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
sske_frame(unsigned long addr,unsigned char skey)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
__storage_key_init_range(unsigned long start,unsigned long end)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
arch_report_meminfo(struct seq_file * m)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
pgt_set(unsigned long * old,unsigned long new,unsigned long addr,unsigned long dtt)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
walk_pte_level(pmd_t * pmdp,unsigned long addr,unsigned long end,unsigned long flags)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
split_pmd_page(pmd_t * pmdp,unsigned long addr)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
modify_pmd_page(pmd_t * pmdp,unsigned long addr,unsigned long flags)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
walk_pmd_level(pud_t * pudp,unsigned long addr,unsigned long end,unsigned long flags)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
split_pud_page(pud_t * pudp,unsigned long addr)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
modify_pud_page(pud_t * pudp,unsigned long addr,unsigned long flags)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
walk_pud_level(p4d_t * p4d,unsigned long addr,unsigned long end,unsigned long flags)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
walk_p4d_level(pgd_t * pgd,unsigned long addr,unsigned long end,unsigned long flags)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 DEFINE_MUTEX(cpa_mutex);
282
change_page_attr(unsigned long addr,unsigned long end,unsigned long flags)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
__set_memory(unsigned long addr,int numpages,unsigned long flags)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
ipte_range(pte_t * pte,unsigned long address,int nr)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
__kernel_map_pages(struct page * page,int numpages,int enable)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