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],9,0" 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 if (!PAGE_DEFAULT_KEY) 27 return; 28 while (start < end) { 29 if (MACHINE_HAS_EDAT1) { 30 /* set storage keys for a 1MB frame */ 31 size = 1UL << 20; 32 boundary = (start + size) & ~(size - 1); 33 if (boundary <= end) { 34 do { 35 start = sske_frame(start, PAGE_DEFAULT_KEY); 36 } while (start < boundary); 37 continue; 38 } 39 } 40 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0); 41 start += PAGE_SIZE; 42 } 43 } 44 45 #ifdef CONFIG_PROC_FS 46 atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX]; 47 48 void arch_report_meminfo(struct seq_file *m) 49 { 50 seq_printf(m, "DirectMap4k: %8lu kB\n", 51 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2); 52 seq_printf(m, "DirectMap1M: %8lu kB\n", 53 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10); 54 seq_printf(m, "DirectMap2G: %8lu kB\n", 55 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21); 56 } 57 #endif /* CONFIG_PROC_FS */ 58 59 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr, 60 unsigned long dtt) 61 { 62 unsigned long table, mask; 63 64 mask = 0; 65 if (MACHINE_HAS_EDAT2) { 66 switch (dtt) { 67 case CRDTE_DTT_REGION3: 68 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1); 69 break; 70 case CRDTE_DTT_SEGMENT: 71 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); 72 break; 73 case CRDTE_DTT_PAGE: 74 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1); 75 break; 76 } 77 table = (unsigned long)old & mask; 78 crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce); 79 } else if (MACHINE_HAS_IDTE) { 80 cspg(old, *old, new); 81 } else { 82 csp((unsigned int *)old + 1, *old, new); 83 } 84 } 85 86 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 87 unsigned long flags) 88 { 89 pte_t *ptep, new; 90 91 ptep = pte_offset(pmdp, addr); 92 do { 93 new = *ptep; 94 if (pte_none(new)) 95 return -EINVAL; 96 if (flags & SET_MEMORY_RO) 97 new = pte_wrprotect(new); 98 else if (flags & SET_MEMORY_RW) 99 new = pte_mkwrite(pte_mkdirty(new)); 100 if (flags & SET_MEMORY_NX) 101 pte_val(new) |= _PAGE_NOEXEC; 102 else if (flags & SET_MEMORY_X) 103 pte_val(new) &= ~_PAGE_NOEXEC; 104 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); 105 ptep++; 106 addr += PAGE_SIZE; 107 cond_resched(); 108 } while (addr < end); 109 return 0; 110 } 111 112 static int split_pmd_page(pmd_t *pmdp, unsigned long addr) 113 { 114 unsigned long pte_addr, prot; 115 pte_t *pt_dir, *ptep; 116 pmd_t new; 117 int i, ro, nx; 118 119 pt_dir = vmem_pte_alloc(); 120 if (!pt_dir) 121 return -ENOMEM; 122 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT; 123 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT); 124 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC); 125 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); 126 if (!nx) 127 prot &= ~_PAGE_NOEXEC; 128 ptep = pt_dir; 129 for (i = 0; i < PTRS_PER_PTE; i++) { 130 pte_val(*ptep) = pte_addr | prot; 131 pte_addr += PAGE_SIZE; 132 ptep++; 133 } 134 pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY; 135 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 136 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); 137 update_page_count(PG_DIRECT_MAP_1M, -1); 138 return 0; 139 } 140 141 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, 142 unsigned long flags) 143 { 144 pmd_t new = *pmdp; 145 146 if (flags & SET_MEMORY_RO) 147 new = pmd_wrprotect(new); 148 else if (flags & SET_MEMORY_RW) 149 new = pmd_mkwrite(pmd_mkdirty(new)); 150 if (flags & SET_MEMORY_NX) 151 pmd_val(new) |= _SEGMENT_ENTRY_NOEXEC; 152 else if (flags & SET_MEMORY_X) 153 pmd_val(new) &= ~_SEGMENT_ENTRY_NOEXEC; 154 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 155 } 156 157 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 158 unsigned long flags) 159 { 160 unsigned long next; 161 pmd_t *pmdp; 162 int rc = 0; 163 164 pmdp = pmd_offset(pudp, addr); 165 do { 166 if (pmd_none(*pmdp)) 167 return -EINVAL; 168 next = pmd_addr_end(addr, end); 169 if (pmd_large(*pmdp)) { 170 if (addr & ~PMD_MASK || addr + PMD_SIZE > next) { 171 rc = split_pmd_page(pmdp, addr); 172 if (rc) 173 return rc; 174 continue; 175 } 176 modify_pmd_page(pmdp, addr, flags); 177 } else { 178 rc = walk_pte_level(pmdp, addr, next, flags); 179 if (rc) 180 return rc; 181 } 182 pmdp++; 183 addr = next; 184 cond_resched(); 185 } while (addr < end); 186 return rc; 187 } 188 189 static int split_pud_page(pud_t *pudp, unsigned long addr) 190 { 191 unsigned long pmd_addr, prot; 192 pmd_t *pm_dir, *pmdp; 193 pud_t new; 194 int i, ro, nx; 195 196 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 197 if (!pm_dir) 198 return -ENOMEM; 199 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; 200 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); 201 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC); 202 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); 203 if (!nx) 204 prot &= ~_SEGMENT_ENTRY_NOEXEC; 205 pmdp = pm_dir; 206 for (i = 0; i < PTRS_PER_PMD; i++) { 207 pmd_val(*pmdp) = pmd_addr | prot; 208 pmd_addr += PMD_SIZE; 209 pmdp++; 210 } 211 pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY; 212 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 213 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); 214 update_page_count(PG_DIRECT_MAP_2G, -1); 215 return 0; 216 } 217 218 static void modify_pud_page(pud_t *pudp, unsigned long addr, 219 unsigned long flags) 220 { 221 pud_t new = *pudp; 222 223 if (flags & SET_MEMORY_RO) 224 new = pud_wrprotect(new); 225 else if (flags & SET_MEMORY_RW) 226 new = pud_mkwrite(pud_mkdirty(new)); 227 if (flags & SET_MEMORY_NX) 228 pud_val(new) |= _REGION_ENTRY_NOEXEC; 229 else if (flags & SET_MEMORY_X) 230 pud_val(new) &= ~_REGION_ENTRY_NOEXEC; 231 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 232 } 233 234 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 235 unsigned long flags) 236 { 237 unsigned long next; 238 pud_t *pudp; 239 int rc = 0; 240 241 pudp = pud_offset(p4d, addr); 242 do { 243 if (pud_none(*pudp)) 244 return -EINVAL; 245 next = pud_addr_end(addr, end); 246 if (pud_large(*pudp)) { 247 if (addr & ~PUD_MASK || addr + PUD_SIZE > next) { 248 rc = split_pud_page(pudp, addr); 249 if (rc) 250 break; 251 continue; 252 } 253 modify_pud_page(pudp, addr, flags); 254 } else { 255 rc = walk_pmd_level(pudp, addr, next, flags); 256 } 257 pudp++; 258 addr = next; 259 cond_resched(); 260 } while (addr < end && !rc); 261 return rc; 262 } 263 264 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end, 265 unsigned long flags) 266 { 267 unsigned long next; 268 p4d_t *p4dp; 269 int rc = 0; 270 271 p4dp = p4d_offset(pgd, addr); 272 do { 273 if (p4d_none(*p4dp)) 274 return -EINVAL; 275 next = p4d_addr_end(addr, end); 276 rc = walk_pud_level(p4dp, addr, next, flags); 277 p4dp++; 278 addr = next; 279 cond_resched(); 280 } while (addr < end && !rc); 281 return rc; 282 } 283 284 static DEFINE_MUTEX(cpa_mutex); 285 286 static int change_page_attr(unsigned long addr, unsigned long end, 287 unsigned long flags) 288 { 289 unsigned long next; 290 int rc = -EINVAL; 291 pgd_t *pgdp; 292 293 if (addr == end) 294 return 0; 295 if (end >= MODULES_END) 296 return -EINVAL; 297 mutex_lock(&cpa_mutex); 298 pgdp = pgd_offset_k(addr); 299 do { 300 if (pgd_none(*pgdp)) 301 break; 302 next = pgd_addr_end(addr, end); 303 rc = walk_p4d_level(pgdp, addr, next, flags); 304 if (rc) 305 break; 306 cond_resched(); 307 } while (pgdp++, addr = next, addr < end && !rc); 308 mutex_unlock(&cpa_mutex); 309 return rc; 310 } 311 312 int __set_memory(unsigned long addr, int numpages, unsigned long flags) 313 { 314 if (!MACHINE_HAS_NX) 315 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X); 316 if (!flags) 317 return 0; 318 addr &= PAGE_MASK; 319 return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags); 320 } 321 322 #ifdef CONFIG_DEBUG_PAGEALLOC 323 324 static void ipte_range(pte_t *pte, unsigned long address, int nr) 325 { 326 int i; 327 328 if (test_facility(13)) { 329 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL); 330 return; 331 } 332 for (i = 0; i < nr; i++) { 333 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL); 334 address += PAGE_SIZE; 335 pte++; 336 } 337 } 338 339 void __kernel_map_pages(struct page *page, int numpages, int enable) 340 { 341 unsigned long address; 342 int nr, i, j; 343 pgd_t *pgd; 344 p4d_t *p4d; 345 pud_t *pud; 346 pmd_t *pmd; 347 pte_t *pte; 348 349 for (i = 0; i < numpages;) { 350 address = page_to_phys(page + i); 351 pgd = pgd_offset_k(address); 352 p4d = p4d_offset(pgd, address); 353 pud = pud_offset(p4d, address); 354 pmd = pmd_offset(pud, address); 355 pte = pte_offset_kernel(pmd, address); 356 nr = (unsigned long)pte >> ilog2(sizeof(long)); 357 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 358 nr = min(numpages - i, nr); 359 if (enable) { 360 for (j = 0; j < nr; j++) { 361 pte_val(*pte) &= ~_PAGE_INVALID; 362 address += PAGE_SIZE; 363 pte++; 364 } 365 } else { 366 ipte_range(pte, address, nr); 367 } 368 i += nr; 369 } 370 } 371 372 #ifdef CONFIG_HIBERNATION 373 bool kernel_page_present(struct page *page) 374 { 375 unsigned long addr; 376 int cc; 377 378 addr = page_to_phys(page); 379 asm volatile( 380 " lra %1,0(%1)\n" 381 " ipm %0\n" 382 " srl %0,28" 383 : "=d" (cc), "+a" (addr) : : "cc"); 384 return cc == 0; 385 } 386 #endif /* CONFIG_HIBERNATION */ 387 388 #endif /* CONFIG_DEBUG_PAGEALLOC */ 389