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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/pgtable.h>
11#include <asm/pgalloc.h>
12#include <asm/page.h>
13#include <asm/set_memory.h>
14
15static 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
22void __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
44atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
45
46void 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
57static 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
84static 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
110static 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
139static 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
155static 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
187static 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
216static 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
232static 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
262static 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
282static DEFINE_MUTEX(cpa_mutex);
283
284static 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
310int __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
322static 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
337void __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
371bool 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 */
1/*
2 * Copyright IBM Corp. 2011
3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
4 */
5#include <linux/module.h>
6#include <linux/mm.h>
7#include <linux/hugetlb.h>
8#include <asm/pgtable.h>
9
10static void change_page_attr(unsigned long addr, int numpages,
11 pte_t (*set) (pte_t))
12{
13 pte_t *ptep, pte;
14 pmd_t *pmdp;
15 pud_t *pudp;
16 pgd_t *pgdp;
17 int i;
18
19 for (i = 0; i < numpages; i++) {
20 pgdp = pgd_offset(&init_mm, addr);
21 pudp = pud_offset(pgdp, addr);
22 pmdp = pmd_offset(pudp, addr);
23 if (pmd_huge(*pmdp)) {
24 WARN_ON_ONCE(1);
25 continue;
26 }
27 ptep = pte_offset_kernel(pmdp, addr);
28
29 pte = *ptep;
30 pte = set(pte);
31 __ptep_ipte(addr, ptep);
32 *ptep = pte;
33 addr += PAGE_SIZE;
34 }
35}
36
37int set_memory_ro(unsigned long addr, int numpages)
38{
39 change_page_attr(addr, numpages, pte_wrprotect);
40 return 0;
41}
42EXPORT_SYMBOL_GPL(set_memory_ro);
43
44int set_memory_rw(unsigned long addr, int numpages)
45{
46 change_page_attr(addr, numpages, pte_mkwrite);
47 return 0;
48}
49EXPORT_SYMBOL_GPL(set_memory_rw);
50
51/* not possible */
52int set_memory_nx(unsigned long addr, int numpages)
53{
54 return 0;
55}
56EXPORT_SYMBOL_GPL(set_memory_nx);
57
58int set_memory_x(unsigned long addr, int numpages)
59{
60 return 0;
61}