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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/*
2 * Copyright IBM Corp. 2006
3 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
4 */
5
6#include <linux/bootmem.h>
7#include <linux/pfn.h>
8#include <linux/mm.h>
9#include <linux/module.h>
10#include <linux/list.h>
11#include <linux/hugetlb.h>
12#include <linux/slab.h>
13#include <asm/pgalloc.h>
14#include <asm/pgtable.h>
15#include <asm/setup.h>
16#include <asm/tlbflush.h>
17#include <asm/sections.h>
18
19static DEFINE_MUTEX(vmem_mutex);
20
21struct memory_segment {
22 struct list_head list;
23 unsigned long start;
24 unsigned long size;
25};
26
27static LIST_HEAD(mem_segs);
28
29static void __ref *vmem_alloc_pages(unsigned int order)
30{
31 if (slab_is_available())
32 return (void *)__get_free_pages(GFP_KERNEL, order);
33 return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
34}
35
36static inline pud_t *vmem_pud_alloc(void)
37{
38 pud_t *pud = NULL;
39
40#ifdef CONFIG_64BIT
41 pud = vmem_alloc_pages(2);
42 if (!pud)
43 return NULL;
44 clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
45#endif
46 return pud;
47}
48
49static inline pmd_t *vmem_pmd_alloc(void)
50{
51 pmd_t *pmd = NULL;
52
53#ifdef CONFIG_64BIT
54 pmd = vmem_alloc_pages(2);
55 if (!pmd)
56 return NULL;
57 clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
58#endif
59 return pmd;
60}
61
62static pte_t __ref *vmem_pte_alloc(unsigned long address)
63{
64 pte_t *pte;
65
66 if (slab_is_available())
67 pte = (pte_t *) page_table_alloc(&init_mm, address);
68 else
69 pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
70 if (!pte)
71 return NULL;
72 clear_table((unsigned long *) pte, _PAGE_INVALID,
73 PTRS_PER_PTE * sizeof(pte_t));
74 return pte;
75}
76
77/*
78 * Add a physical memory range to the 1:1 mapping.
79 */
80static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
81{
82 unsigned long end = start + size;
83 unsigned long address = start;
84 pgd_t *pg_dir;
85 pud_t *pu_dir;
86 pmd_t *pm_dir;
87 pte_t *pt_dir;
88 int ret = -ENOMEM;
89
90 while (address < end) {
91 pg_dir = pgd_offset_k(address);
92 if (pgd_none(*pg_dir)) {
93 pu_dir = vmem_pud_alloc();
94 if (!pu_dir)
95 goto out;
96 pgd_populate(&init_mm, pg_dir, pu_dir);
97 }
98 pu_dir = pud_offset(pg_dir, address);
99#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
100 if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
101 !(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) {
102 pud_val(*pu_dir) = __pa(address) |
103 _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE |
104 (ro ? _REGION_ENTRY_PROTECT : 0);
105 address += PUD_SIZE;
106 continue;
107 }
108#endif
109 if (pud_none(*pu_dir)) {
110 pm_dir = vmem_pmd_alloc();
111 if (!pm_dir)
112 goto out;
113 pud_populate(&init_mm, pu_dir, pm_dir);
114 }
115 pm_dir = pmd_offset(pu_dir, address);
116#if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
117 if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
118 !(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
119 pmd_val(*pm_dir) = __pa(address) |
120 _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
121 _SEGMENT_ENTRY_YOUNG |
122 (ro ? _SEGMENT_ENTRY_PROTECT : 0);
123 address += PMD_SIZE;
124 continue;
125 }
126#endif
127 if (pmd_none(*pm_dir)) {
128 pt_dir = vmem_pte_alloc(address);
129 if (!pt_dir)
130 goto out;
131 pmd_populate(&init_mm, pm_dir, pt_dir);
132 }
133
134 pt_dir = pte_offset_kernel(pm_dir, address);
135 pte_val(*pt_dir) = __pa(address) |
136 pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
137 address += PAGE_SIZE;
138 }
139 ret = 0;
140out:
141 return ret;
142}
143
144/*
145 * Remove a physical memory range from the 1:1 mapping.
146 * Currently only invalidates page table entries.
147 */
148static void vmem_remove_range(unsigned long start, unsigned long size)
149{
150 unsigned long end = start + size;
151 unsigned long address = start;
152 pgd_t *pg_dir;
153 pud_t *pu_dir;
154 pmd_t *pm_dir;
155 pte_t *pt_dir;
156 pte_t pte;
157
158 pte_val(pte) = _PAGE_INVALID;
159 while (address < end) {
160 pg_dir = pgd_offset_k(address);
161 if (pgd_none(*pg_dir)) {
162 address += PGDIR_SIZE;
163 continue;
164 }
165 pu_dir = pud_offset(pg_dir, address);
166 if (pud_none(*pu_dir)) {
167 address += PUD_SIZE;
168 continue;
169 }
170 if (pud_large(*pu_dir)) {
171 pud_clear(pu_dir);
172 address += PUD_SIZE;
173 continue;
174 }
175 pm_dir = pmd_offset(pu_dir, address);
176 if (pmd_none(*pm_dir)) {
177 address += PMD_SIZE;
178 continue;
179 }
180 if (pmd_large(*pm_dir)) {
181 pmd_clear(pm_dir);
182 address += PMD_SIZE;
183 continue;
184 }
185 pt_dir = pte_offset_kernel(pm_dir, address);
186 *pt_dir = pte;
187 address += PAGE_SIZE;
188 }
189 flush_tlb_kernel_range(start, end);
190}
191
192/*
193 * Add a backed mem_map array to the virtual mem_map array.
194 */
195int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
196{
197 unsigned long address = start;
198 pgd_t *pg_dir;
199 pud_t *pu_dir;
200 pmd_t *pm_dir;
201 pte_t *pt_dir;
202 int ret = -ENOMEM;
203
204 for (address = start; address < end;) {
205 pg_dir = pgd_offset_k(address);
206 if (pgd_none(*pg_dir)) {
207 pu_dir = vmem_pud_alloc();
208 if (!pu_dir)
209 goto out;
210 pgd_populate(&init_mm, pg_dir, pu_dir);
211 }
212
213 pu_dir = pud_offset(pg_dir, address);
214 if (pud_none(*pu_dir)) {
215 pm_dir = vmem_pmd_alloc();
216 if (!pm_dir)
217 goto out;
218 pud_populate(&init_mm, pu_dir, pm_dir);
219 }
220
221 pm_dir = pmd_offset(pu_dir, address);
222 if (pmd_none(*pm_dir)) {
223#ifdef CONFIG_64BIT
224 /* Use 1MB frames for vmemmap if available. We always
225 * use large frames even if they are only partially
226 * used.
227 * Otherwise we would have also page tables since
228 * vmemmap_populate gets called for each section
229 * separately. */
230 if (MACHINE_HAS_EDAT1) {
231 void *new_page;
232
233 new_page = vmemmap_alloc_block(PMD_SIZE, node);
234 if (!new_page)
235 goto out;
236 pmd_val(*pm_dir) = __pa(new_page) |
237 _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
238 _SEGMENT_ENTRY_CO;
239 address = (address + PMD_SIZE) & PMD_MASK;
240 continue;
241 }
242#endif
243 pt_dir = vmem_pte_alloc(address);
244 if (!pt_dir)
245 goto out;
246 pmd_populate(&init_mm, pm_dir, pt_dir);
247 } else if (pmd_large(*pm_dir)) {
248 address = (address + PMD_SIZE) & PMD_MASK;
249 continue;
250 }
251
252 pt_dir = pte_offset_kernel(pm_dir, address);
253 if (pte_none(*pt_dir)) {
254 unsigned long new_page;
255
256 new_page =__pa(vmem_alloc_pages(0));
257 if (!new_page)
258 goto out;
259 pte_val(*pt_dir) =
260 __pa(new_page) | pgprot_val(PAGE_KERNEL);
261 }
262 address += PAGE_SIZE;
263 }
264 memset((void *)start, 0, end - start);
265 ret = 0;
266out:
267 return ret;
268}
269
270void vmemmap_free(unsigned long start, unsigned long end)
271{
272}
273
274/*
275 * Add memory segment to the segment list if it doesn't overlap with
276 * an already present segment.
277 */
278static int insert_memory_segment(struct memory_segment *seg)
279{
280 struct memory_segment *tmp;
281
282 if (seg->start + seg->size > VMEM_MAX_PHYS ||
283 seg->start + seg->size < seg->start)
284 return -ERANGE;
285
286 list_for_each_entry(tmp, &mem_segs, list) {
287 if (seg->start >= tmp->start + tmp->size)
288 continue;
289 if (seg->start + seg->size <= tmp->start)
290 continue;
291 return -ENOSPC;
292 }
293 list_add(&seg->list, &mem_segs);
294 return 0;
295}
296
297/*
298 * Remove memory segment from the segment list.
299 */
300static void remove_memory_segment(struct memory_segment *seg)
301{
302 list_del(&seg->list);
303}
304
305static void __remove_shared_memory(struct memory_segment *seg)
306{
307 remove_memory_segment(seg);
308 vmem_remove_range(seg->start, seg->size);
309}
310
311int vmem_remove_mapping(unsigned long start, unsigned long size)
312{
313 struct memory_segment *seg;
314 int ret;
315
316 mutex_lock(&vmem_mutex);
317
318 ret = -ENOENT;
319 list_for_each_entry(seg, &mem_segs, list) {
320 if (seg->start == start && seg->size == size)
321 break;
322 }
323
324 if (seg->start != start || seg->size != size)
325 goto out;
326
327 ret = 0;
328 __remove_shared_memory(seg);
329 kfree(seg);
330out:
331 mutex_unlock(&vmem_mutex);
332 return ret;
333}
334
335int vmem_add_mapping(unsigned long start, unsigned long size)
336{
337 struct memory_segment *seg;
338 int ret;
339
340 mutex_lock(&vmem_mutex);
341 ret = -ENOMEM;
342 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
343 if (!seg)
344 goto out;
345 seg->start = start;
346 seg->size = size;
347
348 ret = insert_memory_segment(seg);
349 if (ret)
350 goto out_free;
351
352 ret = vmem_add_mem(start, size, 0);
353 if (ret)
354 goto out_remove;
355 goto out;
356
357out_remove:
358 __remove_shared_memory(seg);
359out_free:
360 kfree(seg);
361out:
362 mutex_unlock(&vmem_mutex);
363 return ret;
364}
365
366/*
367 * map whole physical memory to virtual memory (identity mapping)
368 * we reserve enough space in the vmalloc area for vmemmap to hotplug
369 * additional memory segments.
370 */
371void __init vmem_map_init(void)
372{
373 unsigned long ro_start, ro_end;
374 unsigned long start, end;
375 int i;
376
377 ro_start = PFN_ALIGN((unsigned long)&_stext);
378 ro_end = (unsigned long)&_eshared & PAGE_MASK;
379 for (i = 0; i < MEMORY_CHUNKS; i++) {
380 if (!memory_chunk[i].size)
381 continue;
382 start = memory_chunk[i].addr;
383 end = memory_chunk[i].addr + memory_chunk[i].size;
384 if (start >= ro_end || end <= ro_start)
385 vmem_add_mem(start, end - start, 0);
386 else if (start >= ro_start && end <= ro_end)
387 vmem_add_mem(start, end - start, 1);
388 else if (start >= ro_start) {
389 vmem_add_mem(start, ro_end - start, 1);
390 vmem_add_mem(ro_end, end - ro_end, 0);
391 } else if (end < ro_end) {
392 vmem_add_mem(start, ro_start - start, 0);
393 vmem_add_mem(ro_start, end - ro_start, 1);
394 } else {
395 vmem_add_mem(start, ro_start - start, 0);
396 vmem_add_mem(ro_start, ro_end - ro_start, 1);
397 vmem_add_mem(ro_end, end - ro_end, 0);
398 }
399 }
400}
401
402/*
403 * Convert memory chunk array to a memory segment list so there is a single
404 * list that contains both r/w memory and shared memory segments.
405 */
406static int __init vmem_convert_memory_chunk(void)
407{
408 struct memory_segment *seg;
409 int i;
410
411 mutex_lock(&vmem_mutex);
412 for (i = 0; i < MEMORY_CHUNKS; i++) {
413 if (!memory_chunk[i].size)
414 continue;
415 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
416 if (!seg)
417 panic("Out of memory...\n");
418 seg->start = memory_chunk[i].addr;
419 seg->size = memory_chunk[i].size;
420 insert_memory_segment(seg);
421 }
422 mutex_unlock(&vmem_mutex);
423 return 0;
424}
425
426core_initcall(vmem_convert_memory_chunk);