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/kfence.h>
12 #include <asm/page.h>
13 #include <asm/set_memory.h>
14
sske_frame(unsigned long addr,unsigned char skey)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
__storage_key_init_range(unsigned long start,unsigned long end)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
arch_report_meminfo(struct seq_file * m)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
pgt_set(unsigned long * old,unsigned long new,unsigned long addr,unsigned long dtt)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
walk_pte_level(pmd_t * pmdp,unsigned long addr,unsigned long end,unsigned long flags)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 if (flags == SET_MEMORY_4K)
90 return 0;
91 ptep = pte_offset_kernel(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
split_pmd_page(pmd_t * pmdp,unsigned long addr)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
modify_pmd_page(pmd_t * pmdp,unsigned long addr,unsigned long flags)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
walk_pmd_level(pud_t * pudp,unsigned long addr,unsigned long end,unsigned long flags)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 int need_split;
162 pmd_t *pmdp;
163 int rc = 0;
164
165 pmdp = pmd_offset(pudp, addr);
166 do {
167 if (pmd_none(*pmdp))
168 return -EINVAL;
169 next = pmd_addr_end(addr, end);
170 if (pmd_large(*pmdp)) {
171 need_split = !!(flags & SET_MEMORY_4K);
172 need_split |= !!(addr & ~PMD_MASK);
173 need_split |= !!(addr + PMD_SIZE > next);
174 if (need_split) {
175 rc = split_pmd_page(pmdp, addr);
176 if (rc)
177 return rc;
178 continue;
179 }
180 modify_pmd_page(pmdp, addr, flags);
181 } else {
182 rc = walk_pte_level(pmdp, addr, next, flags);
183 if (rc)
184 return rc;
185 }
186 pmdp++;
187 addr = next;
188 cond_resched();
189 } while (addr < end);
190 return rc;
191 }
192
split_pud_page(pud_t * pudp,unsigned long addr)193 static int split_pud_page(pud_t *pudp, unsigned long addr)
194 {
195 unsigned long pmd_addr, prot;
196 pmd_t *pm_dir, *pmdp;
197 pud_t new;
198 int i, ro, nx;
199
200 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
201 if (!pm_dir)
202 return -ENOMEM;
203 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
204 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
205 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
206 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
207 if (!nx)
208 prot &= ~_SEGMENT_ENTRY_NOEXEC;
209 pmdp = pm_dir;
210 for (i = 0; i < PTRS_PER_PMD; i++) {
211 pmd_val(*pmdp) = pmd_addr | prot;
212 pmd_addr += PMD_SIZE;
213 pmdp++;
214 }
215 pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY;
216 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
217 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
218 update_page_count(PG_DIRECT_MAP_2G, -1);
219 return 0;
220 }
221
modify_pud_page(pud_t * pudp,unsigned long addr,unsigned long flags)222 static void modify_pud_page(pud_t *pudp, unsigned long addr,
223 unsigned long flags)
224 {
225 pud_t new = *pudp;
226
227 if (flags & SET_MEMORY_RO)
228 new = pud_wrprotect(new);
229 else if (flags & SET_MEMORY_RW)
230 new = pud_mkwrite(pud_mkdirty(new));
231 if (flags & SET_MEMORY_NX)
232 pud_val(new) |= _REGION_ENTRY_NOEXEC;
233 else if (flags & SET_MEMORY_X)
234 pud_val(new) &= ~_REGION_ENTRY_NOEXEC;
235 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
236 }
237
walk_pud_level(p4d_t * p4d,unsigned long addr,unsigned long end,unsigned long flags)238 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
239 unsigned long flags)
240 {
241 unsigned long next;
242 int need_split;
243 pud_t *pudp;
244 int rc = 0;
245
246 pudp = pud_offset(p4d, addr);
247 do {
248 if (pud_none(*pudp))
249 return -EINVAL;
250 next = pud_addr_end(addr, end);
251 if (pud_large(*pudp)) {
252 need_split = !!(flags & SET_MEMORY_4K);
253 need_split |= !!(addr & ~PUD_MASK);
254 need_split |= !!(addr + PUD_SIZE > next);
255 if (need_split) {
256 rc = split_pud_page(pudp, addr);
257 if (rc)
258 break;
259 continue;
260 }
261 modify_pud_page(pudp, addr, flags);
262 } else {
263 rc = walk_pmd_level(pudp, addr, next, flags);
264 }
265 pudp++;
266 addr = next;
267 cond_resched();
268 } while (addr < end && !rc);
269 return rc;
270 }
271
walk_p4d_level(pgd_t * pgd,unsigned long addr,unsigned long end,unsigned long flags)272 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
273 unsigned long flags)
274 {
275 unsigned long next;
276 p4d_t *p4dp;
277 int rc = 0;
278
279 p4dp = p4d_offset(pgd, addr);
280 do {
281 if (p4d_none(*p4dp))
282 return -EINVAL;
283 next = p4d_addr_end(addr, end);
284 rc = walk_pud_level(p4dp, addr, next, flags);
285 p4dp++;
286 addr = next;
287 cond_resched();
288 } while (addr < end && !rc);
289 return rc;
290 }
291
292 DEFINE_MUTEX(cpa_mutex);
293
change_page_attr(unsigned long addr,unsigned long end,unsigned long flags)294 static int change_page_attr(unsigned long addr, unsigned long end,
295 unsigned long flags)
296 {
297 unsigned long next;
298 int rc = -EINVAL;
299 pgd_t *pgdp;
300
301 if (addr == end)
302 return 0;
303 if (end >= MODULES_END)
304 return -EINVAL;
305 mutex_lock(&cpa_mutex);
306 pgdp = pgd_offset_k(addr);
307 do {
308 if (pgd_none(*pgdp))
309 break;
310 next = pgd_addr_end(addr, end);
311 rc = walk_p4d_level(pgdp, addr, next, flags);
312 if (rc)
313 break;
314 cond_resched();
315 } while (pgdp++, addr = next, addr < end && !rc);
316 mutex_unlock(&cpa_mutex);
317 return rc;
318 }
319
__set_memory(unsigned long addr,int numpages,unsigned long flags)320 int __set_memory(unsigned long addr, int numpages, unsigned long flags)
321 {
322 if (!MACHINE_HAS_NX)
323 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
324 if (!flags)
325 return 0;
326 addr &= PAGE_MASK;
327 return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);
328 }
329
330 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
331
ipte_range(pte_t * pte,unsigned long address,int nr)332 static void ipte_range(pte_t *pte, unsigned long address, int nr)
333 {
334 int i;
335
336 if (test_facility(13)) {
337 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
338 return;
339 }
340 for (i = 0; i < nr; i++) {
341 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
342 address += PAGE_SIZE;
343 pte++;
344 }
345 }
346
__kernel_map_pages(struct page * page,int numpages,int enable)347 void __kernel_map_pages(struct page *page, int numpages, int enable)
348 {
349 unsigned long address;
350 int nr, i, j;
351 pte_t *pte;
352
353 for (i = 0; i < numpages;) {
354 address = (unsigned long)page_to_virt(page + i);
355 pte = virt_to_kpte(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 #endif /* CONFIG_DEBUG_PAGEALLOC */
373