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/memblock.h>
40 #include <linux/slab.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/e820/api.h>
51 #include <asm/time.h>
52 #include <asm/set_memory.h>
53 #include <asm/tlbflush.h>
54 #include <asm/x86_init.h>
55 #include <asm/uv/uv.h>
56
57 static struct efi efi_phys __initdata;
58 static efi_system_table_t efi_systab __initdata;
59
60 static efi_config_table_type_t arch_tables[] __initdata = {
61 #ifdef CONFIG_X86_UV
62 {UV_SYSTEM_TABLE_GUID, "UVsystab", &uv_systab_phys},
63 #endif
64 {NULL_GUID, NULL, NULL},
65 };
66
67 static const unsigned long * const efi_tables[] = {
68 &efi.mps,
69 &efi.acpi,
70 &efi.acpi20,
71 &efi.smbios,
72 &efi.smbios3,
73 &efi.boot_info,
74 &efi.hcdp,
75 &efi.uga,
76 #ifdef CONFIG_X86_UV
77 &uv_systab_phys,
78 #endif
79 &efi.fw_vendor,
80 &efi.runtime,
81 &efi.config_table,
82 &efi.esrt,
83 &efi.properties_table,
84 &efi.mem_attr_table,
85 #ifdef CONFIG_EFI_RCI2_TABLE
86 &rci2_table_phys,
87 #endif
88 };
89
90 u64 efi_setup; /* efi setup_data physical address */
91
92 static int add_efi_memmap __initdata;
setup_add_efi_memmap(char * arg)93 static int __init setup_add_efi_memmap(char *arg)
94 {
95 add_efi_memmap = 1;
96 return 0;
97 }
98 early_param("add_efi_memmap", setup_add_efi_memmap);
99
phys_efi_set_virtual_address_map(unsigned long memory_map_size,unsigned long descriptor_size,u32 descriptor_version,efi_memory_desc_t * virtual_map)100 static efi_status_t __init phys_efi_set_virtual_address_map(
101 unsigned long memory_map_size,
102 unsigned long descriptor_size,
103 u32 descriptor_version,
104 efi_memory_desc_t *virtual_map)
105 {
106 efi_status_t status;
107 unsigned long flags;
108 pgd_t *save_pgd;
109
110 save_pgd = efi_call_phys_prolog();
111 if (!save_pgd)
112 return EFI_ABORTED;
113
114 /* Disable interrupts around EFI calls: */
115 local_irq_save(flags);
116 status = efi_call_phys(efi_phys.set_virtual_address_map,
117 memory_map_size, descriptor_size,
118 descriptor_version, virtual_map);
119 local_irq_restore(flags);
120
121 efi_call_phys_epilog(save_pgd);
122
123 return status;
124 }
125
efi_find_mirror(void)126 void __init efi_find_mirror(void)
127 {
128 efi_memory_desc_t *md;
129 u64 mirror_size = 0, total_size = 0;
130
131 for_each_efi_memory_desc(md) {
132 unsigned long long start = md->phys_addr;
133 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
134
135 total_size += size;
136 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
137 memblock_mark_mirror(start, size);
138 mirror_size += size;
139 }
140 }
141 if (mirror_size)
142 pr_info("Memory: %lldM/%lldM mirrored memory\n",
143 mirror_size>>20, total_size>>20);
144 }
145
146 /*
147 * Tell the kernel about the EFI memory map. This might include
148 * more than the max 128 entries that can fit in the e820 legacy
149 * (zeropage) memory map.
150 */
151
do_add_efi_memmap(void)152 static void __init do_add_efi_memmap(void)
153 {
154 efi_memory_desc_t *md;
155
156 for_each_efi_memory_desc(md) {
157 unsigned long long start = md->phys_addr;
158 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
159 int e820_type;
160
161 switch (md->type) {
162 case EFI_LOADER_CODE:
163 case EFI_LOADER_DATA:
164 case EFI_BOOT_SERVICES_CODE:
165 case EFI_BOOT_SERVICES_DATA:
166 case EFI_CONVENTIONAL_MEMORY:
167 if (md->attribute & EFI_MEMORY_WB)
168 e820_type = E820_TYPE_RAM;
169 else
170 e820_type = E820_TYPE_RESERVED;
171 break;
172 case EFI_ACPI_RECLAIM_MEMORY:
173 e820_type = E820_TYPE_ACPI;
174 break;
175 case EFI_ACPI_MEMORY_NVS:
176 e820_type = E820_TYPE_NVS;
177 break;
178 case EFI_UNUSABLE_MEMORY:
179 e820_type = E820_TYPE_UNUSABLE;
180 break;
181 case EFI_PERSISTENT_MEMORY:
182 e820_type = E820_TYPE_PMEM;
183 break;
184 default:
185 /*
186 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
187 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
188 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
189 */
190 e820_type = E820_TYPE_RESERVED;
191 break;
192 }
193 e820__range_add(start, size, e820_type);
194 }
195 e820__update_table(e820_table);
196 }
197
efi_memblock_x86_reserve_range(void)198 int __init efi_memblock_x86_reserve_range(void)
199 {
200 struct efi_info *e = &boot_params.efi_info;
201 struct efi_memory_map_data data;
202 phys_addr_t pmap;
203 int rv;
204
205 if (efi_enabled(EFI_PARAVIRT))
206 return 0;
207
208 #ifdef CONFIG_X86_32
209 /* Can't handle data above 4GB at this time */
210 if (e->efi_memmap_hi) {
211 pr_err("Memory map is above 4GB, disabling EFI.\n");
212 return -EINVAL;
213 }
214 pmap = e->efi_memmap;
215 #else
216 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
217 #endif
218 data.phys_map = pmap;
219 data.size = e->efi_memmap_size;
220 data.desc_size = e->efi_memdesc_size;
221 data.desc_version = e->efi_memdesc_version;
222
223 rv = efi_memmap_init_early(&data);
224 if (rv)
225 return rv;
226
227 if (add_efi_memmap)
228 do_add_efi_memmap();
229
230 WARN(efi.memmap.desc_version != 1,
231 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
232 efi.memmap.desc_version);
233
234 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
235
236 return 0;
237 }
238
239 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
240 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
241 #define U64_HIGH_BIT (~(U64_MAX >> 1))
242
efi_memmap_entry_valid(const efi_memory_desc_t * md,int i)243 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
244 {
245 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
246 u64 end_hi = 0;
247 char buf[64];
248
249 if (md->num_pages == 0) {
250 end = 0;
251 } else if (md->num_pages > EFI_PAGES_MAX ||
252 EFI_PAGES_MAX - md->num_pages <
253 (md->phys_addr >> EFI_PAGE_SHIFT)) {
254 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
255 >> OVERFLOW_ADDR_SHIFT;
256
257 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
258 end_hi += 1;
259 } else {
260 return true;
261 }
262
263 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
264
265 if (end_hi) {
266 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
267 i, efi_md_typeattr_format(buf, sizeof(buf), md),
268 md->phys_addr, end_hi, end);
269 } else {
270 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
271 i, efi_md_typeattr_format(buf, sizeof(buf), md),
272 md->phys_addr, end);
273 }
274 return false;
275 }
276
efi_clean_memmap(void)277 static void __init efi_clean_memmap(void)
278 {
279 efi_memory_desc_t *out = efi.memmap.map;
280 const efi_memory_desc_t *in = out;
281 const efi_memory_desc_t *end = efi.memmap.map_end;
282 int i, n_removal;
283
284 for (i = n_removal = 0; in < end; i++) {
285 if (efi_memmap_entry_valid(in, i)) {
286 if (out != in)
287 memcpy(out, in, efi.memmap.desc_size);
288 out = (void *)out + efi.memmap.desc_size;
289 } else {
290 n_removal++;
291 }
292 in = (void *)in + efi.memmap.desc_size;
293 }
294
295 if (n_removal > 0) {
296 u64 size = efi.memmap.nr_map - n_removal;
297
298 pr_warn("Removing %d invalid memory map entries.\n", n_removal);
299 efi_memmap_install(efi.memmap.phys_map, size);
300 }
301 }
302
efi_print_memmap(void)303 void __init efi_print_memmap(void)
304 {
305 efi_memory_desc_t *md;
306 int i = 0;
307
308 for_each_efi_memory_desc(md) {
309 char buf[64];
310
311 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
312 i++, efi_md_typeattr_format(buf, sizeof(buf), md),
313 md->phys_addr,
314 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
315 (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
316 }
317 }
318
efi_systab_init(void * phys)319 static int __init efi_systab_init(void *phys)
320 {
321 if (efi_enabled(EFI_64BIT)) {
322 efi_system_table_64_t *systab64;
323 struct efi_setup_data *data = NULL;
324 u64 tmp = 0;
325
326 if (efi_setup) {
327 data = early_memremap(efi_setup, sizeof(*data));
328 if (!data)
329 return -ENOMEM;
330 }
331 systab64 = early_memremap((unsigned long)phys,
332 sizeof(*systab64));
333 if (systab64 == NULL) {
334 pr_err("Couldn't map the system table!\n");
335 if (data)
336 early_memunmap(data, sizeof(*data));
337 return -ENOMEM;
338 }
339
340 efi_systab.hdr = systab64->hdr;
341 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
342 systab64->fw_vendor;
343 tmp |= data ? data->fw_vendor : systab64->fw_vendor;
344 efi_systab.fw_revision = systab64->fw_revision;
345 efi_systab.con_in_handle = systab64->con_in_handle;
346 tmp |= systab64->con_in_handle;
347 efi_systab.con_in = systab64->con_in;
348 tmp |= systab64->con_in;
349 efi_systab.con_out_handle = systab64->con_out_handle;
350 tmp |= systab64->con_out_handle;
351 efi_systab.con_out = systab64->con_out;
352 tmp |= systab64->con_out;
353 efi_systab.stderr_handle = systab64->stderr_handle;
354 tmp |= systab64->stderr_handle;
355 efi_systab.stderr = systab64->stderr;
356 tmp |= systab64->stderr;
357 efi_systab.runtime = data ?
358 (void *)(unsigned long)data->runtime :
359 (void *)(unsigned long)systab64->runtime;
360 tmp |= data ? data->runtime : systab64->runtime;
361 efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
362 tmp |= systab64->boottime;
363 efi_systab.nr_tables = systab64->nr_tables;
364 efi_systab.tables = data ? (unsigned long)data->tables :
365 systab64->tables;
366 tmp |= data ? data->tables : systab64->tables;
367
368 early_memunmap(systab64, sizeof(*systab64));
369 if (data)
370 early_memunmap(data, sizeof(*data));
371 #ifdef CONFIG_X86_32
372 if (tmp >> 32) {
373 pr_err("EFI data located above 4GB, disabling EFI.\n");
374 return -EINVAL;
375 }
376 #endif
377 } else {
378 efi_system_table_32_t *systab32;
379
380 systab32 = early_memremap((unsigned long)phys,
381 sizeof(*systab32));
382 if (systab32 == NULL) {
383 pr_err("Couldn't map the system table!\n");
384 return -ENOMEM;
385 }
386
387 efi_systab.hdr = systab32->hdr;
388 efi_systab.fw_vendor = systab32->fw_vendor;
389 efi_systab.fw_revision = systab32->fw_revision;
390 efi_systab.con_in_handle = systab32->con_in_handle;
391 efi_systab.con_in = systab32->con_in;
392 efi_systab.con_out_handle = systab32->con_out_handle;
393 efi_systab.con_out = systab32->con_out;
394 efi_systab.stderr_handle = systab32->stderr_handle;
395 efi_systab.stderr = systab32->stderr;
396 efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
397 efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
398 efi_systab.nr_tables = systab32->nr_tables;
399 efi_systab.tables = systab32->tables;
400
401 early_memunmap(systab32, sizeof(*systab32));
402 }
403
404 efi.systab = &efi_systab;
405
406 /*
407 * Verify the EFI Table
408 */
409 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
410 pr_err("System table signature incorrect!\n");
411 return -EINVAL;
412 }
413 if ((efi.systab->hdr.revision >> 16) == 0)
414 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
415 efi.systab->hdr.revision >> 16,
416 efi.systab->hdr.revision & 0xffff);
417
418 return 0;
419 }
420
efi_runtime_init32(void)421 static int __init efi_runtime_init32(void)
422 {
423 efi_runtime_services_32_t *runtime;
424
425 runtime = early_memremap((unsigned long)efi.systab->runtime,
426 sizeof(efi_runtime_services_32_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_32_t));
441
442 return 0;
443 }
444
efi_runtime_init64(void)445 static int __init efi_runtime_init64(void)
446 {
447 efi_runtime_services_64_t *runtime;
448
449 runtime = early_memremap((unsigned long)efi.systab->runtime,
450 sizeof(efi_runtime_services_64_t));
451 if (!runtime) {
452 pr_err("Could not map the runtime service table!\n");
453 return -ENOMEM;
454 }
455
456 /*
457 * We will only need *early* access to the SetVirtualAddressMap
458 * EFI runtime service. All other runtime services will be called
459 * via the virtual mapping.
460 */
461 efi_phys.set_virtual_address_map =
462 (efi_set_virtual_address_map_t *)
463 (unsigned long)runtime->set_virtual_address_map;
464 early_memunmap(runtime, sizeof(efi_runtime_services_64_t));
465
466 return 0;
467 }
468
efi_runtime_init(void)469 static int __init efi_runtime_init(void)
470 {
471 int rv;
472
473 /*
474 * Check out the runtime services table. We need to map
475 * the runtime services table so that we can grab the physical
476 * address of several of the EFI runtime functions, needed to
477 * set the firmware into virtual mode.
478 *
479 * When EFI_PARAVIRT is in force then we could not map runtime
480 * service memory region because we do not have direct access to it.
481 * However, runtime services are available through proxy functions
482 * (e.g. in case of Xen dom0 EFI implementation they call special
483 * hypercall which executes relevant EFI functions) and that is why
484 * they are always enabled.
485 */
486
487 if (!efi_enabled(EFI_PARAVIRT)) {
488 if (efi_enabled(EFI_64BIT))
489 rv = efi_runtime_init64();
490 else
491 rv = efi_runtime_init32();
492
493 if (rv)
494 return rv;
495 }
496
497 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
498
499 return 0;
500 }
501
efi_init(void)502 void __init efi_init(void)
503 {
504 efi_char16_t *c16;
505 char vendor[100] = "unknown";
506 int i = 0;
507 void *tmp;
508
509 #ifdef CONFIG_X86_32
510 if (boot_params.efi_info.efi_systab_hi ||
511 boot_params.efi_info.efi_memmap_hi) {
512 pr_info("Table located above 4GB, disabling EFI.\n");
513 return;
514 }
515 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
516 #else
517 efi_phys.systab = (efi_system_table_t *)
518 (boot_params.efi_info.efi_systab |
519 ((__u64)boot_params.efi_info.efi_systab_hi<<32));
520 #endif
521
522 if (efi_systab_init(efi_phys.systab))
523 return;
524
525 efi.config_table = (unsigned long)efi.systab->tables;
526 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
527 efi.runtime = (unsigned long)efi.systab->runtime;
528
529 /*
530 * Show what we know for posterity
531 */
532 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2);
533 if (c16) {
534 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
535 vendor[i] = *c16++;
536 vendor[i] = '\0';
537 } else
538 pr_err("Could not map the firmware vendor!\n");
539 early_memunmap(tmp, 2);
540
541 pr_info("EFI v%u.%.02u by %s\n",
542 efi.systab->hdr.revision >> 16,
543 efi.systab->hdr.revision & 0xffff, vendor);
544
545 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
546 return;
547
548 if (efi_config_init(arch_tables))
549 return;
550
551 /*
552 * Note: We currently don't support runtime services on an EFI
553 * that doesn't match the kernel 32/64-bit mode.
554 */
555
556 if (!efi_runtime_supported())
557 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
558 else {
559 if (efi_runtime_disabled() || efi_runtime_init()) {
560 efi_memmap_unmap();
561 return;
562 }
563 }
564
565 efi_clean_memmap();
566
567 if (efi_enabled(EFI_DBG))
568 efi_print_memmap();
569 }
570
efi_set_executable(efi_memory_desc_t * md,bool executable)571 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
572 {
573 u64 addr, npages;
574
575 addr = md->virt_addr;
576 npages = md->num_pages;
577
578 memrange_efi_to_native(&addr, &npages);
579
580 if (executable)
581 set_memory_x(addr, npages);
582 else
583 set_memory_nx(addr, npages);
584 }
585
runtime_code_page_mkexec(void)586 void __init runtime_code_page_mkexec(void)
587 {
588 efi_memory_desc_t *md;
589
590 /* Make EFI runtime service code area executable */
591 for_each_efi_memory_desc(md) {
592 if (md->type != EFI_RUNTIME_SERVICES_CODE)
593 continue;
594
595 efi_set_executable(md, true);
596 }
597 }
598
efi_memory_uc(u64 addr,unsigned long size)599 void __init efi_memory_uc(u64 addr, unsigned long size)
600 {
601 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
602 u64 npages;
603
604 npages = round_up(size, page_shift) / page_shift;
605 memrange_efi_to_native(&addr, &npages);
606 set_memory_uc(addr, npages);
607 }
608
old_map_region(efi_memory_desc_t * md)609 void __init old_map_region(efi_memory_desc_t *md)
610 {
611 u64 start_pfn, end_pfn, end;
612 unsigned long size;
613 void *va;
614
615 start_pfn = PFN_DOWN(md->phys_addr);
616 size = md->num_pages << PAGE_SHIFT;
617 end = md->phys_addr + size;
618 end_pfn = PFN_UP(end);
619
620 if (pfn_range_is_mapped(start_pfn, end_pfn)) {
621 va = __va(md->phys_addr);
622
623 if (!(md->attribute & EFI_MEMORY_WB))
624 efi_memory_uc((u64)(unsigned long)va, size);
625 } else
626 va = efi_ioremap(md->phys_addr, size,
627 md->type, md->attribute);
628
629 md->virt_addr = (u64) (unsigned long) va;
630 if (!va)
631 pr_err("ioremap of 0x%llX failed!\n",
632 (unsigned long long)md->phys_addr);
633 }
634
635 /* Merge contiguous regions of the same type and attribute */
efi_merge_regions(void)636 static void __init efi_merge_regions(void)
637 {
638 efi_memory_desc_t *md, *prev_md = NULL;
639
640 for_each_efi_memory_desc(md) {
641 u64 prev_size;
642
643 if (!prev_md) {
644 prev_md = md;
645 continue;
646 }
647
648 if (prev_md->type != md->type ||
649 prev_md->attribute != md->attribute) {
650 prev_md = md;
651 continue;
652 }
653
654 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
655
656 if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
657 prev_md->num_pages += md->num_pages;
658 md->type = EFI_RESERVED_TYPE;
659 md->attribute = 0;
660 continue;
661 }
662 prev_md = md;
663 }
664 }
665
get_systab_virt_addr(efi_memory_desc_t * md)666 static void __init get_systab_virt_addr(efi_memory_desc_t *md)
667 {
668 unsigned long size;
669 u64 end, systab;
670
671 size = md->num_pages << EFI_PAGE_SHIFT;
672 end = md->phys_addr + size;
673 systab = (u64)(unsigned long)efi_phys.systab;
674 if (md->phys_addr <= systab && systab < end) {
675 systab += md->virt_addr - md->phys_addr;
676 efi.systab = (efi_system_table_t *)(unsigned long)systab;
677 }
678 }
679
realloc_pages(void * old_memmap,int old_shift)680 static void *realloc_pages(void *old_memmap, int old_shift)
681 {
682 void *ret;
683
684 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
685 if (!ret)
686 goto out;
687
688 /*
689 * A first-time allocation doesn't have anything to copy.
690 */
691 if (!old_memmap)
692 return ret;
693
694 memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
695
696 out:
697 free_pages((unsigned long)old_memmap, old_shift);
698 return ret;
699 }
700
701 /*
702 * Iterate the EFI memory map in reverse order because the regions
703 * will be mapped top-down. The end result is the same as if we had
704 * mapped things forward, but doesn't require us to change the
705 * existing implementation of efi_map_region().
706 */
efi_map_next_entry_reverse(void * entry)707 static inline void *efi_map_next_entry_reverse(void *entry)
708 {
709 /* Initial call */
710 if (!entry)
711 return efi.memmap.map_end - efi.memmap.desc_size;
712
713 entry -= efi.memmap.desc_size;
714 if (entry < efi.memmap.map)
715 return NULL;
716
717 return entry;
718 }
719
720 /*
721 * efi_map_next_entry - Return the next EFI memory map descriptor
722 * @entry: Previous EFI memory map descriptor
723 *
724 * This is a helper function to iterate over the EFI memory map, which
725 * we do in different orders depending on the current configuration.
726 *
727 * To begin traversing the memory map @entry must be %NULL.
728 *
729 * Returns %NULL when we reach the end of the memory map.
730 */
efi_map_next_entry(void * entry)731 static void *efi_map_next_entry(void *entry)
732 {
733 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
734 /*
735 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
736 * config table feature requires us to map all entries
737 * in the same order as they appear in the EFI memory
738 * map. That is to say, entry N must have a lower
739 * virtual address than entry N+1. This is because the
740 * firmware toolchain leaves relative references in
741 * the code/data sections, which are split and become
742 * separate EFI memory regions. Mapping things
743 * out-of-order leads to the firmware accessing
744 * unmapped addresses.
745 *
746 * Since we need to map things this way whether or not
747 * the kernel actually makes use of
748 * EFI_PROPERTIES_TABLE, let's just switch to this
749 * scheme by default for 64-bit.
750 */
751 return efi_map_next_entry_reverse(entry);
752 }
753
754 /* Initial call */
755 if (!entry)
756 return efi.memmap.map;
757
758 entry += efi.memmap.desc_size;
759 if (entry >= efi.memmap.map_end)
760 return NULL;
761
762 return entry;
763 }
764
should_map_region(efi_memory_desc_t * md)765 static bool should_map_region(efi_memory_desc_t *md)
766 {
767 /*
768 * Runtime regions always require runtime mappings (obviously).
769 */
770 if (md->attribute & EFI_MEMORY_RUNTIME)
771 return true;
772
773 /*
774 * 32-bit EFI doesn't suffer from the bug that requires us to
775 * reserve boot services regions, and mixed mode support
776 * doesn't exist for 32-bit kernels.
777 */
778 if (IS_ENABLED(CONFIG_X86_32))
779 return false;
780
781 /*
782 * Map all of RAM so that we can access arguments in the 1:1
783 * mapping when making EFI runtime calls.
784 */
785 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
786 if (md->type == EFI_CONVENTIONAL_MEMORY ||
787 md->type == EFI_LOADER_DATA ||
788 md->type == EFI_LOADER_CODE)
789 return true;
790 }
791
792 /*
793 * Map boot services regions as a workaround for buggy
794 * firmware that accesses them even when they shouldn't.
795 *
796 * See efi_{reserve,free}_boot_services().
797 */
798 if (md->type == EFI_BOOT_SERVICES_CODE ||
799 md->type == EFI_BOOT_SERVICES_DATA)
800 return true;
801
802 return false;
803 }
804
805 /*
806 * Map the efi memory ranges of the runtime services and update new_mmap with
807 * virtual addresses.
808 */
efi_map_regions(int * count,int * pg_shift)809 static void * __init efi_map_regions(int *count, int *pg_shift)
810 {
811 void *p, *new_memmap = NULL;
812 unsigned long left = 0;
813 unsigned long desc_size;
814 efi_memory_desc_t *md;
815
816 desc_size = efi.memmap.desc_size;
817
818 p = NULL;
819 while ((p = efi_map_next_entry(p))) {
820 md = p;
821
822 if (!should_map_region(md))
823 continue;
824
825 efi_map_region(md);
826 get_systab_virt_addr(md);
827
828 if (left < desc_size) {
829 new_memmap = realloc_pages(new_memmap, *pg_shift);
830 if (!new_memmap)
831 return NULL;
832
833 left += PAGE_SIZE << *pg_shift;
834 (*pg_shift)++;
835 }
836
837 memcpy(new_memmap + (*count * desc_size), md, desc_size);
838
839 left -= desc_size;
840 (*count)++;
841 }
842
843 return new_memmap;
844 }
845
kexec_enter_virtual_mode(void)846 static void __init kexec_enter_virtual_mode(void)
847 {
848 #ifdef CONFIG_KEXEC_CORE
849 efi_memory_desc_t *md;
850 unsigned int num_pages;
851
852 efi.systab = NULL;
853
854 /*
855 * We don't do virtual mode, since we don't do runtime services, on
856 * non-native EFI. With efi=old_map, we don't do runtime services in
857 * kexec kernel because in the initial boot something else might
858 * have been mapped at these virtual addresses.
859 */
860 if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
861 efi_memmap_unmap();
862 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
863 return;
864 }
865
866 if (efi_alloc_page_tables()) {
867 pr_err("Failed to allocate EFI page tables\n");
868 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
869 return;
870 }
871
872 /*
873 * Map efi regions which were passed via setup_data. The virt_addr is a
874 * fixed addr which was used in first kernel of a kexec boot.
875 */
876 for_each_efi_memory_desc(md) {
877 efi_map_region_fixed(md); /* FIXME: add error handling */
878 get_systab_virt_addr(md);
879 }
880
881 /*
882 * Unregister the early EFI memmap from efi_init() and install
883 * the new EFI memory map.
884 */
885 efi_memmap_unmap();
886
887 if (efi_memmap_init_late(efi.memmap.phys_map,
888 efi.memmap.desc_size * efi.memmap.nr_map)) {
889 pr_err("Failed to remap late EFI memory map\n");
890 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
891 return;
892 }
893
894 BUG_ON(!efi.systab);
895
896 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
897 num_pages >>= PAGE_SHIFT;
898
899 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
900 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
901 return;
902 }
903
904 efi_sync_low_kernel_mappings();
905
906 /*
907 * Now that EFI is in virtual mode, update the function
908 * pointers in the runtime service table to the new virtual addresses.
909 *
910 * Call EFI services through wrapper functions.
911 */
912 efi.runtime_version = efi_systab.hdr.revision;
913
914 efi_native_runtime_setup();
915
916 efi.set_virtual_address_map = NULL;
917
918 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
919 runtime_code_page_mkexec();
920 #endif
921 }
922
923 /*
924 * This function will switch the EFI runtime services to virtual mode.
925 * Essentially, we look through the EFI memmap and map every region that
926 * has the runtime attribute bit set in its memory descriptor into the
927 * efi_pgd page table.
928 *
929 * The old method which used to update that memory descriptor with the
930 * virtual address obtained from ioremap() is still supported when the
931 * kernel is booted with efi=old_map on its command line. Same old
932 * method enabled the runtime services to be called without having to
933 * thunk back into physical mode for every invocation.
934 *
935 * The new method does a pagetable switch in a preemption-safe manner
936 * so that we're in a different address space when calling a runtime
937 * function. For function arguments passing we do copy the PUDs of the
938 * kernel page table into efi_pgd prior to each call.
939 *
940 * Specially for kexec boot, efi runtime maps in previous kernel should
941 * be passed in via setup_data. In that case runtime ranges will be mapped
942 * to the same virtual addresses as the first kernel, see
943 * kexec_enter_virtual_mode().
944 */
__efi_enter_virtual_mode(void)945 static void __init __efi_enter_virtual_mode(void)
946 {
947 int count = 0, pg_shift = 0;
948 void *new_memmap = NULL;
949 efi_status_t status;
950 unsigned long pa;
951
952 efi.systab = NULL;
953
954 if (efi_alloc_page_tables()) {
955 pr_err("Failed to allocate EFI page tables\n");
956 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
957 return;
958 }
959
960 efi_merge_regions();
961 new_memmap = efi_map_regions(&count, &pg_shift);
962 if (!new_memmap) {
963 pr_err("Error reallocating memory, EFI runtime non-functional!\n");
964 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
965 return;
966 }
967
968 pa = __pa(new_memmap);
969
970 /*
971 * Unregister the early EFI memmap from efi_init() and install
972 * the new EFI memory map that we are about to pass to the
973 * firmware via SetVirtualAddressMap().
974 */
975 efi_memmap_unmap();
976
977 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
978 pr_err("Failed to remap late EFI memory map\n");
979 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
980 return;
981 }
982
983 if (efi_enabled(EFI_DBG)) {
984 pr_info("EFI runtime memory map:\n");
985 efi_print_memmap();
986 }
987
988 BUG_ON(!efi.systab);
989
990 if (efi_setup_page_tables(pa, 1 << pg_shift)) {
991 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
992 return;
993 }
994
995 efi_sync_low_kernel_mappings();
996
997 if (efi_is_native()) {
998 status = phys_efi_set_virtual_address_map(
999 efi.memmap.desc_size * count,
1000 efi.memmap.desc_size,
1001 efi.memmap.desc_version,
1002 (efi_memory_desc_t *)pa);
1003 } else {
1004 status = efi_thunk_set_virtual_address_map(
1005 efi_phys.set_virtual_address_map,
1006 efi.memmap.desc_size * count,
1007 efi.memmap.desc_size,
1008 efi.memmap.desc_version,
1009 (efi_memory_desc_t *)pa);
1010 }
1011
1012 if (status != EFI_SUCCESS) {
1013 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
1014 status);
1015 panic("EFI call to SetVirtualAddressMap() failed!");
1016 }
1017
1018 efi_free_boot_services();
1019
1020 /*
1021 * Now that EFI is in virtual mode, update the function
1022 * pointers in the runtime service table to the new virtual addresses.
1023 *
1024 * Call EFI services through wrapper functions.
1025 */
1026 efi.runtime_version = efi_systab.hdr.revision;
1027
1028 if (efi_is_native())
1029 efi_native_runtime_setup();
1030 else
1031 efi_thunk_runtime_setup();
1032
1033 efi.set_virtual_address_map = NULL;
1034
1035 /*
1036 * Apply more restrictive page table mapping attributes now that
1037 * SVAM() has been called and the firmware has performed all
1038 * necessary relocation fixups for the new virtual addresses.
1039 */
1040 efi_runtime_update_mappings();
1041
1042 /* clean DUMMY object */
1043 efi_delete_dummy_variable();
1044 }
1045
efi_enter_virtual_mode(void)1046 void __init efi_enter_virtual_mode(void)
1047 {
1048 if (efi_enabled(EFI_PARAVIRT))
1049 return;
1050
1051 if (efi_setup)
1052 kexec_enter_virtual_mode();
1053 else
1054 __efi_enter_virtual_mode();
1055
1056 efi_dump_pagetable();
1057 }
1058
arch_parse_efi_cmdline(char * str)1059 static int __init arch_parse_efi_cmdline(char *str)
1060 {
1061 if (!str) {
1062 pr_warn("need at least one option\n");
1063 return -EINVAL;
1064 }
1065
1066 if (parse_option_str(str, "old_map"))
1067 set_bit(EFI_OLD_MEMMAP, &efi.flags);
1068
1069 return 0;
1070 }
1071 early_param("efi", arch_parse_efi_cmdline);
1072
efi_is_table_address(unsigned long phys_addr)1073 bool efi_is_table_address(unsigned long phys_addr)
1074 {
1075 unsigned int i;
1076
1077 if (phys_addr == EFI_INVALID_TABLE_ADDR)
1078 return false;
1079
1080 for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
1081 if (*(efi_tables[i]) == phys_addr)
1082 return true;
1083
1084 return false;
1085 }
1086
