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[deliverable/linux.git] / arch / x86 / platform / efi / efi.c
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;
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
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
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
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
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
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
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
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
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
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
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
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
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
463 void __init efi_init(void)
464 {
465 efi_char16_t *c16;
466 char vendor[100] = "unknown";
467 int i = 0;
468 void *tmp;
469
470 #ifdef CONFIG_X86_32
471 if (boot_params.efi_info.efi_systab_hi ||
472 boot_params.efi_info.efi_memmap_hi) {
473 pr_info("Table located above 4GB, disabling EFI.\n");
474 return;
475 }
476 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
477 #else
478 efi_phys.systab = (efi_system_table_t *)
479 (boot_params.efi_info.efi_systab |
480 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
481 #endif
482
483 if (efi_systab_init(efi_phys.systab))
484 return;
485
486 efi.config_table = (unsigned long)efi.systab->tables;
487 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
488 efi.runtime = (unsigned long)efi.systab->runtime;
489
490 /*
491 * Show what we know for posterity
492 */
493 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2);
494 if (c16) {
495 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
496 vendor[i] = *c16++;
497 vendor[i] = '\0';
498 } else
499 pr_err("Could not map the firmware vendor!\n");
500 early_memunmap(tmp, 2);
501
502 pr_info("EFI v%u.%.02u by %s\n",
503 efi.systab->hdr.revision >> 16,
504 efi.systab->hdr.revision & 0xffff, vendor);
505
506 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
507 return;
508
509 if (efi_config_init(arch_tables))
510 return;
511
512 /*
513 * Note: We currently don't support runtime services on an EFI
514 * that doesn't match the kernel 32/64-bit mode.
515 */
516
517 if (!efi_runtime_supported())
518 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
519 else {
520 if (efi_runtime_disabled() || efi_runtime_init())
521 return;
522 }
523 if (efi_memmap_init())
524 return;
525
526 if (efi_enabled(EFI_DBG))
527 efi_print_memmap();
528
529 efi_esrt_init();
530 }
531
532 void __init efi_late_init(void)
533 {
534 efi_bgrt_init();
535 }
536
537 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
538 {
539 u64 addr, npages;
540
541 addr = md->virt_addr;
542 npages = md->num_pages;
543
544 memrange_efi_to_native(&addr, &npages);
545
546 if (executable)
547 set_memory_x(addr, npages);
548 else
549 set_memory_nx(addr, npages);
550 }
551
552 void __init runtime_code_page_mkexec(void)
553 {
554 efi_memory_desc_t *md;
555 void *p;
556
557 /* Make EFI runtime service code area executable */
558 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
559 md = p;
560
561 if (md->type != EFI_RUNTIME_SERVICES_CODE)
562 continue;
563
564 efi_set_executable(md, true);
565 }
566 }
567
568 void __init efi_memory_uc(u64 addr, unsigned long size)
569 {
570 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
571 u64 npages;
572
573 npages = round_up(size, page_shift) / page_shift;
574 memrange_efi_to_native(&addr, &npages);
575 set_memory_uc(addr, npages);
576 }
577
578 void __init old_map_region(efi_memory_desc_t *md)
579 {
580 u64 start_pfn, end_pfn, end;
581 unsigned long size;
582 void *va;
583
584 start_pfn = PFN_DOWN(md->phys_addr);
585 size = md->num_pages << PAGE_SHIFT;
586 end = md->phys_addr + size;
587 end_pfn = PFN_UP(end);
588
589 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
590 va = __va(md->phys_addr);
591
592 if (!(md->attribute & EFI_MEMORY_WB))
593 efi_memory_uc((u64)(unsigned long)va, size);
594 } else
595 va = efi_ioremap(md->phys_addr, size,
596 md->type, md->attribute);
597
598 md->virt_addr = (u64) (unsigned long) va;
599 if (!va)
600 pr_err("ioremap of 0x%llX failed!\n",
601 (unsigned long long)md->phys_addr);
602 }
603
604 /* Merge contiguous regions of the same type and attribute */
605 static void __init efi_merge_regions(void)
606 {
607 void *p;
608 efi_memory_desc_t *md, *prev_md = NULL;
609
610 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
611 u64 prev_size;
612 md = p;
613
614 if (!prev_md) {
615 prev_md = md;
616 continue;
617 }
618
619 if (prev_md->type != md->type ||
620 prev_md->attribute != md->attribute) {
621 prev_md = md;
622 continue;
623 }
624
625 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
626
627 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
628 prev_md->num_pages += md->num_pages;
629 md->type = EFI_RESERVED_TYPE;
630 md->attribute = 0;
631 continue;
632 }
633 prev_md = md;
634 }
635 }
636
637 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
638 {
639 unsigned long size;
640 u64 end, systab;
641
642 size = md->num_pages << EFI_PAGE_SHIFT;
643 end = md->phys_addr + size;
644 systab = (u64)(unsigned long)efi_phys.systab;
645 if (md->phys_addr <= systab && systab < end) {
646 systab += md->virt_addr - md->phys_addr;
647 efi.systab = (efi_system_table_t *)(unsigned long)systab;
648 }
649 }
650
651 static void __init save_runtime_map(void)
652 {
653 #ifdef CONFIG_KEXEC_CORE
654 efi_memory_desc_t *md;
655 void *tmp, *p, *q = NULL;
656 int count = 0;
657
658 if (efi_enabled(EFI_OLD_MEMMAP))
659 return;
660
661 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
662 md = p;
663
664 if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
665 (md->type == EFI_BOOT_SERVICES_CODE) ||
666 (md->type == EFI_BOOT_SERVICES_DATA))
667 continue;
668 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
669 if (!tmp)
670 goto out;
671 q = tmp;
672
673 memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
674 count++;
675 }
676
677 efi_runtime_map_setup(q, count, memmap.desc_size);
678 return;
679
680 out:
681 kfree(q);
682 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
683 #endif
684 }
685
686 static void *realloc_pages(void *old_memmap, int old_shift)
687 {
688 void *ret;
689
690 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
691 if (!ret)
692 goto out;
693
694 /*
695 * A first-time allocation doesn't have anything to copy.
696 */
697 if (!old_memmap)
698 return ret;
699
700 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
701
702 out:
703 free_pages((unsigned long)old_memmap, old_shift);
704 return ret;
705 }
706
707 /*
708 * Iterate the EFI memory map in reverse order because the regions
709 * will be mapped top-down. The end result is the same as if we had
710 * mapped things forward, but doesn't require us to change the
711 * existing implementation of efi_map_region().
712 */
713 static inline void *efi_map_next_entry_reverse(void *entry)
714 {
715 /* Initial call */
716 if (!entry)
717 return memmap.map_end - memmap.desc_size;
718
719 entry -= memmap.desc_size;
720 if (entry < memmap.map)
721 return NULL;
722
723 return entry;
724 }
725
726 /*
727 * efi_map_next_entry - Return the next EFI memory map descriptor
728 * @entry: Previous EFI memory map descriptor
729 *
730 * This is a helper function to iterate over the EFI memory map, which
731 * we do in different orders depending on the current configuration.
732 *
733 * To begin traversing the memory map @entry must be %NULL.
734 *
735 * Returns %NULL when we reach the end of the memory map.
736 */
737 static void *efi_map_next_entry(void *entry)
738 {
739 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
740 /*
741 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
742 * config table feature requires us to map all entries
743 * in the same order as they appear in the EFI memory
744 * map. That is to say, entry N must have a lower
745 * virtual address than entry N+1. This is because the
746 * firmware toolchain leaves relative references in
747 * the code/data sections, which are split and become
748 * separate EFI memory regions. Mapping things
749 * out-of-order leads to the firmware accessing
750 * unmapped addresses.
751 *
752 * Since we need to map things this way whether or not
753 * the kernel actually makes use of
754 * EFI_PROPERTIES_TABLE, let's just switch to this
755 * scheme by default for 64-bit.
756 */
757 return efi_map_next_entry_reverse(entry);
758 }
759
760 /* Initial call */
761 if (!entry)
762 return memmap.map;
763
764 entry += memmap.desc_size;
765 if (entry >= memmap.map_end)
766 return NULL;
767
768 return entry;
769 }
770
771 /*
772 * Map the efi memory ranges of the runtime services and update new_mmap with
773 * virtual addresses.
774 */
775 static void * __init efi_map_regions(int *count, int *pg_shift)
776 {
777 void *p, *new_memmap = NULL;
778 unsigned long left = 0;
779 efi_memory_desc_t *md;
780
781 p = NULL;
782 while ((p = efi_map_next_entry(p))) {
783 md = p;
784 if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
785 #ifdef CONFIG_X86_64
786 if (md->type != EFI_BOOT_SERVICES_CODE &&
787 md->type != EFI_BOOT_SERVICES_DATA)
788 #endif
789 continue;
790 }
791
792 efi_map_region(md);
793 get_systab_virt_addr(md);
794
795 if (left < memmap.desc_size) {
796 new_memmap = realloc_pages(new_memmap, *pg_shift);
797 if (!new_memmap)
798 return NULL;
799
800 left += PAGE_SIZE << *pg_shift;
801 (*pg_shift)++;
802 }
803
804 memcpy(new_memmap + (*count * memmap.desc_size), md,
805 memmap.desc_size);
806
807 left -= memmap.desc_size;
808 (*count)++;
809 }
810
811 return new_memmap;
812 }
813
814 static void __init kexec_enter_virtual_mode(void)
815 {
816 #ifdef CONFIG_KEXEC_CORE
817 efi_memory_desc_t *md;
818 void *p;
819
820 efi.systab = NULL;
821
822 /*
823 * We don't do virtual mode, since we don't do runtime services, on
824 * non-native EFI
825 */
826 if (!efi_is_native()) {
827 efi_unmap_memmap();
828 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
829 return;
830 }
831
832 /*
833 * Map efi regions which were passed via setup_data. The virt_addr is a
834 * fixed addr which was used in first kernel of a kexec boot.
835 */
836 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
837 md = p;
838 efi_map_region_fixed(md); /* FIXME: add error handling */
839 get_systab_virt_addr(md);
840 }
841
842 save_runtime_map();
843
844 BUG_ON(!efi.systab);
845
846 efi_sync_low_kernel_mappings();
847
848 /*
849 * Now that EFI is in virtual mode, update the function
850 * pointers in the runtime service table to the new virtual addresses.
851 *
852 * Call EFI services through wrapper functions.
853 */
854 efi.runtime_version = efi_systab.hdr.revision;
855
856 efi_native_runtime_setup();
857
858 efi.set_virtual_address_map = NULL;
859
860 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
861 runtime_code_page_mkexec();
862
863 /* clean DUMMY object */
864 efi_delete_dummy_variable();
865 #endif
866 }
867
868 /*
869 * This function will switch the EFI runtime services to virtual mode.
870 * Essentially, we look through the EFI memmap and map every region that
871 * has the runtime attribute bit set in its memory descriptor into the
872 * efi_pgd page table.
873 *
874 * The old method which used to update that memory descriptor with the
875 * virtual address obtained from ioremap() is still supported when the
876 * kernel is booted with efi=old_map on its command line. Same old
877 * method enabled the runtime services to be called without having to
878 * thunk back into physical mode for every invocation.
879 *
880 * The new method does a pagetable switch in a preemption-safe manner
881 * so that we're in a different address space when calling a runtime
882 * function. For function arguments passing we do copy the PUDs of the
883 * kernel page table into efi_pgd prior to each call.
884 *
885 * Specially for kexec boot, efi runtime maps in previous kernel should
886 * be passed in via setup_data. In that case runtime ranges will be mapped
887 * to the same virtual addresses as the first kernel, see
888 * kexec_enter_virtual_mode().
889 */
890 static void __init __efi_enter_virtual_mode(void)
891 {
892 int count = 0, pg_shift = 0;
893 void *new_memmap = NULL;
894 efi_status_t status;
895
896 efi.systab = NULL;
897
898 if (efi_alloc_page_tables()) {
899 pr_err("Failed to allocate EFI page tables\n");
900 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
901 return;
902 }
903
904 efi_merge_regions();
905 new_memmap = efi_map_regions(&count, &pg_shift);
906 if (!new_memmap) {
907 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
908 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
909 return;
910 }
911
912 save_runtime_map();
913
914 BUG_ON(!efi.systab);
915
916 if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) {
917 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
918 return;
919 }
920
921 efi_sync_low_kernel_mappings();
922 efi_dump_pagetable();
923
924 if (efi_is_native()) {
925 status = phys_efi_set_virtual_address_map(
926 memmap.desc_size * count,
927 memmap.desc_size,
928 memmap.desc_version,
929 (efi_memory_desc_t *)__pa(new_memmap));
930 } else {
931 status = efi_thunk_set_virtual_address_map(
932 efi_phys.set_virtual_address_map,
933 memmap.desc_size * count,
934 memmap.desc_size,
935 memmap.desc_version,
936 (efi_memory_desc_t *)__pa(new_memmap));
937 }
938
939 if (status != EFI_SUCCESS) {
940 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
941 status);
942 panic("EFI call to SetVirtualAddressMap() failed!");
943 }
944
945 /*
946 * Now that EFI is in virtual mode, update the function
947 * pointers in the runtime service table to the new virtual addresses.
948 *
949 * Call EFI services through wrapper functions.
950 */
951 efi.runtime_version = efi_systab.hdr.revision;
952
953 if (efi_is_native())
954 efi_native_runtime_setup();
955 else
956 efi_thunk_runtime_setup();
957
958 efi.set_virtual_address_map = NULL;
959
960 efi_runtime_mkexec();
961
962 /*
963 * We mapped the descriptor array into the EFI pagetable above
964 * but we're not unmapping it here because if we're running in
965 * EFI mixed mode we need all of memory to be accessible when
966 * we pass parameters to the EFI runtime services in the
967 * thunking code.
968 *
969 * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
970 */
971 free_pages((unsigned long)new_memmap, pg_shift);
972
973 /* clean DUMMY object */
974 efi_delete_dummy_variable();
975 }
976
977 void __init efi_enter_virtual_mode(void)
978 {
979 if (efi_enabled(EFI_PARAVIRT))
980 return;
981
982 if (efi_setup)
983 kexec_enter_virtual_mode();
984 else
985 __efi_enter_virtual_mode();
986 }
987
988 /*
989 * Convenience functions to obtain memory types and attributes
990 */
991 u32 efi_mem_type(unsigned long phys_addr)
992 {
993 efi_memory_desc_t *md;
994 void *p;
995
996 if (!efi_enabled(EFI_MEMMAP))
997 return 0;
998
999 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
1000 md = p;
1001 if ((md->phys_addr <= phys_addr) &&
1002 (phys_addr < (md->phys_addr +
1003 (md->num_pages << EFI_PAGE_SHIFT))))
1004 return md->type;
1005 }
1006 return 0;
1007 }
1008
1009 static int __init arch_parse_efi_cmdline(char *str)
1010 {
1011 if (!str) {
1012 pr_warn("need at least one option\n");
1013 return -EINVAL;
1014 }
1015
1016 if (parse_option_str(str, "old_map"))
1017 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1018
1019 return 0;
1020 }
1021 early_param("efi", arch_parse_efi_cmdline);
Linux kernel - Deliverables
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