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 if (cpu_has_idte()) {
82 cspg(old, *old, new);
83 } else {
84 csp((unsigned int *)old + 1, *old, new);
85 }
86 }
87
walk_pte_level(pmd_t * pmdp,unsigned long addr,unsigned long end,unsigned long flags)88 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
89 unsigned long flags)
90 {
91 pte_t *ptep, new;
92
93 if (flags == SET_MEMORY_4K)
94 return 0;
95 ptep = pte_offset_kernel(pmdp, addr);
96 do {
97 new = *ptep;
98 if (pte_none(new))
99 return -EINVAL;
100 if (flags & SET_MEMORY_RO)
101 new = pte_wrprotect(new);
102 else if (flags & SET_MEMORY_RW)
103 new = pte_mkwrite_novma(pte_mkdirty(new));
104 if (flags & SET_MEMORY_NX)
105 new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC));
106 else if (flags & SET_MEMORY_X)
107 new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC));
108 if (flags & SET_MEMORY_INV) {
109 new = set_pte_bit(new, __pgprot(_PAGE_INVALID));
110 } else if (flags & SET_MEMORY_DEF) {
111 new = __pte(pte_val(new) & PAGE_MASK);
112 new = set_pte_bit(new, PAGE_KERNEL);
113 }
114 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
115 ptep++;
116 addr += PAGE_SIZE;
117 cond_resched();
118 } while (addr < end);
119 return 0;
120 }
121
split_pmd_page(pmd_t * pmdp,unsigned long addr)122 static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
123 {
124 unsigned long pte_addr, prot;
125 pte_t *pt_dir, *ptep;
126 pmd_t new;
127 int i, ro, nx;
128
129 pt_dir = vmem_pte_alloc();
130 if (!pt_dir)
131 return -ENOMEM;
132 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
133 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
134 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
135 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
136 if (!nx)
137 prot &= ~_PAGE_NOEXEC;
138 ptep = pt_dir;
139 for (i = 0; i < PTRS_PER_PTE; i++) {
140 set_pte(ptep, __pte(pte_addr | prot));
141 pte_addr += PAGE_SIZE;
142 ptep++;
143 }
144 new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY);
145 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
146 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
147 update_page_count(PG_DIRECT_MAP_1M, -1);
148 return 0;
149 }
150
modify_pmd_page(pmd_t * pmdp,unsigned long addr,unsigned long flags)151 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
152 unsigned long flags)
153 {
154 pmd_t new = *pmdp;
155
156 if (flags & SET_MEMORY_RO)
157 new = pmd_wrprotect(new);
158 else if (flags & SET_MEMORY_RW)
159 new = pmd_mkwrite_novma(pmd_mkdirty(new));
160 if (flags & SET_MEMORY_NX)
161 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
162 else if (flags & SET_MEMORY_X)
163 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC));
164 if (flags & SET_MEMORY_INV) {
165 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));
166 } else if (flags & SET_MEMORY_DEF) {
167 new = __pmd(pmd_val(new) & PMD_MASK);
168 new = set_pmd_bit(new, SEGMENT_KERNEL);
169 }
170 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
171 }
172
walk_pmd_level(pud_t * pudp,unsigned long addr,unsigned long end,unsigned long flags)173 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end,
174 unsigned long flags)
175 {
176 unsigned long next;
177 int need_split;
178 pmd_t *pmdp;
179 int rc = 0;
180
181 pmdp = pmd_offset(pudp, addr);
182 do {
183 if (pmd_none(*pmdp))
184 return -EINVAL;
185 next = pmd_addr_end(addr, end);
186 if (pmd_leaf(*pmdp)) {
187 need_split = !!(flags & SET_MEMORY_4K);
188 need_split |= !!(addr & ~PMD_MASK);
189 need_split |= !!(addr + PMD_SIZE > next);
190 if (need_split) {
191 rc = split_pmd_page(pmdp, addr);
192 if (rc)
193 return rc;
194 continue;
195 }
196 modify_pmd_page(pmdp, addr, flags);
197 } else {
198 rc = walk_pte_level(pmdp, addr, next, flags);
199 if (rc)
200 return rc;
201 }
202 pmdp++;
203 addr = next;
204 cond_resched();
205 } while (addr < end);
206 return rc;
207 }
208
split_pud_page(pud_t * pudp,unsigned long addr)209 static int split_pud_page(pud_t *pudp, unsigned long addr)
210 {
211 unsigned long pmd_addr, prot;
212 pmd_t *pm_dir, *pmdp;
213 pud_t new;
214 int i, ro, nx;
215
216 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
217 if (!pm_dir)
218 return -ENOMEM;
219 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
220 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
221 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
222 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
223 if (!nx)
224 prot &= ~_SEGMENT_ENTRY_NOEXEC;
225 pmdp = pm_dir;
226 for (i = 0; i < PTRS_PER_PMD; i++) {
227 set_pmd(pmdp, __pmd(pmd_addr | prot));
228 pmd_addr += PMD_SIZE;
229 pmdp++;
230 }
231 new = __pud(__pa(pm_dir) | _REGION3_ENTRY);
232 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
233 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
234 update_page_count(PG_DIRECT_MAP_2G, -1);
235 return 0;
236 }
237
modify_pud_page(pud_t * pudp,unsigned long addr,unsigned long flags)238 static void modify_pud_page(pud_t *pudp, unsigned long addr,
239 unsigned long flags)
240 {
241 pud_t new = *pudp;
242
243 if (flags & SET_MEMORY_RO)
244 new = pud_wrprotect(new);
245 else if (flags & SET_MEMORY_RW)
246 new = pud_mkwrite(pud_mkdirty(new));
247 if (flags & SET_MEMORY_NX)
248 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
249 else if (flags & SET_MEMORY_X)
250 new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC));
251 if (flags & SET_MEMORY_INV) {
252 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID));
253 } else if (flags & SET_MEMORY_DEF) {
254 new = __pud(pud_val(new) & PUD_MASK);
255 new = set_pud_bit(new, REGION3_KERNEL);
256 }
257 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
258 }
259
walk_pud_level(p4d_t * p4d,unsigned long addr,unsigned long end,unsigned long flags)260 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
261 unsigned long flags)
262 {
263 unsigned long next;
264 int need_split;
265 pud_t *pudp;
266 int rc = 0;
267
268 pudp = pud_offset(p4d, addr);
269 do {
270 if (pud_none(*pudp))
271 return -EINVAL;
272 next = pud_addr_end(addr, end);
273 if (pud_leaf(*pudp)) {
274 need_split = !!(flags & SET_MEMORY_4K);
275 need_split |= !!(addr & ~PUD_MASK);
276 need_split |= !!(addr + PUD_SIZE > next);
277 if (need_split) {
278 rc = split_pud_page(pudp, addr);
279 if (rc)
280 break;
281 continue;
282 }
283 modify_pud_page(pudp, addr, flags);
284 } else {
285 rc = walk_pmd_level(pudp, addr, next, flags);
286 }
287 pudp++;
288 addr = next;
289 cond_resched();
290 } while (addr < end && !rc);
291 return rc;
292 }
293
walk_p4d_level(pgd_t * pgd,unsigned long addr,unsigned long end,unsigned long flags)294 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
295 unsigned long flags)
296 {
297 unsigned long next;
298 p4d_t *p4dp;
299 int rc = 0;
300
301 p4dp = p4d_offset(pgd, addr);
302 do {
303 if (p4d_none(*p4dp))
304 return -EINVAL;
305 next = p4d_addr_end(addr, end);
306 rc = walk_pud_level(p4dp, addr, next, flags);
307 p4dp++;
308 addr = next;
309 cond_resched();
310 } while (addr < end && !rc);
311 return rc;
312 }
313
314 DEFINE_MUTEX(cpa_mutex);
315
change_page_attr(unsigned long addr,unsigned long end,unsigned long flags)316 static int change_page_attr(unsigned long addr, unsigned long end,
317 unsigned long flags)
318 {
319 unsigned long next;
320 int rc = -EINVAL;
321 pgd_t *pgdp;
322
323 pgdp = pgd_offset_k(addr);
324 do {
325 if (pgd_none(*pgdp))
326 break;
327 next = pgd_addr_end(addr, end);
328 rc = walk_p4d_level(pgdp, addr, next, flags);
329 if (rc)
330 break;
331 cond_resched();
332 } while (pgdp++, addr = next, addr < end && !rc);
333 return rc;
334 }
335
change_page_attr_alias(unsigned long addr,unsigned long end,unsigned long flags)336 static int change_page_attr_alias(unsigned long addr, unsigned long end,
337 unsigned long flags)
338 {
339 unsigned long alias, offset, va_start, va_end;
340 struct vm_struct *area;
341 int rc = 0;
342
343 /*
344 * Changes to read-only permissions on kernel VA mappings are also
345 * applied to the kernel direct mapping. Execute permissions are
346 * intentionally not transferred to keep all allocated pages within
347 * the direct mapping non-executable.
348 */
349 flags &= SET_MEMORY_RO | SET_MEMORY_RW;
350 if (!flags)
351 return 0;
352 area = NULL;
353 while (addr < end) {
354 if (!area)
355 area = find_vm_area((void *)addr);
356 if (!area || !(area->flags & VM_ALLOC))
357 return 0;
358 va_start = (unsigned long)area->addr;
359 va_end = va_start + area->nr_pages * PAGE_SIZE;
360 offset = (addr - va_start) >> PAGE_SHIFT;
361 alias = (unsigned long)page_address(area->pages[offset]);
362 rc = change_page_attr(alias, alias + PAGE_SIZE, flags);
363 if (rc)
364 break;
365 addr += PAGE_SIZE;
366 if (addr >= va_end)
367 area = NULL;
368 }
369 return rc;
370 }
371
__set_memory(unsigned long addr,unsigned long numpages,unsigned long flags)372 int __set_memory(unsigned long addr, unsigned long numpages, unsigned long flags)
373 {
374 unsigned long end;
375 int rc;
376
377 if (!cpu_has_nx())
378 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
379 if (!flags)
380 return 0;
381 if (!numpages)
382 return 0;
383 addr &= PAGE_MASK;
384 end = addr + numpages * PAGE_SIZE;
385 mutex_lock(&cpa_mutex);
386 rc = change_page_attr(addr, end, flags);
387 if (rc)
388 goto out;
389 rc = change_page_attr_alias(addr, end, flags);
390 out:
391 mutex_unlock(&cpa_mutex);
392 return rc;
393 }
394
set_direct_map_invalid_noflush(struct page * page)395 int set_direct_map_invalid_noflush(struct page *page)
396 {
397 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV);
398 }
399
set_direct_map_default_noflush(struct page * page)400 int set_direct_map_default_noflush(struct page *page)
401 {
402 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF);
403 }
404
set_direct_map_valid_noflush(struct page * page,unsigned nr,bool valid)405 int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
406 {
407 unsigned long flags;
408
409 if (valid)
410 flags = SET_MEMORY_DEF;
411 else
412 flags = SET_MEMORY_INV;
413
414 return __set_memory((unsigned long)page_to_virt(page), nr, flags);
415 }
416
kernel_page_present(struct page * page)417 bool kernel_page_present(struct page *page)
418 {
419 unsigned long addr;
420 unsigned int cc;
421
422 addr = (unsigned long)page_address(page);
423 asm volatile(
424 " lra %[addr],0(%[addr])\n"
425 CC_IPM(cc)
426 : CC_OUT(cc, cc), [addr] "+a" (addr)
427 :
428 : CC_CLOBBER);
429 return CC_TRANSFORM(cc) == 0;
430 }
431
432 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
433
ipte_range(pte_t * pte,unsigned long address,int nr)434 static void ipte_range(pte_t *pte, unsigned long address, int nr)
435 {
436 int i;
437
438 if (test_facility(13)) {
439 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
440 return;
441 }
442 for (i = 0; i < nr; i++) {
443 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
444 address += PAGE_SIZE;
445 pte++;
446 }
447 }
448
__kernel_map_pages(struct page * page,int numpages,int enable)449 void __kernel_map_pages(struct page *page, int numpages, int enable)
450 {
451 unsigned long address;
452 pte_t *ptep, pte;
453 int nr, i, j;
454
455 for (i = 0; i < numpages;) {
456 address = (unsigned long)page_to_virt(page + i);
457 ptep = virt_to_kpte(address);
458 nr = (unsigned long)ptep >> ilog2(sizeof(long));
459 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
460 nr = min(numpages - i, nr);
461 if (enable) {
462 for (j = 0; j < nr; j++) {
463 pte = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID));
464 set_pte(ptep, pte);
465 address += PAGE_SIZE;
466 ptep++;
467 }
468 } else {
469 ipte_range(ptep, address, nr);
470 }
471 i += nr;
472 }
473 }
474
475 #endif /* CONFIG_DEBUG_PAGEALLOC */
476