1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corp. 2011 4 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> 5 */ 6 #include <linux/hugetlb.h> 7 #include <linux/mm.h> 8 #include <asm/cacheflush.h> 9 #include <asm/facility.h> 10 #include <asm/pgtable.h> 11 #include <asm/pgalloc.h> 12 #include <asm/page.h> 13 #include <asm/set_memory.h> 14 15 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) 16 { 17 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0" 18 : [addr] "+a" (addr) : [skey] "d" (skey)); 19 return addr; 20 } 21 22 void __storage_key_init_range(unsigned long start, unsigned long end) 23 { 24 unsigned long boundary, size; 25 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, 1); 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 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 85 unsigned long flags) 86 { 87 pte_t *ptep, new; 88 89 ptep = pte_offset(pmdp, addr); 90 do { 91 new = *ptep; 92 if (pte_none(new)) 93 return -EINVAL; 94 if (flags & SET_MEMORY_RO) 95 new = pte_wrprotect(new); 96 else if (flags & SET_MEMORY_RW) 97 new = pte_mkwrite(pte_mkdirty(new)); 98 if (flags & SET_MEMORY_NX) 99 pte_val(new) |= _PAGE_NOEXEC; 100 else if (flags & SET_MEMORY_X) 101 pte_val(new) &= ~_PAGE_NOEXEC; 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, nx; 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 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC); 123 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); 124 if (!nx) 125 prot &= ~_PAGE_NOEXEC; 126 ptep = pt_dir; 127 for (i = 0; i < PTRS_PER_PTE; i++) { 128 pte_val(*ptep) = pte_addr | prot; 129 pte_addr += PAGE_SIZE; 130 ptep++; 131 } 132 pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY; 133 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 134 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); 135 update_page_count(PG_DIRECT_MAP_1M, -1); 136 return 0; 137 } 138 139 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, 140 unsigned long flags) 141 { 142 pmd_t new = *pmdp; 143 144 if (flags & SET_MEMORY_RO) 145 new = pmd_wrprotect(new); 146 else if (flags & SET_MEMORY_RW) 147 new = pmd_mkwrite(pmd_mkdirty(new)); 148 if (flags & SET_MEMORY_NX) 149 pmd_val(new) |= _SEGMENT_ENTRY_NOEXEC; 150 else if (flags & SET_MEMORY_X) 151 pmd_val(new) &= ~_SEGMENT_ENTRY_NOEXEC; 152 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 153 } 154 155 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 156 unsigned long flags) 157 { 158 unsigned long next; 159 pmd_t *pmdp; 160 int rc = 0; 161 162 pmdp = pmd_offset(pudp, addr); 163 do { 164 if (pmd_none(*pmdp)) 165 return -EINVAL; 166 next = pmd_addr_end(addr, end); 167 if (pmd_large(*pmdp)) { 168 if (addr & ~PMD_MASK || addr + PMD_SIZE > next) { 169 rc = split_pmd_page(pmdp, addr); 170 if (rc) 171 return rc; 172 continue; 173 } 174 modify_pmd_page(pmdp, addr, flags); 175 } else { 176 rc = walk_pte_level(pmdp, addr, next, flags); 177 if (rc) 178 return rc; 179 } 180 pmdp++; 181 addr = next; 182 cond_resched(); 183 } while (addr < end); 184 return rc; 185 } 186 187 static int split_pud_page(pud_t *pudp, unsigned long addr) 188 { 189 unsigned long pmd_addr, prot; 190 pmd_t *pm_dir, *pmdp; 191 pud_t new; 192 int i, ro, nx; 193 194 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 195 if (!pm_dir) 196 return -ENOMEM; 197 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; 198 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); 199 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC); 200 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); 201 if (!nx) 202 prot &= ~_SEGMENT_ENTRY_NOEXEC; 203 pmdp = pm_dir; 204 for (i = 0; i < PTRS_PER_PMD; i++) { 205 pmd_val(*pmdp) = pmd_addr | prot; 206 pmd_addr += PMD_SIZE; 207 pmdp++; 208 } 209 pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY; 210 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 211 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); 212 update_page_count(PG_DIRECT_MAP_2G, -1); 213 return 0; 214 } 215 216 static void modify_pud_page(pud_t *pudp, unsigned long addr, 217 unsigned long flags) 218 { 219 pud_t new = *pudp; 220 221 if (flags & SET_MEMORY_RO) 222 new = pud_wrprotect(new); 223 else if (flags & SET_MEMORY_RW) 224 new = pud_mkwrite(pud_mkdirty(new)); 225 if (flags & SET_MEMORY_NX) 226 pud_val(new) |= _REGION_ENTRY_NOEXEC; 227 else if (flags & SET_MEMORY_X) 228 pud_val(new) &= ~_REGION_ENTRY_NOEXEC; 229 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 230 } 231 232 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 233 unsigned long flags) 234 { 235 unsigned long next; 236 pud_t *pudp; 237 int rc = 0; 238 239 pudp = pud_offset(p4d, addr); 240 do { 241 if (pud_none(*pudp)) 242 return -EINVAL; 243 next = pud_addr_end(addr, end); 244 if (pud_large(*pudp)) { 245 if (addr & ~PUD_MASK || addr + PUD_SIZE > next) { 246 rc = split_pud_page(pudp, addr); 247 if (rc) 248 break; 249 continue; 250 } 251 modify_pud_page(pudp, addr, flags); 252 } else { 253 rc = walk_pmd_level(pudp, addr, next, flags); 254 } 255 pudp++; 256 addr = next; 257 cond_resched(); 258 } while (addr < end && !rc); 259 return rc; 260 } 261 262 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end, 263 unsigned long flags) 264 { 265 unsigned long next; 266 p4d_t *p4dp; 267 int rc = 0; 268 269 p4dp = p4d_offset(pgd, addr); 270 do { 271 if (p4d_none(*p4dp)) 272 return -EINVAL; 273 next = p4d_addr_end(addr, end); 274 rc = walk_pud_level(p4dp, addr, next, flags); 275 p4dp++; 276 addr = next; 277 cond_resched(); 278 } while (addr < end && !rc); 279 return rc; 280 } 281 282 static DEFINE_MUTEX(cpa_mutex); 283 284 static int change_page_attr(unsigned long addr, unsigned long end, 285 unsigned long flags) 286 { 287 unsigned long next; 288 int rc = -EINVAL; 289 pgd_t *pgdp; 290 291 if (addr == end) 292 return 0; 293 if (end >= MODULES_END) 294 return -EINVAL; 295 mutex_lock(&cpa_mutex); 296 pgdp = pgd_offset_k(addr); 297 do { 298 if (pgd_none(*pgdp)) 299 break; 300 next = pgd_addr_end(addr, end); 301 rc = walk_p4d_level(pgdp, addr, next, flags); 302 if (rc) 303 break; 304 cond_resched(); 305 } while (pgdp++, addr = next, addr < end && !rc); 306 mutex_unlock(&cpa_mutex); 307 return rc; 308 } 309 310 int __set_memory(unsigned long addr, int numpages, unsigned long flags) 311 { 312 if (!MACHINE_HAS_NX) 313 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X); 314 if (!flags) 315 return 0; 316 addr &= PAGE_MASK; 317 return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags); 318 } 319 320 #ifdef CONFIG_DEBUG_PAGEALLOC 321 322 static void ipte_range(pte_t *pte, unsigned long address, int nr) 323 { 324 int i; 325 326 if (test_facility(13)) { 327 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL); 328 return; 329 } 330 for (i = 0; i < nr; i++) { 331 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL); 332 address += PAGE_SIZE; 333 pte++; 334 } 335 } 336 337 void __kernel_map_pages(struct page *page, int numpages, int enable) 338 { 339 unsigned long address; 340 int nr, i, j; 341 pgd_t *pgd; 342 p4d_t *p4d; 343 pud_t *pud; 344 pmd_t *pmd; 345 pte_t *pte; 346 347 for (i = 0; i < numpages;) { 348 address = page_to_phys(page + i); 349 pgd = pgd_offset_k(address); 350 p4d = p4d_offset(pgd, address); 351 pud = pud_offset(p4d, address); 352 pmd = pmd_offset(pud, address); 353 pte = pte_offset_kernel(pmd, address); 354 nr = (unsigned long)pte >> ilog2(sizeof(long)); 355 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 356 nr = min(numpages - i, nr); 357 if (enable) { 358 for (j = 0; j < nr; j++) { 359 pte_val(*pte) &= ~_PAGE_INVALID; 360 address += PAGE_SIZE; 361 pte++; 362 } 363 } else { 364 ipte_range(pte, address, nr); 365 } 366 i += nr; 367 } 368 } 369 370 #ifdef CONFIG_HIBERNATION 371 bool kernel_page_present(struct page *page) 372 { 373 unsigned long addr; 374 int cc; 375 376 addr = page_to_phys(page); 377 asm volatile( 378 " lra %1,0(%1)\n" 379 " ipm %0\n" 380 " srl %0,28" 381 : "=d" (cc), "+a" (addr) : : "cc"); 382 return cc == 0; 383 } 384 #endif /* CONFIG_HIBERNATION */ 385 386 #endif /* CONFIG_DEBUG_PAGEALLOC */ 387