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/cpufeature.h>
7 #include <linux/hugetlb.h>
8 #include <linux/proc_fs.h>
9 #include <linux/vmalloc.h>
10 #include <linux/mm.h>
11 #include <asm/cacheflush.h>
12 #include <asm/facility.h>
13 #include <asm/pgalloc.h>
14 #include <asm/kfence.h>
15 #include <asm/page.h>
16 #include <asm/asm.h>
17 #include <asm/set_memory.h>
18
sske_frame(unsigned long addr,unsigned char skey)19 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
20 {
21 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0"
22 : [addr] "+a" (addr) : [skey] "d" (skey));
23 return addr;
24 }
25
__storage_key_init_range(unsigned long start,unsigned long end)26 void __storage_key_init_range(unsigned long start, unsigned long end)
27 {
28 unsigned long boundary, size;
29
30 while (start < end) {
31 if (cpu_has_edat1()) {
32 /* set storage keys for a 1MB frame */
33 size = 1UL << 20;
34 boundary = (start + size) & ~(size - 1);
35 if (boundary <= end) {
36 do {
37 start = sske_frame(start, PAGE_DEFAULT_KEY);
38 } while (start < boundary);
39 continue;
40 }
41 }
42 page_set_storage_key(start, PAGE_DEFAULT_KEY, 1);
43 start += PAGE_SIZE;
44 }
45 }
46
47 #ifdef CONFIG_PROC_FS
48 atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
49
arch_report_meminfo(struct seq_file * m)50 void arch_report_meminfo(struct seq_file *m)
51 {
52 seq_printf(m, "DirectMap4k: %8lu kB\n",
53 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2);
54 seq_printf(m, "DirectMap1M: %8lu kB\n",
55 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10);
56 seq_printf(m, "DirectMap2G: %8lu kB\n",
57 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21);
58 }
59 #endif /* CONFIG_PROC_FS */
60
pgt_set(unsigned long * old,unsigned long new,unsigned long addr,unsigned long dtt)61 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
62 unsigned long dtt)
63 {
64 unsigned long *table, mask;
65
66 mask = 0;
67 if (cpu_has_edat2()) {
68 switch (dtt) {
69 case CRDTE_DTT_REGION3:
70 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1);
71 break;
72 case CRDTE_DTT_SEGMENT:
73 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
74 break;
75 case CRDTE_DTT_PAGE:
76 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
77 break;
78 }
79 table = (unsigned long *)((unsigned long)old & mask);
80 crdte(*old, new, table, dtt, addr, get_lowcore()->kernel_asce.val);
81 } else {
82 cspg(old, *old, new);
83 }
84 }
85
walk_pte_level(pmd_t * pmdp,unsigned long addr,unsigned long end,unsigned long flags)86 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
87 unsigned long flags)
88 {
89 pte_t *ptep, new;
90
91 if (flags == SET_MEMORY_4K)
92 return 0;
93 ptep = pte_offset_kernel(pmdp, addr);
94 do {
95 new = *ptep;
96 if (pte_none(new))
97 return -EINVAL;
98 if (flags & SET_MEMORY_RO)
99 new = pte_wrprotect(new);
100 else if (flags & SET_MEMORY_RW)
101 new = pte_mkwrite_novma(pte_mkdirty(new));
102 if (flags & SET_MEMORY_NX)
103 new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC));
104 else if (flags & SET_MEMORY_X)
105 new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));
106 if (flags & SET_MEMORY_INV) {
107 new = set_pte_bit(new, __pgprot(_PAGE_INVALID));
108 } else if (flags & SET_MEMORY_DEF) {
109 new = __pte(pte_val(new) & PAGE_MASK);
110 new = set_pte_bit(new, PAGE_KERNEL);
111 }
112 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
113 ptep++;
114 addr += PAGE_SIZE;
115 cond_resched();
116 } while (addr < end);
117 return 0;
118 }
119
split_pmd_page(pmd_t * pmdp,unsigned long addr)120 static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
121 {
122 unsigned long pte_addr, prot;
123 pte_t *pt_dir, *ptep;
124 pmd_t new;
125 int i, ro, nx;
126
127 pt_dir = vmem_pte_alloc();
128 if (!pt_dir)
129 return -ENOMEM;
130 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
131 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
132 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
133 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
134 if (!nx)
135 prot &= ~_PAGE_NOEXEC;
136 ptep = pt_dir;
137 for (i = 0; i < PTRS_PER_PTE; i++) {
138 set_pte(ptep, __pte(pte_addr | prot));
139 pte_addr += PAGE_SIZE;
140 ptep++;
141 }
142 new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY);
143 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
144 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
145 update_page_count(PG_DIRECT_MAP_1M, -1);
146 return 0;
147 }
148
modify_pmd_page(pmd_t * pmdp,unsigned long addr,unsigned long flags)149 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
150 unsigned long flags)
151 {
152 pmd_t new = *pmdp;
153
154 if (flags & SET_MEMORY_RO)
155 new = pmd_wrprotect(new);
156 else if (flags & SET_MEMORY_RW)
157 new = pmd_mkwrite_novma(pmd_mkdirty(new));
158 if (flags & SET_MEMORY_NX)
159 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
160 else if (flags & SET_MEMORY_X)
161 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
162 if (flags & SET_MEMORY_INV) {
163 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));
164 } else if (flags & SET_MEMORY_DEF) {
165 new = __pmd(pmd_val(new) & PMD_MASK);
166 new = set_pmd_bit(new, SEGMENT_KERNEL);
167 }
168 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
169 }
170
walk_pmd_level(pud_t * pudp,unsigned long addr,unsigned long end,unsigned long flags)171 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end,
172 unsigned long flags)
173 {
174 unsigned long next;
175 int need_split;
176 pmd_t *pmdp;
177 int rc = 0;
178
179 pmdp = pmd_offset(pudp, addr);
180 do {
181 if (pmd_none(*pmdp))
182 return -EINVAL;
183 next = pmd_addr_end(addr, end);
184 if (pmd_leaf(*pmdp)) {
185 need_split = !!(flags & SET_MEMORY_4K);
186 need_split |= !!(addr & ~PMD_MASK);
187 need_split |= !!(addr + PMD_SIZE > next);
188 if (need_split) {
189 rc = split_pmd_page(pmdp, addr);
190 if (rc)
191 return rc;
192 continue;
193 }
194 modify_pmd_page(pmdp, addr, flags);
195 } else {
196 rc = walk_pte_level(pmdp, addr, next, flags);
197 if (rc)
198 return rc;
199 }
200 pmdp++;
201 addr = next;
202 cond_resched();
203 } while (addr < end);
204 return rc;
205 }
206
split_pud_page(pud_t * pudp,unsigned long addr)207 int split_pud_page(pud_t *pudp, unsigned long addr)
208 {
209 unsigned long pmd_addr, prot;
210 pmd_t *pm_dir, *pmdp;
211 pud_t new;
212 int i, ro, nx;
213
214 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
215 if (!pm_dir)
216 return -ENOMEM;
217 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
218 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
219 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
220 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
221 if (!nx)
222 prot &= ~_SEGMENT_ENTRY_NOEXEC;
223 pmdp = pm_dir;
224 for (i = 0; i < PTRS_PER_PMD; i++) {
225 set_pmd(pmdp, __pmd(pmd_addr | prot));
226 pmd_addr += PMD_SIZE;
227 pmdp++;
228 }
229 new = __pud(__pa(pm_dir) | _REGION3_ENTRY);
230 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
231 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
232 update_page_count(PG_DIRECT_MAP_2G, -1);
233 return 0;
234 }
235
modify_pud_page(pud_t * pudp,unsigned long addr,unsigned long flags)236 static void modify_pud_page(pud_t *pudp, unsigned long addr,
237 unsigned long flags)
238 {
239 pud_t new = *pudp;
240
241 if (flags & SET_MEMORY_RO)
242 new = pud_wrprotect(new);
243 else if (flags & SET_MEMORY_RW)
244 new = pud_mkwrite(pud_mkdirty(new));
245 if (flags & SET_MEMORY_NX)
246 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
247 else if (flags & SET_MEMORY_X)
248 new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
249 if (flags & SET_MEMORY_INV) {
250 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID));
251 } else if (flags & SET_MEMORY_DEF) {
252 new = __pud(pud_val(new) & PUD_MASK);
253 new = set_pud_bit(new, REGION3_KERNEL);
254 }
255 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
256 }
257
walk_pud_level(p4d_t * p4d,unsigned long addr,unsigned long end,unsigned long flags)258 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
259 unsigned long flags)
260 {
261 unsigned long next;
262 int need_split;
263 pud_t *pudp;
264 int rc = 0;
265
266 pudp = pud_offset(p4d, addr);
267 do {
268 if (pud_none(*pudp))
269 return -EINVAL;
270 next = pud_addr_end(addr, end);
271 if (pud_leaf(*pudp)) {
272 need_split = !!(flags & SET_MEMORY_4K);
273 need_split |= !!(addr & ~PUD_MASK);
274 need_split |= !!(addr + PUD_SIZE > next);
275 if (need_split) {
276 rc = split_pud_page(pudp, addr);
277 if (rc)
278 break;
279 continue;
280 }
281 modify_pud_page(pudp, addr, flags);
282 } else {
283 rc = walk_pmd_level(pudp, addr, next, flags);
284 }
285 pudp++;
286 addr = next;
287 cond_resched();
288 } while (addr < end && !rc);
289 return rc;
290 }
291
walk_p4d_level(pgd_t * pgd,unsigned long addr,unsigned long end,unsigned long flags)292 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
293 unsigned long flags)
294 {
295 unsigned long next;
296 p4d_t *p4dp;
297 int rc = 0;
298
299 p4dp = p4d_offset(pgd, addr);
300 do {
301 if (p4d_none(*p4dp))
302 return -EINVAL;
303 next = p4d_addr_end(addr, end);
304 rc = walk_pud_level(p4dp, addr, next, flags);
305 p4dp++;
306 addr = next;
307 cond_resched();
308 } while (addr < end && !rc);
309 return rc;
310 }
311
312 DEFINE_MUTEX(cpa_mutex);
313
change_page_attr(unsigned long addr,unsigned long end,unsigned long flags)314 static int change_page_attr(unsigned long addr, unsigned long end,
315 unsigned long flags)
316 {
317 unsigned long next;
318 int rc = -EINVAL;
319 pgd_t *pgdp;
320
321 pgdp = pgd_offset_k(addr);
322 do {
323 if (pgd_none(*pgdp))
324 break;
325 next = pgd_addr_end(addr, end);
326 rc = walk_p4d_level(pgdp, addr, next, flags);
327 if (rc)
328 break;
329 cond_resched();
330 } while (pgdp++, addr = next, addr < end && !rc);
331 return rc;
332 }
333
change_page_attr_alias(unsigned long addr,unsigned long end,unsigned long flags)334 static int change_page_attr_alias(unsigned long addr, unsigned long end,
335 unsigned long flags)
336 {
337 unsigned long alias, offset, va_start, va_end;
338 struct vm_struct *area;
339 int rc = 0;
340
341 /*
342 * Changes to read-only permissions on kernel VA mappings are also
343 * applied to the kernel direct mapping. Execute permissions are
344 * intentionally not transferred to keep all allocated pages within
345 * the direct mapping non-executable.
346 */
347 flags &= SET_MEMORY_RO | SET_MEMORY_RW;
348 if (!flags)
349 return 0;
350 area = NULL;
351 while (addr < end) {
352 if (!area)
353 area = find_vm_area((void *)addr);
354 if (!area || !(area->flags & VM_ALLOC))
355 return 0;
356 va_start = (unsigned long)area->addr;
357 va_end = va_start + area->nr_pages * PAGE_SIZE;
358 offset = (addr - va_start) >> PAGE_SHIFT;
359 alias = (unsigned long)page_address(area->pages[offset]);
360 rc = change_page_attr(alias, alias + PAGE_SIZE, flags);
361 if (rc)
362 break;
363 addr += PAGE_SIZE;
364 if (addr >= va_end)
365 area = NULL;
366 }
367 return rc;
368 }
369
__set_memory(unsigned long addr,unsigned long numpages,unsigned long flags)370 int __set_memory(unsigned long addr, unsigned long numpages, unsigned long flags)
371 {
372 unsigned long end;
373 int rc;
374
375 if (!cpu_has_nx())
376 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
377 if (!flags)
378 return 0;
379 if (!numpages)
380 return 0;
381 addr &= PAGE_MASK;
382 end = addr + numpages * PAGE_SIZE;
383 mutex_lock(&cpa_mutex);
384 rc = change_page_attr(addr, end, flags);
385 if (rc)
386 goto out;
387 rc = change_page_attr_alias(addr, end, flags);
388 out:
389 mutex_unlock(&cpa_mutex);
390 return rc;
391 }
392
set_direct_map_invalid_noflush(struct page * page)393 int set_direct_map_invalid_noflush(struct page *page)
394 {
395 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV);
396 }
397
set_direct_map_default_noflush(struct page * page)398 int set_direct_map_default_noflush(struct page *page)
399 {
400 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF);
401 }
402
set_direct_map_valid_noflush(struct page * page,unsigned nr,bool valid)403 int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
404 {
405 unsigned long flags;
406
407 if (valid)
408 flags = SET_MEMORY_DEF;
409 else
410 flags = SET_MEMORY_INV;
411
412 return __set_memory((unsigned long)page_to_virt(page), nr, flags);
413 }
414
kernel_page_present(struct page * page)415 bool kernel_page_present(struct page *page)
416 {
417 unsigned long addr;
418 unsigned int cc;
419
420 addr = (unsigned long)page_address(page);
421 asm volatile(
422 " lra %[addr],0(%[addr])\n"
423 CC_IPM(cc)
424 : CC_OUT(cc, cc), [addr] "+a" (addr)
425 :
426 : CC_CLOBBER);
427 return CC_TRANSFORM(cc) == 0;
428 }
429
430 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
431
ipte_range(pte_t * pte,unsigned long address,int nr)432 static void ipte_range(pte_t *pte, unsigned long address, int nr)
433 {
434 int i;
435
436 if (test_facility(13)) {
437 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
438 return;
439 }
440 for (i = 0; i < nr; i++) {
441 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
442 address += PAGE_SIZE;
443 pte++;
444 }
445 }
446
__kernel_map_pages(struct page * page,int numpages,int enable)447 void __kernel_map_pages(struct page *page, int numpages, int enable)
448 {
449 unsigned long address;
450 pte_t *ptep, pte;
451 int nr, i, j;
452
453 for (i = 0; i < numpages;) {
454 address = (unsigned long)page_to_virt(page + i);
455 ptep = virt_to_kpte(address);
456 nr = (unsigned long)ptep >> ilog2(sizeof(long));
457 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
458 nr = min(numpages - i, nr);
459 if (enable) {
460 for (j = 0; j < nr; j++) {
461 pte = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID));
462 set_pte(ptep, pte);
463 address += PAGE_SIZE;
464 ptep++;
465 }
466 } else {
467 ipte_range(ptep, address, nr);
468 }
469 i += nr;
470 }
471 }
472
473 #endif /* CONFIG_DEBUG_PAGEALLOC */
474