Merge tag 'acpi-6.6-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[platform/kernel/linux-rpi.git] / drivers / firmware / efi / libstub / x86-stub.c
1 // SPDX-License-Identifier: GPL-2.0-only
2
3 /* -----------------------------------------------------------------------
4  *
5  *   Copyright 2011 Intel Corporation; author Matt Fleming
6  *
7  * ----------------------------------------------------------------------- */
8
9 #include <linux/efi.h>
10 #include <linux/pci.h>
11 #include <linux/stddef.h>
12
13 #include <asm/efi.h>
14 #include <asm/e820/types.h>
15 #include <asm/setup.h>
16 #include <asm/desc.h>
17 #include <asm/boot.h>
18 #include <asm/kaslr.h>
19 #include <asm/sev.h>
20
21 #include "efistub.h"
22 #include "x86-stub.h"
23
24 const efi_system_table_t *efi_system_table;
25 const efi_dxe_services_table_t *efi_dxe_table;
26 static efi_loaded_image_t *image = NULL;
27 static efi_memory_attribute_protocol_t *memattr;
28
29 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
30 union sev_memory_acceptance_protocol {
31         struct {
32                 efi_status_t (__efiapi * allow_unaccepted_memory)(
33                         sev_memory_acceptance_protocol_t *);
34         };
35         struct {
36                 u32 allow_unaccepted_memory;
37         } mixed_mode;
38 };
39
40 static efi_status_t
41 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
42 {
43         struct pci_setup_rom *rom = NULL;
44         efi_status_t status;
45         unsigned long size;
46         uint64_t romsize;
47         void *romimage;
48
49         /*
50          * Some firmware images contain EFI function pointers at the place where
51          * the romimage and romsize fields are supposed to be. Typically the EFI
52          * code is mapped at high addresses, translating to an unrealistically
53          * large romsize. The UEFI spec limits the size of option ROMs to 16
54          * MiB so we reject any ROMs over 16 MiB in size to catch this.
55          */
56         romimage = efi_table_attr(pci, romimage);
57         romsize = efi_table_attr(pci, romsize);
58         if (!romimage || !romsize || romsize > SZ_16M)
59                 return EFI_INVALID_PARAMETER;
60
61         size = romsize + sizeof(*rom);
62
63         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
64                              (void **)&rom);
65         if (status != EFI_SUCCESS) {
66                 efi_err("Failed to allocate memory for 'rom'\n");
67                 return status;
68         }
69
70         memset(rom, 0, sizeof(*rom));
71
72         rom->data.type  = SETUP_PCI;
73         rom->data.len   = size - sizeof(struct setup_data);
74         rom->data.next  = 0;
75         rom->pcilen     = romsize;
76         *__rom = rom;
77
78         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
79                                 PCI_VENDOR_ID, 1, &rom->vendor);
80
81         if (status != EFI_SUCCESS) {
82                 efi_err("Failed to read rom->vendor\n");
83                 goto free_struct;
84         }
85
86         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
87                                 PCI_DEVICE_ID, 1, &rom->devid);
88
89         if (status != EFI_SUCCESS) {
90                 efi_err("Failed to read rom->devid\n");
91                 goto free_struct;
92         }
93
94         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
95                                 &rom->device, &rom->function);
96
97         if (status != EFI_SUCCESS)
98                 goto free_struct;
99
100         memcpy(rom->romdata, romimage, romsize);
101         return status;
102
103 free_struct:
104         efi_bs_call(free_pool, rom);
105         return status;
106 }
107
108 /*
109  * There's no way to return an informative status from this function,
110  * because any analysis (and printing of error messages) needs to be
111  * done directly at the EFI function call-site.
112  *
113  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
114  * just didn't find any PCI devices, but there's no way to tell outside
115  * the context of the call.
116  */
117 static void setup_efi_pci(struct boot_params *params)
118 {
119         efi_status_t status;
120         void **pci_handle = NULL;
121         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
122         unsigned long size = 0;
123         struct setup_data *data;
124         efi_handle_t h;
125         int i;
126
127         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
128                              &pci_proto, NULL, &size, pci_handle);
129
130         if (status == EFI_BUFFER_TOO_SMALL) {
131                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
132                                      (void **)&pci_handle);
133
134                 if (status != EFI_SUCCESS) {
135                         efi_err("Failed to allocate memory for 'pci_handle'\n");
136                         return;
137                 }
138
139                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
140                                      &pci_proto, NULL, &size, pci_handle);
141         }
142
143         if (status != EFI_SUCCESS)
144                 goto free_handle;
145
146         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
147
148         while (data && data->next)
149                 data = (struct setup_data *)(unsigned long)data->next;
150
151         for_each_efi_handle(h, pci_handle, size, i) {
152                 efi_pci_io_protocol_t *pci = NULL;
153                 struct pci_setup_rom *rom;
154
155                 status = efi_bs_call(handle_protocol, h, &pci_proto,
156                                      (void **)&pci);
157                 if (status != EFI_SUCCESS || !pci)
158                         continue;
159
160                 status = preserve_pci_rom_image(pci, &rom);
161                 if (status != EFI_SUCCESS)
162                         continue;
163
164                 if (data)
165                         data->next = (unsigned long)rom;
166                 else
167                         params->hdr.setup_data = (unsigned long)rom;
168
169                 data = (struct setup_data *)rom;
170         }
171
172 free_handle:
173         efi_bs_call(free_pool, pci_handle);
174 }
175
176 static void retrieve_apple_device_properties(struct boot_params *boot_params)
177 {
178         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
179         struct setup_data *data, *new;
180         efi_status_t status;
181         u32 size = 0;
182         apple_properties_protocol_t *p;
183
184         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
185         if (status != EFI_SUCCESS)
186                 return;
187
188         if (efi_table_attr(p, version) != 0x10000) {
189                 efi_err("Unsupported properties proto version\n");
190                 return;
191         }
192
193         efi_call_proto(p, get_all, NULL, &size);
194         if (!size)
195                 return;
196
197         do {
198                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
199                                      size + sizeof(struct setup_data),
200                                      (void **)&new);
201                 if (status != EFI_SUCCESS) {
202                         efi_err("Failed to allocate memory for 'properties'\n");
203                         return;
204                 }
205
206                 status = efi_call_proto(p, get_all, new->data, &size);
207
208                 if (status == EFI_BUFFER_TOO_SMALL)
209                         efi_bs_call(free_pool, new);
210         } while (status == EFI_BUFFER_TOO_SMALL);
211
212         new->type = SETUP_APPLE_PROPERTIES;
213         new->len  = size;
214         new->next = 0;
215
216         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
217         if (!data) {
218                 boot_params->hdr.setup_data = (unsigned long)new;
219         } else {
220                 while (data->next)
221                         data = (struct setup_data *)(unsigned long)data->next;
222                 data->next = (unsigned long)new;
223         }
224 }
225
226 void efi_adjust_memory_range_protection(unsigned long start,
227                                         unsigned long size)
228 {
229         efi_status_t status;
230         efi_gcd_memory_space_desc_t desc;
231         unsigned long end, next;
232         unsigned long rounded_start, rounded_end;
233         unsigned long unprotect_start, unprotect_size;
234
235         rounded_start = rounddown(start, EFI_PAGE_SIZE);
236         rounded_end = roundup(start + size, EFI_PAGE_SIZE);
237
238         if (memattr != NULL) {
239                 efi_call_proto(memattr, clear_memory_attributes, rounded_start,
240                                rounded_end - rounded_start, EFI_MEMORY_XP);
241                 return;
242         }
243
244         if (efi_dxe_table == NULL)
245                 return;
246
247         /*
248          * Don't modify memory region attributes, they are
249          * already suitable, to lower the possibility to
250          * encounter firmware bugs.
251          */
252
253         for (end = start + size; start < end; start = next) {
254
255                 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
256
257                 if (status != EFI_SUCCESS)
258                         return;
259
260                 next = desc.base_address + desc.length;
261
262                 /*
263                  * Only system memory is suitable for trampoline/kernel image placement,
264                  * so only this type of memory needs its attributes to be modified.
265                  */
266
267                 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
268                     (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
269                         continue;
270
271                 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
272                 unprotect_size = min(rounded_end, next) - unprotect_start;
273
274                 status = efi_dxe_call(set_memory_space_attributes,
275                                       unprotect_start, unprotect_size,
276                                       EFI_MEMORY_WB);
277
278                 if (status != EFI_SUCCESS) {
279                         efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
280                                  unprotect_start,
281                                  unprotect_start + unprotect_size,
282                                  status);
283                 }
284         }
285 }
286
287 static void setup_unaccepted_memory(void)
288 {
289         efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
290         sev_memory_acceptance_protocol_t *proto;
291         efi_status_t status;
292
293         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
294                 return;
295
296         /*
297          * Enable unaccepted memory before calling exit boot services in order
298          * for the UEFI to not accept all memory on EBS.
299          */
300         status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
301                              (void **)&proto);
302         if (status != EFI_SUCCESS)
303                 return;
304
305         status = efi_call_proto(proto, allow_unaccepted_memory);
306         if (status != EFI_SUCCESS)
307                 efi_err("Memory acceptance protocol failed\n");
308 }
309
310 static const efi_char16_t apple[] = L"Apple";
311
312 static void setup_quirks(struct boot_params *boot_params)
313 {
314         efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
315                 efi_table_attr(efi_system_table, fw_vendor);
316
317         if (!memcmp(fw_vendor, apple, sizeof(apple))) {
318                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
319                         retrieve_apple_device_properties(boot_params);
320         }
321 }
322
323 /*
324  * See if we have Universal Graphics Adapter (UGA) protocol
325  */
326 static efi_status_t
327 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
328 {
329         efi_status_t status;
330         u32 width, height;
331         void **uga_handle = NULL;
332         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
333         efi_handle_t handle;
334         int i;
335
336         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
337                              (void **)&uga_handle);
338         if (status != EFI_SUCCESS)
339                 return status;
340
341         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
342                              uga_proto, NULL, &size, uga_handle);
343         if (status != EFI_SUCCESS)
344                 goto free_handle;
345
346         height = 0;
347         width = 0;
348
349         first_uga = NULL;
350         for_each_efi_handle(handle, uga_handle, size, i) {
351                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
352                 u32 w, h, depth, refresh;
353                 void *pciio;
354
355                 status = efi_bs_call(handle_protocol, handle, uga_proto,
356                                      (void **)&uga);
357                 if (status != EFI_SUCCESS)
358                         continue;
359
360                 pciio = NULL;
361                 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
362
363                 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
364                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
365                         width = w;
366                         height = h;
367
368                         /*
369                          * Once we've found a UGA supporting PCIIO,
370                          * don't bother looking any further.
371                          */
372                         if (pciio)
373                                 break;
374
375                         first_uga = uga;
376                 }
377         }
378
379         if (!width && !height)
380                 goto free_handle;
381
382         /* EFI framebuffer */
383         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
384
385         si->lfb_depth           = 32;
386         si->lfb_width           = width;
387         si->lfb_height          = height;
388
389         si->red_size            = 8;
390         si->red_pos             = 16;
391         si->green_size          = 8;
392         si->green_pos           = 8;
393         si->blue_size           = 8;
394         si->blue_pos            = 0;
395         si->rsvd_size           = 8;
396         si->rsvd_pos            = 24;
397
398 free_handle:
399         efi_bs_call(free_pool, uga_handle);
400
401         return status;
402 }
403
404 static void setup_graphics(struct boot_params *boot_params)
405 {
406         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
407         struct screen_info *si;
408         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
409         efi_status_t status;
410         unsigned long size;
411         void **gop_handle = NULL;
412         void **uga_handle = NULL;
413
414         si = &boot_params->screen_info;
415         memset(si, 0, sizeof(*si));
416
417         size = 0;
418         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
419                              &graphics_proto, NULL, &size, gop_handle);
420         if (status == EFI_BUFFER_TOO_SMALL)
421                 status = efi_setup_gop(si, &graphics_proto, size);
422
423         if (status != EFI_SUCCESS) {
424                 size = 0;
425                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
426                                      &uga_proto, NULL, &size, uga_handle);
427                 if (status == EFI_BUFFER_TOO_SMALL)
428                         setup_uga(si, &uga_proto, size);
429         }
430 }
431
432
433 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
434 {
435         efi_bs_call(exit, handle, status, 0, NULL);
436         for(;;)
437                 asm("hlt");
438 }
439
440 void __noreturn efi_stub_entry(efi_handle_t handle,
441                                efi_system_table_t *sys_table_arg,
442                                struct boot_params *boot_params);
443
444 /*
445  * Because the x86 boot code expects to be passed a boot_params we
446  * need to create one ourselves (usually the bootloader would create
447  * one for us).
448  */
449 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
450                                    efi_system_table_t *sys_table_arg)
451 {
452         struct boot_params *boot_params;
453         struct setup_header *hdr;
454         void *image_base;
455         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
456         int options_size = 0;
457         efi_status_t status;
458         char *cmdline_ptr;
459
460         efi_system_table = sys_table_arg;
461
462         /* Check if we were booted by the EFI firmware */
463         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
464                 efi_exit(handle, EFI_INVALID_PARAMETER);
465
466         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
467         if (status != EFI_SUCCESS) {
468                 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
469                 efi_exit(handle, status);
470         }
471
472         image_base = efi_table_attr(image, image_base);
473
474         status = efi_allocate_pages(sizeof(struct boot_params),
475                                     (unsigned long *)&boot_params, ULONG_MAX);
476         if (status != EFI_SUCCESS) {
477                 efi_err("Failed to allocate lowmem for boot params\n");
478                 efi_exit(handle, status);
479         }
480
481         memset(boot_params, 0x0, sizeof(struct boot_params));
482
483         hdr = &boot_params->hdr;
484
485         /* Copy the setup header from the second sector to boot_params */
486         memcpy(&hdr->jump, image_base + 512,
487                sizeof(struct setup_header) - offsetof(struct setup_header, jump));
488
489         /*
490          * Fill out some of the header fields ourselves because the
491          * EFI firmware loader doesn't load the first sector.
492          */
493         hdr->root_flags = 1;
494         hdr->vid_mode   = 0xffff;
495         hdr->boot_flag  = 0xAA55;
496
497         hdr->type_of_loader = 0x21;
498
499         /* Convert unicode cmdline to ascii */
500         cmdline_ptr = efi_convert_cmdline(image, &options_size);
501         if (!cmdline_ptr)
502                 goto fail;
503
504         efi_set_u64_split((unsigned long)cmdline_ptr,
505                           &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr);
506
507         hdr->ramdisk_image = 0;
508         hdr->ramdisk_size = 0;
509
510         /*
511          * Disregard any setup data that was provided by the bootloader:
512          * setup_data could be pointing anywhere, and we have no way of
513          * authenticating or validating the payload.
514          */
515         hdr->setup_data = 0;
516
517         efi_stub_entry(handle, sys_table_arg, boot_params);
518         /* not reached */
519
520 fail:
521         efi_free(sizeof(struct boot_params), (unsigned long)boot_params);
522
523         efi_exit(handle, status);
524 }
525
526 static void add_e820ext(struct boot_params *params,
527                         struct setup_data *e820ext, u32 nr_entries)
528 {
529         struct setup_data *data;
530
531         e820ext->type = SETUP_E820_EXT;
532         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
533         e820ext->next = 0;
534
535         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
536
537         while (data && data->next)
538                 data = (struct setup_data *)(unsigned long)data->next;
539
540         if (data)
541                 data->next = (unsigned long)e820ext;
542         else
543                 params->hdr.setup_data = (unsigned long)e820ext;
544 }
545
546 static efi_status_t
547 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
548 {
549         struct boot_e820_entry *entry = params->e820_table;
550         struct efi_info *efi = &params->efi_info;
551         struct boot_e820_entry *prev = NULL;
552         u32 nr_entries;
553         u32 nr_desc;
554         int i;
555
556         nr_entries = 0;
557         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
558
559         for (i = 0; i < nr_desc; i++) {
560                 efi_memory_desc_t *d;
561                 unsigned int e820_type = 0;
562                 unsigned long m = efi->efi_memmap;
563
564 #ifdef CONFIG_X86_64
565                 m |= (u64)efi->efi_memmap_hi << 32;
566 #endif
567
568                 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
569                 switch (d->type) {
570                 case EFI_RESERVED_TYPE:
571                 case EFI_RUNTIME_SERVICES_CODE:
572                 case EFI_RUNTIME_SERVICES_DATA:
573                 case EFI_MEMORY_MAPPED_IO:
574                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
575                 case EFI_PAL_CODE:
576                         e820_type = E820_TYPE_RESERVED;
577                         break;
578
579                 case EFI_UNUSABLE_MEMORY:
580                         e820_type = E820_TYPE_UNUSABLE;
581                         break;
582
583                 case EFI_ACPI_RECLAIM_MEMORY:
584                         e820_type = E820_TYPE_ACPI;
585                         break;
586
587                 case EFI_LOADER_CODE:
588                 case EFI_LOADER_DATA:
589                 case EFI_BOOT_SERVICES_CODE:
590                 case EFI_BOOT_SERVICES_DATA:
591                 case EFI_CONVENTIONAL_MEMORY:
592                         if (efi_soft_reserve_enabled() &&
593                             (d->attribute & EFI_MEMORY_SP))
594                                 e820_type = E820_TYPE_SOFT_RESERVED;
595                         else
596                                 e820_type = E820_TYPE_RAM;
597                         break;
598
599                 case EFI_ACPI_MEMORY_NVS:
600                         e820_type = E820_TYPE_NVS;
601                         break;
602
603                 case EFI_PERSISTENT_MEMORY:
604                         e820_type = E820_TYPE_PMEM;
605                         break;
606
607                 case EFI_UNACCEPTED_MEMORY:
608                         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
609                                 continue;
610                         e820_type = E820_TYPE_RAM;
611                         process_unaccepted_memory(d->phys_addr,
612                                                   d->phys_addr + PAGE_SIZE * d->num_pages);
613                         break;
614                 default:
615                         continue;
616                 }
617
618                 /* Merge adjacent mappings */
619                 if (prev && prev->type == e820_type &&
620                     (prev->addr + prev->size) == d->phys_addr) {
621                         prev->size += d->num_pages << 12;
622                         continue;
623                 }
624
625                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
626                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
627                                    sizeof(struct setup_data);
628
629                         if (!e820ext || e820ext_size < need)
630                                 return EFI_BUFFER_TOO_SMALL;
631
632                         /* boot_params map full, switch to e820 extended */
633                         entry = (struct boot_e820_entry *)e820ext->data;
634                 }
635
636                 entry->addr = d->phys_addr;
637                 entry->size = d->num_pages << PAGE_SHIFT;
638                 entry->type = e820_type;
639                 prev = entry++;
640                 nr_entries++;
641         }
642
643         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
644                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
645
646                 add_e820ext(params, e820ext, nr_e820ext);
647                 nr_entries -= nr_e820ext;
648         }
649
650         params->e820_entries = (u8)nr_entries;
651
652         return EFI_SUCCESS;
653 }
654
655 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
656                                   u32 *e820ext_size)
657 {
658         efi_status_t status;
659         unsigned long size;
660
661         size = sizeof(struct setup_data) +
662                 sizeof(struct e820_entry) * nr_desc;
663
664         if (*e820ext) {
665                 efi_bs_call(free_pool, *e820ext);
666                 *e820ext = NULL;
667                 *e820ext_size = 0;
668         }
669
670         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
671                              (void **)e820ext);
672         if (status == EFI_SUCCESS)
673                 *e820ext_size = size;
674
675         return status;
676 }
677
678 static efi_status_t allocate_e820(struct boot_params *params,
679                                   struct setup_data **e820ext,
680                                   u32 *e820ext_size)
681 {
682         struct efi_boot_memmap *map;
683         efi_status_t status;
684         __u32 nr_desc;
685
686         status = efi_get_memory_map(&map, false);
687         if (status != EFI_SUCCESS)
688                 return status;
689
690         nr_desc = map->map_size / map->desc_size;
691         if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
692                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
693                                  EFI_MMAP_NR_SLACK_SLOTS;
694
695                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
696         }
697
698         if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
699                 status = allocate_unaccepted_bitmap(nr_desc, map);
700
701         efi_bs_call(free_pool, map);
702         return status;
703 }
704
705 struct exit_boot_struct {
706         struct boot_params      *boot_params;
707         struct efi_info         *efi;
708 };
709
710 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
711                                    void *priv)
712 {
713         const char *signature;
714         struct exit_boot_struct *p = priv;
715
716         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
717                                    : EFI32_LOADER_SIGNATURE;
718         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
719
720         efi_set_u64_split((unsigned long)efi_system_table,
721                           &p->efi->efi_systab, &p->efi->efi_systab_hi);
722         p->efi->efi_memdesc_size        = map->desc_size;
723         p->efi->efi_memdesc_version     = map->desc_ver;
724         efi_set_u64_split((unsigned long)map->map,
725                           &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
726         p->efi->efi_memmap_size         = map->map_size;
727
728         return EFI_SUCCESS;
729 }
730
731 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
732 {
733         struct setup_data *e820ext = NULL;
734         __u32 e820ext_size = 0;
735         efi_status_t status;
736         struct exit_boot_struct priv;
737
738         priv.boot_params        = boot_params;
739         priv.efi                = &boot_params->efi_info;
740
741         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
742         if (status != EFI_SUCCESS)
743                 return status;
744
745         /* Might as well exit boot services now */
746         status = efi_exit_boot_services(handle, &priv, exit_boot_func);
747         if (status != EFI_SUCCESS)
748                 return status;
749
750         /* Historic? */
751         boot_params->alt_mem_k  = 32 * 1024;
752
753         status = setup_e820(boot_params, e820ext, e820ext_size);
754         if (status != EFI_SUCCESS)
755                 return status;
756
757         return EFI_SUCCESS;
758 }
759
760 static bool have_unsupported_snp_features(void)
761 {
762         u64 unsupported;
763
764         unsupported = snp_get_unsupported_features(sev_get_status());
765         if (unsupported) {
766                 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
767                         unsupported);
768                 return true;
769         }
770         return false;
771 }
772
773 static void efi_get_seed(void *seed, int size)
774 {
775         efi_get_random_bytes(size, seed);
776
777         /*
778          * This only updates seed[0] when running on 32-bit, but in that case,
779          * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
780          */
781         *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
782 }
783
784 static void error(char *str)
785 {
786         efi_warn("Decompression failed: %s\n", str);
787 }
788
789 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
790 {
791         unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
792         unsigned long addr, alloc_size, entry;
793         efi_status_t status;
794         u32 seed[2] = {};
795
796         /* determine the required size of the allocation */
797         alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
798                            MIN_KERNEL_ALIGN);
799
800         if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
801                 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
802
803                 efi_get_seed(seed, sizeof(seed));
804
805                 virt_addr += (range * seed[1]) >> 32;
806                 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
807         }
808
809         status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
810                                   seed[0], EFI_LOADER_CODE,
811                                   EFI_X86_KERNEL_ALLOC_LIMIT);
812         if (status != EFI_SUCCESS)
813                 return status;
814
815         entry = decompress_kernel((void *)addr, virt_addr, error);
816         if (entry == ULONG_MAX) {
817                 efi_free(alloc_size, addr);
818                 return EFI_LOAD_ERROR;
819         }
820
821         *kernel_entry = addr + entry;
822
823         efi_adjust_memory_range_protection(addr, kernel_total_size);
824
825         return EFI_SUCCESS;
826 }
827
828 static void __noreturn enter_kernel(unsigned long kernel_addr,
829                                     struct boot_params *boot_params)
830 {
831         /* enter decompressed kernel with boot_params pointer in RSI/ESI */
832         asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
833
834         unreachable();
835 }
836
837 /*
838  * On success, this routine will jump to the relocated image directly and never
839  * return.  On failure, it will exit to the firmware via efi_exit() instead of
840  * returning.
841  */
842 void __noreturn efi_stub_entry(efi_handle_t handle,
843                                efi_system_table_t *sys_table_arg,
844                                struct boot_params *boot_params)
845 {
846         efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
847         struct setup_header *hdr = &boot_params->hdr;
848         const struct linux_efi_initrd *initrd = NULL;
849         unsigned long kernel_entry;
850         efi_status_t status;
851
852         boot_params_pointer = boot_params;
853
854         efi_system_table = sys_table_arg;
855         /* Check if we were booted by the EFI firmware */
856         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
857                 efi_exit(handle, EFI_INVALID_PARAMETER);
858
859         if (have_unsupported_snp_features())
860                 efi_exit(handle, EFI_UNSUPPORTED);
861
862         if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
863                 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
864                 if (efi_dxe_table &&
865                     efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
866                         efi_warn("Ignoring DXE services table: invalid signature\n");
867                         efi_dxe_table = NULL;
868                 }
869         }
870
871         /* grab the memory attributes protocol if it exists */
872         efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
873
874         status = efi_setup_5level_paging();
875         if (status != EFI_SUCCESS) {
876                 efi_err("efi_setup_5level_paging() failed!\n");
877                 goto fail;
878         }
879
880 #ifdef CONFIG_CMDLINE_BOOL
881         status = efi_parse_options(CONFIG_CMDLINE);
882         if (status != EFI_SUCCESS) {
883                 efi_err("Failed to parse options\n");
884                 goto fail;
885         }
886 #endif
887         if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
888                 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
889                                                ((u64)boot_params->ext_cmd_line_ptr << 32));
890                 status = efi_parse_options((char *)cmdline_paddr);
891                 if (status != EFI_SUCCESS) {
892                         efi_err("Failed to parse options\n");
893                         goto fail;
894                 }
895         }
896
897         status = efi_decompress_kernel(&kernel_entry);
898         if (status != EFI_SUCCESS) {
899                 efi_err("Failed to decompress kernel\n");
900                 goto fail;
901         }
902
903         /*
904          * At this point, an initrd may already have been loaded by the
905          * bootloader and passed via bootparams. We permit an initrd loaded
906          * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
907          *
908          * If the device path is not present, any command-line initrd=
909          * arguments will be processed only if image is not NULL, which will be
910          * the case only if we were loaded via the PE entry point.
911          */
912         status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
913                                  &initrd);
914         if (status != EFI_SUCCESS)
915                 goto fail;
916         if (initrd && initrd->size > 0) {
917                 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
918                                   &boot_params->ext_ramdisk_image);
919                 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
920                                   &boot_params->ext_ramdisk_size);
921         }
922
923
924         /*
925          * If the boot loader gave us a value for secure_boot then we use that,
926          * otherwise we ask the BIOS.
927          */
928         if (boot_params->secure_boot == efi_secureboot_mode_unset)
929                 boot_params->secure_boot = efi_get_secureboot();
930
931         /* Ask the firmware to clear memory on unclean shutdown */
932         efi_enable_reset_attack_mitigation();
933
934         efi_random_get_seed();
935
936         efi_retrieve_tpm2_eventlog();
937
938         setup_graphics(boot_params);
939
940         setup_efi_pci(boot_params);
941
942         setup_quirks(boot_params);
943
944         setup_unaccepted_memory();
945
946         status = exit_boot(boot_params, handle);
947         if (status != EFI_SUCCESS) {
948                 efi_err("exit_boot() failed!\n");
949                 goto fail;
950         }
951
952         /*
953          * Call the SEV init code while still running with the firmware's
954          * GDT/IDT, so #VC exceptions will be handled by EFI.
955          */
956         sev_enable(boot_params);
957
958         efi_5level_switch();
959
960         enter_kernel(kernel_entry, boot_params);
961 fail:
962         efi_err("efi_stub_entry() failed!\n");
963
964         efi_exit(handle, status);
965 }
966
967 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
968 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
969                         struct boot_params *boot_params)
970 {
971         extern char _bss[], _ebss[];
972
973         memset(_bss, 0, _ebss - _bss);
974         efi_stub_entry(handle, sys_table_arg, boot_params);
975 }
976
977 #ifndef CONFIG_EFI_MIXED
978 extern __alias(efi_handover_entry)
979 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
980                       struct boot_params *boot_params);
981
982 extern __alias(efi_handover_entry)
983 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
984                       struct boot_params *boot_params);
985 #endif
986 #endif