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18#define pr_fmt(fmt) "efi: " fmt
19
20#include <linux/kernel.h>
21#include <linux/init.h>
22#include <linux/mm.h>
23#include <linux/types.h>
24#include <linux/spinlock.h>
25#include <linux/bootmem.h>
26#include <linux/ioport.h>
27#include <linux/module.h>
28#include <linux/efi.h>
29#include <linux/uaccess.h>
30#include <linux/io.h>
31#include <linux/reboot.h>
32#include <linux/slab.h>
33
34#include <asm/setup.h>
35#include <asm/page.h>
36#include <asm/e820.h>
37#include <asm/pgtable.h>
38#include <asm/tlbflush.h>
39#include <asm/proto.h>
40#include <asm/efi.h>
41#include <asm/cacheflush.h>
42#include <asm/fixmap.h>
43#include <asm/realmode.h>
44#include <asm/time.h>
45#include <asm/pgalloc.h>
46
47
48
49
50
51static u64 efi_va = EFI_VA_START;
52
53struct efi_scratch efi_scratch;
54
55static void __init early_code_mapping_set_exec(int executable)
56{
57 efi_memory_desc_t *md;
58 void *p;
59
60 if (!(__supported_pte_mask & _PAGE_NX))
61 return;
62
63
64 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
65 md = p;
66 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
67 md->type == EFI_BOOT_SERVICES_CODE)
68 efi_set_executable(md, executable);
69 }
70}
71
72pgd_t * __init efi_call_phys_prolog(void)
73{
74 unsigned long vaddress;
75 pgd_t *save_pgd;
76
77 int pgd;
78 int n_pgds;
79
80 if (!efi_enabled(EFI_OLD_MEMMAP)) {
81 save_pgd = (pgd_t *)read_cr3();
82 write_cr3((unsigned long)efi_scratch.efi_pgt);
83 goto out;
84 }
85
86 early_code_mapping_set_exec(1);
87
88 n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
89 save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
90
91 for (pgd = 0; pgd < n_pgds; pgd++) {
92 save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
93 vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
94 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
95 }
96out:
97 __flush_tlb_all();
98
99 return save_pgd;
100}
101
102void __init efi_call_phys_epilog(pgd_t *save_pgd)
103{
104
105
106
107 int pgd_idx;
108 int nr_pgds;
109
110 if (!efi_enabled(EFI_OLD_MEMMAP)) {
111 write_cr3((unsigned long)save_pgd);
112 __flush_tlb_all();
113 return;
114 }
115
116 nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
117
118 for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++)
119 set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
120
121 kfree(save_pgd);
122
123 __flush_tlb_all();
124 early_code_mapping_set_exec(0);
125}
126
127static pgd_t *efi_pgd;
128
129
130
131
132
133
134
135int __init efi_alloc_page_tables(void)
136{
137 pgd_t *pgd;
138 pud_t *pud;
139 gfp_t gfp_mask;
140
141 if (efi_enabled(EFI_OLD_MEMMAP))
142 return 0;
143
144 gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO;
145 efi_pgd = (pgd_t *)__get_free_page(gfp_mask);
146 if (!efi_pgd)
147 return -ENOMEM;
148
149 pgd = efi_pgd + pgd_index(EFI_VA_END);
150
151 pud = pud_alloc_one(NULL, 0);
152 if (!pud) {
153 free_page((unsigned long)efi_pgd);
154 return -ENOMEM;
155 }
156
157 pgd_populate(NULL, pgd, pud);
158
159 return 0;
160}
161
162
163
164
165void efi_sync_low_kernel_mappings(void)
166{
167 unsigned num_entries;
168 pgd_t *pgd_k, *pgd_efi;
169 pud_t *pud_k, *pud_efi;
170
171 if (efi_enabled(EFI_OLD_MEMMAP))
172 return;
173
174
175
176
177
178
179
180
181
182 BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
183 BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
184 (EFI_VA_END & PGDIR_MASK));
185
186 pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
187 pgd_k = pgd_offset_k(PAGE_OFFSET);
188
189 num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
190 memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
191
192
193
194
195
196 BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
197 BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
198
199 pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
200 pud_efi = pud_offset(pgd_efi, 0);
201
202 pgd_k = pgd_offset_k(EFI_VA_END);
203 pud_k = pud_offset(pgd_k, 0);
204
205 num_entries = pud_index(EFI_VA_END);
206 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
207
208 pud_efi = pud_offset(pgd_efi, EFI_VA_START);
209 pud_k = pud_offset(pgd_k, EFI_VA_START);
210
211 num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
212 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
213}
214
215int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
216{
217 unsigned long pfn, text;
218 efi_memory_desc_t *md;
219 struct page *page;
220 unsigned npages;
221 pgd_t *pgd;
222
223 if (efi_enabled(EFI_OLD_MEMMAP))
224 return 0;
225
226 efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd);
227 pgd = efi_pgd;
228
229
230
231
232
233
234
235 pfn = pa_memmap >> PAGE_SHIFT;
236 if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX | _PAGE_RW)) {
237 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
238 return 1;
239 }
240
241 efi_scratch.use_pgd = true;
242
243
244
245
246
247
248
249 if (!IS_ENABLED(CONFIG_EFI_MIXED))
250 return 0;
251
252
253
254
255
256 for_each_efi_memory_desc(&memmap, md) {
257 if (md->type != EFI_CONVENTIONAL_MEMORY &&
258 md->type != EFI_LOADER_DATA &&
259 md->type != EFI_LOADER_CODE)
260 continue;
261
262 pfn = md->phys_addr >> PAGE_SHIFT;
263 npages = md->num_pages;
264
265 if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, npages, _PAGE_RW)) {
266 pr_err("Failed to map 1:1 memory\n");
267 return 1;
268 }
269 }
270
271 page = alloc_page(GFP_KERNEL|__GFP_DMA32);
272 if (!page)
273 panic("Unable to allocate EFI runtime stack < 4GB\n");
274
275 efi_scratch.phys_stack = virt_to_phys(page_address(page));
276 efi_scratch.phys_stack += PAGE_SIZE;
277
278 npages = (_etext - _text) >> PAGE_SHIFT;
279 text = __pa(_text);
280 pfn = text >> PAGE_SHIFT;
281
282 if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) {
283 pr_err("Failed to map kernel text 1:1\n");
284 return 1;
285 }
286
287 return 0;
288}
289
290void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
291{
292 kernel_unmap_pages_in_pgd(efi_pgd, pa_memmap, num_pages);
293}
294
295static void __init __map_region(efi_memory_desc_t *md, u64 va)
296{
297 unsigned long flags = _PAGE_RW;
298 unsigned long pfn;
299 pgd_t *pgd = efi_pgd;
300
301 if (!(md->attribute & EFI_MEMORY_WB))
302 flags |= _PAGE_PCD;
303
304 pfn = md->phys_addr >> PAGE_SHIFT;
305 if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
306 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
307 md->phys_addr, va);
308}
309
310void __init efi_map_region(efi_memory_desc_t *md)
311{
312 unsigned long size = md->num_pages << PAGE_SHIFT;
313 u64 pa = md->phys_addr;
314
315 if (efi_enabled(EFI_OLD_MEMMAP))
316 return old_map_region(md);
317
318
319
320
321
322
323 __map_region(md, md->phys_addr);
324
325
326
327
328
329
330 if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
331 md->virt_addr = md->phys_addr;
332 return;
333 }
334
335 efi_va -= size;
336
337
338 if (!(pa & (PMD_SIZE - 1))) {
339 efi_va &= PMD_MASK;
340 } else {
341 u64 pa_offset = pa & (PMD_SIZE - 1);
342 u64 prev_va = efi_va;
343
344
345 efi_va = (efi_va & PMD_MASK) + pa_offset;
346
347 if (efi_va > prev_va)
348 efi_va -= PMD_SIZE;
349 }
350
351 if (efi_va < EFI_VA_END) {
352 pr_warn(FW_WARN "VA address range overflow!\n");
353 return;
354 }
355
356
357 __map_region(md, efi_va);
358 md->virt_addr = efi_va;
359}
360
361
362
363
364
365
366void __init efi_map_region_fixed(efi_memory_desc_t *md)
367{
368 __map_region(md, md->virt_addr);
369}
370
371void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
372 u32 type, u64 attribute)
373{
374 unsigned long last_map_pfn;
375
376 if (type == EFI_MEMORY_MAPPED_IO)
377 return ioremap(phys_addr, size);
378
379 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
380 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
381 unsigned long top = last_map_pfn << PAGE_SHIFT;
382 efi_ioremap(top, size - (top - phys_addr), type, attribute);
383 }
384
385 if (!(attribute & EFI_MEMORY_WB))
386 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
387
388 return (void __iomem *)__va(phys_addr);
389}
390
391void __init parse_efi_setup(u64 phys_addr, u32 data_len)
392{
393 efi_setup = phys_addr + sizeof(struct setup_data);
394}
395
396void __init efi_runtime_update_mappings(void)
397{
398 unsigned long pfn;
399 pgd_t *pgd = efi_pgd;
400 efi_memory_desc_t *md;
401 void *p;
402
403 if (efi_enabled(EFI_OLD_MEMMAP)) {
404 if (__supported_pte_mask & _PAGE_NX)
405 runtime_code_page_mkexec();
406 return;
407 }
408
409 if (!efi_enabled(EFI_NX_PE_DATA))
410 return;
411
412 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
413 unsigned long pf = 0;
414 md = p;
415
416 if (!(md->attribute & EFI_MEMORY_RUNTIME))
417 continue;
418
419 if (!(md->attribute & EFI_MEMORY_WB))
420 pf |= _PAGE_PCD;
421
422 if ((md->attribute & EFI_MEMORY_XP) ||
423 (md->type == EFI_RUNTIME_SERVICES_DATA))
424 pf |= _PAGE_NX;
425
426 if (!(md->attribute & EFI_MEMORY_RO) &&
427 (md->type != EFI_RUNTIME_SERVICES_CODE))
428 pf |= _PAGE_RW;
429
430
431 pfn = md->phys_addr >> PAGE_SHIFT;
432 if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf))
433 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
434 md->phys_addr, md->virt_addr);
435
436 if (kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf))
437 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
438 md->phys_addr, md->virt_addr);
439 }
440}
441
442void __init efi_dump_pagetable(void)
443{
444#ifdef CONFIG_EFI_PGT_DUMP
445 ptdump_walk_pgd_level(NULL, efi_pgd);
446#endif
447}
448
449#ifdef CONFIG_EFI_MIXED
450extern efi_status_t efi64_thunk(u32, ...);
451
452#define runtime_service32(func) \
453({ \
454 u32 table = (u32)(unsigned long)efi.systab; \
455 u32 *rt, *___f; \
456 \
457 rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime)); \
458 ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
459 *___f; \
460})
461
462
463
464
465
466
467
468
469
470#define efi_thunk(f, ...) \
471({ \
472 efi_status_t __s; \
473 unsigned long flags; \
474 u32 func; \
475 \
476 efi_sync_low_kernel_mappings(); \
477 local_irq_save(flags); \
478 \
479 efi_scratch.prev_cr3 = read_cr3(); \
480 write_cr3((unsigned long)efi_scratch.efi_pgt); \
481 __flush_tlb_all(); \
482 \
483 func = runtime_service32(f); \
484 __s = efi64_thunk(func, __VA_ARGS__); \
485 \
486 write_cr3(efi_scratch.prev_cr3); \
487 __flush_tlb_all(); \
488 local_irq_restore(flags); \
489 \
490 __s; \
491})
492
493efi_status_t efi_thunk_set_virtual_address_map(
494 void *phys_set_virtual_address_map,
495 unsigned long memory_map_size,
496 unsigned long descriptor_size,
497 u32 descriptor_version,
498 efi_memory_desc_t *virtual_map)
499{
500 efi_status_t status;
501 unsigned long flags;
502 u32 func;
503
504 efi_sync_low_kernel_mappings();
505 local_irq_save(flags);
506
507 efi_scratch.prev_cr3 = read_cr3();
508 write_cr3((unsigned long)efi_scratch.efi_pgt);
509 __flush_tlb_all();
510
511 func = (u32)(unsigned long)phys_set_virtual_address_map;
512 status = efi64_thunk(func, memory_map_size, descriptor_size,
513 descriptor_version, virtual_map);
514
515 write_cr3(efi_scratch.prev_cr3);
516 __flush_tlb_all();
517 local_irq_restore(flags);
518
519 return status;
520}
521
522static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
523{
524 efi_status_t status;
525 u32 phys_tm, phys_tc;
526
527 spin_lock(&rtc_lock);
528
529 phys_tm = virt_to_phys(tm);
530 phys_tc = virt_to_phys(tc);
531
532 status = efi_thunk(get_time, phys_tm, phys_tc);
533
534 spin_unlock(&rtc_lock);
535
536 return status;
537}
538
539static efi_status_t efi_thunk_set_time(efi_time_t *tm)
540{
541 efi_status_t status;
542 u32 phys_tm;
543
544 spin_lock(&rtc_lock);
545
546 phys_tm = virt_to_phys(tm);
547
548 status = efi_thunk(set_time, phys_tm);
549
550 spin_unlock(&rtc_lock);
551
552 return status;
553}
554
555static efi_status_t
556efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
557 efi_time_t *tm)
558{
559 efi_status_t status;
560 u32 phys_enabled, phys_pending, phys_tm;
561
562 spin_lock(&rtc_lock);
563
564 phys_enabled = virt_to_phys(enabled);
565 phys_pending = virt_to_phys(pending);
566 phys_tm = virt_to_phys(tm);
567
568 status = efi_thunk(get_wakeup_time, phys_enabled,
569 phys_pending, phys_tm);
570
571 spin_unlock(&rtc_lock);
572
573 return status;
574}
575
576static efi_status_t
577efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
578{
579 efi_status_t status;
580 u32 phys_tm;
581
582 spin_lock(&rtc_lock);
583
584 phys_tm = virt_to_phys(tm);
585
586 status = efi_thunk(set_wakeup_time, enabled, phys_tm);
587
588 spin_unlock(&rtc_lock);
589
590 return status;
591}
592
593
594static efi_status_t
595efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
596 u32 *attr, unsigned long *data_size, void *data)
597{
598 efi_status_t status;
599 u32 phys_name, phys_vendor, phys_attr;
600 u32 phys_data_size, phys_data;
601
602 phys_data_size = virt_to_phys(data_size);
603 phys_vendor = virt_to_phys(vendor);
604 phys_name = virt_to_phys(name);
605 phys_attr = virt_to_phys(attr);
606 phys_data = virt_to_phys(data);
607
608 status = efi_thunk(get_variable, phys_name, phys_vendor,
609 phys_attr, phys_data_size, phys_data);
610
611 return status;
612}
613
614static efi_status_t
615efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
616 u32 attr, unsigned long data_size, void *data)
617{
618 u32 phys_name, phys_vendor, phys_data;
619 efi_status_t status;
620
621 phys_name = virt_to_phys(name);
622 phys_vendor = virt_to_phys(vendor);
623 phys_data = virt_to_phys(data);
624
625
626 status = efi_thunk(set_variable, phys_name, phys_vendor,
627 attr, data_size, phys_data);
628
629 return status;
630}
631
632static efi_status_t
633efi_thunk_get_next_variable(unsigned long *name_size,
634 efi_char16_t *name,
635 efi_guid_t *vendor)
636{
637 efi_status_t status;
638 u32 phys_name_size, phys_name, phys_vendor;
639
640 phys_name_size = virt_to_phys(name_size);
641 phys_vendor = virt_to_phys(vendor);
642 phys_name = virt_to_phys(name);
643
644 status = efi_thunk(get_next_variable, phys_name_size,
645 phys_name, phys_vendor);
646
647 return status;
648}
649
650static efi_status_t
651efi_thunk_get_next_high_mono_count(u32 *count)
652{
653 efi_status_t status;
654 u32 phys_count;
655
656 phys_count = virt_to_phys(count);
657 status = efi_thunk(get_next_high_mono_count, phys_count);
658
659 return status;
660}
661
662static void
663efi_thunk_reset_system(int reset_type, efi_status_t status,
664 unsigned long data_size, efi_char16_t *data)
665{
666 u32 phys_data;
667
668 phys_data = virt_to_phys(data);
669
670 efi_thunk(reset_system, reset_type, status, data_size, phys_data);
671}
672
673static efi_status_t
674efi_thunk_update_capsule(efi_capsule_header_t **capsules,
675 unsigned long count, unsigned long sg_list)
676{
677
678
679
680
681
682 return EFI_UNSUPPORTED;
683}
684
685static efi_status_t
686efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
687 u64 *remaining_space,
688 u64 *max_variable_size)
689{
690 efi_status_t status;
691 u32 phys_storage, phys_remaining, phys_max;
692
693 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
694 return EFI_UNSUPPORTED;
695
696 phys_storage = virt_to_phys(storage_space);
697 phys_remaining = virt_to_phys(remaining_space);
698 phys_max = virt_to_phys(max_variable_size);
699
700 status = efi_thunk(query_variable_info, attr, phys_storage,
701 phys_remaining, phys_max);
702
703 return status;
704}
705
706static efi_status_t
707efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
708 unsigned long count, u64 *max_size,
709 int *reset_type)
710{
711
712
713
714
715
716 return EFI_UNSUPPORTED;
717}
718
719void efi_thunk_runtime_setup(void)
720{
721 efi.get_time = efi_thunk_get_time;
722 efi.set_time = efi_thunk_set_time;
723 efi.get_wakeup_time = efi_thunk_get_wakeup_time;
724 efi.set_wakeup_time = efi_thunk_set_wakeup_time;
725 efi.get_variable = efi_thunk_get_variable;
726 efi.get_next_variable = efi_thunk_get_next_variable;
727 efi.set_variable = efi_thunk_set_variable;
728 efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
729 efi.reset_system = efi_thunk_reset_system;
730 efi.query_variable_info = efi_thunk_query_variable_info;
731 efi.update_capsule = efi_thunk_update_capsule;
732 efi.query_capsule_caps = efi_thunk_query_capsule_caps;
733}
734#endif
735