pmdp++; 173 addr = next; 174 cond_resched(); 175 } while (addr < end); 176 return rc; 177 } 178 179 static int split_pud_page(pud_t *pudp, unsigned long addr) 180 { 181 unsigned long pmd_addr, prot; 182 pmd_t *pm_dir, *pmdp; 183 pud_t new; 184 int i, ro; 185 186 pm_dir = vmem_pmd_alloc(); 187 if (!pm_dir) 188 return -ENOMEM; 189 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; 190 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); 191 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); 192 pmdp = pm_dir; 193 for (i = 0; i < PTRS_PER_PMD; i++) { 194 pmd_val(*pmdp) = pmd_addr | prot; 195 pmd_addr += PMD_SIZE; 196 pmdp++; 197 } 198 pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY; 199 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 200 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); 201 update_page_count(PG_DIRECT_MAP_2G, -1); 202 return 0; 203 } 204 205 static void modify_pud_page(pud_t *pudp, unsigned long addr, struct cpa cpa) 206 { 207 pud_t new; 208 209 if (cpa.set_ro) 210 new = pud_wrprotect(*pudp); 211 else if (cpa.clear_ro) 212 new = pud_mkwrite(pud_mkdirty(*pudp)); 213 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 214 } 215 216 static int walk_pud_level(pgd_t *pgd, unsigned long addr, unsigned long end, 217 struct cpa cpa) 218 { 219 unsigned long next; 220 pud_t *pudp; 221 int rc = 0; 222 223 pudp = pud_offset(pgd, addr); 224 do { 225 if (pud_none(*pudp)) 226 return -EINVAL; 227 next = pud_addr_end(addr, end); 228 if (pud_large(*pudp)) { 229 if (addr & ~PUD_MASK || addr + PUD_SIZE > next) { 230 rc = split_pud_page(pudp, addr); 231 if (rc) 232 break; 233 continue; 234 } 235 modify_pud_page(pudp, addr, cpa); 236 } else { 237 rc = walk_pmd_level(pudp, addr, next, cpa); 238 } 239 pudp++; 240 addr = next; 241 cond_resched(); 242 } while (addr < end && !rc); 243 return rc; 244 } 245 246 static DEFINE_MUTEX(cpa_mutex); 247 248 static int change_page_attr(unsigned long addr, unsigned long end, 249 struct cpa cpa) 250 { 251 unsigned long next; 252 int rc = -EINVAL; 253 pgd_t *pgdp; 254 255 if (addr == end) 256 return 0; 257 if (end >= MODULES_END) 258 return -EINVAL; 259 mutex_lock(&cpa_mutex); 260 pgdp = pgd_offset_k(addr); 261 do { 262 if (pgd_none(*pgdp)) 263 break; 264 next = pgd_addr_end(addr, end); 265 rc = walk_pud_level(pgdp, addr, next, cpa); 266 if (rc) 267 break; 268 cond_resched(); 269 } while (pgdp++, addr = next, addr < end && !rc); 270 mutex_unlock(&cpa_mutex); 271 return rc; 272 } 273 274 int set_memory_ro(unsigned long addr, int numpages) 275 { 276 struct cpa cpa = { 277 .set_ro = 1, 278 }; 279 280 addr &= PAGE_MASK; 281 return change_page_attr(addr, addr + numpages * PAGE_SIZE, cpa); 282 } 283 284 int set_memory_rw(unsigned long addr, int numpages) 285 { 286 struct cpa cpa = { 287 .clear_ro = 1, 288 }; 289 290 addr &= PAGE_MASK; 291 return change_page_attr(addr, addr + numpages * PAGE_SIZE, cpa); 292 } 293 294 /* not possible */ 295 int set_memory_nx(unsigned long addr, int numpages) 296 { 297 return 0; 298 } 299 300 int set_memory_x(unsigned long addr, int numpages) 301 { 302 return 0; 303 } 304 305 #ifdef CONFIG_DEBUG_PAGEALLOC 306 307 static void ipte_range(pte_t *pte, unsigned long address, int nr) 308 { 309 int i; 310 311 if (test_facility(13)) { 312 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL); 313 return; 314 } 315 for (i = 0; i < nr; i++) { 316 __ptep_ipte(address, pte, IPTE_GLOBAL); 317 address += PAGE_SIZE; 318 pte++; 319 } 320 } 321 322 void __kernel_map_pages(struct page *page, int numpages, int enable) 323 { 324 unsigned long address; 325 int nr, i, j; 326 pgd_t *pgd; 327 pud_t *pud; 328 pmd_t *pmd; 329 pte_t *pte; 330 331 for (i = 0; i < numpages;) { 332 address = page_to_phys(page + i); 333 pgd = pgd_offset_k(address); 334 pud = pud_offset(pgd, address); 335 pmd = pmd_offset(pud, address); 336 pte = pte_offset_kernel(pmd, address); 337 nr = (unsigned long)pte >> ilog2(sizeof(long)); 338 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 339 nr = min(numpages - i, nr); 340 if (enable) { 341 for (j = 0; j < nr; j++) { 342 pte_val(*pte) = address | pgprot_val(PAGE_KERNEL); 343 address += PAGE_SIZE; 344 pte++; 345 } 346 } else { 347 ipte_range(pte, address, nr); 348 } 349 i += nr; 350 } 351 } 352 353 #ifdef CONFIG_HIBERNATION 354 bool kernel_page_present(struct page *page) 355 { 356 unsigned long addr; 357 int cc; 358 359 addr = page_to_phys(page); 360 asm volatile( 361 " lra %1,0(%1)\n" 362 " ipm %0\n" 363 " srl %0,28" 364 : "=d" (cc), "+a" (addr) : : "cc"); 365 return cc == 0; 366 } 367 #endif /* CONFIG_HIBERNATION */ 368 369 #endif /* CONFIG_DEBUG_PAGEALLOC */ 370