Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2006
4 */
5
6#include <linux/memory_hotplug.h>
7#include <linux/memblock.h>
8#include <linux/pfn.h>
9#include <linux/mm.h>
10#include <linux/init.h>
11#include <linux/list.h>
12#include <linux/hugetlb.h>
13#include <linux/slab.h>
14#include <linux/sort.h>
15#include <asm/page-states.h>
16#include <asm/cacheflush.h>
17#include <asm/nospec-branch.h>
18#include <asm/ctlreg.h>
19#include <asm/pgalloc.h>
20#include <asm/setup.h>
21#include <asm/tlbflush.h>
22#include <asm/sections.h>
23#include <asm/set_memory.h>
24
25static DEFINE_MUTEX(vmem_mutex);
26
27static void __ref *vmem_alloc_pages(unsigned int order)
28{
29 unsigned long size = PAGE_SIZE << order;
30
31 if (slab_is_available())
32 return (void *)__get_free_pages(GFP_KERNEL, order);
33 return memblock_alloc(size, size);
34}
35
36static void vmem_free_pages(unsigned long addr, int order)
37{
38 /* We don't expect boot memory to be removed ever. */
39 if (!slab_is_available() ||
40 WARN_ON_ONCE(PageReserved(virt_to_page((void *)addr))))
41 return;
42 free_pages(addr, order);
43}
44
45void *vmem_crst_alloc(unsigned long val)
46{
47 unsigned long *table;
48
49 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
50 if (!table)
51 return NULL;
52 crst_table_init(table, val);
53 __arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
54 return table;
55}
56
57pte_t __ref *vmem_pte_alloc(void)
58{
59 unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
60 pte_t *pte;
61
62 if (slab_is_available())
63 pte = (pte_t *) page_table_alloc(&init_mm);
64 else
65 pte = (pte_t *) memblock_alloc(size, size);
66 if (!pte)
67 return NULL;
68 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
69 __arch_set_page_dat(pte, 1);
70 return pte;
71}
72
73static void vmem_pte_free(unsigned long *table)
74{
75 /* We don't expect boot memory to be removed ever. */
76 if (!slab_is_available() ||
77 WARN_ON_ONCE(PageReserved(virt_to_page(table))))
78 return;
79 page_table_free(&init_mm, table);
80}
81
82#define PAGE_UNUSED 0xFD
83
84/*
85 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
86 * from unused_sub_pmd_start to next PMD_SIZE boundary.
87 */
88static unsigned long unused_sub_pmd_start;
89
90static void vmemmap_flush_unused_sub_pmd(void)
91{
92 if (!unused_sub_pmd_start)
93 return;
94 memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
95 ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
96 unused_sub_pmd_start = 0;
97}
98
99static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
100{
101 /*
102 * As we expect to add in the same granularity as we remove, it's
103 * sufficient to mark only some piece used to block the memmap page from
104 * getting removed (just in case the memmap never gets initialized,
105 * e.g., because the memory block never gets onlined).
106 */
107 memset((void *)start, 0, sizeof(struct page));
108}
109
110static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
111{
112 /*
113 * We only optimize if the new used range directly follows the
114 * previously unused range (esp., when populating consecutive sections).
115 */
116 if (unused_sub_pmd_start == start) {
117 unused_sub_pmd_start = end;
118 if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
119 unused_sub_pmd_start = 0;
120 return;
121 }
122 vmemmap_flush_unused_sub_pmd();
123 vmemmap_mark_sub_pmd_used(start, end);
124}
125
126static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
127{
128 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
129
130 vmemmap_flush_unused_sub_pmd();
131
132 /* Could be our memmap page is filled with PAGE_UNUSED already ... */
133 vmemmap_mark_sub_pmd_used(start, end);
134
135 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */
136 if (!IS_ALIGNED(start, PMD_SIZE))
137 memset((void *)page, PAGE_UNUSED, start - page);
138 /*
139 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
140 * consecutive sections. Remember for the last added PMD the last
141 * unused range in the populated PMD.
142 */
143 if (!IS_ALIGNED(end, PMD_SIZE))
144 unused_sub_pmd_start = end;
145}
146
147/* Returns true if the PMD is completely unused and can be freed. */
148static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
149{
150 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
151
152 vmemmap_flush_unused_sub_pmd();
153 memset((void *)start, PAGE_UNUSED, end - start);
154 return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
155}
156
157/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
158static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
159 unsigned long end, bool add, bool direct)
160{
161 unsigned long prot, pages = 0;
162 int ret = -ENOMEM;
163 pte_t *pte;
164
165 prot = pgprot_val(PAGE_KERNEL);
166 if (!MACHINE_HAS_NX)
167 prot &= ~_PAGE_NOEXEC;
168
169 pte = pte_offset_kernel(pmd, addr);
170 for (; addr < end; addr += PAGE_SIZE, pte++) {
171 if (!add) {
172 if (pte_none(*pte))
173 continue;
174 if (!direct)
175 vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0);
176 pte_clear(&init_mm, addr, pte);
177 } else if (pte_none(*pte)) {
178 if (!direct) {
179 void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
180
181 if (!new_page)
182 goto out;
183 set_pte(pte, __pte(__pa(new_page) | prot));
184 } else {
185 set_pte(pte, __pte(__pa(addr) | prot));
186 }
187 } else {
188 continue;
189 }
190 pages++;
191 }
192 ret = 0;
193out:
194 if (direct)
195 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
196 return ret;
197}
198
199static void try_free_pte_table(pmd_t *pmd, unsigned long start)
200{
201 pte_t *pte;
202 int i;
203
204 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */
205 pte = pte_offset_kernel(pmd, start);
206 for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
207 if (!pte_none(*pte))
208 return;
209 }
210 vmem_pte_free((unsigned long *) pmd_deref(*pmd));
211 pmd_clear(pmd);
212}
213
214/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
215static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
216 unsigned long end, bool add, bool direct)
217{
218 unsigned long next, prot, pages = 0;
219 int ret = -ENOMEM;
220 pmd_t *pmd;
221 pte_t *pte;
222
223 prot = pgprot_val(SEGMENT_KERNEL);
224 if (!MACHINE_HAS_NX)
225 prot &= ~_SEGMENT_ENTRY_NOEXEC;
226
227 pmd = pmd_offset(pud, addr);
228 for (; addr < end; addr = next, pmd++) {
229 next = pmd_addr_end(addr, end);
230 if (!add) {
231 if (pmd_none(*pmd))
232 continue;
233 if (pmd_large(*pmd)) {
234 if (IS_ALIGNED(addr, PMD_SIZE) &&
235 IS_ALIGNED(next, PMD_SIZE)) {
236 if (!direct)
237 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
238 pmd_clear(pmd);
239 pages++;
240 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
241 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
242 pmd_clear(pmd);
243 }
244 continue;
245 }
246 } else if (pmd_none(*pmd)) {
247 if (IS_ALIGNED(addr, PMD_SIZE) &&
248 IS_ALIGNED(next, PMD_SIZE) &&
249 MACHINE_HAS_EDAT1 && direct &&
250 !debug_pagealloc_enabled()) {
251 set_pmd(pmd, __pmd(__pa(addr) | prot));
252 pages++;
253 continue;
254 } else if (!direct && MACHINE_HAS_EDAT1) {
255 void *new_page;
256
257 /*
258 * Use 1MB frames for vmemmap if available. We
259 * always use large frames even if they are only
260 * partially used. Otherwise we would have also
261 * page tables since vmemmap_populate gets
262 * called for each section separately.
263 */
264 new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
265 if (new_page) {
266 set_pmd(pmd, __pmd(__pa(new_page) | prot));
267 if (!IS_ALIGNED(addr, PMD_SIZE) ||
268 !IS_ALIGNED(next, PMD_SIZE)) {
269 vmemmap_use_new_sub_pmd(addr, next);
270 }
271 continue;
272 }
273 }
274 pte = vmem_pte_alloc();
275 if (!pte)
276 goto out;
277 pmd_populate(&init_mm, pmd, pte);
278 } else if (pmd_large(*pmd)) {
279 if (!direct)
280 vmemmap_use_sub_pmd(addr, next);
281 continue;
282 }
283 ret = modify_pte_table(pmd, addr, next, add, direct);
284 if (ret)
285 goto out;
286 if (!add)
287 try_free_pte_table(pmd, addr & PMD_MASK);
288 }
289 ret = 0;
290out:
291 if (direct)
292 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
293 return ret;
294}
295
296static void try_free_pmd_table(pud_t *pud, unsigned long start)
297{
298 pmd_t *pmd;
299 int i;
300
301 pmd = pmd_offset(pud, start);
302 for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
303 if (!pmd_none(*pmd))
304 return;
305 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
306 pud_clear(pud);
307}
308
309static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
310 bool add, bool direct)
311{
312 unsigned long next, prot, pages = 0;
313 int ret = -ENOMEM;
314 pud_t *pud;
315 pmd_t *pmd;
316
317 prot = pgprot_val(REGION3_KERNEL);
318 if (!MACHINE_HAS_NX)
319 prot &= ~_REGION_ENTRY_NOEXEC;
320 pud = pud_offset(p4d, addr);
321 for (; addr < end; addr = next, pud++) {
322 next = pud_addr_end(addr, end);
323 if (!add) {
324 if (pud_none(*pud))
325 continue;
326 if (pud_large(*pud)) {
327 if (IS_ALIGNED(addr, PUD_SIZE) &&
328 IS_ALIGNED(next, PUD_SIZE)) {
329 pud_clear(pud);
330 pages++;
331 }
332 continue;
333 }
334 } else if (pud_none(*pud)) {
335 if (IS_ALIGNED(addr, PUD_SIZE) &&
336 IS_ALIGNED(next, PUD_SIZE) &&
337 MACHINE_HAS_EDAT2 && direct &&
338 !debug_pagealloc_enabled()) {
339 set_pud(pud, __pud(__pa(addr) | prot));
340 pages++;
341 continue;
342 }
343 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
344 if (!pmd)
345 goto out;
346 pud_populate(&init_mm, pud, pmd);
347 } else if (pud_large(*pud)) {
348 continue;
349 }
350 ret = modify_pmd_table(pud, addr, next, add, direct);
351 if (ret)
352 goto out;
353 if (!add)
354 try_free_pmd_table(pud, addr & PUD_MASK);
355 }
356 ret = 0;
357out:
358 if (direct)
359 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
360 return ret;
361}
362
363static void try_free_pud_table(p4d_t *p4d, unsigned long start)
364{
365 pud_t *pud;
366 int i;
367
368 pud = pud_offset(p4d, start);
369 for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
370 if (!pud_none(*pud))
371 return;
372 }
373 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
374 p4d_clear(p4d);
375}
376
377static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
378 bool add, bool direct)
379{
380 unsigned long next;
381 int ret = -ENOMEM;
382 p4d_t *p4d;
383 pud_t *pud;
384
385 p4d = p4d_offset(pgd, addr);
386 for (; addr < end; addr = next, p4d++) {
387 next = p4d_addr_end(addr, end);
388 if (!add) {
389 if (p4d_none(*p4d))
390 continue;
391 } else if (p4d_none(*p4d)) {
392 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
393 if (!pud)
394 goto out;
395 p4d_populate(&init_mm, p4d, pud);
396 }
397 ret = modify_pud_table(p4d, addr, next, add, direct);
398 if (ret)
399 goto out;
400 if (!add)
401 try_free_pud_table(p4d, addr & P4D_MASK);
402 }
403 ret = 0;
404out:
405 return ret;
406}
407
408static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
409{
410 p4d_t *p4d;
411 int i;
412
413 p4d = p4d_offset(pgd, start);
414 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
415 if (!p4d_none(*p4d))
416 return;
417 }
418 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
419 pgd_clear(pgd);
420}
421
422static int modify_pagetable(unsigned long start, unsigned long end, bool add,
423 bool direct)
424{
425 unsigned long addr, next;
426 int ret = -ENOMEM;
427 pgd_t *pgd;
428 p4d_t *p4d;
429
430 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
431 return -EINVAL;
432 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
433 if (WARN_ON_ONCE(end > VMALLOC_START))
434 return -EINVAL;
435 for (addr = start; addr < end; addr = next) {
436 next = pgd_addr_end(addr, end);
437 pgd = pgd_offset_k(addr);
438
439 if (!add) {
440 if (pgd_none(*pgd))
441 continue;
442 } else if (pgd_none(*pgd)) {
443 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
444 if (!p4d)
445 goto out;
446 pgd_populate(&init_mm, pgd, p4d);
447 }
448 ret = modify_p4d_table(pgd, addr, next, add, direct);
449 if (ret)
450 goto out;
451 if (!add)
452 try_free_p4d_table(pgd, addr & PGDIR_MASK);
453 }
454 ret = 0;
455out:
456 if (!add)
457 flush_tlb_kernel_range(start, end);
458 return ret;
459}
460
461static int add_pagetable(unsigned long start, unsigned long end, bool direct)
462{
463 return modify_pagetable(start, end, true, direct);
464}
465
466static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
467{
468 return modify_pagetable(start, end, false, direct);
469}
470
471/*
472 * Add a physical memory range to the 1:1 mapping.
473 */
474static int vmem_add_range(unsigned long start, unsigned long size)
475{
476 start = (unsigned long)__va(start);
477 return add_pagetable(start, start + size, true);
478}
479
480/*
481 * Remove a physical memory range from the 1:1 mapping.
482 */
483static void vmem_remove_range(unsigned long start, unsigned long size)
484{
485 start = (unsigned long)__va(start);
486 remove_pagetable(start, start + size, true);
487}
488
489/*
490 * Add a backed mem_map array to the virtual mem_map array.
491 */
492int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
493 struct vmem_altmap *altmap)
494{
495 int ret;
496
497 mutex_lock(&vmem_mutex);
498 /* We don't care about the node, just use NUMA_NO_NODE on allocations */
499 ret = add_pagetable(start, end, false);
500 if (ret)
501 remove_pagetable(start, end, false);
502 mutex_unlock(&vmem_mutex);
503 return ret;
504}
505
506#ifdef CONFIG_MEMORY_HOTPLUG
507
508void vmemmap_free(unsigned long start, unsigned long end,
509 struct vmem_altmap *altmap)
510{
511 mutex_lock(&vmem_mutex);
512 remove_pagetable(start, end, false);
513 mutex_unlock(&vmem_mutex);
514}
515
516#endif
517
518void vmem_remove_mapping(unsigned long start, unsigned long size)
519{
520 mutex_lock(&vmem_mutex);
521 vmem_remove_range(start, size);
522 mutex_unlock(&vmem_mutex);
523}
524
525struct range arch_get_mappable_range(void)
526{
527 struct range mhp_range;
528
529 mhp_range.start = 0;
530 mhp_range.end = max_mappable - 1;
531 return mhp_range;
532}
533
534int vmem_add_mapping(unsigned long start, unsigned long size)
535{
536 struct range range = arch_get_mappable_range();
537 int ret;
538
539 if (start < range.start ||
540 start + size > range.end + 1 ||
541 start + size < start)
542 return -ERANGE;
543
544 mutex_lock(&vmem_mutex);
545 ret = vmem_add_range(start, size);
546 if (ret)
547 vmem_remove_range(start, size);
548 mutex_unlock(&vmem_mutex);
549 return ret;
550}
551
552/*
553 * Allocate new or return existing page-table entry, but do not map it
554 * to any physical address. If missing, allocate segment- and region-
555 * table entries along. Meeting a large segment- or region-table entry
556 * while traversing is an error, since the function is expected to be
557 * called against virtual regions reserved for 4KB mappings only.
558 */
559pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
560{
561 pte_t *ptep = NULL;
562 pgd_t *pgd;
563 p4d_t *p4d;
564 pud_t *pud;
565 pmd_t *pmd;
566 pte_t *pte;
567
568 pgd = pgd_offset_k(addr);
569 if (pgd_none(*pgd)) {
570 if (!alloc)
571 goto out;
572 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
573 if (!p4d)
574 goto out;
575 pgd_populate(&init_mm, pgd, p4d);
576 }
577 p4d = p4d_offset(pgd, addr);
578 if (p4d_none(*p4d)) {
579 if (!alloc)
580 goto out;
581 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
582 if (!pud)
583 goto out;
584 p4d_populate(&init_mm, p4d, pud);
585 }
586 pud = pud_offset(p4d, addr);
587 if (pud_none(*pud)) {
588 if (!alloc)
589 goto out;
590 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
591 if (!pmd)
592 goto out;
593 pud_populate(&init_mm, pud, pmd);
594 } else if (WARN_ON_ONCE(pud_large(*pud))) {
595 goto out;
596 }
597 pmd = pmd_offset(pud, addr);
598 if (pmd_none(*pmd)) {
599 if (!alloc)
600 goto out;
601 pte = vmem_pte_alloc();
602 if (!pte)
603 goto out;
604 pmd_populate(&init_mm, pmd, pte);
605 } else if (WARN_ON_ONCE(pmd_large(*pmd))) {
606 goto out;
607 }
608 ptep = pte_offset_kernel(pmd, addr);
609out:
610 return ptep;
611}
612
613int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
614{
615 pte_t *ptep, pte;
616
617 if (!IS_ALIGNED(addr, PAGE_SIZE))
618 return -EINVAL;
619 ptep = vmem_get_alloc_pte(addr, alloc);
620 if (!ptep)
621 return -ENOMEM;
622 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
623 pte = mk_pte_phys(phys, prot);
624 set_pte(ptep, pte);
625 return 0;
626}
627
628int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
629{
630 int rc;
631
632 mutex_lock(&vmem_mutex);
633 rc = __vmem_map_4k_page(addr, phys, prot, true);
634 mutex_unlock(&vmem_mutex);
635 return rc;
636}
637
638void vmem_unmap_4k_page(unsigned long addr)
639{
640 pte_t *ptep;
641
642 mutex_lock(&vmem_mutex);
643 ptep = virt_to_kpte(addr);
644 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
645 pte_clear(&init_mm, addr, ptep);
646 mutex_unlock(&vmem_mutex);
647}
648
649void __init vmem_map_init(void)
650{
651 __set_memory_rox(_stext, _etext);
652 __set_memory_ro(_etext, __end_rodata);
653 __set_memory_rox(_sinittext, _einittext);
654 __set_memory_rox(__stext_amode31, __etext_amode31);
655 /*
656 * If the BEAR-enhancement facility is not installed the first
657 * prefix page is used to return to the previous context with
658 * an LPSWE instruction and therefore must be executable.
659 */
660 if (!static_key_enabled(&cpu_has_bear))
661 set_memory_x(0, 1);
662 if (debug_pagealloc_enabled()) {
663 /*
664 * Use RELOC_HIDE() as long as __va(0) translates to NULL,
665 * since performing pointer arithmetic on a NULL pointer
666 * has undefined behavior and generates compiler warnings.
667 */
668 __set_memory_4k(__va(0), RELOC_HIDE(__va(0), ident_map_size));
669 }
670 if (MACHINE_HAS_NX)
671 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
672 pr_info("Write protected kernel read-only data: %luk\n",
673 (unsigned long)(__end_rodata - _stext) >> 10);
674}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2006
4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
5 */
6
7#include <linux/memblock.h>
8#include <linux/pfn.h>
9#include <linux/mm.h>
10#include <linux/init.h>
11#include <linux/list.h>
12#include <linux/hugetlb.h>
13#include <linux/slab.h>
14#include <asm/cacheflush.h>
15#include <asm/pgalloc.h>
16#include <asm/setup.h>
17#include <asm/tlbflush.h>
18#include <asm/sections.h>
19#include <asm/set_memory.h>
20
21static DEFINE_MUTEX(vmem_mutex);
22
23static void __ref *vmem_alloc_pages(unsigned int order)
24{
25 unsigned long size = PAGE_SIZE << order;
26
27 if (slab_is_available())
28 return (void *)__get_free_pages(GFP_KERNEL, order);
29 return (void *) memblock_phys_alloc(size, size);
30}
31
32static void vmem_free_pages(unsigned long addr, int order)
33{
34 /* We don't expect boot memory to be removed ever. */
35 if (!slab_is_available() ||
36 WARN_ON_ONCE(PageReserved(phys_to_page(addr))))
37 return;
38 free_pages(addr, order);
39}
40
41void *vmem_crst_alloc(unsigned long val)
42{
43 unsigned long *table;
44
45 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
46 if (table)
47 crst_table_init(table, val);
48 return table;
49}
50
51pte_t __ref *vmem_pte_alloc(void)
52{
53 unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
54 pte_t *pte;
55
56 if (slab_is_available())
57 pte = (pte_t *) page_table_alloc(&init_mm);
58 else
59 pte = (pte_t *) memblock_phys_alloc(size, size);
60 if (!pte)
61 return NULL;
62 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
63 return pte;
64}
65
66static void vmem_pte_free(unsigned long *table)
67{
68 /* We don't expect boot memory to be removed ever. */
69 if (!slab_is_available() ||
70 WARN_ON_ONCE(PageReserved(virt_to_page(table))))
71 return;
72 page_table_free(&init_mm, table);
73}
74
75#define PAGE_UNUSED 0xFD
76
77/*
78 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
79 * from unused_pmd_start to next PMD_SIZE boundary.
80 */
81static unsigned long unused_pmd_start;
82
83static void vmemmap_flush_unused_pmd(void)
84{
85 if (!unused_pmd_start)
86 return;
87 memset(__va(unused_pmd_start), PAGE_UNUSED,
88 ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start);
89 unused_pmd_start = 0;
90}
91
92static void __vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
93{
94 /*
95 * As we expect to add in the same granularity as we remove, it's
96 * sufficient to mark only some piece used to block the memmap page from
97 * getting removed (just in case the memmap never gets initialized,
98 * e.g., because the memory block never gets onlined).
99 */
100 memset(__va(start), 0, sizeof(struct page));
101}
102
103static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
104{
105 /*
106 * We only optimize if the new used range directly follows the
107 * previously unused range (esp., when populating consecutive sections).
108 */
109 if (unused_pmd_start == start) {
110 unused_pmd_start = end;
111 if (likely(IS_ALIGNED(unused_pmd_start, PMD_SIZE)))
112 unused_pmd_start = 0;
113 return;
114 }
115 vmemmap_flush_unused_pmd();
116 __vmemmap_use_sub_pmd(start, end);
117}
118
119static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
120{
121 void *page = __va(ALIGN_DOWN(start, PMD_SIZE));
122
123 vmemmap_flush_unused_pmd();
124
125 /* Could be our memmap page is filled with PAGE_UNUSED already ... */
126 __vmemmap_use_sub_pmd(start, end);
127
128 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */
129 if (!IS_ALIGNED(start, PMD_SIZE))
130 memset(page, PAGE_UNUSED, start - __pa(page));
131 /*
132 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
133 * consecutive sections. Remember for the last added PMD the last
134 * unused range in the populated PMD.
135 */
136 if (!IS_ALIGNED(end, PMD_SIZE))
137 unused_pmd_start = end;
138}
139
140/* Returns true if the PMD is completely unused and can be freed. */
141static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
142{
143 void *page = __va(ALIGN_DOWN(start, PMD_SIZE));
144
145 vmemmap_flush_unused_pmd();
146 memset(__va(start), PAGE_UNUSED, end - start);
147 return !memchr_inv(page, PAGE_UNUSED, PMD_SIZE);
148}
149
150/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
151static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
152 unsigned long end, bool add, bool direct)
153{
154 unsigned long prot, pages = 0;
155 int ret = -ENOMEM;
156 pte_t *pte;
157
158 prot = pgprot_val(PAGE_KERNEL);
159 if (!MACHINE_HAS_NX)
160 prot &= ~_PAGE_NOEXEC;
161
162 pte = pte_offset_kernel(pmd, addr);
163 for (; addr < end; addr += PAGE_SIZE, pte++) {
164 if (!add) {
165 if (pte_none(*pte))
166 continue;
167 if (!direct)
168 vmem_free_pages(pfn_to_phys(pte_pfn(*pte)), 0);
169 pte_clear(&init_mm, addr, pte);
170 } else if (pte_none(*pte)) {
171 if (!direct) {
172 void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
173
174 if (!new_page)
175 goto out;
176 pte_val(*pte) = __pa(new_page) | prot;
177 } else {
178 pte_val(*pte) = addr | prot;
179 }
180 } else {
181 continue;
182 }
183 pages++;
184 }
185 ret = 0;
186out:
187 if (direct)
188 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
189 return ret;
190}
191
192static void try_free_pte_table(pmd_t *pmd, unsigned long start)
193{
194 pte_t *pte;
195 int i;
196
197 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */
198 pte = pte_offset_kernel(pmd, start);
199 for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
200 if (!pte_none(*pte))
201 return;
202 }
203 vmem_pte_free(__va(pmd_deref(*pmd)));
204 pmd_clear(pmd);
205}
206
207/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
208static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
209 unsigned long end, bool add, bool direct)
210{
211 unsigned long next, prot, pages = 0;
212 int ret = -ENOMEM;
213 pmd_t *pmd;
214 pte_t *pte;
215
216 prot = pgprot_val(SEGMENT_KERNEL);
217 if (!MACHINE_HAS_NX)
218 prot &= ~_SEGMENT_ENTRY_NOEXEC;
219
220 pmd = pmd_offset(pud, addr);
221 for (; addr < end; addr = next, pmd++) {
222 next = pmd_addr_end(addr, end);
223 if (!add) {
224 if (pmd_none(*pmd))
225 continue;
226 if (pmd_large(*pmd) && !add) {
227 if (IS_ALIGNED(addr, PMD_SIZE) &&
228 IS_ALIGNED(next, PMD_SIZE)) {
229 if (!direct)
230 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
231 pmd_clear(pmd);
232 pages++;
233 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
234 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
235 pmd_clear(pmd);
236 }
237 continue;
238 }
239 } else if (pmd_none(*pmd)) {
240 if (IS_ALIGNED(addr, PMD_SIZE) &&
241 IS_ALIGNED(next, PMD_SIZE) &&
242 MACHINE_HAS_EDAT1 && addr && direct &&
243 !debug_pagealloc_enabled()) {
244 pmd_val(*pmd) = addr | prot;
245 pages++;
246 continue;
247 } else if (!direct && MACHINE_HAS_EDAT1) {
248 void *new_page;
249
250 /*
251 * Use 1MB frames for vmemmap if available. We
252 * always use large frames even if they are only
253 * partially used. Otherwise we would have also
254 * page tables since vmemmap_populate gets
255 * called for each section separately.
256 */
257 new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
258 if (new_page) {
259 pmd_val(*pmd) = __pa(new_page) | prot;
260 if (!IS_ALIGNED(addr, PMD_SIZE) ||
261 !IS_ALIGNED(next, PMD_SIZE)) {
262 vmemmap_use_new_sub_pmd(addr, next);
263 }
264 continue;
265 }
266 }
267 pte = vmem_pte_alloc();
268 if (!pte)
269 goto out;
270 pmd_populate(&init_mm, pmd, pte);
271 } else if (pmd_large(*pmd)) {
272 if (!direct)
273 vmemmap_use_sub_pmd(addr, next);
274 continue;
275 }
276 ret = modify_pte_table(pmd, addr, next, add, direct);
277 if (ret)
278 goto out;
279 if (!add)
280 try_free_pte_table(pmd, addr & PMD_MASK);
281 }
282 ret = 0;
283out:
284 if (direct)
285 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
286 return ret;
287}
288
289static void try_free_pmd_table(pud_t *pud, unsigned long start)
290{
291 const unsigned long end = start + PUD_SIZE;
292 pmd_t *pmd;
293 int i;
294
295 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
296 if (end > VMALLOC_START)
297 return;
298#ifdef CONFIG_KASAN
299 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
300 return;
301#endif
302 pmd = pmd_offset(pud, start);
303 for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
304 if (!pmd_none(*pmd))
305 return;
306 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
307 pud_clear(pud);
308}
309
310static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
311 bool add, bool direct)
312{
313 unsigned long next, prot, pages = 0;
314 int ret = -ENOMEM;
315 pud_t *pud;
316 pmd_t *pmd;
317
318 prot = pgprot_val(REGION3_KERNEL);
319 if (!MACHINE_HAS_NX)
320 prot &= ~_REGION_ENTRY_NOEXEC;
321 pud = pud_offset(p4d, addr);
322 for (; addr < end; addr = next, pud++) {
323 next = pud_addr_end(addr, end);
324 if (!add) {
325 if (pud_none(*pud))
326 continue;
327 if (pud_large(*pud)) {
328 if (IS_ALIGNED(addr, PUD_SIZE) &&
329 IS_ALIGNED(next, PUD_SIZE)) {
330 pud_clear(pud);
331 pages++;
332 }
333 continue;
334 }
335 } else if (pud_none(*pud)) {
336 if (IS_ALIGNED(addr, PUD_SIZE) &&
337 IS_ALIGNED(next, PUD_SIZE) &&
338 MACHINE_HAS_EDAT2 && addr && direct &&
339 !debug_pagealloc_enabled()) {
340 pud_val(*pud) = addr | prot;
341 pages++;
342 continue;
343 }
344 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
345 if (!pmd)
346 goto out;
347 pud_populate(&init_mm, pud, pmd);
348 } else if (pud_large(*pud)) {
349 continue;
350 }
351 ret = modify_pmd_table(pud, addr, next, add, direct);
352 if (ret)
353 goto out;
354 if (!add)
355 try_free_pmd_table(pud, addr & PUD_MASK);
356 }
357 ret = 0;
358out:
359 if (direct)
360 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
361 return ret;
362}
363
364static void try_free_pud_table(p4d_t *p4d, unsigned long start)
365{
366 const unsigned long end = start + P4D_SIZE;
367 pud_t *pud;
368 int i;
369
370 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
371 if (end > VMALLOC_START)
372 return;
373#ifdef CONFIG_KASAN
374 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
375 return;
376#endif
377
378 pud = pud_offset(p4d, start);
379 for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
380 if (!pud_none(*pud))
381 return;
382 }
383 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
384 p4d_clear(p4d);
385}
386
387static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
388 bool add, bool direct)
389{
390 unsigned long next;
391 int ret = -ENOMEM;
392 p4d_t *p4d;
393 pud_t *pud;
394
395 p4d = p4d_offset(pgd, addr);
396 for (; addr < end; addr = next, p4d++) {
397 next = p4d_addr_end(addr, end);
398 if (!add) {
399 if (p4d_none(*p4d))
400 continue;
401 } else if (p4d_none(*p4d)) {
402 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
403 if (!pud)
404 goto out;
405 p4d_populate(&init_mm, p4d, pud);
406 }
407 ret = modify_pud_table(p4d, addr, next, add, direct);
408 if (ret)
409 goto out;
410 if (!add)
411 try_free_pud_table(p4d, addr & P4D_MASK);
412 }
413 ret = 0;
414out:
415 return ret;
416}
417
418static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
419{
420 const unsigned long end = start + PGDIR_SIZE;
421 p4d_t *p4d;
422 int i;
423
424 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
425 if (end > VMALLOC_START)
426 return;
427#ifdef CONFIG_KASAN
428 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
429 return;
430#endif
431
432 p4d = p4d_offset(pgd, start);
433 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
434 if (!p4d_none(*p4d))
435 return;
436 }
437 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
438 pgd_clear(pgd);
439}
440
441static int modify_pagetable(unsigned long start, unsigned long end, bool add,
442 bool direct)
443{
444 unsigned long addr, next;
445 int ret = -ENOMEM;
446 pgd_t *pgd;
447 p4d_t *p4d;
448
449 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
450 return -EINVAL;
451 for (addr = start; addr < end; addr = next) {
452 next = pgd_addr_end(addr, end);
453 pgd = pgd_offset_k(addr);
454
455 if (!add) {
456 if (pgd_none(*pgd))
457 continue;
458 } else if (pgd_none(*pgd)) {
459 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
460 if (!p4d)
461 goto out;
462 pgd_populate(&init_mm, pgd, p4d);
463 }
464 ret = modify_p4d_table(pgd, addr, next, add, direct);
465 if (ret)
466 goto out;
467 if (!add)
468 try_free_p4d_table(pgd, addr & PGDIR_MASK);
469 }
470 ret = 0;
471out:
472 if (!add)
473 flush_tlb_kernel_range(start, end);
474 return ret;
475}
476
477static int add_pagetable(unsigned long start, unsigned long end, bool direct)
478{
479 return modify_pagetable(start, end, true, direct);
480}
481
482static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
483{
484 return modify_pagetable(start, end, false, direct);
485}
486
487/*
488 * Add a physical memory range to the 1:1 mapping.
489 */
490static int vmem_add_range(unsigned long start, unsigned long size)
491{
492 return add_pagetable(start, start + size, true);
493}
494
495/*
496 * Remove a physical memory range from the 1:1 mapping.
497 */
498static void vmem_remove_range(unsigned long start, unsigned long size)
499{
500 remove_pagetable(start, start + size, true);
501}
502
503/*
504 * Add a backed mem_map array to the virtual mem_map array.
505 */
506int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
507 struct vmem_altmap *altmap)
508{
509 int ret;
510
511 mutex_lock(&vmem_mutex);
512 /* We don't care about the node, just use NUMA_NO_NODE on allocations */
513 ret = add_pagetable(start, end, false);
514 if (ret)
515 remove_pagetable(start, end, false);
516 mutex_unlock(&vmem_mutex);
517 return ret;
518}
519
520void vmemmap_free(unsigned long start, unsigned long end,
521 struct vmem_altmap *altmap)
522{
523 mutex_lock(&vmem_mutex);
524 remove_pagetable(start, end, false);
525 mutex_unlock(&vmem_mutex);
526}
527
528void vmem_remove_mapping(unsigned long start, unsigned long size)
529{
530 mutex_lock(&vmem_mutex);
531 vmem_remove_range(start, size);
532 mutex_unlock(&vmem_mutex);
533}
534
535int vmem_add_mapping(unsigned long start, unsigned long size)
536{
537 int ret;
538
539 if (start + size > VMEM_MAX_PHYS ||
540 start + size < start)
541 return -ERANGE;
542
543 mutex_lock(&vmem_mutex);
544 ret = vmem_add_range(start, size);
545 if (ret)
546 vmem_remove_range(start, size);
547 mutex_unlock(&vmem_mutex);
548 return ret;
549}
550
551/*
552 * map whole physical memory to virtual memory (identity mapping)
553 * we reserve enough space in the vmalloc area for vmemmap to hotplug
554 * additional memory segments.
555 */
556void __init vmem_map_init(void)
557{
558 struct memblock_region *reg;
559
560 for_each_memblock(memory, reg)
561 vmem_add_range(reg->base, reg->size);
562 __set_memory((unsigned long)_stext,
563 (unsigned long)(_etext - _stext) >> PAGE_SHIFT,
564 SET_MEMORY_RO | SET_MEMORY_X);
565 __set_memory((unsigned long)_etext,
566 (unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT,
567 SET_MEMORY_RO);
568 __set_memory((unsigned long)_sinittext,
569 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
570 SET_MEMORY_RO | SET_MEMORY_X);
571 __set_memory(__stext_dma, (__etext_dma - __stext_dma) >> PAGE_SHIFT,
572 SET_MEMORY_RO | SET_MEMORY_X);
573
574 /* we need lowcore executable for our LPSWE instructions */
575 set_memory_x(0, 1);
576
577 pr_info("Write protected kernel read-only data: %luk\n",
578 (unsigned long)(__end_rodata - _stext) >> 10);
579}