1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2006
4 */
5
6 #include <linux/memory_hotplug.h>
7 #include <linux/bootmem_info.h>
8 #include <linux/cpufeature.h>
9 #include <linux/memblock.h>
10 #include <linux/pfn.h>
11 #include <linux/mm.h>
12 #include <linux/init.h>
13 #include <linux/list.h>
14 #include <linux/hugetlb.h>
15 #include <linux/slab.h>
16 #include <linux/sort.h>
17 #include <asm/page-states.h>
18 #include <asm/abs_lowcore.h>
19 #include <asm/cacheflush.h>
20 #include <asm/maccess.h>
21 #include <asm/nospec-branch.h>
22 #include <asm/ctlreg.h>
23 #include <asm/pgalloc.h>
24 #include <asm/setup.h>
25 #include <asm/tlbflush.h>
26 #include <asm/sections.h>
27 #include <asm/set_memory.h>
28 #include <asm/physmem_info.h>
29
30 static DEFINE_MUTEX(vmem_mutex);
31
vmem_alloc_pages(unsigned int order)32 static void __ref *vmem_alloc_pages(unsigned int order)
33 {
34 unsigned long size = PAGE_SIZE << order;
35
36 if (slab_is_available())
37 return (void *)__get_free_pages(GFP_KERNEL, order);
38 return memblock_alloc(size, size);
39 }
40
vmem_free_pages(unsigned long addr,int order,struct vmem_altmap * altmap)41 static void vmem_free_pages(unsigned long addr, int order, struct vmem_altmap *altmap)
42 {
43 unsigned int nr_pages = 1 << order;
44 struct page *page;
45
46 if (altmap) {
47 vmem_altmap_free(altmap, 1 << order);
48 return;
49 }
50 page = virt_to_page((void *)addr);
51 if (PageReserved(page)) {
52 /* allocated from memblock */
53 while (nr_pages--)
54 free_bootmem_page(page++);
55 } else {
56 free_pages(addr, order);
57 }
58 }
59
vmem_crst_alloc(unsigned long val)60 void *vmem_crst_alloc(unsigned long val)
61 {
62 unsigned long *table;
63
64 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
65 if (!table)
66 return NULL;
67 crst_table_init(table, val);
68 __arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
69 return table;
70 }
71
vmem_pte_alloc(void)72 pte_t __ref *vmem_pte_alloc(void)
73 {
74 pte_t *pte;
75
76 if (slab_is_available())
77 pte = (pte_t *)page_table_alloc(&init_mm);
78 else
79 pte = (pte_t *)memblock_alloc(PAGE_SIZE, PAGE_SIZE);
80 if (!pte)
81 return NULL;
82 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
83 __arch_set_page_dat(pte, 1);
84 return pte;
85 }
86
vmem_pte_free(unsigned long * table)87 static void vmem_pte_free(unsigned long *table)
88 {
89 page_table_free(&init_mm, table);
90 }
91
92 #define PAGE_UNUSED 0xFD
93
94 /*
95 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
96 * from unused_sub_pmd_start to next PMD_SIZE boundary.
97 */
98 static unsigned long unused_sub_pmd_start;
99
vmemmap_flush_unused_sub_pmd(void)100 static void vmemmap_flush_unused_sub_pmd(void)
101 {
102 if (!unused_sub_pmd_start)
103 return;
104 memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
105 ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
106 unused_sub_pmd_start = 0;
107 }
108
vmemmap_mark_sub_pmd_used(unsigned long start,unsigned long end)109 static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
110 {
111 /*
112 * As we expect to add in the same granularity as we remove, it's
113 * sufficient to mark only some piece used to block the memmap page from
114 * getting removed (just in case the memmap never gets initialized,
115 * e.g., because the memory block never gets onlined).
116 */
117 memset((void *)start, 0, sizeof(struct page));
118 }
119
vmemmap_use_sub_pmd(unsigned long start,unsigned long end)120 static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
121 {
122 /*
123 * We only optimize if the new used range directly follows the
124 * previously unused range (esp., when populating consecutive sections).
125 */
126 if (unused_sub_pmd_start == start) {
127 unused_sub_pmd_start = end;
128 if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
129 unused_sub_pmd_start = 0;
130 return;
131 }
132 vmemmap_flush_unused_sub_pmd();
133 vmemmap_mark_sub_pmd_used(start, end);
134 }
135
vmemmap_use_new_sub_pmd(unsigned long start,unsigned long end)136 static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
137 {
138 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
139
140 vmemmap_flush_unused_sub_pmd();
141
142 /* Could be our memmap page is filled with PAGE_UNUSED already ... */
143 vmemmap_mark_sub_pmd_used(start, end);
144
145 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */
146 if (!IS_ALIGNED(start, PMD_SIZE))
147 memset((void *)page, PAGE_UNUSED, start - page);
148 /*
149 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
150 * consecutive sections. Remember for the last added PMD the last
151 * unused range in the populated PMD.
152 */
153 if (!IS_ALIGNED(end, PMD_SIZE))
154 unused_sub_pmd_start = end;
155 }
156
157 /* Returns true if the PMD is completely unused and can be freed. */
vmemmap_unuse_sub_pmd(unsigned long start,unsigned long end)158 static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
159 {
160 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
161
162 vmemmap_flush_unused_sub_pmd();
163 memset((void *)start, PAGE_UNUSED, end - start);
164 return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
165 }
166
167 /* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
modify_pte_table(pmd_t * pmd,unsigned long addr,unsigned long end,bool add,bool direct,struct vmem_altmap * altmap)168 static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
169 unsigned long end, bool add, bool direct,
170 struct vmem_altmap *altmap)
171 {
172 unsigned long prot, pages = 0;
173 int ret = -ENOMEM;
174 pte_t *pte;
175
176 prot = pgprot_val(PAGE_KERNEL);
177 pte = pte_offset_kernel(pmd, addr);
178 for (; addr < end; addr += PAGE_SIZE, pte++) {
179 if (!add) {
180 if (pte_none(*pte))
181 continue;
182 if (!direct)
183 vmem_free_pages((unsigned long)pfn_to_virt(pte_pfn(*pte)), get_order(PAGE_SIZE), altmap);
184 pte_clear(&init_mm, addr, pte);
185 } else if (pte_none(*pte)) {
186 if (!direct) {
187 void *new_page = vmemmap_alloc_block_buf(PAGE_SIZE, NUMA_NO_NODE, altmap);
188
189 if (!new_page)
190 goto out;
191 set_pte(pte, __pte(__pa(new_page) | prot));
192 } else {
193 set_pte(pte, __pte(__pa(addr) | prot));
194 }
195 } else {
196 continue;
197 }
198 pages++;
199 }
200 ret = 0;
201 out:
202 if (direct)
203 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
204 return ret;
205 }
206
try_free_pte_table(pmd_t * pmd,unsigned long start)207 static void try_free_pte_table(pmd_t *pmd, unsigned long start)
208 {
209 pte_t *pte;
210 int i;
211
212 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */
213 pte = pte_offset_kernel(pmd, start);
214 for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
215 if (!pte_none(*pte))
216 return;
217 }
218 vmem_pte_free((unsigned long *) pmd_deref(*pmd));
219 pmd_clear(pmd);
220 }
221
222 /* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
modify_pmd_table(pud_t * pud,unsigned long addr,unsigned long end,bool add,bool direct,struct vmem_altmap * altmap)223 static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
224 unsigned long end, bool add, bool direct,
225 struct vmem_altmap *altmap)
226 {
227 unsigned long next, prot, pages = 0;
228 int ret = -ENOMEM;
229 pmd_t *pmd;
230 pte_t *pte;
231
232 prot = pgprot_val(SEGMENT_KERNEL);
233 pmd = pmd_offset(pud, addr);
234 for (; addr < end; addr = next, pmd++) {
235 next = pmd_addr_end(addr, end);
236 if (!add) {
237 if (pmd_none(*pmd))
238 continue;
239 if (pmd_leaf(*pmd)) {
240 if (IS_ALIGNED(addr, PMD_SIZE) &&
241 IS_ALIGNED(next, PMD_SIZE)) {
242 if (!direct)
243 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE), altmap);
244 pmd_clear(pmd);
245 pages++;
246 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
247 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE), altmap);
248 pmd_clear(pmd);
249 }
250 continue;
251 }
252 } else if (pmd_none(*pmd)) {
253 if (IS_ALIGNED(addr, PMD_SIZE) &&
254 IS_ALIGNED(next, PMD_SIZE) &&
255 cpu_has_edat1() && direct &&
256 !debug_pagealloc_enabled()) {
257 set_pmd(pmd, __pmd(__pa(addr) | prot));
258 pages++;
259 continue;
260 } else if (!direct && cpu_has_edat1()) {
261 void *new_page;
262
263 /*
264 * Use 1MB frames for vmemmap if available. We
265 * always use large frames even if they are only
266 * partially used. Otherwise we would have also
267 * page tables since vmemmap_populate gets
268 * called for each section separately.
269 */
270 new_page = vmemmap_alloc_block_buf(PMD_SIZE, NUMA_NO_NODE, altmap);
271 if (new_page) {
272 set_pmd(pmd, __pmd(__pa(new_page) | prot));
273 if (!IS_ALIGNED(addr, PMD_SIZE) ||
274 !IS_ALIGNED(next, PMD_SIZE)) {
275 vmemmap_use_new_sub_pmd(addr, next);
276 }
277 continue;
278 }
279 }
280 pte = vmem_pte_alloc();
281 if (!pte)
282 goto out;
283 pmd_populate(&init_mm, pmd, pte);
284 } else if (pmd_leaf(*pmd)) {
285 if (!direct)
286 vmemmap_use_sub_pmd(addr, next);
287 continue;
288 }
289 ret = modify_pte_table(pmd, addr, next, add, direct, altmap);
290 if (ret)
291 goto out;
292 if (!add)
293 try_free_pte_table(pmd, addr & PMD_MASK);
294 }
295 ret = 0;
296 out:
297 if (direct)
298 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
299 return ret;
300 }
301
try_free_pmd_table(pud_t * pud,unsigned long start)302 static void try_free_pmd_table(pud_t *pud, unsigned long start)
303 {
304 pmd_t *pmd;
305 int i;
306
307 pmd = pmd_offset(pud, start);
308 for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
309 if (!pmd_none(*pmd))
310 return;
311 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER, NULL);
312 pud_clear(pud);
313 }
314
modify_pud_table(p4d_t * p4d,unsigned long addr,unsigned long end,bool add,bool direct,struct vmem_altmap * altmap)315 static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
316 bool add, bool direct, struct vmem_altmap *altmap)
317 {
318 unsigned long next, prot, pages = 0;
319 int ret = -ENOMEM;
320 pud_t *pud;
321 pmd_t *pmd;
322
323 prot = pgprot_val(REGION3_KERNEL);
324 pud = pud_offset(p4d, addr);
325 for (; addr < end; addr = next, pud++) {
326 next = pud_addr_end(addr, end);
327 if (!add) {
328 if (pud_none(*pud))
329 continue;
330 if (pud_leaf(*pud)) {
331 if (IS_ALIGNED(addr, PUD_SIZE) &&
332 IS_ALIGNED(next, PUD_SIZE)) {
333 if (!direct)
334 vmem_free_pages(pud_deref(*pud), get_order(PUD_SIZE), altmap);
335 pud_clear(pud);
336 pages++;
337 continue;
338 } else {
339 split_pud_page(pud, addr & PUD_MASK);
340 }
341 }
342 } else if (pud_none(*pud)) {
343 if (IS_ALIGNED(addr, PUD_SIZE) &&
344 IS_ALIGNED(next, PUD_SIZE) &&
345 cpu_has_edat2() && direct &&
346 !debug_pagealloc_enabled()) {
347 set_pud(pud, __pud(__pa(addr) | prot));
348 pages++;
349 continue;
350 }
351 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
352 if (!pmd)
353 goto out;
354 pud_populate(&init_mm, pud, pmd);
355 } else if (pud_leaf(*pud)) {
356 continue;
357 }
358 ret = modify_pmd_table(pud, addr, next, add, direct, altmap);
359 if (ret)
360 goto out;
361 if (!add)
362 try_free_pmd_table(pud, addr & PUD_MASK);
363 }
364 ret = 0;
365 out:
366 if (direct)
367 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
368 return ret;
369 }
370
try_free_pud_table(p4d_t * p4d,unsigned long start)371 static void try_free_pud_table(p4d_t *p4d, unsigned long start)
372 {
373 pud_t *pud;
374 int i;
375
376 pud = pud_offset(p4d, start);
377 for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
378 if (!pud_none(*pud))
379 return;
380 }
381 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER, NULL);
382 p4d_clear(p4d);
383 }
384
modify_p4d_table(pgd_t * pgd,unsigned long addr,unsigned long end,bool add,bool direct,struct vmem_altmap * altmap)385 static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
386 bool add, bool direct, struct vmem_altmap *altmap)
387 {
388 unsigned long next;
389 int ret = -ENOMEM;
390 p4d_t *p4d;
391 pud_t *pud;
392
393 p4d = p4d_offset(pgd, addr);
394 for (; addr < end; addr = next, p4d++) {
395 next = p4d_addr_end(addr, end);
396 if (!add) {
397 if (p4d_none(*p4d))
398 continue;
399 } else if (p4d_none(*p4d)) {
400 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
401 if (!pud)
402 goto out;
403 p4d_populate(&init_mm, p4d, pud);
404 }
405 ret = modify_pud_table(p4d, addr, next, add, direct, altmap);
406 if (ret)
407 goto out;
408 if (!add)
409 try_free_pud_table(p4d, addr & P4D_MASK);
410 }
411 ret = 0;
412 out:
413 return ret;
414 }
415
try_free_p4d_table(pgd_t * pgd,unsigned long start)416 static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
417 {
418 p4d_t *p4d;
419 int i;
420
421 p4d = p4d_offset(pgd, start);
422 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
423 if (!p4d_none(*p4d))
424 return;
425 }
426 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER, NULL);
427 pgd_clear(pgd);
428 }
429
modify_pagetable(unsigned long start,unsigned long end,bool add,bool direct,struct vmem_altmap * altmap)430 static int modify_pagetable(unsigned long start, unsigned long end, bool add,
431 bool direct, struct vmem_altmap *altmap)
432 {
433 unsigned long addr, next;
434 int ret = -ENOMEM;
435 pgd_t *pgd;
436 p4d_t *p4d;
437
438 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
439 return -EINVAL;
440 /* Don't mess with any tables not fully in 1:1 mapping, vmemmap & kasan area */
441 #ifdef CONFIG_KASAN
442 if (WARN_ON_ONCE(!(start >= KASAN_SHADOW_START && end <= KASAN_SHADOW_END) &&
443 end > __abs_lowcore))
444 return -EINVAL;
445 #else
446 if (WARN_ON_ONCE(end > __abs_lowcore))
447 return -EINVAL;
448 #endif
449 for (addr = start; addr < end; addr = next) {
450 next = pgd_addr_end(addr, end);
451 pgd = pgd_offset_k(addr);
452
453 if (!add) {
454 if (pgd_none(*pgd))
455 continue;
456 } else if (pgd_none(*pgd)) {
457 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
458 if (!p4d)
459 goto out;
460 pgd_populate(&init_mm, pgd, p4d);
461 }
462 ret = modify_p4d_table(pgd, addr, next, add, direct, altmap);
463 if (ret)
464 goto out;
465 if (!add)
466 try_free_p4d_table(pgd, addr & PGDIR_MASK);
467 }
468 ret = 0;
469 out:
470 if (!add)
471 flush_tlb_kernel_range(start, end);
472 return ret;
473 }
474
add_pagetable(unsigned long start,unsigned long end,bool direct,struct vmem_altmap * altmap)475 static int add_pagetable(unsigned long start, unsigned long end, bool direct,
476 struct vmem_altmap *altmap)
477 {
478 return modify_pagetable(start, end, true, direct, altmap);
479 }
480
remove_pagetable(unsigned long start,unsigned long end,bool direct,struct vmem_altmap * altmap)481 static int remove_pagetable(unsigned long start, unsigned long end, bool direct,
482 struct vmem_altmap *altmap)
483 {
484 return modify_pagetable(start, end, false, direct, altmap);
485 }
486
487 /*
488 * Add a physical memory range to the 1:1 mapping.
489 */
vmem_add_range(unsigned long start,unsigned long size)490 static int vmem_add_range(unsigned long start, unsigned long size)
491 {
492 start = (unsigned long)__va(start);
493 return add_pagetable(start, start + size, true, NULL);
494 }
495
496 /*
497 * Remove a physical memory range from the 1:1 mapping.
498 */
vmem_remove_range(unsigned long start,unsigned long size)499 static void vmem_remove_range(unsigned long start, unsigned long size)
500 {
501 start = (unsigned long)__va(start);
502 remove_pagetable(start, start + size, true, NULL);
503 }
504
505 /*
506 * Add a backed mem_map array to the virtual mem_map array.
507 */
vmemmap_populate(unsigned long start,unsigned long end,int node,struct vmem_altmap * altmap)508 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
509 struct vmem_altmap *altmap)
510 {
511 int ret;
512
513 mutex_lock(&vmem_mutex);
514 /* We don't care about the node, just use NUMA_NO_NODE on allocations */
515 ret = add_pagetable(start, end, false, altmap);
516 if (ret)
517 remove_pagetable(start, end, false, altmap);
518 mutex_unlock(&vmem_mutex);
519 return ret;
520 }
521
522 #ifdef CONFIG_MEMORY_HOTPLUG
523
vmemmap_free(unsigned long start,unsigned long end,struct vmem_altmap * altmap)524 void vmemmap_free(unsigned long start, unsigned long end,
525 struct vmem_altmap *altmap)
526 {
527 mutex_lock(&vmem_mutex);
528 remove_pagetable(start, end, false, altmap);
529 mutex_unlock(&vmem_mutex);
530 }
531
532 #endif
533
vmem_remove_mapping(unsigned long start,unsigned long size)534 void vmem_remove_mapping(unsigned long start, unsigned long size)
535 {
536 mutex_lock(&vmem_mutex);
537 vmem_remove_range(start, size);
538 mutex_unlock(&vmem_mutex);
539 }
540
arch_get_mappable_range(void)541 struct range arch_get_mappable_range(void)
542 {
543 struct range mhp_range;
544
545 mhp_range.start = 0;
546 mhp_range.end = max_mappable - 1;
547 return mhp_range;
548 }
549
vmem_add_mapping(unsigned long start,unsigned long size)550 int vmem_add_mapping(unsigned long start, unsigned long size)
551 {
552 struct range range = arch_get_mappable_range();
553 int ret;
554
555 if (start < range.start ||
556 start + size > range.end + 1 ||
557 start + size < start)
558 return -ERANGE;
559
560 mutex_lock(&vmem_mutex);
561 ret = vmem_add_range(start, size);
562 if (ret)
563 vmem_remove_range(start, size);
564 mutex_unlock(&vmem_mutex);
565 return ret;
566 }
567
568 /*
569 * Allocate new or return existing page-table entry, but do not map it
570 * to any physical address. If missing, allocate segment- and region-
571 * table entries along. Meeting a large segment- or region-table entry
572 * while traversing is an error, since the function is expected to be
573 * called against virtual regions reserved for 4KB mappings only.
574 */
vmem_get_alloc_pte(unsigned long addr,bool alloc)575 pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
576 {
577 pte_t *ptep = NULL;
578 pgd_t *pgd;
579 p4d_t *p4d;
580 pud_t *pud;
581 pmd_t *pmd;
582 pte_t *pte;
583
584 pgd = pgd_offset_k(addr);
585 if (pgd_none(*pgd)) {
586 if (!alloc)
587 goto out;
588 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
589 if (!p4d)
590 goto out;
591 pgd_populate(&init_mm, pgd, p4d);
592 }
593 p4d = p4d_offset(pgd, addr);
594 if (p4d_none(*p4d)) {
595 if (!alloc)
596 goto out;
597 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
598 if (!pud)
599 goto out;
600 p4d_populate(&init_mm, p4d, pud);
601 }
602 pud = pud_offset(p4d, addr);
603 if (pud_none(*pud)) {
604 if (!alloc)
605 goto out;
606 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
607 if (!pmd)
608 goto out;
609 pud_populate(&init_mm, pud, pmd);
610 } else if (WARN_ON_ONCE(pud_leaf(*pud))) {
611 goto out;
612 }
613 pmd = pmd_offset(pud, addr);
614 if (pmd_none(*pmd)) {
615 if (!alloc)
616 goto out;
617 pte = vmem_pte_alloc();
618 if (!pte)
619 goto out;
620 pmd_populate(&init_mm, pmd, pte);
621 } else if (WARN_ON_ONCE(pmd_leaf(*pmd))) {
622 goto out;
623 }
624 ptep = pte_offset_kernel(pmd, addr);
625 out:
626 return ptep;
627 }
628
__vmem_map_4k_page(unsigned long addr,unsigned long phys,pgprot_t prot,bool alloc)629 int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
630 {
631 pte_t *ptep, pte;
632
633 if (!IS_ALIGNED(addr, PAGE_SIZE))
634 return -EINVAL;
635 ptep = vmem_get_alloc_pte(addr, alloc);
636 if (!ptep)
637 return -ENOMEM;
638 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
639 pte = mk_pte_phys(phys, prot);
640 set_pte(ptep, pte);
641 return 0;
642 }
643
vmem_map_4k_page(unsigned long addr,unsigned long phys,pgprot_t prot)644 int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
645 {
646 int rc;
647
648 mutex_lock(&vmem_mutex);
649 rc = __vmem_map_4k_page(addr, phys, prot, true);
650 mutex_unlock(&vmem_mutex);
651 return rc;
652 }
653
vmem_unmap_4k_page(unsigned long addr)654 void vmem_unmap_4k_page(unsigned long addr)
655 {
656 pte_t *ptep;
657
658 mutex_lock(&vmem_mutex);
659 ptep = virt_to_kpte(addr);
660 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
661 pte_clear(&init_mm, addr, ptep);
662 mutex_unlock(&vmem_mutex);
663 }
664
vmem_map_init(void)665 void __init vmem_map_init(void)
666 {
667 __set_memory_rox(_stext, _etext);
668 __set_memory_ro(_etext, __end_rodata);
669 __set_memory_rox(__stext_amode31, __etext_amode31);
670 /*
671 * If the BEAR-enhancement facility is not installed the first
672 * prefix page is used to return to the previous context with
673 * an LPSWE instruction and therefore must be executable.
674 */
675 if (!cpu_has_bear())
676 set_memory_x(0, 1);
677 if (debug_pagealloc_enabled())
678 __set_memory_4k(__va(0), absolute_pointer(__va(0)) + ident_map_size);
679 pr_info("Write protected kernel read-only data: %luk\n",
680 (unsigned long)(__end_rodata - _stext) >> 10);
681 }
682