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