1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Common EFI (Extensible Firmware Interface) support functions
4 * Based on Extensible Firmware Interface Specification version 1.0
5 *
6 * Copyright (C) 1999 VA Linux Systems
7 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
8 * Copyright (C) 1999-2002 Hewlett-Packard Co.
9 * David Mosberger-Tang <davidm@hpl.hp.com>
10 * Stephane Eranian <eranian@hpl.hp.com>
11 * Copyright (C) 2005-2008 Intel Co.
12 * Fenghua Yu <fenghua.yu@intel.com>
13 * Bibo Mao <bibo.mao@intel.com>
14 * Chandramouli Narayanan <mouli@linux.intel.com>
15 * Huang Ying <ying.huang@intel.com>
16 * Copyright (C) 2013 SuSE Labs
17 * Borislav Petkov <bp@suse.de> - runtime services VA mapping
18 *
19 * Copied from efi_32.c to eliminate the duplicated code between EFI
20 * 32/64 support code. --ying 2007-10-26
21 *
22 * All EFI Runtime Services are not implemented yet as EFI only
23 * supports physical mode addressing on SoftSDV. This is to be fixed
24 * in a future version. --drummond 1999-07-20
25 *
26 * Implemented EFI runtime services and virtual mode calls. --davidm
27 *
28 * Goutham Rao: <goutham.rao@intel.com>
29 * Skip non-WB memory and ignore empty memory ranges.
30 */
31
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34 #include <linux/kernel.h>
35 #include <linux/init.h>
36 #include <linux/efi.h>
37 #include <linux/efi-bgrt.h>
38 #include <linux/export.h>
39 #include <linux/bootmem.h>
40 #include <linux/slab.h>
41 #include <linux/memblock.h>
42 #include <linux/spinlock.h>
43 #include <linux/uaccess.h>
44 #include <linux/time.h>
45 #include <linux/io.h>
46 #include <linux/reboot.h>
47 #include <linux/bcd.h>
48
49 #include <asm/setup.h>
50 #include <asm/efi.h>
51 #include <asm/e820/api.h>
52 #include <asm/time.h>
53 #include <asm/set_memory.h>
54 #include <asm/tlbflush.h>
55 #include <asm/x86_init.h>
56 #include <asm/uv/uv.h>
57
58 static struct efi efi_phys __initdata;
59 static efi_system_table_t efi_systab __initdata;
60
61 static efi_config_table_type_t arch_tables[] __initdata = {
62 #ifdef CONFIG_X86_UV
63 {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
64 #endif
65 {NULL_GUID, NULL, NULL},
66 };
67
68 u64 efi_setup; /* efi setup_data physical address */
69
70 static int add_efi_memmap __initdata;
setup_add_efi_memmap(char * arg)71 static int __init setup_add_efi_memmap(char *arg)
72 {
73 add_efi_memmap = 1;
74 return 0;
75 }
76 early_param("add_efi_memmap", setup_add_efi_memmap);
77
phys_efi_set_virtual_address_map(unsigned long memory_map_size,unsigned long descriptor_size,u32 descriptor_version,efi_memory_desc_t * virtual_map)78 static efi_status_t __init phys_efi_set_virtual_address_map(
79 unsigned long memory_map_size,
80 unsigned long descriptor_size,
81 u32 descriptor_version,
82 efi_memory_desc_t *virtual_map)
83 {
84 efi_status_t status;
85 unsigned long flags;
86 pgd_t *save_pgd;
87
88 save_pgd = efi_call_phys_prolog();
89
90 /* Disable interrupts around EFI calls: */
91 local_irq_save(flags);
92 status = efi_call_phys(efi_phys.set_virtual_address_map,
93 memory_map_size, descriptor_size,
94 descriptor_version, virtual_map);
95 local_irq_restore(flags);
96
97 efi_call_phys_epilog(save_pgd);
98
99 return status;
100 }
101
efi_find_mirror(void)102 void __init efi_find_mirror(void)
103 {
104 efi_memory_desc_t *md;
105 u64 mirror_size = 0, total_size = 0;
106
107 for_each_efi_memory_desc(md) {
108 unsigned long long start = md->phys_addr;
109 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
110
111 total_size += size;
112 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
113 memblock_mark_mirror(start, size);
114 mirror_size += size;
115 }
116 }
117 if (mirror_size)
118 pr_info("Memory: %lldM/%lldM mirrored memory\n",
119 mirror_size>>20, total_size>>20);
120 }
121
122 /*
123 * Tell the kernel about the EFI memory map. This might include
124 * more than the max 128 entries that can fit in the e820 legacy
125 * (zeropage) memory map.
126 */
127
do_add_efi_memmap(void)128 static void __init do_add_efi_memmap(void)
129 {
130 efi_memory_desc_t *md;
131
132 for_each_efi_memory_desc(md) {
133 unsigned long long start = md->phys_addr;
134 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
135 int e820_type;
136
137 switch (md->type) {
138 case EFI_LOADER_CODE:
139 case EFI_LOADER_DATA:
140 case EFI_BOOT_SERVICES_CODE:
141 case EFI_BOOT_SERVICES_DATA:
142 case EFI_CONVENTIONAL_MEMORY:
143 if (md->attribute & EFI_MEMORY_WB)
144 e820_type = E820_TYPE_RAM;
145 else
146 e820_type = E820_TYPE_RESERVED;
147 break;
148 case EFI_ACPI_RECLAIM_MEMORY:
149 e820_type = E820_TYPE_ACPI;
150 break;
151 case EFI_ACPI_MEMORY_NVS:
152 e820_type = E820_TYPE_NVS;
153 break;
154 case EFI_UNUSABLE_MEMORY:
155 e820_type = E820_TYPE_UNUSABLE;
156 break;
157 case EFI_PERSISTENT_MEMORY:
158 e820_type = E820_TYPE_PMEM;
159 break;
160 default:
161 /*
162 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
163 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
164 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
165 */
166 e820_type = E820_TYPE_RESERVED;
167 break;
168 }
169 e820__range_add(start, size, e820_type);
170 }
171 e820__update_table(e820_table);
172 }
173
efi_memblock_x86_reserve_range(void)174 int __init efi_memblock_x86_reserve_range(void)
175 {
176 struct efi_info *e = &boot_params.efi_info;
177 struct efi_memory_map_data data;
178 phys_addr_t pmap;
179 int rv;
180
181 if (efi_enabled(EFI_PARAVIRT))
182 return 0;
183
184 #ifdef CONFIG_X86_32
185 /* Can't handle data above 4GB at this time */
186 if (e->efi_memmap_hi) {
187 pr_err("Memory map is above 4GB, disabling EFI.\n");
188 return -EINVAL;
189 }
190 pmap = e->efi_memmap;
191 #else
192 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
193 #endif
194 data.phys_map = pmap;
195 data.size = e->efi_memmap_size;
196 data.desc_size = e->efi_memdesc_size;
197 data.desc_version = e->efi_memdesc_version;
198
199 rv = efi_memmap_init_early(&data);
200 if (rv)
201 return rv;
202
203 if (add_efi_memmap)
204 do_add_efi_memmap();
205
206 WARN(efi.memmap.desc_version != 1,
207 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
208 efi.memmap.desc_version);
209
210 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
211
212 return 0;
213 }
214
215 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
216 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
217 #define U64_HIGH_BIT (~(U64_MAX >> 1))
218
efi_memmap_entry_valid(const efi_memory_desc_t * md,int i)219 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
220 {
221 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
222 u64 end_hi = 0;
223 char buf[64];
224
225 if (md->num_pages == 0) {
226 end = 0;
227 } else if (md->num_pages > EFI_PAGES_MAX ||
228 EFI_PAGES_MAX - md->num_pages <
229 (md->phys_addr >> EFI_PAGE_SHIFT)) {
230 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
231 >> OVERFLOW_ADDR_SHIFT;
232
233 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
234 end_hi += 1;
235 } else {
236 return true;
237 }
238
239 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
240
241 if (end_hi) {
242 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
243 i, efi_md_typeattr_format(buf, sizeof(buf), md),
244 md->phys_addr, end_hi, end);
245 } else {
246 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
247 i, efi_md_typeattr_format(buf, sizeof(buf), md),
248 md->phys_addr, end);
249 }
250 return false;
251 }
252
efi_clean_memmap(void)253 static void __init efi_clean_memmap(void)
254 {
255 efi_memory_desc_t *out = efi.memmap.map;
256 const efi_memory_desc_t *in = out;
257 const efi_memory_desc_t *end = efi.memmap.map_end;
258 int i, n_removal;
259
260 for (i = n_removal = 0; in < end; i++) {
261 if (efi_memmap_entry_valid(in, i)) {
262 if (out != in)
263 memcpy(out, in, efi.memmap.desc_size);
264 out = (void *)out + efi.memmap.desc_size;
265 } else {
266 n_removal++;
267 }
268 in = (void *)in + efi.memmap.desc_size;
269 }
270
271 if (n_removal > 0) {
272 u64 size = efi.memmap.nr_map - n_removal;
273
274 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
275 efi_memmap_install(efi.memmap.phys_map, size);
276 }
277 }
278
efi_print_memmap(void)279 void __init efi_print_memmap(void)
280 {
281 efi_memory_desc_t *md;
282 int i = 0;
283
284 for_each_efi_memory_desc(md) {
285 char buf[64];
286
287 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
288 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
289 md->phys_addr,
290 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
291 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
292 }
293 }
294
efi_systab_init(void * phys)295 static int __init efi_systab_init(void *phys)
296 {
297 if (efi_enabled(EFI_64BIT)) {
298 efi_system_table_64_t *systab64;
299 struct efi_setup_data *data = NULL;
300 u64 tmp = 0;
301
302 if (efi_setup) {
303 data = early_memremap(efi_setup, sizeof(*data));
304 if (!data)
305 return -ENOMEM;
306 }
307 systab64 = early_memremap((unsigned long)phys,
308 sizeof(*systab64));
309 if (systab64 == NULL) {
310 pr_err("Couldn't map the system table!\n");
311 if (data)
312 early_memunmap(data, sizeof(*data));
313 return -ENOMEM;
314 }
315
316 efi_systab.hdr = systab64->hdr;
317 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
318 systab64->fw_vendor;
319 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
320 efi_systab.fw_revision = systab64->fw_revision;
321 efi_systab.con_in_handle = systab64->con_in_handle;
322 tmp |= systab64->con_in_handle;
323 efi_systab.con_in = systab64->con_in;
324 tmp |= systab64->con_in;
325 efi_systab.con_out_handle = systab64->con_out_handle;
326 tmp |= systab64->con_out_handle;
327 efi_systab.con_out = systab64->con_out;
328 tmp |= systab64->con_out;
329 efi_systab.stderr_handle = systab64->stderr_handle;
330 tmp |= systab64->stderr_handle;
331 efi_systab.stderr = systab64->stderr;
332 tmp |= systab64->stderr;
333 efi_systab.runtime = data ?
334 (void *)(unsigned long)data->runtime :
335 (void *)(unsigned long)systab64->runtime;
336 tmp |= data ? data->runtime : systab64->runtime;
337 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
338 tmp |= systab64->boottime;
339 efi_systab.nr_tables = systab64->nr_tables;
340 efi_systab.tables = data ? (unsigned long)data->tables :
341 systab64->tables;
342 tmp |= data ? data->tables : systab64->tables;
343
344 early_memunmap(systab64, sizeof(*systab64));
345 if (data)
346 early_memunmap(data, sizeof(*data));
347 #ifdef CONFIG_X86_32
348 if (tmp >> 32) {
349 pr_err("EFI data located above 4GB, disabling EFI.\n");
350 return -EINVAL;
351 }
352 #endif
353 } else {
354 efi_system_table_32_t *systab32;
355
356 systab32 = early_memremap((unsigned long)phys,
357 sizeof(*systab32));
358 if (systab32 == NULL) {
359 pr_err("Couldn't map the system table!\n");
360 return -ENOMEM;
361 }
362
363 efi_systab.hdr = systab32->hdr;
364 efi_systab.fw_vendor = systab32->fw_vendor;
365 efi_systab.fw_revision = systab32->fw_revision;
366 efi_systab.con_in_handle = systab32->con_in_handle;
367 efi_systab.con_in = systab32->con_in;
368 efi_systab.con_out_handle = systab32->con_out_handle;
369 efi_systab.con_out = systab32->con_out;
370 efi_systab.stderr_handle = systab32->stderr_handle;
371 efi_systab.stderr = systab32->stderr;
372 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
373 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
374 efi_systab.nr_tables = systab32->nr_tables;
375 efi_systab.tables = systab32->tables;
376
377 early_memunmap(systab32, sizeof(*systab32));
378 }
379
380 efi.systab = &efi_systab;
381
382 /*
383 * Verify the EFI Table
384 */
385 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
386 pr_err("System table signature incorrect!\n");
387 return -EINVAL;
388 }
389 if ((efi.systab->hdr.revision >> 16) == 0)
390 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
391 efi.systab->hdr.revision >> 16,
392 efi.systab->hdr.revision & 0xffff);
393
394 return 0;
395 }
396
efi_runtime_init32(void)397 static int __init efi_runtime_init32(void)
398 {
399 efi_runtime_services_32_t *runtime;
400
401 runtime = early_memremap((unsigned long)efi.systab->runtime,
402 sizeof(efi_runtime_services_32_t));
403 if (!runtime) {
404 pr_err("Could not map the runtime service table!\n");
405 return -ENOMEM;
406 }
407
408 /*
409 * We will only need *early* access to the SetVirtualAddressMap
410 * EFI runtime service. All other runtime services will be called
411 * via the virtual mapping.
412 */
413 efi_phys.set_virtual_address_map =
414 (efi_set_virtual_address_map_t *)
415 (unsigned long)runtime->set_virtual_address_map;
416 early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
417
418 return 0;
419 }
420
efi_runtime_init64(void)421 static int __init efi_runtime_init64(void)
422 {
423 efi_runtime_services_64_t *runtime;
424
425 runtime = early_memremap((unsigned long)efi.systab->runtime,
426 sizeof(efi_runtime_services_64_t));
427 if (!runtime) {
428 pr_err("Could not map the runtime service table!\n");
429 return -ENOMEM;
430 }
431
432 /*
433 * We will only need *early* access to the SetVirtualAddressMap
434 * EFI runtime service. All other runtime services will be called
435 * via the virtual mapping.
436 */
437 efi_phys.set_virtual_address_map =
438 (efi_set_virtual_address_map_t *)
439 (unsigned long)runtime->set_virtual_address_map;
440 early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
441
442 return 0;
443 }
444
efi_runtime_init(void)445 static int __init efi_runtime_init(void)
446 {
447 int rv;
448
449 /*
450 * Check out the runtime services table. We need to map
451 * the runtime services table so that we can grab the physical
452 * address of several of the EFI runtime functions, needed to
453 * set the firmware into virtual mode.
454 *
455 * When EFI_PARAVIRT is in force then we could not map runtime
456 * service memory region because we do not have direct access to it.
457 * However, runtime services are available through proxy functions
458 * (e.g. in case of Xen dom0 EFI implementation they call special
459 * hypercall which executes relevant EFI functions) and that is why
460 * they are always enabled.
461 */
462
463 if (!efi_enabled(EFI_PARAVIRT)) {
464 if (efi_enabled(EFI_64BIT))
465 rv = efi_runtime_init64();
466 else
467 rv = efi_runtime_init32();
468
469 if (rv)
470 return rv;
471 }
472
473 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
474
475 return 0;
476 }
477
efi_init(void)478 void __init efi_init(void)
479 {
480 efi_char16_t *c16;
481 char vendor[100] = "unknown";
482 int i = 0;
483
484 #ifdef CONFIG_X86_32
485 if (boot_params.efi_info.efi_systab_hi ||
486 boot_params.efi_info.efi_memmap_hi) {
487 pr_info("Table located above 4GB, disabling EFI.\n");
488 return;
489 }
490 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
491 #else
492 efi_phys.systab = (efi_system_table_t *)
493 (boot_params.efi_info.efi_systab |
494 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
495 #endif
496
497 if (efi_systab_init(efi_phys.systab))
498 return;
499
500 efi.config_table = (unsigned long)efi.systab->tables;
501 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
502 efi.runtime = (unsigned long)efi.systab->runtime;
503
504 /*
505 * Show what we know for posterity
506 */
507 c16 = early_memremap_ro(efi.systab->fw_vendor,
508 sizeof(vendor) * sizeof(efi_char16_t));
509 if (c16) {
510 for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
511 vendor[i] = c16[i];
512 vendor[i] = '\0';
513 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
514 } else {
515 pr_err("Could not map the firmware vendor!\n");
516 }
517
518 pr_info("EFI v%u.%.02u by %s\n",
519 efi.systab->hdr.revision >> 16,
520 efi.systab->hdr.revision & 0xffff, vendor);
521
522 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
523 return;
524
525 if (efi_config_init(arch_tables))
526 return;
527
528 /*
529 * Note: We currently don't support runtime services on an EFI
530 * that doesn't match the kernel 32/64-bit mode.
531 */
532
533 if (!efi_runtime_supported())
534 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
535 else {
536 if (efi_runtime_disabled() || efi_runtime_init()) {
537 efi_memmap_unmap();
538 return;
539 }
540 }
541
542 efi_clean_memmap();
543
544 if (efi_enabled(EFI_DBG))
545 efi_print_memmap();
546 }
547
efi_set_executable(efi_memory_desc_t * md,bool executable)548 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
549 {
550 u64 addr, npages;
551
552 addr = md->virt_addr;
553 npages = md->num_pages;
554
555 memrange_efi_to_native(&addr, &npages);
556
557 if (executable)
558 set_memory_x(addr, npages);
559 else
560 set_memory_nx(addr, npages);
561 }
562
runtime_code_page_mkexec(void)563 void __init runtime_code_page_mkexec(void)
564 {
565 efi_memory_desc_t *md;
566
567 /* Make EFI runtime service code area executable */
568 for_each_efi_memory_desc(md) {
569 if (md->type != EFI_RUNTIME_SERVICES_CODE)
570 continue;
571
572 efi_set_executable(md, true);
573 }
574 }
575
efi_memory_uc(u64 addr,unsigned long size)576 void __init efi_memory_uc(u64 addr, unsigned long size)
577 {
578 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
579 u64 npages;
580
581 npages = round_up(size, page_shift) / page_shift;
582 memrange_efi_to_native(&addr, &npages);
583 set_memory_uc(addr, npages);
584 }
585
old_map_region(efi_memory_desc_t * md)586 void __init old_map_region(efi_memory_desc_t *md)
587 {
588 u64 start_pfn, end_pfn, end;
589 unsigned long size;
590 void *va;
591
592 start_pfn = PFN_DOWN(md->phys_addr);
593 size = md->num_pages << PAGE_SHIFT;
594 end = md->phys_addr + size;
595 end_pfn = PFN_UP(end);
596
597 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
598 va = __va(md->phys_addr);
599
600 if (!(md->attribute & EFI_MEMORY_WB))
601 efi_memory_uc((u64)(unsigned long)va, size);
602 } else
603 va = efi_ioremap(md->phys_addr, size,
604 md->type, md->attribute);
605
606 md->virt_addr = (u64) (unsigned long) va;
607 if (!va)
608 pr_err("ioremap of 0x%llX failed!\n",
609 (unsigned long long)md->phys_addr);
610 }
611
612 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)613 static void __init efi_merge_regions(void)
614 {
615 efi_memory_desc_t *md, *prev_md = NULL;
616
617 for_each_efi_memory_desc(md) {
618 u64 prev_size;
619
620 if (!prev_md) {
621 prev_md = md;
622 continue;
623 }
624
625 if (prev_md->type != md->type ||
626 prev_md->attribute != md->attribute) {
627 prev_md = md;
628 continue;
629 }
630
631 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
632
633 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
634 prev_md->num_pages += md->num_pages;
635 md->type = EFI_RESERVED_TYPE;
636 md->attribute = 0;
637 continue;
638 }
639 prev_md = md;
640 }
641 }
642
get_systab_virt_addr(efi_memory_desc_t * md)643 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
644 {
645 unsigned long size;
646 u64 end, systab;
647
648 size = md->num_pages << EFI_PAGE_SHIFT;
649 end = md->phys_addr + size;
650 systab = (u64)(unsigned long)efi_phys.systab;
651 if (md->phys_addr <= systab && systab < end) {
652 systab += md->virt_addr - md->phys_addr;
653 efi.systab = (efi_system_table_t *)(unsigned long)systab;
654 }
655 }
656
realloc_pages(void * old_memmap,int old_shift)657 static void *realloc_pages(void *old_memmap, int old_shift)
658 {
659 void *ret;
660
661 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
662 if (!ret)
663 goto out;
664
665 /*
666 * A first-time allocation doesn't have anything to copy.
667 */
668 if (!old_memmap)
669 return ret;
670
671 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
672
673 out:
674 free_pages((unsigned long)old_memmap, old_shift);
675 return ret;
676 }
677
678 /*
679 * Iterate the EFI memory map in reverse order because the regions
680 * will be mapped top-down. The end result is the same as if we had
681 * mapped things forward, but doesn't require us to change the
682 * existing implementation of efi_map_region().
683 */
efi_map_next_entry_reverse(void * entry)684 static inline void *efi_map_next_entry_reverse(void *entry)
685 {
686 /* Initial call */
687 if (!entry)
688 return efi.memmap.map_end - efi.memmap.desc_size;
689
690 entry -= efi.memmap.desc_size;
691 if (entry < efi.memmap.map)
692 return NULL;
693
694 return entry;
695 }
696
697 /*
698 * efi_map_next_entry - Return the next EFI memory map descriptor
699 * @entry: Previous EFI memory map descriptor
700 *
701 * This is a helper function to iterate over the EFI memory map, which
702 * we do in different orders depending on the current configuration.
703 *
704 * To begin traversing the memory map @entry must be %NULL.
705 *
706 * Returns %NULL when we reach the end of the memory map.
707 */
efi_map_next_entry(void * entry)708 static void *efi_map_next_entry(void *entry)
709 {
710 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
711 /*
712 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
713 * config table feature requires us to map all entries
714 * in the same order as they appear in the EFI memory
715 * map. That is to say, entry N must have a lower
716 * virtual address than entry N+1. This is because the
717 * firmware toolchain leaves relative references in
718 * the code/data sections, which are split and become
719 * separate EFI memory regions. Mapping things
720 * out-of-order leads to the firmware accessing
721 * unmapped addresses.
722 *
723 * Since we need to map things this way whether or not
724 * the kernel actually makes use of
725 * EFI_PROPERTIES_TABLE, let's just switch to this
726 * scheme by default for 64-bit.
727 */
728 return efi_map_next_entry_reverse(entry);
729 }
730
731 /* Initial call */
732 if (!entry)
733 return efi.memmap.map;
734
735 entry += efi.memmap.desc_size;
736 if (entry >= efi.memmap.map_end)
737 return NULL;
738
739 return entry;
740 }
741
should_map_region(efi_memory_desc_t * md)742 static bool should_map_region(efi_memory_desc_t *md)
743 {
744 /*
745 * Runtime regions always require runtime mappings (obviously).
746 */
747 if (md->attribute & EFI_MEMORY_RUNTIME)
748 return true;
749
750 /*
751 * 32-bit EFI doesn't suffer from the bug that requires us to
752 * reserve boot services regions, and mixed mode support
753 * doesn't exist for 32-bit kernels.
754 */
755 if (IS_ENABLED(CONFIG_X86_32))
756 return false;
757
758 /*
759 * Map all of RAM so that we can access arguments in the 1:1
760 * mapping when making EFI runtime calls.
761 */
762 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
763 if (md->type == EFI_CONVENTIONAL_MEMORY ||
764 md->type == EFI_LOADER_DATA ||
765 md->type == EFI_LOADER_CODE)
766 return true;
767 }
768
769 /*
770 * Map boot services regions as a workaround for buggy
771 * firmware that accesses them even when they shouldn't.
772 *
773 * See efi_{reserve,free}_boot_services().
774 */
775 if (md->type == EFI_BOOT_SERVICES_CODE ||
776 md->type == EFI_BOOT_SERVICES_DATA)
777 return true;
778
779 return false;
780 }
781
782 /*
783 * Map the efi memory ranges of the runtime services and update new_mmap with
784 * virtual addresses.
785 */
efi_map_regions(int * count,int * pg_shift)786 static void * __init efi_map_regions(int *count, int *pg_shift)
787 {
788 void *p, *new_memmap = NULL;
789 unsigned long left = 0;
790 unsigned long desc_size;
791 efi_memory_desc_t *md;
792
793 desc_size = efi.memmap.desc_size;
794
795 p = NULL;
796 while ((p = efi_map_next_entry(p))) {
797 md = p;
798
799 if (!should_map_region(md))
800 continue;
801
802 efi_map_region(md);
803 get_systab_virt_addr(md);
804
805 if (left < desc_size) {
806 new_memmap = realloc_pages(new_memmap, *pg_shift);
807 if (!new_memmap)
808 return NULL;
809
810 left += PAGE_SIZE << *pg_shift;
811 (*pg_shift)++;
812 }
813
814 memcpy(new_memmap + (*count * desc_size), md, desc_size);
815
816 left -= desc_size;
817 (*count)++;
818 }
819
820 return new_memmap;
821 }
822
kexec_enter_virtual_mode(void)823 static void __init kexec_enter_virtual_mode(void)
824 {
825 #ifdef CONFIG_KEXEC_CORE
826 efi_memory_desc_t *md;
827 unsigned int num_pages;
828
829 efi.systab = NULL;
830
831 /*
832 * We don't do virtual mode, since we don't do runtime services, on
833 * non-native EFI. With efi=old_map, we don't do runtime services in
834 * kexec kernel because in the initial boot something else might
835 * have been mapped at these virtual addresses.
836 */
837 if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
838 efi_memmap_unmap();
839 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
840 return;
841 }
842
843 if (efi_alloc_page_tables()) {
844 pr_err("Failed to allocate EFI page tables\n");
845 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
846 return;
847 }
848
849 /*
850 * Map efi regions which were passed via setup_data. The virt_addr is a
851 * fixed addr which was used in first kernel of a kexec boot.
852 */
853 for_each_efi_memory_desc(md) {
854 efi_map_region_fixed(md); /* FIXME: add error handling */
855 get_systab_virt_addr(md);
856 }
857
858 /*
859 * Unregister the early EFI memmap from efi_init() and install
860 * the new EFI memory map.
861 */
862 efi_memmap_unmap();
863
864 if (efi_memmap_init_late(efi.memmap.phys_map,
865 efi.memmap.desc_size * efi.memmap.nr_map)) {
866 pr_err("Failed to remap late EFI memory map\n");
867 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
868 return;
869 }
870
871 BUG_ON(!efi.systab);
872
873 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
874 num_pages >>= PAGE_SHIFT;
875
876 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
877 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
878 return;
879 }
880
881 efi_sync_low_kernel_mappings();
882
883 /*
884 * Now that EFI is in virtual mode, update the function
885 * pointers in the runtime service table to the new virtual addresses.
886 *
887 * Call EFI services through wrapper functions.
888 */
889 efi.runtime_version = efi_systab.hdr.revision;
890
891 efi_native_runtime_setup();
892
893 efi.set_virtual_address_map = NULL;
894
895 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
896 runtime_code_page_mkexec();
897 #endif
898 }
899
900 /*
901 * This function will switch the EFI runtime services to virtual mode.
902 * Essentially, we look through the EFI memmap and map every region that
903 * has the runtime attribute bit set in its memory descriptor into the
904 * efi_pgd page table.
905 *
906 * The old method which used to update that memory descriptor with the
907 * virtual address obtained from ioremap() is still supported when the
908 * kernel is booted with efi=old_map on its command line. Same old
909 * method enabled the runtime services to be called without having to
910 * thunk back into physical mode for every invocation.
911 *
912 * The new method does a pagetable switch in a preemption-safe manner
913 * so that we're in a different address space when calling a runtime
914 * function. For function arguments passing we do copy the PUDs of the
915 * kernel page table into efi_pgd prior to each call.
916 *
917 * Specially for kexec boot, efi runtime maps in previous kernel should
918 * be passed in via setup_data. In that case runtime ranges will be mapped
919 * to the same virtual addresses as the first kernel, see
920 * kexec_enter_virtual_mode().
921 */
__efi_enter_virtual_mode(void)922 static void __init __efi_enter_virtual_mode(void)
923 {
924 int count = 0, pg_shift = 0;
925 void *new_memmap = NULL;
926 efi_status_t status;
927 unsigned long pa;
928
929 efi.systab = NULL;
930
931 if (efi_alloc_page_tables()) {
932 pr_err("Failed to allocate EFI page tables\n");
933 goto err;
934 }
935
936 efi_merge_regions();
937 new_memmap = efi_map_regions(&count, &pg_shift);
938 if (!new_memmap) {
939 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
940 goto err;
941 }
942
943 pa = __pa(new_memmap);
944
945 /*
946 * Unregister the early EFI memmap from efi_init() and install
947 * the new EFI memory map that we are about to pass to the
948 * firmware via SetVirtualAddressMap().
949 */
950 efi_memmap_unmap();
951
952 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
953 pr_err("Failed to remap late EFI memory map\n");
954 goto err;
955 }
956
957 if (efi_enabled(EFI_DBG)) {
958 pr_info("EFI runtime memory map:\n");
959 efi_print_memmap();
960 }
961
962 if (WARN_ON(!efi.systab))
963 goto err;
964
965 if (efi_setup_page_tables(pa, 1 << pg_shift))
966 goto err;
967
968 efi_sync_low_kernel_mappings();
969
970 if (efi_is_native()) {
971 status = phys_efi_set_virtual_address_map(
972 efi.memmap.desc_size * count,
973 efi.memmap.desc_size,
974 efi.memmap.desc_version,
975 (efi_memory_desc_t *)pa);
976 } else {
977 status = efi_thunk_set_virtual_address_map(
978 efi_phys.set_virtual_address_map,
979 efi.memmap.desc_size * count,
980 efi.memmap.desc_size,
981 efi.memmap.desc_version,
982 (efi_memory_desc_t *)pa);
983 }
984
985 if (status != EFI_SUCCESS) {
986 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n",
987 status);
988 goto err;
989 }
990
991 /*
992 * Now that EFI is in virtual mode, update the function
993 * pointers in the runtime service table to the new virtual addresses.
994 *
995 * Call EFI services through wrapper functions.
996 */
997 efi.runtime_version = efi_systab.hdr.revision;
998
999 if (efi_is_native())
1000 efi_native_runtime_setup();
1001 else
1002 efi_thunk_runtime_setup();
1003
1004 efi.set_virtual_address_map = NULL;
1005
1006 /*
1007 * Apply more restrictive page table mapping attributes now that
1008 * SVAM() has been called and the firmware has performed all
1009 * necessary relocation fixups for the new virtual addresses.
1010 */
1011 efi_runtime_update_mappings();
1012
1013 /* clean DUMMY object */
1014 efi_delete_dummy_variable();
1015 return;
1016
1017 err:
1018 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
1019 }
1020
efi_enter_virtual_mode(void)1021 void __init efi_enter_virtual_mode(void)
1022 {
1023 if (efi_enabled(EFI_PARAVIRT))
1024 return;
1025
1026 if (efi_setup)
1027 kexec_enter_virtual_mode();
1028 else
1029 __efi_enter_virtual_mode();
1030
1031 efi_dump_pagetable();
1032 }
1033
arch_parse_efi_cmdline(char * str)1034 static int __init arch_parse_efi_cmdline(char *str)
1035 {
1036 if (!str) {
1037 pr_warn("need at least one option\n");
1038 return -EINVAL;
1039 }
1040
1041 if (parse_option_str(str, "old_map"))
1042 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1043
1044 return 0;
1045 }
1046 early_param("efi", arch_parse_efi_cmdline);
1047