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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 <asm/cacheflush.h>
15#include <asm/nospec-branch.h>
16#include <asm/pgalloc.h>
17#include <asm/setup.h>
18#include <asm/tlbflush.h>
19#include <asm/sections.h>
20#include <asm/set_memory.h>
21
22static DEFINE_MUTEX(vmem_mutex);
23
24static void __ref *vmem_alloc_pages(unsigned int order)
25{
26 unsigned long size = PAGE_SIZE << order;
27
28 if (slab_is_available())
29 return (void *)__get_free_pages(GFP_KERNEL, order);
30 return memblock_alloc(size, size);
31}
32
33static void vmem_free_pages(unsigned long addr, int order)
34{
35 /* We don't expect boot memory to be removed ever. */
36 if (!slab_is_available() ||
37 WARN_ON_ONCE(PageReserved(virt_to_page(addr))))
38 return;
39 free_pages(addr, order);
40}
41
42void *vmem_crst_alloc(unsigned long val)
43{
44 unsigned long *table;
45
46 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
47 if (table)
48 crst_table_init(table, val);
49 return table;
50}
51
52pte_t __ref *vmem_pte_alloc(void)
53{
54 unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
55 pte_t *pte;
56
57 if (slab_is_available())
58 pte = (pte_t *) page_table_alloc(&init_mm);
59 else
60 pte = (pte_t *) memblock_alloc(size, size);
61 if (!pte)
62 return NULL;
63 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
64 return pte;
65}
66
67static void vmem_pte_free(unsigned long *table)
68{
69 /* We don't expect boot memory to be removed ever. */
70 if (!slab_is_available() ||
71 WARN_ON_ONCE(PageReserved(virt_to_page(table))))
72 return;
73 page_table_free(&init_mm, table);
74}
75
76#define PAGE_UNUSED 0xFD
77
78/*
79 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
80 * from unused_sub_pmd_start to next PMD_SIZE boundary.
81 */
82static unsigned long unused_sub_pmd_start;
83
84static void vmemmap_flush_unused_sub_pmd(void)
85{
86 if (!unused_sub_pmd_start)
87 return;
88 memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
89 ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
90 unused_sub_pmd_start = 0;
91}
92
93static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
94{
95 /*
96 * As we expect to add in the same granularity as we remove, it's
97 * sufficient to mark only some piece used to block the memmap page from
98 * getting removed (just in case the memmap never gets initialized,
99 * e.g., because the memory block never gets onlined).
100 */
101 memset((void *)start, 0, sizeof(struct page));
102}
103
104static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
105{
106 /*
107 * We only optimize if the new used range directly follows the
108 * previously unused range (esp., when populating consecutive sections).
109 */
110 if (unused_sub_pmd_start == start) {
111 unused_sub_pmd_start = end;
112 if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
113 unused_sub_pmd_start = 0;
114 return;
115 }
116 vmemmap_flush_unused_sub_pmd();
117 vmemmap_mark_sub_pmd_used(start, end);
118}
119
120static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
121{
122 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
123
124 vmemmap_flush_unused_sub_pmd();
125
126 /* Could be our memmap page is filled with PAGE_UNUSED already ... */
127 vmemmap_mark_sub_pmd_used(start, end);
128
129 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */
130 if (!IS_ALIGNED(start, PMD_SIZE))
131 memset((void *)page, PAGE_UNUSED, start - page);
132 /*
133 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
134 * consecutive sections. Remember for the last added PMD the last
135 * unused range in the populated PMD.
136 */
137 if (!IS_ALIGNED(end, PMD_SIZE))
138 unused_sub_pmd_start = end;
139}
140
141/* Returns true if the PMD is completely unused and can be freed. */
142static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
143{
144 unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
145
146 vmemmap_flush_unused_sub_pmd();
147 memset((void *)start, PAGE_UNUSED, end - start);
148 return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
149}
150
151/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
152static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
153 unsigned long end, bool add, bool direct)
154{
155 unsigned long prot, pages = 0;
156 int ret = -ENOMEM;
157 pte_t *pte;
158
159 prot = pgprot_val(PAGE_KERNEL);
160 if (!MACHINE_HAS_NX)
161 prot &= ~_PAGE_NOEXEC;
162
163 pte = pte_offset_kernel(pmd, addr);
164 for (; addr < end; addr += PAGE_SIZE, pte++) {
165 if (!add) {
166 if (pte_none(*pte))
167 continue;
168 if (!direct)
169 vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0);
170 pte_clear(&init_mm, addr, pte);
171 } else if (pte_none(*pte)) {
172 if (!direct) {
173 void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
174
175 if (!new_page)
176 goto out;
177 set_pte(pte, __pte(__pa(new_page) | prot));
178 } else {
179 set_pte(pte, __pte(__pa(addr) | prot));
180 }
181 } else {
182 continue;
183 }
184 pages++;
185 }
186 ret = 0;
187out:
188 if (direct)
189 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
190 return ret;
191}
192
193static void try_free_pte_table(pmd_t *pmd, unsigned long start)
194{
195 pte_t *pte;
196 int i;
197
198 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */
199 pte = pte_offset_kernel(pmd, start);
200 for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
201 if (!pte_none(*pte))
202 return;
203 }
204 vmem_pte_free((unsigned long *) pmd_deref(*pmd));
205 pmd_clear(pmd);
206}
207
208/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
209static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
210 unsigned long end, bool add, bool direct)
211{
212 unsigned long next, prot, pages = 0;
213 int ret = -ENOMEM;
214 pmd_t *pmd;
215 pte_t *pte;
216
217 prot = pgprot_val(SEGMENT_KERNEL);
218 if (!MACHINE_HAS_NX)
219 prot &= ~_SEGMENT_ENTRY_NOEXEC;
220
221 pmd = pmd_offset(pud, addr);
222 for (; addr < end; addr = next, pmd++) {
223 next = pmd_addr_end(addr, end);
224 if (!add) {
225 if (pmd_none(*pmd))
226 continue;
227 if (pmd_large(*pmd)) {
228 if (IS_ALIGNED(addr, PMD_SIZE) &&
229 IS_ALIGNED(next, PMD_SIZE)) {
230 if (!direct)
231 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
232 pmd_clear(pmd);
233 pages++;
234 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
235 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
236 pmd_clear(pmd);
237 }
238 continue;
239 }
240 } else if (pmd_none(*pmd)) {
241 if (IS_ALIGNED(addr, PMD_SIZE) &&
242 IS_ALIGNED(next, PMD_SIZE) &&
243 MACHINE_HAS_EDAT1 && direct &&
244 !debug_pagealloc_enabled()) {
245 set_pmd(pmd, __pmd(__pa(addr) | prot));
246 pages++;
247 continue;
248 } else if (!direct && MACHINE_HAS_EDAT1) {
249 void *new_page;
250
251 /*
252 * Use 1MB frames for vmemmap if available. We
253 * always use large frames even if they are only
254 * partially used. Otherwise we would have also
255 * page tables since vmemmap_populate gets
256 * called for each section separately.
257 */
258 new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
259 if (new_page) {
260 set_pmd(pmd, __pmd(__pa(new_page) | prot));
261 if (!IS_ALIGNED(addr, PMD_SIZE) ||
262 !IS_ALIGNED(next, PMD_SIZE)) {
263 vmemmap_use_new_sub_pmd(addr, next);
264 }
265 continue;
266 }
267 }
268 pte = vmem_pte_alloc();
269 if (!pte)
270 goto out;
271 pmd_populate(&init_mm, pmd, pte);
272 } else if (pmd_large(*pmd)) {
273 if (!direct)
274 vmemmap_use_sub_pmd(addr, next);
275 continue;
276 }
277 ret = modify_pte_table(pmd, addr, next, add, direct);
278 if (ret)
279 goto out;
280 if (!add)
281 try_free_pte_table(pmd, addr & PMD_MASK);
282 }
283 ret = 0;
284out:
285 if (direct)
286 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
287 return ret;
288}
289
290static void try_free_pmd_table(pud_t *pud, unsigned long start)
291{
292 const unsigned long end = start + PUD_SIZE;
293 pmd_t *pmd;
294 int i;
295
296 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
297 if (end > VMALLOC_START)
298 return;
299#ifdef CONFIG_KASAN
300 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
301 return;
302#endif
303 pmd = pmd_offset(pud, start);
304 for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
305 if (!pmd_none(*pmd))
306 return;
307 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
308 pud_clear(pud);
309}
310
311static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
312 bool add, bool direct)
313{
314 unsigned long next, prot, pages = 0;
315 int ret = -ENOMEM;
316 pud_t *pud;
317 pmd_t *pmd;
318
319 prot = pgprot_val(REGION3_KERNEL);
320 if (!MACHINE_HAS_NX)
321 prot &= ~_REGION_ENTRY_NOEXEC;
322 pud = pud_offset(p4d, addr);
323 for (; addr < end; addr = next, pud++) {
324 next = pud_addr_end(addr, end);
325 if (!add) {
326 if (pud_none(*pud))
327 continue;
328 if (pud_large(*pud)) {
329 if (IS_ALIGNED(addr, PUD_SIZE) &&
330 IS_ALIGNED(next, PUD_SIZE)) {
331 pud_clear(pud);
332 pages++;
333 }
334 continue;
335 }
336 } else if (pud_none(*pud)) {
337 if (IS_ALIGNED(addr, PUD_SIZE) &&
338 IS_ALIGNED(next, PUD_SIZE) &&
339 MACHINE_HAS_EDAT2 && direct &&
340 !debug_pagealloc_enabled()) {
341 set_pud(pud, __pud(__pa(addr) | prot));
342 pages++;
343 continue;
344 }
345 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
346 if (!pmd)
347 goto out;
348 pud_populate(&init_mm, pud, pmd);
349 } else if (pud_large(*pud)) {
350 continue;
351 }
352 ret = modify_pmd_table(pud, addr, next, add, direct);
353 if (ret)
354 goto out;
355 if (!add)
356 try_free_pmd_table(pud, addr & PUD_MASK);
357 }
358 ret = 0;
359out:
360 if (direct)
361 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
362 return ret;
363}
364
365static void try_free_pud_table(p4d_t *p4d, unsigned long start)
366{
367 const unsigned long end = start + P4D_SIZE;
368 pud_t *pud;
369 int i;
370
371 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
372 if (end > VMALLOC_START)
373 return;
374#ifdef CONFIG_KASAN
375 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
376 return;
377#endif
378
379 pud = pud_offset(p4d, start);
380 for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
381 if (!pud_none(*pud))
382 return;
383 }
384 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
385 p4d_clear(p4d);
386}
387
388static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
389 bool add, bool direct)
390{
391 unsigned long next;
392 int ret = -ENOMEM;
393 p4d_t *p4d;
394 pud_t *pud;
395
396 p4d = p4d_offset(pgd, addr);
397 for (; addr < end; addr = next, p4d++) {
398 next = p4d_addr_end(addr, end);
399 if (!add) {
400 if (p4d_none(*p4d))
401 continue;
402 } else if (p4d_none(*p4d)) {
403 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
404 if (!pud)
405 goto out;
406 p4d_populate(&init_mm, p4d, pud);
407 }
408 ret = modify_pud_table(p4d, addr, next, add, direct);
409 if (ret)
410 goto out;
411 if (!add)
412 try_free_pud_table(p4d, addr & P4D_MASK);
413 }
414 ret = 0;
415out:
416 return ret;
417}
418
419static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
420{
421 const unsigned long end = start + PGDIR_SIZE;
422 p4d_t *p4d;
423 int i;
424
425 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
426 if (end > VMALLOC_START)
427 return;
428#ifdef CONFIG_KASAN
429 if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
430 return;
431#endif
432
433 p4d = p4d_offset(pgd, start);
434 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
435 if (!p4d_none(*p4d))
436 return;
437 }
438 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
439 pgd_clear(pgd);
440}
441
442static int modify_pagetable(unsigned long start, unsigned long end, bool add,
443 bool direct)
444{
445 unsigned long addr, next;
446 int ret = -ENOMEM;
447 pgd_t *pgd;
448 p4d_t *p4d;
449
450 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
451 return -EINVAL;
452 for (addr = start; addr < end; addr = next) {
453 next = pgd_addr_end(addr, end);
454 pgd = pgd_offset_k(addr);
455
456 if (!add) {
457 if (pgd_none(*pgd))
458 continue;
459 } else if (pgd_none(*pgd)) {
460 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
461 if (!p4d)
462 goto out;
463 pgd_populate(&init_mm, pgd, p4d);
464 }
465 ret = modify_p4d_table(pgd, addr, next, add, direct);
466 if (ret)
467 goto out;
468 if (!add)
469 try_free_p4d_table(pgd, addr & PGDIR_MASK);
470 }
471 ret = 0;
472out:
473 if (!add)
474 flush_tlb_kernel_range(start, end);
475 return ret;
476}
477
478static int add_pagetable(unsigned long start, unsigned long end, bool direct)
479{
480 return modify_pagetable(start, end, true, direct);
481}
482
483static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
484{
485 return modify_pagetable(start, end, false, direct);
486}
487
488/*
489 * Add a physical memory range to the 1:1 mapping.
490 */
491static int vmem_add_range(unsigned long start, unsigned long size)
492{
493 return add_pagetable(start, start + size, true);
494}
495
496/*
497 * Remove a physical memory range from the 1:1 mapping.
498 */
499static void vmem_remove_range(unsigned long start, unsigned long size)
500{
501 remove_pagetable(start, start + size, true);
502}
503
504/*
505 * Add a backed mem_map array to the virtual mem_map array.
506 */
507int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
508 struct vmem_altmap *altmap)
509{
510 int ret;
511
512 mutex_lock(&vmem_mutex);
513 /* We don't care about the node, just use NUMA_NO_NODE on allocations */
514 ret = add_pagetable(start, end, false);
515 if (ret)
516 remove_pagetable(start, end, false);
517 mutex_unlock(&vmem_mutex);
518 return ret;
519}
520
521void vmemmap_free(unsigned long start, unsigned long end,
522 struct vmem_altmap *altmap)
523{
524 mutex_lock(&vmem_mutex);
525 remove_pagetable(start, end, false);
526 mutex_unlock(&vmem_mutex);
527}
528
529void vmem_remove_mapping(unsigned long start, unsigned long size)
530{
531 mutex_lock(&vmem_mutex);
532 vmem_remove_range(start, size);
533 mutex_unlock(&vmem_mutex);
534}
535
536struct range arch_get_mappable_range(void)
537{
538 struct range mhp_range;
539
540 mhp_range.start = 0;
541 mhp_range.end = VMEM_MAX_PHYS - 1;
542 return mhp_range;
543}
544
545int vmem_add_mapping(unsigned long start, unsigned long size)
546{
547 struct range range = arch_get_mappable_range();
548 int ret;
549
550 if (start < range.start ||
551 start + size > range.end + 1 ||
552 start + size < start)
553 return -ERANGE;
554
555 mutex_lock(&vmem_mutex);
556 ret = vmem_add_range(start, size);
557 if (ret)
558 vmem_remove_range(start, size);
559 mutex_unlock(&vmem_mutex);
560 return ret;
561}
562
563/*
564 * Allocate new or return existing page-table entry, but do not map it
565 * to any physical address. If missing, allocate segment- and region-
566 * table entries along. Meeting a large segment- or region-table entry
567 * while traversing is an error, since the function is expected to be
568 * called against virtual regions reserverd for 4KB mappings only.
569 */
570pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
571{
572 pte_t *ptep = NULL;
573 pgd_t *pgd;
574 p4d_t *p4d;
575 pud_t *pud;
576 pmd_t *pmd;
577 pte_t *pte;
578
579 pgd = pgd_offset_k(addr);
580 if (pgd_none(*pgd)) {
581 if (!alloc)
582 goto out;
583 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
584 if (!p4d)
585 goto out;
586 pgd_populate(&init_mm, pgd, p4d);
587 }
588 p4d = p4d_offset(pgd, addr);
589 if (p4d_none(*p4d)) {
590 if (!alloc)
591 goto out;
592 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
593 if (!pud)
594 goto out;
595 p4d_populate(&init_mm, p4d, pud);
596 }
597 pud = pud_offset(p4d, addr);
598 if (pud_none(*pud)) {
599 if (!alloc)
600 goto out;
601 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
602 if (!pmd)
603 goto out;
604 pud_populate(&init_mm, pud, pmd);
605 } else if (WARN_ON_ONCE(pud_large(*pud))) {
606 goto out;
607 }
608 pmd = pmd_offset(pud, addr);
609 if (pmd_none(*pmd)) {
610 if (!alloc)
611 goto out;
612 pte = vmem_pte_alloc();
613 if (!pte)
614 goto out;
615 pmd_populate(&init_mm, pmd, pte);
616 } else if (WARN_ON_ONCE(pmd_large(*pmd))) {
617 goto out;
618 }
619 ptep = pte_offset_kernel(pmd, addr);
620out:
621 return ptep;
622}
623
624int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
625{
626 pte_t *ptep, pte;
627
628 if (!IS_ALIGNED(addr, PAGE_SIZE))
629 return -EINVAL;
630 ptep = vmem_get_alloc_pte(addr, alloc);
631 if (!ptep)
632 return -ENOMEM;
633 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
634 pte = mk_pte_phys(phys, prot);
635 set_pte(ptep, pte);
636 return 0;
637}
638
639int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
640{
641 int rc;
642
643 mutex_lock(&vmem_mutex);
644 rc = __vmem_map_4k_page(addr, phys, prot, true);
645 mutex_unlock(&vmem_mutex);
646 return rc;
647}
648
649void vmem_unmap_4k_page(unsigned long addr)
650{
651 pte_t *ptep;
652
653 mutex_lock(&vmem_mutex);
654 ptep = virt_to_kpte(addr);
655 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
656 pte_clear(&init_mm, addr, ptep);
657 mutex_unlock(&vmem_mutex);
658}
659
660/*
661 * map whole physical memory to virtual memory (identity mapping)
662 * we reserve enough space in the vmalloc area for vmemmap to hotplug
663 * additional memory segments.
664 */
665void __init vmem_map_init(void)
666{
667 phys_addr_t base, end;
668 u64 i;
669
670 for_each_mem_range(i, &base, &end)
671 vmem_add_range(base, end - base);
672 __set_memory((unsigned long)_stext,
673 (unsigned long)(_etext - _stext) >> PAGE_SHIFT,
674 SET_MEMORY_RO | SET_MEMORY_X);
675 __set_memory((unsigned long)_etext,
676 (unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT,
677 SET_MEMORY_RO);
678 __set_memory((unsigned long)_sinittext,
679 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
680 SET_MEMORY_RO | SET_MEMORY_X);
681 __set_memory(__stext_amode31, (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT,
682 SET_MEMORY_RO | SET_MEMORY_X);
683
684 /* lowcore requires 4k mapping for real addresses / prefixing */
685 set_memory_4k(0, LC_PAGES);
686
687 /* lowcore must be executable for LPSWE */
688 if (!static_key_enabled(&cpu_has_bear))
689 set_memory_x(0, 1);
690
691 pr_info("Write protected kernel read-only data: %luk\n",
692 (unsigned long)(__end_rodata - _stext) >> 10);
693}
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/bootmem.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/memblock.h>
15#include <asm/cacheflush.h>
16#include <asm/pgalloc.h>
17#include <asm/pgtable.h>
18#include <asm/setup.h>
19#include <asm/tlbflush.h>
20#include <asm/sections.h>
21#include <asm/set_memory.h>
22
23static DEFINE_MUTEX(vmem_mutex);
24
25struct memory_segment {
26 struct list_head list;
27 unsigned long start;
28 unsigned long size;
29};
30
31static LIST_HEAD(mem_segs);
32
33static void __ref *vmem_alloc_pages(unsigned int order)
34{
35 unsigned long size = PAGE_SIZE << order;
36
37 if (slab_is_available())
38 return (void *)__get_free_pages(GFP_KERNEL, order);
39 return (void *) memblock_alloc(size, size);
40}
41
42void *vmem_crst_alloc(unsigned long val)
43{
44 unsigned long *table;
45
46 table = vmem_alloc_pages(CRST_ALLOC_ORDER);
47 if (table)
48 crst_table_init(table, val);
49 return table;
50}
51
52pte_t __ref *vmem_pte_alloc(void)
53{
54 unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
55 pte_t *pte;
56
57 if (slab_is_available())
58 pte = (pte_t *) page_table_alloc(&init_mm);
59 else
60 pte = (pte_t *) memblock_alloc(size, size);
61 if (!pte)
62 return NULL;
63 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
64 return pte;
65}
66
67/*
68 * Add a physical memory range to the 1:1 mapping.
69 */
70static int vmem_add_mem(unsigned long start, unsigned long size)
71{
72 unsigned long pgt_prot, sgt_prot, r3_prot;
73 unsigned long pages4k, pages1m, pages2g;
74 unsigned long end = start + size;
75 unsigned long address = start;
76 pgd_t *pg_dir;
77 p4d_t *p4_dir;
78 pud_t *pu_dir;
79 pmd_t *pm_dir;
80 pte_t *pt_dir;
81 int ret = -ENOMEM;
82
83 pgt_prot = pgprot_val(PAGE_KERNEL);
84 sgt_prot = pgprot_val(SEGMENT_KERNEL);
85 r3_prot = pgprot_val(REGION3_KERNEL);
86 if (!MACHINE_HAS_NX) {
87 pgt_prot &= ~_PAGE_NOEXEC;
88 sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
89 r3_prot &= ~_REGION_ENTRY_NOEXEC;
90 }
91 pages4k = pages1m = pages2g = 0;
92 while (address < end) {
93 pg_dir = pgd_offset_k(address);
94 if (pgd_none(*pg_dir)) {
95 p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
96 if (!p4_dir)
97 goto out;
98 pgd_populate(&init_mm, pg_dir, p4_dir);
99 }
100 p4_dir = p4d_offset(pg_dir, address);
101 if (p4d_none(*p4_dir)) {
102 pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
103 if (!pu_dir)
104 goto out;
105 p4d_populate(&init_mm, p4_dir, pu_dir);
106 }
107 pu_dir = pud_offset(p4_dir, address);
108 if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
109 !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) &&
110 !debug_pagealloc_enabled()) {
111 pud_val(*pu_dir) = address | r3_prot;
112 address += PUD_SIZE;
113 pages2g++;
114 continue;
115 }
116 if (pud_none(*pu_dir)) {
117 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
118 if (!pm_dir)
119 goto out;
120 pud_populate(&init_mm, pu_dir, pm_dir);
121 }
122 pm_dir = pmd_offset(pu_dir, address);
123 if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
124 !(address & ~PMD_MASK) && (address + PMD_SIZE <= end) &&
125 !debug_pagealloc_enabled()) {
126 pmd_val(*pm_dir) = address | sgt_prot;
127 address += PMD_SIZE;
128 pages1m++;
129 continue;
130 }
131 if (pmd_none(*pm_dir)) {
132 pt_dir = vmem_pte_alloc();
133 if (!pt_dir)
134 goto out;
135 pmd_populate(&init_mm, pm_dir, pt_dir);
136 }
137
138 pt_dir = pte_offset_kernel(pm_dir, address);
139 pte_val(*pt_dir) = address | pgt_prot;
140 address += PAGE_SIZE;
141 pages4k++;
142 }
143 ret = 0;
144out:
145 update_page_count(PG_DIRECT_MAP_4K, pages4k);
146 update_page_count(PG_DIRECT_MAP_1M, pages1m);
147 update_page_count(PG_DIRECT_MAP_2G, pages2g);
148 return ret;
149}
150
151/*
152 * Remove a physical memory range from the 1:1 mapping.
153 * Currently only invalidates page table entries.
154 */
155static void vmem_remove_range(unsigned long start, unsigned long size)
156{
157 unsigned long pages4k, pages1m, pages2g;
158 unsigned long end = start + size;
159 unsigned long address = start;
160 pgd_t *pg_dir;
161 p4d_t *p4_dir;
162 pud_t *pu_dir;
163 pmd_t *pm_dir;
164 pte_t *pt_dir;
165
166 pages4k = pages1m = pages2g = 0;
167 while (address < end) {
168 pg_dir = pgd_offset_k(address);
169 if (pgd_none(*pg_dir)) {
170 address += PGDIR_SIZE;
171 continue;
172 }
173 p4_dir = p4d_offset(pg_dir, address);
174 if (p4d_none(*p4_dir)) {
175 address += P4D_SIZE;
176 continue;
177 }
178 pu_dir = pud_offset(p4_dir, address);
179 if (pud_none(*pu_dir)) {
180 address += PUD_SIZE;
181 continue;
182 }
183 if (pud_large(*pu_dir)) {
184 pud_clear(pu_dir);
185 address += PUD_SIZE;
186 pages2g++;
187 continue;
188 }
189 pm_dir = pmd_offset(pu_dir, address);
190 if (pmd_none(*pm_dir)) {
191 address += PMD_SIZE;
192 continue;
193 }
194 if (pmd_large(*pm_dir)) {
195 pmd_clear(pm_dir);
196 address += PMD_SIZE;
197 pages1m++;
198 continue;
199 }
200 pt_dir = pte_offset_kernel(pm_dir, address);
201 pte_clear(&init_mm, address, pt_dir);
202 address += PAGE_SIZE;
203 pages4k++;
204 }
205 flush_tlb_kernel_range(start, end);
206 update_page_count(PG_DIRECT_MAP_4K, -pages4k);
207 update_page_count(PG_DIRECT_MAP_1M, -pages1m);
208 update_page_count(PG_DIRECT_MAP_2G, -pages2g);
209}
210
211/*
212 * Add a backed mem_map array to the virtual mem_map array.
213 */
214int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
215 struct vmem_altmap *altmap)
216{
217 unsigned long pgt_prot, sgt_prot;
218 unsigned long address = start;
219 pgd_t *pg_dir;
220 p4d_t *p4_dir;
221 pud_t *pu_dir;
222 pmd_t *pm_dir;
223 pte_t *pt_dir;
224 int ret = -ENOMEM;
225
226 pgt_prot = pgprot_val(PAGE_KERNEL);
227 sgt_prot = pgprot_val(SEGMENT_KERNEL);
228 if (!MACHINE_HAS_NX) {
229 pgt_prot &= ~_PAGE_NOEXEC;
230 sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
231 }
232 for (address = start; address < end;) {
233 pg_dir = pgd_offset_k(address);
234 if (pgd_none(*pg_dir)) {
235 p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
236 if (!p4_dir)
237 goto out;
238 pgd_populate(&init_mm, pg_dir, p4_dir);
239 }
240
241 p4_dir = p4d_offset(pg_dir, address);
242 if (p4d_none(*p4_dir)) {
243 pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
244 if (!pu_dir)
245 goto out;
246 p4d_populate(&init_mm, p4_dir, pu_dir);
247 }
248
249 pu_dir = pud_offset(p4_dir, address);
250 if (pud_none(*pu_dir)) {
251 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
252 if (!pm_dir)
253 goto out;
254 pud_populate(&init_mm, pu_dir, pm_dir);
255 }
256
257 pm_dir = pmd_offset(pu_dir, address);
258 if (pmd_none(*pm_dir)) {
259 /* Use 1MB frames for vmemmap if available. We always
260 * use large frames even if they are only partially
261 * used.
262 * Otherwise we would have also page tables since
263 * vmemmap_populate gets called for each section
264 * separately. */
265 if (MACHINE_HAS_EDAT1) {
266 void *new_page;
267
268 new_page = vmemmap_alloc_block(PMD_SIZE, node);
269 if (!new_page)
270 goto out;
271 pmd_val(*pm_dir) = __pa(new_page) | sgt_prot;
272 address = (address + PMD_SIZE) & PMD_MASK;
273 continue;
274 }
275 pt_dir = vmem_pte_alloc();
276 if (!pt_dir)
277 goto out;
278 pmd_populate(&init_mm, pm_dir, pt_dir);
279 } else if (pmd_large(*pm_dir)) {
280 address = (address + PMD_SIZE) & PMD_MASK;
281 continue;
282 }
283
284 pt_dir = pte_offset_kernel(pm_dir, address);
285 if (pte_none(*pt_dir)) {
286 void *new_page;
287
288 new_page = vmemmap_alloc_block(PAGE_SIZE, node);
289 if (!new_page)
290 goto out;
291 pte_val(*pt_dir) = __pa(new_page) | pgt_prot;
292 }
293 address += PAGE_SIZE;
294 }
295 ret = 0;
296out:
297 return ret;
298}
299
300void vmemmap_free(unsigned long start, unsigned long end,
301 struct vmem_altmap *altmap)
302{
303}
304
305/*
306 * Add memory segment to the segment list if it doesn't overlap with
307 * an already present segment.
308 */
309static int insert_memory_segment(struct memory_segment *seg)
310{
311 struct memory_segment *tmp;
312
313 if (seg->start + seg->size > VMEM_MAX_PHYS ||
314 seg->start + seg->size < seg->start)
315 return -ERANGE;
316
317 list_for_each_entry(tmp, &mem_segs, list) {
318 if (seg->start >= tmp->start + tmp->size)
319 continue;
320 if (seg->start + seg->size <= tmp->start)
321 continue;
322 return -ENOSPC;
323 }
324 list_add(&seg->list, &mem_segs);
325 return 0;
326}
327
328/*
329 * Remove memory segment from the segment list.
330 */
331static void remove_memory_segment(struct memory_segment *seg)
332{
333 list_del(&seg->list);
334}
335
336static void __remove_shared_memory(struct memory_segment *seg)
337{
338 remove_memory_segment(seg);
339 vmem_remove_range(seg->start, seg->size);
340}
341
342int vmem_remove_mapping(unsigned long start, unsigned long size)
343{
344 struct memory_segment *seg;
345 int ret;
346
347 mutex_lock(&vmem_mutex);
348
349 ret = -ENOENT;
350 list_for_each_entry(seg, &mem_segs, list) {
351 if (seg->start == start && seg->size == size)
352 break;
353 }
354
355 if (seg->start != start || seg->size != size)
356 goto out;
357
358 ret = 0;
359 __remove_shared_memory(seg);
360 kfree(seg);
361out:
362 mutex_unlock(&vmem_mutex);
363 return ret;
364}
365
366int vmem_add_mapping(unsigned long start, unsigned long size)
367{
368 struct memory_segment *seg;
369 int ret;
370
371 mutex_lock(&vmem_mutex);
372 ret = -ENOMEM;
373 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
374 if (!seg)
375 goto out;
376 seg->start = start;
377 seg->size = size;
378
379 ret = insert_memory_segment(seg);
380 if (ret)
381 goto out_free;
382
383 ret = vmem_add_mem(start, size);
384 if (ret)
385 goto out_remove;
386 goto out;
387
388out_remove:
389 __remove_shared_memory(seg);
390out_free:
391 kfree(seg);
392out:
393 mutex_unlock(&vmem_mutex);
394 return ret;
395}
396
397/*
398 * map whole physical memory to virtual memory (identity mapping)
399 * we reserve enough space in the vmalloc area for vmemmap to hotplug
400 * additional memory segments.
401 */
402void __init vmem_map_init(void)
403{
404 struct memblock_region *reg;
405
406 for_each_memblock(memory, reg)
407 vmem_add_mem(reg->base, reg->size);
408 __set_memory((unsigned long)_stext,
409 (unsigned long)(_etext - _stext) >> PAGE_SHIFT,
410 SET_MEMORY_RO | SET_MEMORY_X);
411 __set_memory((unsigned long)_etext,
412 (unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT,
413 SET_MEMORY_RO);
414 __set_memory((unsigned long)_sinittext,
415 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
416 SET_MEMORY_RO | SET_MEMORY_X);
417 pr_info("Write protected kernel read-only data: %luk\n",
418 (unsigned long)(__end_rodata - _stext) >> 10);
419}
420
421/*
422 * Convert memblock.memory to a memory segment list so there is a single
423 * list that contains all memory segments.
424 */
425static int __init vmem_convert_memory_chunk(void)
426{
427 struct memblock_region *reg;
428 struct memory_segment *seg;
429
430 mutex_lock(&vmem_mutex);
431 for_each_memblock(memory, reg) {
432 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
433 if (!seg)
434 panic("Out of memory...\n");
435 seg->start = reg->base;
436 seg->size = reg->size;
437 insert_memory_segment(seg);
438 }
439 mutex_unlock(&vmem_mutex);
440 return 0;
441}
442
443core_initcall(vmem_convert_memory_chunk);