1 /*
2 * Common EFI (Extensible Firmware Interface) support functions
3 * Based on Extensible Firmware Interface Specification version 1.0
4 *
5 * Copyright (C) 1999 VA Linux Systems
6 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
7 * Copyright (C) 1999-2002 Hewlett-Packard Co.
8 * David Mosberger-Tang <davidm@hpl.hp.com>
9 * Stephane Eranian <eranian@hpl.hp.com>
10 * Copyright (C) 2005-2008 Intel Co.
11 * Fenghua Yu <fenghua.yu@intel.com>
12 * Bibo Mao <bibo.mao@intel.com>
13 * Chandramouli Narayanan <mouli@linux.intel.com>
14 * Huang Ying <ying.huang@intel.com>
15 * Copyright (C) 2013 SuSE Labs
16 * Borislav Petkov <bp@suse.de> - runtime services VA mapping
17 *
18 * Copied from efi_32.c to eliminate the duplicated code between EFI
19 * 32/64 support code. --ying 2007-10-26
20 *
21 * All EFI Runtime Services are not implemented yet as EFI only
22 * supports physical mode addressing on SoftSDV. This is to be fixed
23 * in a future version. --drummond 1999-07-20
24 *
25 * Implemented EFI runtime services and virtual mode calls. --davidm
26 *
27 * Goutham Rao: <goutham.rao@intel.com>
28 * Skip non-WB memory and ignore empty memory ranges.
29 */
30
31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/efi.h>
36 #include <linux/efi-bgrt.h>
37 #include <linux/export.h>
38 #include <linux/bootmem.h>
39 #include <linux/slab.h>
40 #include <linux/memblock.h>
41 #include <linux/spinlock.h>
42 #include <linux/uaccess.h>
43 #include <linux/time.h>
44 #include <linux/io.h>
45 #include <linux/reboot.h>
46 #include <linux/bcd.h>
47
48 #include <asm/setup.h>
49 #include <asm/efi.h>
50 #include <asm/time.h>
51 #include <asm/cacheflush.h>
52 #include <asm/tlbflush.h>
53 #include <asm/x86_init.h>
54 #include <asm/rtc.h>
55 #include <asm/uv/uv.h>
56
57 #define EFI_DEBUG
58
59 struct efi_memory_map memmap;
60
61 static struct efi efi_phys __initdata;
62 static efi_system_table_t efi_systab __initdata;
63
64 static efi_config_table_type_t arch_tables[] __initdata = {
65 #ifdef CONFIG_X86_UV
66 {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
67 #endif
68 {NULL_GUID, NULL, NULL},
69 };
70
71 u64 efi_setup; /* efi setup_data physical address */
72
73 static int add_efi_memmap __initdata;
setup_add_efi_memmap(char * arg)74 static int __init setup_add_efi_memmap(char *arg)
75 {
76 add_efi_memmap = 1;
77 return 0;
78 }
79 early_param("add_efi_memmap", setup_add_efi_memmap);
80
phys_efi_set_virtual_address_map(unsigned long memory_map_size,unsigned long descriptor_size,u32 descriptor_version,efi_memory_desc_t * virtual_map)81 static efi_status_t __init phys_efi_set_virtual_address_map(
82 unsigned long memory_map_size,
83 unsigned long descriptor_size,
84 u32 descriptor_version,
85 efi_memory_desc_t *virtual_map)
86 {
87 efi_status_t status;
88 unsigned long flags;
89 pgd_t *save_pgd;
90
91 save_pgd = efi_call_phys_prolog();
92
93 /* Disable interrupts around EFI calls: */
94 local_irq_save(flags);
95 status = efi_call_phys(efi_phys.set_virtual_address_map,
96 memory_map_size, descriptor_size,
97 descriptor_version, virtual_map);
98 local_irq_restore(flags);
99
100 efi_call_phys_epilog(save_pgd);
101
102 return status;
103 }
104
efi_get_time(struct timespec * now)105 void efi_get_time(struct timespec *now)
106 {
107 efi_status_t status;
108 efi_time_t eft;
109 efi_time_cap_t cap;
110
111 status = efi.get_time(&eft, &cap);
112 if (status != EFI_SUCCESS)
113 pr_err("Oops: efitime: can't read time!\n");
114
115 now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
116 eft.minute, eft.second);
117 now->tv_nsec = 0;
118 }
119
efi_find_mirror(void)120 void __init efi_find_mirror(void)
121 {
122 void *p;
123 u64 mirror_size = 0, total_size = 0;
124
125 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
126 efi_memory_desc_t *md = p;
127 unsigned long long start = md->phys_addr;
128 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
129
130 total_size += size;
131 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
132 memblock_mark_mirror(start, size);
133 mirror_size += size;
134 }
135 }
136 if (mirror_size)
137 pr_info("Memory: %lldM/%lldM mirrored memory\n",
138 mirror_size>>20, total_size>>20);
139 }
140
141 /*
142 * Tell the kernel about the EFI memory map. This might include
143 * more than the max 128 entries that can fit in the e820 legacy
144 * (zeropage) memory map.
145 */
146
do_add_efi_memmap(void)147 static void __init do_add_efi_memmap(void)
148 {
149 void *p;
150
151 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
152 efi_memory_desc_t *md = p;
153 unsigned long long start = md->phys_addr;
154 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
155 int e820_type;
156
157 switch (md->type) {
158 case EFI_LOADER_CODE:
159 case EFI_LOADER_DATA:
160 case EFI_BOOT_SERVICES_CODE:
161 case EFI_BOOT_SERVICES_DATA:
162 case EFI_CONVENTIONAL_MEMORY:
163 if (md->attribute & EFI_MEMORY_WB)
164 e820_type = E820_RAM;
165 else
166 e820_type = E820_RESERVED;
167 break;
168 case EFI_ACPI_RECLAIM_MEMORY:
169 e820_type = E820_ACPI;
170 break;
171 case EFI_ACPI_MEMORY_NVS:
172 e820_type = E820_NVS;
173 break;
174 case EFI_UNUSABLE_MEMORY:
175 e820_type = E820_UNUSABLE;
176 break;
177 case EFI_PERSISTENT_MEMORY:
178 e820_type = E820_PMEM;
179 break;
180 default:
181 /*
182 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
183 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
184 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
185 */
186 e820_type = E820_RESERVED;
187 break;
188 }
189 e820_add_region(start, size, e820_type);
190 }
191 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
192 }
193
efi_memblock_x86_reserve_range(void)194 int __init efi_memblock_x86_reserve_range(void)
195 {
196 struct efi_info *e = &boot_params.efi_info;
197 phys_addr_t pmap;
198
199 if (efi_enabled(EFI_PARAVIRT))
200 return 0;
201
202 #ifdef CONFIG_X86_32
203 /* Can't handle data above 4GB at this time */
204 if (e->efi_memmap_hi) {
205 pr_err("Memory map is above 4GB, disabling EFI.\n");
206 return -EINVAL;
207 }
208 pmap = e->efi_memmap;
209 #else
210 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
211 #endif
212 memmap.phys_map = pmap;
213 memmap.nr_map = e->efi_memmap_size /
214 e->efi_memdesc_size;
215 memmap.desc_size = e->efi_memdesc_size;
216 memmap.desc_version = e->efi_memdesc_version;
217
218 memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
219
220 efi.memmap = &memmap;
221
222 return 0;
223 }
224
efi_print_memmap(void)225 void __init efi_print_memmap(void)
226 {
227 #ifdef EFI_DEBUG
228 efi_memory_desc_t *md;
229 void *p;
230 int i;
231
232 for (p = memmap.map, i = 0;
233 p < memmap.map_end;
234 p += memmap.desc_size, i++) {
235 char buf[64];
236
237 md = p;
238 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
239 i, efi_md_typeattr_format(buf, sizeof(buf), md),
240 md->phys_addr,
241 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
242 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
243 }
244 #endif /* EFI_DEBUG */
245 }
246
efi_unmap_memmap(void)247 void __init efi_unmap_memmap(void)
248 {
249 clear_bit(EFI_MEMMAP, &efi.flags);
250 if (memmap.map) {
251 early_memunmap(memmap.map, memmap.nr_map * memmap.desc_size);
252 memmap.map = NULL;
253 }
254 }
255
efi_systab_init(void * phys)256 static int __init efi_systab_init(void *phys)
257 {
258 if (efi_enabled(EFI_64BIT)) {
259 efi_system_table_64_t *systab64;
260 struct efi_setup_data *data = NULL;
261 u64 tmp = 0;
262
263 if (efi_setup) {
264 data = early_memremap(efi_setup, sizeof(*data));
265 if (!data)
266 return -ENOMEM;
267 }
268 systab64 = early_memremap((unsigned long)phys,
269 sizeof(*systab64));
270 if (systab64 == NULL) {
271 pr_err("Couldn't map the system table!\n");
272 if (data)
273 early_memunmap(data, sizeof(*data));
274 return -ENOMEM;
275 }
276
277 efi_systab.hdr = systab64->hdr;
278 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
279 systab64->fw_vendor;
280 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
281 efi_systab.fw_revision = systab64->fw_revision;
282 efi_systab.con_in_handle = systab64->con_in_handle;
283 tmp |= systab64->con_in_handle;
284 efi_systab.con_in = systab64->con_in;
285 tmp |= systab64->con_in;
286 efi_systab.con_out_handle = systab64->con_out_handle;
287 tmp |= systab64->con_out_handle;
288 efi_systab.con_out = systab64->con_out;
289 tmp |= systab64->con_out;
290 efi_systab.stderr_handle = systab64->stderr_handle;
291 tmp |= systab64->stderr_handle;
292 efi_systab.stderr = systab64->stderr;
293 tmp |= systab64->stderr;
294 efi_systab.runtime = data ?
295 (void *)(unsigned long)data->runtime :
296 (void *)(unsigned long)systab64->runtime;
297 tmp |= data ? data->runtime : systab64->runtime;
298 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
299 tmp |= systab64->boottime;
300 efi_systab.nr_tables = systab64->nr_tables;
301 efi_systab.tables = data ? (unsigned long)data->tables :
302 systab64->tables;
303 tmp |= data ? data->tables : systab64->tables;
304
305 early_memunmap(systab64, sizeof(*systab64));
306 if (data)
307 early_memunmap(data, sizeof(*data));
308 #ifdef CONFIG_X86_32
309 if (tmp >> 32) {
310 pr_err("EFI data located above 4GB, disabling EFI.\n");
311 return -EINVAL;
312 }
313 #endif
314 } else {
315 efi_system_table_32_t *systab32;
316
317 systab32 = early_memremap((unsigned long)phys,
318 sizeof(*systab32));
319 if (systab32 == NULL) {
320 pr_err("Couldn't map the system table!\n");
321 return -ENOMEM;
322 }
323
324 efi_systab.hdr = systab32->hdr;
325 efi_systab.fw_vendor = systab32->fw_vendor;
326 efi_systab.fw_revision = systab32->fw_revision;
327 efi_systab.con_in_handle = systab32->con_in_handle;
328 efi_systab.con_in = systab32->con_in;
329 efi_systab.con_out_handle = systab32->con_out_handle;
330 efi_systab.con_out = systab32->con_out;
331 efi_systab.stderr_handle = systab32->stderr_handle;
332 efi_systab.stderr = systab32->stderr;
333 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
334 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
335 efi_systab.nr_tables = systab32->nr_tables;
336 efi_systab.tables = systab32->tables;
337
338 early_memunmap(systab32, sizeof(*systab32));
339 }
340
341 efi.systab = &efi_systab;
342
343 /*
344 * Verify the EFI Table
345 */
346 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
347 pr_err("System table signature incorrect!\n");
348 return -EINVAL;
349 }
350 if ((efi.systab->hdr.revision >> 16) == 0)
351 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
352 efi.systab->hdr.revision >> 16,
353 efi.systab->hdr.revision & 0xffff);
354
355 set_bit(EFI_SYSTEM_TABLES, &efi.flags);
356
357 return 0;
358 }
359
efi_runtime_init32(void)360 static int __init efi_runtime_init32(void)
361 {
362 efi_runtime_services_32_t *runtime;
363
364 runtime = early_memremap((unsigned long)efi.systab->runtime,
365 sizeof(efi_runtime_services_32_t));
366 if (!runtime) {
367 pr_err("Could not map the runtime service table!\n");
368 return -ENOMEM;
369 }
370
371 /*
372 * We will only need *early* access to the SetVirtualAddressMap
373 * EFI runtime service. All other runtime services will be called
374 * via the virtual mapping.
375 */
376 efi_phys.set_virtual_address_map =
377 (efi_set_virtual_address_map_t *)
378 (unsigned long)runtime->set_virtual_address_map;
379 early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
380
381 return 0;
382 }
383
efi_runtime_init64(void)384 static int __init efi_runtime_init64(void)
385 {
386 efi_runtime_services_64_t *runtime;
387
388 runtime = early_memremap((unsigned long)efi.systab->runtime,
389 sizeof(efi_runtime_services_64_t));
390 if (!runtime) {
391 pr_err("Could not map the runtime service table!\n");
392 return -ENOMEM;
393 }
394
395 /*
396 * We will only need *early* access to the SetVirtualAddressMap
397 * EFI runtime service. All other runtime services will be called
398 * via the virtual mapping.
399 */
400 efi_phys.set_virtual_address_map =
401 (efi_set_virtual_address_map_t *)
402 (unsigned long)runtime->set_virtual_address_map;
403 early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
404
405 return 0;
406 }
407
efi_runtime_init(void)408 static int __init efi_runtime_init(void)
409 {
410 int rv;
411
412 /*
413 * Check out the runtime services table. We need to map
414 * the runtime services table so that we can grab the physical
415 * address of several of the EFI runtime functions, needed to
416 * set the firmware into virtual mode.
417 *
418 * When EFI_PARAVIRT is in force then we could not map runtime
419 * service memory region because we do not have direct access to it.
420 * However, runtime services are available through proxy functions
421 * (e.g. in case of Xen dom0 EFI implementation they call special
422 * hypercall which executes relevant EFI functions) and that is why
423 * they are always enabled.
424 */
425
426 if (!efi_enabled(EFI_PARAVIRT)) {
427 if (efi_enabled(EFI_64BIT))
428 rv = efi_runtime_init64();
429 else
430 rv = efi_runtime_init32();
431
432 if (rv)
433 return rv;
434 }
435
436 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
437
438 return 0;
439 }
440
efi_memmap_init(void)441 static int __init efi_memmap_init(void)
442 {
443 if (efi_enabled(EFI_PARAVIRT))
444 return 0;
445
446 /* Map the EFI memory map */
447 memmap.map = early_memremap((unsigned long)memmap.phys_map,
448 memmap.nr_map * memmap.desc_size);
449 if (memmap.map == NULL) {
450 pr_err("Could not map the memory map!\n");
451 return -ENOMEM;
452 }
453 memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
454
455 if (add_efi_memmap)
456 do_add_efi_memmap();
457
458 set_bit(EFI_MEMMAP, &efi.flags);
459
460 return 0;
461 }
462
efi_init(void)463 void __init efi_init(void)
464 {
465 efi_char16_t *c16;
466 char vendor[100] = "unknown";
467 int i = 0;
468
469 #ifdef CONFIG_X86_32
470 if (boot_params.efi_info.efi_systab_hi ||
471 boot_params.efi_info.efi_memmap_hi) {
472 pr_info("Table located above 4GB, disabling EFI.\n");
473 return;
474 }
475 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
476 #else
477 efi_phys.systab = (efi_system_table_t *)
478 (boot_params.efi_info.efi_systab |
479 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
480 #endif
481
482 if (efi_systab_init(efi_phys.systab))
483 return;
484
485 efi.config_table = (unsigned long)efi.systab->tables;
486 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
487 efi.runtime = (unsigned long)efi.systab->runtime;
488
489 /*
490 * Show what we know for posterity
491 */
492 c16 = early_memremap_ro(efi.systab->fw_vendor,
493 sizeof(vendor) * sizeof(efi_char16_t));
494 if (c16) {
495 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
496 vendor[i] = c16[i];
497 vendor[i] = '\0';
498 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
499 } else {
500 pr_err("Could not map the firmware vendor!\n");
501 }
502
503 pr_info("EFI v%u.%.02u by %s\n",
504 efi.systab->hdr.revision >> 16,
505 efi.systab->hdr.revision & 0xffff, vendor);
506
507 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
508 return;
509
510 if (efi_config_init(arch_tables))
511 return;
512
513 /*
514 * Note: We currently don't support runtime services on an EFI
515 * that doesn't match the kernel 32/64-bit mode.
516 */
517
518 if (!efi_runtime_supported())
519 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
520 else {
521 if (efi_runtime_disabled() || efi_runtime_init())
522 return;
523 }
524 if (efi_memmap_init())
525 return;
526
527 if (efi_enabled(EFI_DBG))
528 efi_print_memmap();
529
530 efi_esrt_init();
531 }
532
efi_late_init(void)533 void __init efi_late_init(void)
534 {
535 efi_bgrt_init();
536 }
537
efi_set_executable(efi_memory_desc_t * md,bool executable)538 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
539 {
540 u64 addr, npages;
541
542 addr = md->virt_addr;
543 npages = md->num_pages;
544
545 memrange_efi_to_native(&addr, &npages);
546
547 if (executable)
548 set_memory_x(addr, npages);
549 else
550 set_memory_nx(addr, npages);
551 }
552
runtime_code_page_mkexec(void)553 void __init runtime_code_page_mkexec(void)
554 {
555 efi_memory_desc_t *md;
556 void *p;
557
558 /* Make EFI runtime service code area executable */
559 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
560 md = p;
561
562 if (md->type != EFI_RUNTIME_SERVICES_CODE)
563 continue;
564
565 efi_set_executable(md, true);
566 }
567 }
568
efi_memory_uc(u64 addr,unsigned long size)569 void __init efi_memory_uc(u64 addr, unsigned long size)
570 {
571 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
572 u64 npages;
573
574 npages = round_up(size, page_shift) / page_shift;
575 memrange_efi_to_native(&addr, &npages);
576 set_memory_uc(addr, npages);
577 }
578
old_map_region(efi_memory_desc_t * md)579 void __init old_map_region(efi_memory_desc_t *md)
580 {
581 u64 start_pfn, end_pfn, end;
582 unsigned long size;
583 void *va;
584
585 start_pfn = PFN_DOWN(md->phys_addr);
586 size = md->num_pages << PAGE_SHIFT;
587 end = md->phys_addr + size;
588 end_pfn = PFN_UP(end);
589
590 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
591 va = __va(md->phys_addr);
592
593 if (!(md->attribute & EFI_MEMORY_WB))
594 efi_memory_uc((u64)(unsigned long)va, size);
595 } else
596 va = efi_ioremap(md->phys_addr, size,
597 md->type, md->attribute);
598
599 md->virt_addr = (u64) (unsigned long) va;
600 if (!va)
601 pr_err("ioremap of 0x%llX failed!\n",
602 (unsigned long long)md->phys_addr);
603 }
604
605 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)606 static void __init efi_merge_regions(void)
607 {
608 void *p;
609 efi_memory_desc_t *md, *prev_md = NULL;
610
611 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
612 u64 prev_size;
613 md = p;
614
615 if (!prev_md) {
616 prev_md = md;
617 continue;
618 }
619
620 if (prev_md->type != md->type ||
621 prev_md->attribute != md->attribute) {
622 prev_md = md;
623 continue;
624 }
625
626 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
627
628 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
629 prev_md->num_pages += md->num_pages;
630 md->type = EFI_RESERVED_TYPE;
631 md->attribute = 0;
632 continue;
633 }
634 prev_md = md;
635 }
636 }
637
get_systab_virt_addr(efi_memory_desc_t * md)638 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
639 {
640 unsigned long size;
641 u64 end, systab;
642
643 size = md->num_pages << EFI_PAGE_SHIFT;
644 end = md->phys_addr + size;
645 systab = (u64)(unsigned long)efi_phys.systab;
646 if (md->phys_addr <= systab && systab < end) {
647 systab += md->virt_addr - md->phys_addr;
648 efi.systab = (efi_system_table_t *)(unsigned long)systab;
649 }
650 }
651
save_runtime_map(void)652 static void __init save_runtime_map(void)
653 {
654 #ifdef CONFIG_KEXEC_CORE
655 efi_memory_desc_t *md;
656 void *tmp, *p, *q = NULL;
657 int count = 0;
658
659 if (efi_enabled(EFI_OLD_MEMMAP))
660 return;
661
662 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
663 md = p;
664
665 if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
666 (md->type == EFI_BOOT_SERVICES_CODE) ||
667 (md->type == EFI_BOOT_SERVICES_DATA))
668 continue;
669 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
670 if (!tmp)
671 goto out;
672 q = tmp;
673
674 memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
675 count++;
676 }
677
678 efi_runtime_map_setup(q, count, memmap.desc_size);
679 return;
680
681 out:
682 kfree(q);
683 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
684 #endif
685 }
686
realloc_pages(void * old_memmap,int old_shift)687 static void *realloc_pages(void *old_memmap, int old_shift)
688 {
689 void *ret;
690
691 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
692 if (!ret)
693 goto out;
694
695 /*
696 * A first-time allocation doesn't have anything to copy.
697 */
698 if (!old_memmap)
699 return ret;
700
701 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
702
703 out:
704 free_pages((unsigned long)old_memmap, old_shift);
705 return ret;
706 }
707
708 /*
709 * Iterate the EFI memory map in reverse order because the regions
710 * will be mapped top-down. The end result is the same as if we had
711 * mapped things forward, but doesn't require us to change the
712 * existing implementation of efi_map_region().
713 */
efi_map_next_entry_reverse(void * entry)714 static inline void *efi_map_next_entry_reverse(void *entry)
715 {
716 /* Initial call */
717 if (!entry)
718 return memmap.map_end - memmap.desc_size;
719
720 entry -= memmap.desc_size;
721 if (entry < memmap.map)
722 return NULL;
723
724 return entry;
725 }
726
727 /*
728 * efi_map_next_entry - Return the next EFI memory map descriptor
729 * @entry: Previous EFI memory map descriptor
730 *
731 * This is a helper function to iterate over the EFI memory map, which
732 * we do in different orders depending on the current configuration.
733 *
734 * To begin traversing the memory map @entry must be %NULL.
735 *
736 * Returns %NULL when we reach the end of the memory map.
737 */
efi_map_next_entry(void * entry)738 static void *efi_map_next_entry(void *entry)
739 {
740 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
741 /*
742 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
743 * config table feature requires us to map all entries
744 * in the same order as they appear in the EFI memory
745 * map. That is to say, entry N must have a lower
746 * virtual address than entry N+1. This is because the
747 * firmware toolchain leaves relative references in
748 * the code/data sections, which are split and become
749 * separate EFI memory regions. Mapping things
750 * out-of-order leads to the firmware accessing
751 * unmapped addresses.
752 *
753 * Since we need to map things this way whether or not
754 * the kernel actually makes use of
755 * EFI_PROPERTIES_TABLE, let's just switch to this
756 * scheme by default for 64-bit.
757 */
758 return efi_map_next_entry_reverse(entry);
759 }
760
761 /* Initial call */
762 if (!entry)
763 return memmap.map;
764
765 entry += memmap.desc_size;
766 if (entry >= memmap.map_end)
767 return NULL;
768
769 return entry;
770 }
771
772 /*
773 * Map the efi memory ranges of the runtime services and update new_mmap with
774 * virtual addresses.
775 */
efi_map_regions(int * count,int * pg_shift)776 static void * __init efi_map_regions(int *count, int *pg_shift)
777 {
778 void *p, *new_memmap = NULL;
779 unsigned long left = 0;
780 efi_memory_desc_t *md;
781
782 p = NULL;
783 while ((p = efi_map_next_entry(p))) {
784 md = p;
785 if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
786 #ifdef CONFIG_X86_64
787 if (md->type != EFI_BOOT_SERVICES_CODE &&
788 md->type != EFI_BOOT_SERVICES_DATA)
789 #endif
790 continue;
791 }
792
793 efi_map_region(md);
794 get_systab_virt_addr(md);
795
796 if (left < memmap.desc_size) {
797 new_memmap = realloc_pages(new_memmap, *pg_shift);
798 if (!new_memmap)
799 return NULL;
800
801 left += PAGE_SIZE << *pg_shift;
802 (*pg_shift)++;
803 }
804
805 memcpy(new_memmap + (*count * memmap.desc_size), md,
806 memmap.desc_size);
807
808 left -= memmap.desc_size;
809 (*count)++;
810 }
811
812 return new_memmap;
813 }
814
kexec_enter_virtual_mode(void)815 static void __init kexec_enter_virtual_mode(void)
816 {
817 #ifdef CONFIG_KEXEC_CORE
818 efi_memory_desc_t *md;
819 void *p;
820
821 efi.systab = NULL;
822
823 /*
824 * We don't do virtual mode, since we don't do runtime services, on
825 * non-native EFI
826 */
827 if (!efi_is_native()) {
828 efi_unmap_memmap();
829 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
830 return;
831 }
832
833 /*
834 * Map efi regions which were passed via setup_data. The virt_addr is a
835 * fixed addr which was used in first kernel of a kexec boot.
836 */
837 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
838 md = p;
839 efi_map_region_fixed(md); /* FIXME: add error handling */
840 get_systab_virt_addr(md);
841 }
842
843 save_runtime_map();
844
845 BUG_ON(!efi.systab);
846
847 efi_sync_low_kernel_mappings();
848
849 /*
850 * Now that EFI is in virtual mode, update the function
851 * pointers in the runtime service table to the new virtual addresses.
852 *
853 * Call EFI services through wrapper functions.
854 */
855 efi.runtime_version = efi_systab.hdr.revision;
856
857 efi_native_runtime_setup();
858
859 efi.set_virtual_address_map = NULL;
860
861 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
862 runtime_code_page_mkexec();
863 #endif
864 }
865
866 /*
867 * This function will switch the EFI runtime services to virtual mode.
868 * Essentially, we look through the EFI memmap and map every region that
869 * has the runtime attribute bit set in its memory descriptor into the
870 * ->trampoline_pgd page table using a top-down VA allocation scheme.
871 *
872 * The old method which used to update that memory descriptor with the
873 * virtual address obtained from ioremap() is still supported when the
874 * kernel is booted with efi=old_map on its command line. Same old
875 * method enabled the runtime services to be called without having to
876 * thunk back into physical mode for every invocation.
877 *
878 * The new method does a pagetable switch in a preemption-safe manner
879 * so that we're in a different address space when calling a runtime
880 * function. For function arguments passing we do copy the PGDs of the
881 * kernel page table into ->trampoline_pgd prior to each call.
882 *
883 * Specially for kexec boot, efi runtime maps in previous kernel should
884 * be passed in via setup_data. In that case runtime ranges will be mapped
885 * to the same virtual addresses as the first kernel, see
886 * kexec_enter_virtual_mode().
887 */
__efi_enter_virtual_mode(void)888 static void __init __efi_enter_virtual_mode(void)
889 {
890 int count = 0, pg_shift = 0;
891 void *new_memmap = NULL;
892 efi_status_t status;
893
894 efi.systab = NULL;
895
896 efi_merge_regions();
897 new_memmap = efi_map_regions(&count, &pg_shift);
898 if (!new_memmap) {
899 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
900 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
901 return;
902 }
903
904 save_runtime_map();
905
906 BUG_ON(!efi.systab);
907
908 if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) {
909 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
910 return;
911 }
912
913 efi_sync_low_kernel_mappings();
914 efi_dump_pagetable();
915
916 if (efi_is_native()) {
917 status = phys_efi_set_virtual_address_map(
918 memmap.desc_size * count,
919 memmap.desc_size,
920 memmap.desc_version,
921 (efi_memory_desc_t *)__pa(new_memmap));
922 } else {
923 status = efi_thunk_set_virtual_address_map(
924 efi_phys.set_virtual_address_map,
925 memmap.desc_size * count,
926 memmap.desc_size,
927 memmap.desc_version,
928 (efi_memory_desc_t *)__pa(new_memmap));
929 }
930
931 if (status != EFI_SUCCESS) {
932 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
933 status);
934 panic("EFI call to SetVirtualAddressMap() failed!");
935 }
936
937 /*
938 * Now that EFI is in virtual mode, update the function
939 * pointers in the runtime service table to the new virtual addresses.
940 *
941 * Call EFI services through wrapper functions.
942 */
943 efi.runtime_version = efi_systab.hdr.revision;
944
945 if (efi_is_native())
946 efi_native_runtime_setup();
947 else
948 efi_thunk_runtime_setup();
949
950 efi.set_virtual_address_map = NULL;
951
952 efi_runtime_mkexec();
953
954 /*
955 * We mapped the descriptor array into the EFI pagetable above but we're
956 * not unmapping it here. Here's why:
957 *
958 * We're copying select PGDs from the kernel page table to the EFI page
959 * table and when we do so and make changes to those PGDs like unmapping
960 * stuff from them, those changes appear in the kernel page table and we
961 * go boom.
962 *
963 * From setup_real_mode():
964 *
965 * ...
966 * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
967 *
968 * In this particular case, our allocation is in PGD 0 of the EFI page
969 * table but we've copied that PGD from PGD[272] of the EFI page table:
970 *
971 * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
972 *
973 * where the direct memory mapping in kernel space is.
974 *
975 * new_memmap's VA comes from that direct mapping and thus clearing it,
976 * it would get cleared in the kernel page table too.
977 *
978 * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
979 */
980 free_pages((unsigned long)new_memmap, pg_shift);
981
982 /* clean DUMMY object */
983 efi_delete_dummy_variable();
984 }
985
efi_enter_virtual_mode(void)986 void __init efi_enter_virtual_mode(void)
987 {
988 if (efi_enabled(EFI_PARAVIRT))
989 return;
990
991 if (efi_setup)
992 kexec_enter_virtual_mode();
993 else
994 __efi_enter_virtual_mode();
995 }
996
997 /*
998 * Convenience functions to obtain memory types and attributes
999 */
efi_mem_type(unsigned long phys_addr)1000 u32 efi_mem_type(unsigned long phys_addr)
1001 {
1002 efi_memory_desc_t *md;
1003 void *p;
1004
1005 if (!efi_enabled(EFI_MEMMAP))
1006 return 0;
1007
1008 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1009 md = p;
1010 if ((md->phys_addr <= phys_addr) &&
1011 (phys_addr < (md->phys_addr +
1012 (md->num_pages << EFI_PAGE_SHIFT))))
1013 return md->type;
1014 }
1015 return 0;
1016 }
1017
arch_parse_efi_cmdline(char * str)1018 static int __init arch_parse_efi_cmdline(char *str)
1019 {
1020 if (!str) {
1021 pr_warn("need at least one option\n");
1022 return -EINVAL;
1023 }
1024
1025 if (parse_option_str(str, "old_map"))
1026 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1027
1028 return 0;
1029 }
1030 early_param("efi", arch_parse_efi_cmdline);
1031