linux/arch/s390/mm/pageattr.c
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   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
  14static 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
  21void __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
  43atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
  44
  45void 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
  56static 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
  83static 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
 109static 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
 138static 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
 154static 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
 186static 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
 215static 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
 231static 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
 261static 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
 281DEFINE_MUTEX(cpa_mutex);
 282
 283static 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
 309int __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
 321static 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
 336void __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