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/pgalloc.h> 11 #include <asm/page.h> 12 #include <asm/set_memory.h> 13 14 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) 15 { 16 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0" 17 : [addr] "+a" (addr) : [skey] "d" (skey)); 18 return addr; 19 } 20 21 void __storage_key_init_range(unsigned long start, unsigned long end) 22 { 23 unsigned long boundary, size; 24 25 while (start < end) { 26 if (MACHINE_HAS_EDAT1) { 27 /* set storage keys for a 1MB frame */ 28 size = 1UL << 20; 29 boundary = (start + size) & ~(size - 1); 30 if (boundary <= end) { 31 do { 32 start = sske_frame(start, PAGE_DEFAULT_KEY); 33 } while (start < boundary); 34 continue; 35 } 36 } 37 page_set_storage_key(start, PAGE_DEFAULT_KEY, 1); 38 start += PAGE_SIZE; 39 } 40 } 41 42 #ifdef CONFIG_PROC_FS 43 atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX]; 44 45 void arch_report_meminfo(struct seq_file *m) 46 { 47 seq_printf(m, "DirectMap4k: %8lu kB\n", 48 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2); 49 seq_printf(m, "DirectMap1M: %8lu kB\n", 50 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10); 51 seq_printf(m, "DirectMap2G: %8lu kB\n", 52 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21); 53 } 54 #endif /* CONFIG_PROC_FS */ 55 56 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr, 57 unsigned long dtt) 58 { 59 unsigned long table, mask; 60 61 mask = 0; 62 if (MACHINE_HAS_EDAT2) { 63 switch (dtt) { 64 case CRDTE_DTT_REGION3: 65 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1); 66 break; 67 case CRDTE_DTT_SEGMENT: 68 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); 69 break; 70 case CRDTE_DTT_PAGE: 71 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1); 72 break; 73 } 74 table = (unsigned long)old & mask; 75 crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce); 76 } else if (MACHINE_HAS_IDTE) { 77 cspg(old, *old, new); 78 } else { 79 csp((unsigned int *)old + 1, *old, new); 80 } 81 } 82 83 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, 84 unsigned long flags) 85 { 86 pte_t *ptep, new; 87 88 ptep = pte_offset_kernel(pmdp, addr); 89 do { 90 new = *ptep; 91 if (pte_none(new)) 92 return -EINVAL; 93 if (flags & SET_MEMORY_RO) 94 new = pte_wrprotect(new); 95 else if (flags & SET_MEMORY_RW) 96 new = pte_mkwrite(pte_mkdirty(new)); 97 if (flags & SET_MEMORY_NX) 98 pte_val(new) |= _PAGE_NOEXEC; 99 else if (flags & SET_MEMORY_X) 100 pte_val(new) &= ~_PAGE_NOEXEC; 101 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); 102 ptep++; 103 addr += PAGE_SIZE; 104 cond_resched(); 105 } while (addr < end); 106 return 0; 107 } 108 109 static int split_pmd_page(pmd_t *pmdp, unsigned long addr) 110 { 111 unsigned long pte_addr, prot; 112 pte_t *pt_dir, *ptep; 113 pmd_t new; 114 int i, ro, nx; 115 116 pt_dir = vmem_pte_alloc(); 117 if (!pt_dir) 118 return -ENOMEM; 119 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT; 120 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT); 121 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC); 122 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); 123 if (!nx) 124 prot &= ~_PAGE_NOEXEC; 125 ptep = pt_dir; 126 for (i = 0; i < PTRS_PER_PTE; i++) { 127 pte_val(*ptep) = pte_addr | prot; 128 pte_addr += PAGE_SIZE; 129 ptep++; 130 } 131 pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY; 132 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 133 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); 134 update_page_count(PG_DIRECT_MAP_1M, -1); 135 return 0; 136 } 137 138 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, 139 unsigned long flags) 140 { 141 pmd_t new = *pmdp; 142 143 if (flags & SET_MEMORY_RO) 144 new = pmd_wrprotect(new); 145 else if (flags & SET_MEMORY_RW) 146 new = pmd_mkwrite(pmd_mkdirty(new)); 147 if (flags & SET_MEMORY_NX) 148 pmd_val(new) |= _SEGMENT_ENTRY_NOEXEC; 149 else if (flags & SET_MEMORY_X) 150 pmd_val(new) &= ~_SEGMENT_ENTRY_NOEXEC; 151 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 152 } 153 154 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 155 unsigned long flags) 156 { 157 unsigned long next; 158 pmd_t *pmdp; 159 int rc = 0; 160 161 pmdp = pmd_offset(pudp, addr); 162 do { 163 if (pmd_none(*pmdp)) 164 return -EINVAL; 165 next = pmd_addr_end(addr, end); 166 if (pmd_large(*pmdp)) { 167 if (addr & ~PMD_MASK || addr + PMD_SIZE > next) { 168 rc = split_pmd_page(pmdp, addr); 169 if (rc) 170 return rc; 171 continue; 172 } 173 modify_pmd_page(pmdp, addr, flags); 174 } else { 175 rc = walk_pte_level(pmdp, addr, next, flags); 176 if (rc) 177 return rc; 178 } 179 pmdp++; 180 addr = next; 181 cond_resched(); 182 } while (addr < end); 183 return rc; 184 } 185 186 static int split_pud_page(pud_t *pudp, unsigned long addr) 187 { 188 unsigned long pmd_addr, prot; 189 pmd_t *pm_dir, *pmdp; 190 pud_t new; 191 int i, ro, nx; 192 193 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 194 if (!pm_dir) 195 return -ENOMEM; 196 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; 197 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); 198 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC); 199 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); 200 if (!nx) 201 prot &= ~_SEGMENT_ENTRY_NOEXEC; 202 pmdp = pm_dir; 203 for (i = 0; i < PTRS_PER_PMD; i++) { 204 pmd_val(*pmdp) = pmd_addr | prot; 205 pmd_addr += PMD_SIZE; 206 pmdp++; 207 } 208 pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY; 209 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 210 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); 211 update_page_count(PG_DIRECT_MAP_2G, -1); 212 return 0; 213 } 214 215 static void modify_pud_page(pud_t *pudp, unsigned long addr, 216 unsigned long flags) 217 { 218 pud_t new = *pudp; 219 220 if (flags & SET_MEMORY_RO) 221 new = pud_wrprotect(new); 222 else if (flags & SET_MEMORY_RW) 223 new = pud_mkwrite(pud_mkdirty(new)); 224 if (flags & SET_MEMORY_NX) 225 pud_val(new) |= _REGION_ENTRY_NOEXEC; 226 else if (flags & SET_MEMORY_X) 227 pud_val(new) &= ~_REGION_ENTRY_NOEXEC; 228 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 229 } 230 231 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 232 unsigned long flags) 233 { 234 unsigned long next; 235 pud_t *pudp; 236 int rc = 0; 237 238 pudp = pud_offset(p4d, addr); 239 do { 240 if (pud_none(*pudp)) 241 return -EINVAL; 242 next = pud_addr_end(addr, end); 243 if (pud_large(*pudp)) { 244 if (addr & ~PUD_MASK || addr + PUD_SIZE > next) { 245 rc = split_pud_page(pudp, addr); 246 if (rc) 247 break; 248 continue; 249 } 250 modify_pud_page(pudp, addr, flags); 251 } else { 252 rc = walk_pmd_level(pudp, addr, next, flags); 253 } 254 pudp++; 255 addr = next; 256 cond_resched(); 257 } while (addr < end && !rc); 258 return rc; 259 } 260 261 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end, 262 unsigned long flags) 263 { 264 unsigned long next; 265 p4d_t *p4dp; 266 int rc = 0; 267 268 p4dp = p4d_offset(pgd, addr); 269 do { 270 if (p4d_none(*p4dp)) 271 return -EINVAL; 272 next = p4d_addr_end(addr, end); 273 rc = walk_pud_level(p4dp, addr, next, flags); 274 p4dp++; 275 addr = next; 276 cond_resched(); 277 } while (addr < end && !rc); 278 return rc; 279 } 280 281 static DEFINE_MUTEX(cpa_mutex); 282 283 static int change_page_attr(unsigned long addr, unsigned long end, 284 unsigned long flags) 285 { 286 unsigned long next; 287 int rc = -EINVAL; 288 pgd_t *pgdp; 289 290 if (addr == end) 291 return 0; 292 if (end >= MODULES_END) 293 return -EINVAL; 294 mutex_lock(&cpa_mutex); 295 pgdp = pgd_offset_k(addr); 296 do { 297 if (pgd_none(*pgdp)) 298 break; 299 next = pgd_addr_end(addr, end); 300 rc = walk_p4d_level(pgdp, addr, next, flags); 301 if (rc) 302 break; 303 cond_resched(); 304 } while (pgdp++, addr = next, addr < end && !rc); 305 mutex_unlock(&cpa_mutex); 306 return rc; 307 } 308 309 int __set_memory(unsigned long addr, int numpages, unsigned long flags) 310 { 311 if (!MACHINE_HAS_NX) 312 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X); 313 if (!flags) 314 return 0; 315 addr &= PAGE_MASK; 316 return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags); 317 } 318 319 #ifdef CONFIG_DEBUG_PAGEALLOC 320 321 static void ipte_range(pte_t *pte, unsigned long address, int nr) 322 { 323 int i; 324 325 if (test_facility(13)) { 326 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL); 327 return; 328 } 329 for (i = 0; i < nr; i++) { 330 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL); 331 address += PAGE_SIZE; 332 pte++; 333 } 334 } 335 336 void __kernel_map_pages(struct page *page, int numpages, int enable) 337 { 338 unsigned long address; 339 int nr, i, j; 340 pte_t *pte; 341 342 for (i = 0; i < numpages;) { 343 address = page_to_phys(page + i); 344 pte = virt_to_kpte(address); 345 nr = (unsigned long)pte >> ilog2(sizeof(long)); 346 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 347 nr = min(numpages - i, nr); 348 if (enable) { 349 for (j = 0; j < nr; j++) { 350 pte_val(*pte) &= ~_PAGE_INVALID; 351 address += PAGE_SIZE; 352 pte++; 353 } 354 } else { 355 ipte_range(pte, address, nr); 356 } 357 i += nr; 358 } 359 } 360 361 #endif /* CONFIG_DEBUG_PAGEALLOC */ 362