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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 <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/pgtable.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
24struct memory_segment {
25 struct list_head list;
26 unsigned long start;
27 unsigned long size;
28};
29
30static LIST_HEAD(mem_segs);
31
32static 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 (void *) memblock_phys_alloc(size, size);
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
66/*
67 * Add a physical memory range to the 1:1 mapping.
68 */
69static int vmem_add_mem(unsigned long start, unsigned long size)
70{
71 unsigned long pgt_prot, sgt_prot, r3_prot;
72 unsigned long pages4k, pages1m, pages2g;
73 unsigned long end = start + size;
74 unsigned long address = start;
75 pgd_t *pg_dir;
76 p4d_t *p4_dir;
77 pud_t *pu_dir;
78 pmd_t *pm_dir;
79 pte_t *pt_dir;
80 int ret = -ENOMEM;
81
82 pgt_prot = pgprot_val(PAGE_KERNEL);
83 sgt_prot = pgprot_val(SEGMENT_KERNEL);
84 r3_prot = pgprot_val(REGION3_KERNEL);
85 if (!MACHINE_HAS_NX) {
86 pgt_prot &= ~_PAGE_NOEXEC;
87 sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
88 r3_prot &= ~_REGION_ENTRY_NOEXEC;
89 }
90 pages4k = pages1m = pages2g = 0;
91 while (address < end) {
92 pg_dir = pgd_offset_k(address);
93 if (pgd_none(*pg_dir)) {
94 p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
95 if (!p4_dir)
96 goto out;
97 pgd_populate(&init_mm, pg_dir, p4_dir);
98 }
99 p4_dir = p4d_offset(pg_dir, address);
100 if (p4d_none(*p4_dir)) {
101 pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
102 if (!pu_dir)
103 goto out;
104 p4d_populate(&init_mm, p4_dir, pu_dir);
105 }
106 pu_dir = pud_offset(p4_dir, address);
107 if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
108 !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) &&
109 !debug_pagealloc_enabled()) {
110 pud_val(*pu_dir) = address | r3_prot;
111 address += PUD_SIZE;
112 pages2g++;
113 continue;
114 }
115 if (pud_none(*pu_dir)) {
116 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
117 if (!pm_dir)
118 goto out;
119 pud_populate(&init_mm, pu_dir, pm_dir);
120 }
121 pm_dir = pmd_offset(pu_dir, address);
122 if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
123 !(address & ~PMD_MASK) && (address + PMD_SIZE <= end) &&
124 !debug_pagealloc_enabled()) {
125 pmd_val(*pm_dir) = address | sgt_prot;
126 address += PMD_SIZE;
127 pages1m++;
128 continue;
129 }
130 if (pmd_none(*pm_dir)) {
131 pt_dir = vmem_pte_alloc();
132 if (!pt_dir)
133 goto out;
134 pmd_populate(&init_mm, pm_dir, pt_dir);
135 }
136
137 pt_dir = pte_offset_kernel(pm_dir, address);
138 pte_val(*pt_dir) = address | pgt_prot;
139 address += PAGE_SIZE;
140 pages4k++;
141 }
142 ret = 0;
143out:
144 update_page_count(PG_DIRECT_MAP_4K, pages4k);
145 update_page_count(PG_DIRECT_MAP_1M, pages1m);
146 update_page_count(PG_DIRECT_MAP_2G, pages2g);
147 return ret;
148}
149
150/*
151 * Remove a physical memory range from the 1:1 mapping.
152 * Currently only invalidates page table entries.
153 */
154static void vmem_remove_range(unsigned long start, unsigned long size)
155{
156 unsigned long pages4k, pages1m, pages2g;
157 unsigned long end = start + size;
158 unsigned long address = start;
159 pgd_t *pg_dir;
160 p4d_t *p4_dir;
161 pud_t *pu_dir;
162 pmd_t *pm_dir;
163 pte_t *pt_dir;
164
165 pages4k = pages1m = pages2g = 0;
166 while (address < end) {
167 pg_dir = pgd_offset_k(address);
168 if (pgd_none(*pg_dir)) {
169 address += PGDIR_SIZE;
170 continue;
171 }
172 p4_dir = p4d_offset(pg_dir, address);
173 if (p4d_none(*p4_dir)) {
174 address += P4D_SIZE;
175 continue;
176 }
177 pu_dir = pud_offset(p4_dir, address);
178 if (pud_none(*pu_dir)) {
179 address += PUD_SIZE;
180 continue;
181 }
182 if (pud_large(*pu_dir)) {
183 pud_clear(pu_dir);
184 address += PUD_SIZE;
185 pages2g++;
186 continue;
187 }
188 pm_dir = pmd_offset(pu_dir, address);
189 if (pmd_none(*pm_dir)) {
190 address += PMD_SIZE;
191 continue;
192 }
193 if (pmd_large(*pm_dir)) {
194 pmd_clear(pm_dir);
195 address += PMD_SIZE;
196 pages1m++;
197 continue;
198 }
199 pt_dir = pte_offset_kernel(pm_dir, address);
200 pte_clear(&init_mm, address, pt_dir);
201 address += PAGE_SIZE;
202 pages4k++;
203 }
204 flush_tlb_kernel_range(start, end);
205 update_page_count(PG_DIRECT_MAP_4K, -pages4k);
206 update_page_count(PG_DIRECT_MAP_1M, -pages1m);
207 update_page_count(PG_DIRECT_MAP_2G, -pages2g);
208}
209
210/*
211 * Add a backed mem_map array to the virtual mem_map array.
212 */
213int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
214 struct vmem_altmap *altmap)
215{
216 unsigned long pgt_prot, sgt_prot;
217 unsigned long address = start;
218 pgd_t *pg_dir;
219 p4d_t *p4_dir;
220 pud_t *pu_dir;
221 pmd_t *pm_dir;
222 pte_t *pt_dir;
223 int ret = -ENOMEM;
224
225 pgt_prot = pgprot_val(PAGE_KERNEL);
226 sgt_prot = pgprot_val(SEGMENT_KERNEL);
227 if (!MACHINE_HAS_NX) {
228 pgt_prot &= ~_PAGE_NOEXEC;
229 sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
230 }
231 for (address = start; address < end;) {
232 pg_dir = pgd_offset_k(address);
233 if (pgd_none(*pg_dir)) {
234 p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
235 if (!p4_dir)
236 goto out;
237 pgd_populate(&init_mm, pg_dir, p4_dir);
238 }
239
240 p4_dir = p4d_offset(pg_dir, address);
241 if (p4d_none(*p4_dir)) {
242 pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
243 if (!pu_dir)
244 goto out;
245 p4d_populate(&init_mm, p4_dir, pu_dir);
246 }
247
248 pu_dir = pud_offset(p4_dir, address);
249 if (pud_none(*pu_dir)) {
250 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
251 if (!pm_dir)
252 goto out;
253 pud_populate(&init_mm, pu_dir, pm_dir);
254 }
255
256 pm_dir = pmd_offset(pu_dir, address);
257 if (pmd_none(*pm_dir)) {
258 /* Use 1MB frames for vmemmap if available. We always
259 * use large frames even if they are only partially
260 * used.
261 * Otherwise we would have also page tables since
262 * vmemmap_populate gets called for each section
263 * separately. */
264 if (MACHINE_HAS_EDAT1) {
265 void *new_page;
266
267 new_page = vmemmap_alloc_block(PMD_SIZE, node);
268 if (!new_page)
269 goto out;
270 pmd_val(*pm_dir) = __pa(new_page) | sgt_prot;
271 address = (address + PMD_SIZE) & PMD_MASK;
272 continue;
273 }
274 pt_dir = vmem_pte_alloc();
275 if (!pt_dir)
276 goto out;
277 pmd_populate(&init_mm, pm_dir, pt_dir);
278 } else if (pmd_large(*pm_dir)) {
279 address = (address + PMD_SIZE) & PMD_MASK;
280 continue;
281 }
282
283 pt_dir = pte_offset_kernel(pm_dir, address);
284 if (pte_none(*pt_dir)) {
285 void *new_page;
286
287 new_page = vmemmap_alloc_block(PAGE_SIZE, node);
288 if (!new_page)
289 goto out;
290 pte_val(*pt_dir) = __pa(new_page) | pgt_prot;
291 }
292 address += PAGE_SIZE;
293 }
294 ret = 0;
295out:
296 return ret;
297}
298
299void vmemmap_free(unsigned long start, unsigned long end,
300 struct vmem_altmap *altmap)
301{
302}
303
304/*
305 * Add memory segment to the segment list if it doesn't overlap with
306 * an already present segment.
307 */
308static int insert_memory_segment(struct memory_segment *seg)
309{
310 struct memory_segment *tmp;
311
312 if (seg->start + seg->size > VMEM_MAX_PHYS ||
313 seg->start + seg->size < seg->start)
314 return -ERANGE;
315
316 list_for_each_entry(tmp, &mem_segs, list) {
317 if (seg->start >= tmp->start + tmp->size)
318 continue;
319 if (seg->start + seg->size <= tmp->start)
320 continue;
321 return -ENOSPC;
322 }
323 list_add(&seg->list, &mem_segs);
324 return 0;
325}
326
327/*
328 * Remove memory segment from the segment list.
329 */
330static void remove_memory_segment(struct memory_segment *seg)
331{
332 list_del(&seg->list);
333}
334
335static void __remove_shared_memory(struct memory_segment *seg)
336{
337 remove_memory_segment(seg);
338 vmem_remove_range(seg->start, seg->size);
339}
340
341int vmem_remove_mapping(unsigned long start, unsigned long size)
342{
343 struct memory_segment *seg;
344 int ret;
345
346 mutex_lock(&vmem_mutex);
347
348 ret = -ENOENT;
349 list_for_each_entry(seg, &mem_segs, list) {
350 if (seg->start == start && seg->size == size)
351 break;
352 }
353
354 if (seg->start != start || seg->size != size)
355 goto out;
356
357 ret = 0;
358 __remove_shared_memory(seg);
359 kfree(seg);
360out:
361 mutex_unlock(&vmem_mutex);
362 return ret;
363}
364
365int vmem_add_mapping(unsigned long start, unsigned long size)
366{
367 struct memory_segment *seg;
368 int ret;
369
370 mutex_lock(&vmem_mutex);
371 ret = -ENOMEM;
372 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
373 if (!seg)
374 goto out;
375 seg->start = start;
376 seg->size = size;
377
378 ret = insert_memory_segment(seg);
379 if (ret)
380 goto out_free;
381
382 ret = vmem_add_mem(start, size);
383 if (ret)
384 goto out_remove;
385 goto out;
386
387out_remove:
388 __remove_shared_memory(seg);
389out_free:
390 kfree(seg);
391out:
392 mutex_unlock(&vmem_mutex);
393 return ret;
394}
395
396/*
397 * map whole physical memory to virtual memory (identity mapping)
398 * we reserve enough space in the vmalloc area for vmemmap to hotplug
399 * additional memory segments.
400 */
401void __init vmem_map_init(void)
402{
403 struct memblock_region *reg;
404
405 for_each_memblock(memory, reg)
406 vmem_add_mem(reg->base, reg->size);
407 __set_memory((unsigned long)_stext,
408 (unsigned long)(_etext - _stext) >> PAGE_SHIFT,
409 SET_MEMORY_RO | SET_MEMORY_X);
410 __set_memory((unsigned long)_etext,
411 (unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT,
412 SET_MEMORY_RO);
413 __set_memory((unsigned long)_sinittext,
414 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
415 SET_MEMORY_RO | SET_MEMORY_X);
416 __set_memory(__stext_dma, (__etext_dma - __stext_dma) >> PAGE_SHIFT,
417 SET_MEMORY_RO | SET_MEMORY_X);
418 pr_info("Write protected kernel read-only data: %luk\n",
419 (unsigned long)(__end_rodata - _stext) >> 10);
420}
421
422/*
423 * Convert memblock.memory to a memory segment list so there is a single
424 * list that contains all memory segments.
425 */
426static int __init vmem_convert_memory_chunk(void)
427{
428 struct memblock_region *reg;
429 struct memory_segment *seg;
430
431 mutex_lock(&vmem_mutex);
432 for_each_memblock(memory, reg) {
433 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
434 if (!seg)
435 panic("Out of memory...\n");
436 seg->start = reg->base;
437 seg->size = reg->size;
438 insert_memory_segment(seg);
439 }
440 mutex_unlock(&vmem_mutex);
441 return 0;
442}
443
444core_initcall(vmem_convert_memory_chunk);