1// SPDX-License-Identifier: GPL-2.0
2/*
3 * x86_64 specific EFI support functions
4 * Based on Extensible Firmware Interface Specification version 1.0
5 *
6 * Copyright (C) 2005-2008 Intel Co.
7 * Fenghua Yu <fenghua.yu@intel.com>
8 * Bibo Mao <bibo.mao@intel.com>
9 * Chandramouli Narayanan <mouli@linux.intel.com>
10 * Huang Ying <ying.huang@intel.com>
11 *
12 * Code to convert EFI to E820 map has been implemented in elilo bootloader
13 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
14 * is setup appropriately for EFI runtime code.
15 * - mouli 06/14/2007.
16 *
17 */
18
19#define pr_fmt(fmt) "efi: " fmt
20
21#include <linux/kernel.h>
22#include <linux/init.h>
23#include <linux/mm.h>
24#include <linux/types.h>
25#include <linux/spinlock.h>
26#include <linux/memblock.h>
27#include <linux/ioport.h>
28#include <linux/mc146818rtc.h>
29#include <linux/efi.h>
30#include <linux/export.h>
31#include <linux/uaccess.h>
32#include <linux/io.h>
33#include <linux/reboot.h>
34#include <linux/slab.h>
35#include <linux/ucs2_string.h>
36#include <linux/cc_platform.h>
37#include <linux/sched/task.h>
38
39#include <asm/setup.h>
40#include <asm/page.h>
41#include <asm/e820/api.h>
42#include <asm/tlbflush.h>
43#include <asm/proto.h>
44#include <asm/efi.h>
45#include <asm/cacheflush.h>
46#include <asm/fixmap.h>
47#include <asm/realmode.h>
48#include <asm/time.h>
49#include <asm/pgalloc.h>
50#include <asm/sev.h>
51
52/*
53 * We allocate runtime services regions top-down, starting from -4G, i.e.
54 * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
55 */
56static u64 efi_va = EFI_VA_START;
57static struct mm_struct *efi_prev_mm;
58
59/*
60 * We need our own copy of the higher levels of the page tables
61 * because we want to avoid inserting EFI region mappings (EFI_VA_END
62 * to EFI_VA_START) into the standard kernel page tables. Everything
63 * else can be shared, see efi_sync_low_kernel_mappings().
64 *
65 * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
66 * allocation.
67 */
68int __init efi_alloc_page_tables(void)
69{
70 pgd_t *pgd, *efi_pgd;
71 p4d_t *p4d;
72 pud_t *pud;
73 gfp_t gfp_mask;
74
75 gfp_mask = GFP_KERNEL | __GFP_ZERO;
76 efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
77 if (!efi_pgd)
78 goto fail;
79
80 pgd = efi_pgd + pgd_index(EFI_VA_END);
81 p4d = p4d_alloc(mm: &init_mm, pgd, EFI_VA_END);
82 if (!p4d)
83 goto free_pgd;
84
85 pud = pud_alloc(mm: &init_mm, p4d, EFI_VA_END);
86 if (!pud)
87 goto free_p4d;
88
89 efi_mm.pgd = efi_pgd;
90 mm_init_cpumask(mm: &efi_mm);
91 init_new_context(NULL, mm: &efi_mm);
92
93 return 0;
94
95free_p4d:
96 if (pgtable_l5_enabled())
97 free_page((unsigned long)pgd_page_vaddr(*pgd));
98free_pgd:
99 free_pages(addr: (unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
100fail:
101 return -ENOMEM;
102}
103
104/*
105 * Add low kernel mappings for passing arguments to EFI functions.
106 */
107void efi_sync_low_kernel_mappings(void)
108{
109 unsigned num_entries;
110 pgd_t *pgd_k, *pgd_efi;
111 p4d_t *p4d_k, *p4d_efi;
112 pud_t *pud_k, *pud_efi;
113 pgd_t *efi_pgd = efi_mm.pgd;
114
115 pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
116 pgd_k = pgd_offset_k(PAGE_OFFSET);
117
118 num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
119 memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
120
121 pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
122 pgd_k = pgd_offset_k(EFI_VA_END);
123 p4d_efi = p4d_offset(pgd: pgd_efi, address: 0);
124 p4d_k = p4d_offset(pgd: pgd_k, address: 0);
125
126 num_entries = p4d_index(EFI_VA_END);
127 memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
128
129 /*
130 * We share all the PUD entries apart from those that map the
131 * EFI regions. Copy around them.
132 */
133 BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
134 BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
135
136 p4d_efi = p4d_offset(pgd: pgd_efi, EFI_VA_END);
137 p4d_k = p4d_offset(pgd: pgd_k, EFI_VA_END);
138 pud_efi = pud_offset(p4d: p4d_efi, address: 0);
139 pud_k = pud_offset(p4d: p4d_k, address: 0);
140
141 num_entries = pud_index(EFI_VA_END);
142 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
143
144 pud_efi = pud_offset(p4d: p4d_efi, EFI_VA_START);
145 pud_k = pud_offset(p4d: p4d_k, EFI_VA_START);
146
147 num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
148 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
149}
150
151/*
152 * Wrapper for slow_virt_to_phys() that handles NULL addresses.
153 */
154static inline phys_addr_t
155virt_to_phys_or_null_size(void *va, unsigned long size)
156{
157 phys_addr_t pa;
158
159 if (!va)
160 return 0;
161
162 if (virt_addr_valid(va))
163 return virt_to_phys(address: va);
164
165 pa = slow_virt_to_phys(address: va);
166
167 /* check if the object crosses a page boundary */
168 if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
169 return 0;
170
171 return pa;
172}
173
174#define virt_to_phys_or_null(addr) \
175 virt_to_phys_or_null_size((addr), sizeof(*(addr)))
176
177int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
178{
179 extern const u8 __efi64_thunk_ret_tramp[];
180 unsigned long pfn, text, pf, rodata, tramp;
181 struct page *page;
182 unsigned npages;
183 pgd_t *pgd = efi_mm.pgd;
184
185 /*
186 * It can happen that the physical address of new_memmap lands in memory
187 * which is not mapped in the EFI page table. Therefore we need to go
188 * and ident-map those pages containing the map before calling
189 * phys_efi_set_virtual_address_map().
190 */
191 pfn = pa_memmap >> PAGE_SHIFT;
192 pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
193 if (kernel_map_pages_in_pgd(pgd, pfn, address: pa_memmap, numpages: num_pages, page_flags: pf)) {
194 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
195 return 1;
196 }
197
198 /*
199 * Certain firmware versions are way too sentimental and still believe
200 * they are exclusive and unquestionable owners of the first physical page,
201 * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
202 * (but then write-access it later during SetVirtualAddressMap()).
203 *
204 * Create a 1:1 mapping for this page, to avoid triple faults during early
205 * boot with such firmware. We are free to hand this page to the BIOS,
206 * as trim_bios_range() will reserve the first page and isolate it away
207 * from memory allocators anyway.
208 */
209 if (kernel_map_pages_in_pgd(pgd, pfn: 0x0, address: 0x0, numpages: 1, page_flags: pf)) {
210 pr_err("Failed to create 1:1 mapping for the first page!\n");
211 return 1;
212 }
213
214 /*
215 * When SEV-ES is active, the GHCB as set by the kernel will be used
216 * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
217 */
218 if (sev_es_efi_map_ghcbs(pgd)) {
219 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
220 return 1;
221 }
222
223 /*
224 * When making calls to the firmware everything needs to be 1:1
225 * mapped and addressable with 32-bit pointers. Map the kernel
226 * text and allocate a new stack because we can't rely on the
227 * stack pointer being < 4GB.
228 */
229 if (!efi_is_mixed())
230 return 0;
231
232 page = alloc_page(GFP_KERNEL|__GFP_DMA32);
233 if (!page) {
234 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
235 return 1;
236 }
237
238 efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */
239
240 npages = (_etext - _text) >> PAGE_SHIFT;
241 text = __pa(_text);
242
243 if (kernel_unmap_pages_in_pgd(pgd, address: text, numpages: npages)) {
244 pr_err("Failed to unmap kernel text 1:1 mapping\n");
245 return 1;
246 }
247
248 npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
249 rodata = __pa(__start_rodata);
250 pfn = rodata >> PAGE_SHIFT;
251
252 pf = _PAGE_NX | _PAGE_ENC;
253 if (kernel_map_pages_in_pgd(pgd, pfn, address: rodata, numpages: npages, page_flags: pf)) {
254 pr_err("Failed to map kernel rodata 1:1\n");
255 return 1;
256 }
257
258 tramp = __pa(__efi64_thunk_ret_tramp);
259 pfn = tramp >> PAGE_SHIFT;
260
261 pf = _PAGE_ENC;
262 if (kernel_map_pages_in_pgd(pgd, pfn, address: tramp, numpages: 1, page_flags: pf)) {
263 pr_err("Failed to map mixed mode return trampoline\n");
264 return 1;
265 }
266
267 return 0;
268}
269
270static void __init __map_region(efi_memory_desc_t *md, u64 va)
271{
272 unsigned long flags = _PAGE_RW;
273 unsigned long pfn;
274 pgd_t *pgd = efi_mm.pgd;
275
276 /*
277 * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
278 * executable images in memory that consist of both R-X and
279 * RW- sections, so we cannot apply read-only or non-exec
280 * permissions just yet. However, modern EFI systems provide
281 * a memory attributes table that describes those sections
282 * with the appropriate restricted permissions, which are
283 * applied in efi_runtime_update_mappings() below. All other
284 * regions can be mapped non-executable at this point, with
285 * the exception of boot services code regions, but those will
286 * be unmapped again entirely in efi_free_boot_services().
287 */
288 if (md->type != EFI_BOOT_SERVICES_CODE &&
289 md->type != EFI_RUNTIME_SERVICES_CODE)
290 flags |= _PAGE_NX;
291
292 if (!(md->attribute & EFI_MEMORY_WB))
293 flags |= _PAGE_PCD;
294
295 if (cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT) &&
296 md->type != EFI_MEMORY_MAPPED_IO)
297 flags |= _PAGE_ENC;
298
299 pfn = md->phys_addr >> PAGE_SHIFT;
300 if (kernel_map_pages_in_pgd(pgd, pfn, address: va, numpages: md->num_pages, page_flags: flags))
301 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
302 md->phys_addr, va);
303}
304
305void __init efi_map_region(efi_memory_desc_t *md)
306{
307 unsigned long size = md->num_pages << PAGE_SHIFT;
308 u64 pa = md->phys_addr;
309
310 /*
311 * Make sure the 1:1 mappings are present as a catch-all for b0rked
312 * firmware which doesn't update all internal pointers after switching
313 * to virtual mode and would otherwise crap on us.
314 */
315 __map_region(md, va: md->phys_addr);
316
317 /*
318 * Enforce the 1:1 mapping as the default virtual address when
319 * booting in EFI mixed mode, because even though we may be
320 * running a 64-bit kernel, the firmware may only be 32-bit.
321 */
322 if (efi_is_mixed()) {
323 md->virt_addr = md->phys_addr;
324 return;
325 }
326
327 efi_va -= size;
328
329 /* Is PA 2M-aligned? */
330 if (!(pa & (PMD_SIZE - 1))) {
331 efi_va &= PMD_MASK;
332 } else {
333 u64 pa_offset = pa & (PMD_SIZE - 1);
334 u64 prev_va = efi_va;
335
336 /* get us the same offset within this 2M page */
337 efi_va = (efi_va & PMD_MASK) + pa_offset;
338
339 if (efi_va > prev_va)
340 efi_va -= PMD_SIZE;
341 }
342
343 if (efi_va < EFI_VA_END) {
344 pr_warn(FW_WARN "VA address range overflow!\n");
345 return;
346 }
347
348 /* Do the VA map */
349 __map_region(md, va: efi_va);
350 md->virt_addr = efi_va;
351}
352
353/*
354 * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
355 * md->virt_addr is the original virtual address which had been mapped in kexec
356 * 1st kernel.
357 */
358void __init efi_map_region_fixed(efi_memory_desc_t *md)
359{
360 __map_region(md, va: md->phys_addr);
361 __map_region(md, va: md->virt_addr);
362}
363
364void __init parse_efi_setup(u64 phys_addr, u32 data_len)
365{
366 efi_setup = phys_addr + sizeof(struct setup_data);
367}
368
369static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
370{
371 unsigned long pfn;
372 pgd_t *pgd = efi_mm.pgd;
373 int err1, err2;
374
375 /* Update the 1:1 mapping */
376 pfn = md->phys_addr >> PAGE_SHIFT;
377 err1 = kernel_map_pages_in_pgd(pgd, pfn, address: md->phys_addr, numpages: md->num_pages, page_flags: pf);
378 if (err1) {
379 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
380 md->phys_addr, md->virt_addr);
381 }
382
383 err2 = kernel_map_pages_in_pgd(pgd, pfn, address: md->virt_addr, numpages: md->num_pages, page_flags: pf);
384 if (err2) {
385 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
386 md->phys_addr, md->virt_addr);
387 }
388
389 return err1 || err2;
390}
391
392bool efi_disable_ibt_for_runtime __ro_after_init = true;
393
394static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md,
395 bool has_ibt)
396{
397 unsigned long pf = 0;
398
399 efi_disable_ibt_for_runtime |= !has_ibt;
400
401 if (md->attribute & EFI_MEMORY_XP)
402 pf |= _PAGE_NX;
403
404 if (!(md->attribute & EFI_MEMORY_RO))
405 pf |= _PAGE_RW;
406
407 if (cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT))
408 pf |= _PAGE_ENC;
409
410 return efi_update_mappings(md, pf);
411}
412
413void __init efi_runtime_update_mappings(void)
414{
415 efi_memory_desc_t *md;
416
417 /*
418 * Use the EFI Memory Attribute Table for mapping permissions if it
419 * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
420 */
421 if (efi_enabled(EFI_MEM_ATTR)) {
422 efi_disable_ibt_for_runtime = false;
423 efi_memattr_apply_permissions(NULL, fn: efi_update_mem_attr);
424 return;
425 }
426
427 /*
428 * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
429 * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
430 * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
431 * published by the firmware. Even if we find a buggy implementation of
432 * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
433 * EFI_PROPERTIES_TABLE, because of the same reason.
434 */
435
436 if (!efi_enabled(EFI_NX_PE_DATA))
437 return;
438
439 for_each_efi_memory_desc(md) {
440 unsigned long pf = 0;
441
442 if (!(md->attribute & EFI_MEMORY_RUNTIME))
443 continue;
444
445 if (!(md->attribute & EFI_MEMORY_WB))
446 pf |= _PAGE_PCD;
447
448 if ((md->attribute & EFI_MEMORY_XP) ||
449 (md->type == EFI_RUNTIME_SERVICES_DATA))
450 pf |= _PAGE_NX;
451
452 if (!(md->attribute & EFI_MEMORY_RO) &&
453 (md->type != EFI_RUNTIME_SERVICES_CODE))
454 pf |= _PAGE_RW;
455
456 if (cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT))
457 pf |= _PAGE_ENC;
458
459 efi_update_mappings(md, pf);
460 }
461}
462
463void __init efi_dump_pagetable(void)
464{
465#ifdef CONFIG_EFI_PGT_DUMP
466 ptdump_walk_pgd_level(NULL, mm: &efi_mm);
467#endif
468}
469
470/*
471 * Makes the calling thread switch to/from efi_mm context. Can be used
472 * in a kernel thread and user context. Preemption needs to remain disabled
473 * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
474 * can not change under us.
475 * It should be ensured that there are no concurrent calls to this function.
476 */
477static void efi_enter_mm(void)
478{
479 efi_prev_mm = current->active_mm;
480 current->active_mm = &efi_mm;
481 switch_mm(prev: efi_prev_mm, next: &efi_mm, NULL);
482}
483
484static void efi_leave_mm(void)
485{
486 current->active_mm = efi_prev_mm;
487 switch_mm(prev: &efi_mm, next: efi_prev_mm, NULL);
488}
489
490void arch_efi_call_virt_setup(void)
491{
492 efi_sync_low_kernel_mappings();
493 efi_fpu_begin();
494 firmware_restrict_branch_speculation_start();
495 efi_enter_mm();
496}
497
498void arch_efi_call_virt_teardown(void)
499{
500 efi_leave_mm();
501 firmware_restrict_branch_speculation_end();
502 efi_fpu_end();
503}
504
505static DEFINE_SPINLOCK(efi_runtime_lock);
506
507/*
508 * DS and ES contain user values. We need to save them.
509 * The 32-bit EFI code needs a valid DS, ES, and SS. There's no
510 * need to save the old SS: __KERNEL_DS is always acceptable.
511 */
512#define __efi_thunk(func, ...) \
513({ \
514 unsigned short __ds, __es; \
515 efi_status_t ____s; \
516 \
517 savesegment(ds, __ds); \
518 savesegment(es, __es); \
519 \
520 loadsegment(ss, __KERNEL_DS); \
521 loadsegment(ds, __KERNEL_DS); \
522 loadsegment(es, __KERNEL_DS); \
523 \
524 ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
525 \
526 loadsegment(ds, __ds); \
527 loadsegment(es, __es); \
528 \
529 ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32; \
530 ____s; \
531})
532
533/*
534 * Switch to the EFI page tables early so that we can access the 1:1
535 * runtime services mappings which are not mapped in any other page
536 * tables.
537 *
538 * Also, disable interrupts because the IDT points to 64-bit handlers,
539 * which aren't going to function correctly when we switch to 32-bit.
540 */
541#define efi_thunk(func...) \
542({ \
543 efi_status_t __s; \
544 \
545 arch_efi_call_virt_setup(); \
546 \
547 __s = __efi_thunk(func); \
548 \
549 arch_efi_call_virt_teardown(); \
550 \
551 __s; \
552})
553
554static efi_status_t __init __no_sanitize_address
555efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
556 unsigned long descriptor_size,
557 u32 descriptor_version,
558 efi_memory_desc_t *virtual_map)
559{
560 efi_status_t status;
561 unsigned long flags;
562
563 efi_sync_low_kernel_mappings();
564 local_irq_save(flags);
565
566 efi_enter_mm();
567
568 status = __efi_thunk(set_virtual_address_map, memory_map_size,
569 descriptor_size, descriptor_version, virtual_map);
570
571 efi_leave_mm();
572 local_irq_restore(flags);
573
574 return status;
575}
576
577static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
578{
579 return EFI_UNSUPPORTED;
580}
581
582static efi_status_t efi_thunk_set_time(efi_time_t *tm)
583{
584 return EFI_UNSUPPORTED;
585}
586
587static efi_status_t
588efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
589 efi_time_t *tm)
590{
591 return EFI_UNSUPPORTED;
592}
593
594static efi_status_t
595efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
596{
597 return EFI_UNSUPPORTED;
598}
599
600static unsigned long efi_name_size(efi_char16_t *name)
601{
602 return ucs2_strsize(data: name, EFI_VAR_NAME_LEN) + 1;
603}
604
605static efi_status_t
606efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
607 u32 *attr, unsigned long *data_size, void *data)
608{
609 u8 buf[24] __aligned(8);
610 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
611 efi_status_t status;
612 u32 phys_name, phys_vendor, phys_attr;
613 u32 phys_data_size, phys_data;
614 unsigned long flags;
615
616 spin_lock_irqsave(&efi_runtime_lock, flags);
617
618 *vnd = *vendor;
619
620 phys_data_size = virt_to_phys_or_null(data_size);
621 phys_vendor = virt_to_phys_or_null(vnd);
622 phys_name = virt_to_phys_or_null_size(va: name, size: efi_name_size(name));
623 phys_attr = virt_to_phys_or_null(attr);
624 phys_data = virt_to_phys_or_null_size(va: data, size: *data_size);
625
626 if (!phys_name || (data && !phys_data))
627 status = EFI_INVALID_PARAMETER;
628 else
629 status = efi_thunk(get_variable, phys_name, phys_vendor,
630 phys_attr, phys_data_size, phys_data);
631
632 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
633
634 return status;
635}
636
637static efi_status_t
638efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
639 u32 attr, unsigned long data_size, void *data)
640{
641 u8 buf[24] __aligned(8);
642 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
643 u32 phys_name, phys_vendor, phys_data;
644 efi_status_t status;
645 unsigned long flags;
646
647 spin_lock_irqsave(&efi_runtime_lock, flags);
648
649 *vnd = *vendor;
650
651 phys_name = virt_to_phys_or_null_size(va: name, size: efi_name_size(name));
652 phys_vendor = virt_to_phys_or_null(vnd);
653 phys_data = virt_to_phys_or_null_size(va: data, size: data_size);
654
655 if (!phys_name || (data && !phys_data))
656 status = EFI_INVALID_PARAMETER;
657 else
658 status = efi_thunk(set_variable, phys_name, phys_vendor,
659 attr, data_size, phys_data);
660
661 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
662
663 return status;
664}
665
666static efi_status_t
667efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
668 u32 attr, unsigned long data_size,
669 void *data)
670{
671 u8 buf[24] __aligned(8);
672 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
673 u32 phys_name, phys_vendor, phys_data;
674 efi_status_t status;
675 unsigned long flags;
676
677 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
678 return EFI_NOT_READY;
679
680 *vnd = *vendor;
681
682 phys_name = virt_to_phys_or_null_size(va: name, size: efi_name_size(name));
683 phys_vendor = virt_to_phys_or_null(vnd);
684 phys_data = virt_to_phys_or_null_size(va: data, size: data_size);
685
686 if (!phys_name || (data && !phys_data))
687 status = EFI_INVALID_PARAMETER;
688 else
689 status = efi_thunk(set_variable, phys_name, phys_vendor,
690 attr, data_size, phys_data);
691
692 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
693
694 return status;
695}
696
697static efi_status_t
698efi_thunk_get_next_variable(unsigned long *name_size,
699 efi_char16_t *name,
700 efi_guid_t *vendor)
701{
702 u8 buf[24] __aligned(8);
703 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
704 efi_status_t status;
705 u32 phys_name_size, phys_name, phys_vendor;
706 unsigned long flags;
707
708 spin_lock_irqsave(&efi_runtime_lock, flags);
709
710 *vnd = *vendor;
711
712 phys_name_size = virt_to_phys_or_null(name_size);
713 phys_vendor = virt_to_phys_or_null(vnd);
714 phys_name = virt_to_phys_or_null_size(va: name, size: *name_size);
715
716 if (!phys_name)
717 status = EFI_INVALID_PARAMETER;
718 else
719 status = efi_thunk(get_next_variable, phys_name_size,
720 phys_name, phys_vendor);
721
722 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
723
724 *vendor = *vnd;
725 return status;
726}
727
728static efi_status_t
729efi_thunk_get_next_high_mono_count(u32 *count)
730{
731 return EFI_UNSUPPORTED;
732}
733
734static void
735efi_thunk_reset_system(int reset_type, efi_status_t status,
736 unsigned long data_size, efi_char16_t *data)
737{
738 u32 phys_data;
739 unsigned long flags;
740
741 spin_lock_irqsave(&efi_runtime_lock, flags);
742
743 phys_data = virt_to_phys_or_null_size(va: data, size: data_size);
744
745 efi_thunk(reset_system, reset_type, status, data_size, phys_data);
746
747 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
748}
749
750static efi_status_t
751efi_thunk_update_capsule(efi_capsule_header_t **capsules,
752 unsigned long count, unsigned long sg_list)
753{
754 /*
755 * To properly support this function we would need to repackage
756 * 'capsules' because the firmware doesn't understand 64-bit
757 * pointers.
758 */
759 return EFI_UNSUPPORTED;
760}
761
762static efi_status_t
763efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
764 u64 *remaining_space,
765 u64 *max_variable_size)
766{
767 efi_status_t status;
768 u32 phys_storage, phys_remaining, phys_max;
769 unsigned long flags;
770
771 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
772 return EFI_UNSUPPORTED;
773
774 spin_lock_irqsave(&efi_runtime_lock, flags);
775
776 phys_storage = virt_to_phys_or_null(storage_space);
777 phys_remaining = virt_to_phys_or_null(remaining_space);
778 phys_max = virt_to_phys_or_null(max_variable_size);
779
780 status = efi_thunk(query_variable_info, attr, phys_storage,
781 phys_remaining, phys_max);
782
783 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
784
785 return status;
786}
787
788static efi_status_t
789efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
790 u64 *remaining_space,
791 u64 *max_variable_size)
792{
793 efi_status_t status;
794 u32 phys_storage, phys_remaining, phys_max;
795 unsigned long flags;
796
797 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
798 return EFI_UNSUPPORTED;
799
800 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
801 return EFI_NOT_READY;
802
803 phys_storage = virt_to_phys_or_null(storage_space);
804 phys_remaining = virt_to_phys_or_null(remaining_space);
805 phys_max = virt_to_phys_or_null(max_variable_size);
806
807 status = efi_thunk(query_variable_info, attr, phys_storage,
808 phys_remaining, phys_max);
809
810 spin_unlock_irqrestore(lock: &efi_runtime_lock, flags);
811
812 return status;
813}
814
815static efi_status_t
816efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
817 unsigned long count, u64 *max_size,
818 int *reset_type)
819{
820 /*
821 * To properly support this function we would need to repackage
822 * 'capsules' because the firmware doesn't understand 64-bit
823 * pointers.
824 */
825 return EFI_UNSUPPORTED;
826}
827
828void __init efi_thunk_runtime_setup(void)
829{
830 if (!IS_ENABLED(CONFIG_EFI_MIXED))
831 return;
832
833 efi.get_time = efi_thunk_get_time;
834 efi.set_time = efi_thunk_set_time;
835 efi.get_wakeup_time = efi_thunk_get_wakeup_time;
836 efi.set_wakeup_time = efi_thunk_set_wakeup_time;
837 efi.get_variable = efi_thunk_get_variable;
838 efi.get_next_variable = efi_thunk_get_next_variable;
839 efi.set_variable = efi_thunk_set_variable;
840 efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
841 efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
842 efi.reset_system = efi_thunk_reset_system;
843 efi.query_variable_info = efi_thunk_query_variable_info;
844 efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
845 efi.update_capsule = efi_thunk_update_capsule;
846 efi.query_capsule_caps = efi_thunk_query_capsule_caps;
847}
848
849efi_status_t __init __no_sanitize_address
850efi_set_virtual_address_map(unsigned long memory_map_size,
851 unsigned long descriptor_size,
852 u32 descriptor_version,
853 efi_memory_desc_t *virtual_map,
854 unsigned long systab_phys)
855{
856 const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
857 efi_status_t status;
858 unsigned long flags;
859
860 if (efi_is_mixed())
861 return efi_thunk_set_virtual_address_map(memory_map_size,
862 descriptor_size,
863 descriptor_version,
864 virtual_map);
865 efi_enter_mm();
866
867 efi_fpu_begin();
868
869 /* Disable interrupts around EFI calls: */
870 local_irq_save(flags);
871 status = arch_efi_call_virt(efi.runtime, set_virtual_address_map,
872 memory_map_size, descriptor_size,
873 descriptor_version, virtual_map);
874 local_irq_restore(flags);
875
876 efi_fpu_end();
877
878 /* grab the virtually remapped EFI runtime services table pointer */
879 efi.runtime = READ_ONCE(systab->runtime);
880
881 efi_leave_mm();
882
883 return status;
884}
885

source code of linux/arch/x86/platform/efi/efi_64.c