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/mem_encrypt.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-es.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
58 struct efi_scratch efi_scratch;
59
60 EXPORT_SYMBOL_GPL(efi_mm);
61
62 /*
63 * We need our own copy of the higher levels of the page tables
64 * because we want to avoid inserting EFI region mappings (EFI_VA_END
65 * to EFI_VA_START) into the standard kernel page tables. Everything
66 * else can be shared, see efi_sync_low_kernel_mappings().
67 *
68 * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
69 * allocation.
70 */
efi_alloc_page_tables(void)71 int __init efi_alloc_page_tables(void)
72 {
73 pgd_t *pgd, *efi_pgd;
74 p4d_t *p4d;
75 pud_t *pud;
76 gfp_t gfp_mask;
77
78 gfp_mask = GFP_KERNEL | __GFP_ZERO;
79 efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
80 if (!efi_pgd)
81 goto fail;
82
83 pgd = efi_pgd + pgd_index(EFI_VA_END);
84 p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
85 if (!p4d)
86 goto free_pgd;
87
88 pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
89 if (!pud)
90 goto free_p4d;
91
92 efi_mm.pgd = efi_pgd;
93 mm_init_cpumask(&efi_mm);
94 init_new_context(NULL, &efi_mm);
95
96 return 0;
97
98 free_p4d:
99 if (pgtable_l5_enabled())
100 free_page((unsigned long)pgd_page_vaddr(*pgd));
101 free_pgd:
102 free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
103 fail:
104 return -ENOMEM;
105 }
106
107 /*
108 * Add low kernel mappings for passing arguments to EFI functions.
109 */
efi_sync_low_kernel_mappings(void)110 void efi_sync_low_kernel_mappings(void)
111 {
112 unsigned num_entries;
113 pgd_t *pgd_k, *pgd_efi;
114 p4d_t *p4d_k, *p4d_efi;
115 pud_t *pud_k, *pud_efi;
116 pgd_t *efi_pgd = efi_mm.pgd;
117
118 /*
119 * We can share all PGD entries apart from the one entry that
120 * covers the EFI runtime mapping space.
121 *
122 * Make sure the EFI runtime region mappings are guaranteed to
123 * only span a single PGD entry and that the entry also maps
124 * other important kernel regions.
125 */
126 MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
127 MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
128 (EFI_VA_END & PGDIR_MASK));
129
130 pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
131 pgd_k = pgd_offset_k(PAGE_OFFSET);
132
133 num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
134 memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
135
136 /*
137 * As with PGDs, we share all P4D entries apart from the one entry
138 * that covers the EFI runtime mapping space.
139 */
140 BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
141 BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
142
143 pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
144 pgd_k = pgd_offset_k(EFI_VA_END);
145 p4d_efi = p4d_offset(pgd_efi, 0);
146 p4d_k = p4d_offset(pgd_k, 0);
147
148 num_entries = p4d_index(EFI_VA_END);
149 memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
150
151 /*
152 * We share all the PUD entries apart from those that map the
153 * EFI regions. Copy around them.
154 */
155 BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
156 BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
157
158 p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
159 p4d_k = p4d_offset(pgd_k, EFI_VA_END);
160 pud_efi = pud_offset(p4d_efi, 0);
161 pud_k = pud_offset(p4d_k, 0);
162
163 num_entries = pud_index(EFI_VA_END);
164 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
165
166 pud_efi = pud_offset(p4d_efi, EFI_VA_START);
167 pud_k = pud_offset(p4d_k, EFI_VA_START);
168
169 num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
170 memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
171 }
172
173 /*
174 * Wrapper for slow_virt_to_phys() that handles NULL addresses.
175 */
176 static inline phys_addr_t
virt_to_phys_or_null_size(void * va,unsigned long size)177 virt_to_phys_or_null_size(void *va, unsigned long size)
178 {
179 phys_addr_t pa;
180
181 if (!va)
182 return 0;
183
184 if (virt_addr_valid(va))
185 return virt_to_phys(va);
186
187 pa = slow_virt_to_phys(va);
188
189 /* check if the object crosses a page boundary */
190 if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
191 return 0;
192
193 return pa;
194 }
195
196 #define virt_to_phys_or_null(addr) \
197 virt_to_phys_or_null_size((addr), sizeof(*(addr)))
198
efi_setup_page_tables(unsigned long pa_memmap,unsigned num_pages)199 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
200 {
201 unsigned long pfn, text, pf, rodata;
202 struct page *page;
203 unsigned npages;
204 pgd_t *pgd = efi_mm.pgd;
205
206 /*
207 * It can happen that the physical address of new_memmap lands in memory
208 * which is not mapped in the EFI page table. Therefore we need to go
209 * and ident-map those pages containing the map before calling
210 * phys_efi_set_virtual_address_map().
211 */
212 pfn = pa_memmap >> PAGE_SHIFT;
213 pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
214 if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
215 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
216 return 1;
217 }
218
219 /*
220 * Certain firmware versions are way too sentimential and still believe
221 * they are exclusive and unquestionable owners of the first physical page,
222 * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
223 * (but then write-access it later during SetVirtualAddressMap()).
224 *
225 * Create a 1:1 mapping for this page, to avoid triple faults during early
226 * boot with such firmware. We are free to hand this page to the BIOS,
227 * as trim_bios_range() will reserve the first page and isolate it away
228 * from memory allocators anyway.
229 */
230 if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
231 pr_err("Failed to create 1:1 mapping for the first page!\n");
232 return 1;
233 }
234
235 /*
236 * When SEV-ES is active, the GHCB as set by the kernel will be used
237 * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
238 */
239 if (sev_es_efi_map_ghcbs(pgd)) {
240 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
241 return 1;
242 }
243
244 /*
245 * When making calls to the firmware everything needs to be 1:1
246 * mapped and addressable with 32-bit pointers. Map the kernel
247 * text and allocate a new stack because we can't rely on the
248 * stack pointer being < 4GB.
249 */
250 if (!efi_is_mixed())
251 return 0;
252
253 page = alloc_page(GFP_KERNEL|__GFP_DMA32);
254 if (!page) {
255 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
256 return 1;
257 }
258
259 efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */
260
261 npages = (_etext - _text) >> PAGE_SHIFT;
262 text = __pa(_text);
263 pfn = text >> PAGE_SHIFT;
264
265 pf = _PAGE_ENC;
266 if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
267 pr_err("Failed to map kernel text 1:1\n");
268 return 1;
269 }
270
271 npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
272 rodata = __pa(__start_rodata);
273 pfn = rodata >> PAGE_SHIFT;
274
275 pf = _PAGE_NX | _PAGE_ENC;
276 if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
277 pr_err("Failed to map kernel rodata 1:1\n");
278 return 1;
279 }
280
281 return 0;
282 }
283
__map_region(efi_memory_desc_t * md,u64 va)284 static void __init __map_region(efi_memory_desc_t *md, u64 va)
285 {
286 unsigned long flags = _PAGE_RW;
287 unsigned long pfn;
288 pgd_t *pgd = efi_mm.pgd;
289
290 /*
291 * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
292 * executable images in memory that consist of both R-X and
293 * RW- sections, so we cannot apply read-only or non-exec
294 * permissions just yet. However, modern EFI systems provide
295 * a memory attributes table that describes those sections
296 * with the appropriate restricted permissions, which are
297 * applied in efi_runtime_update_mappings() below. All other
298 * regions can be mapped non-executable at this point, with
299 * the exception of boot services code regions, but those will
300 * be unmapped again entirely in efi_free_boot_services().
301 */
302 if (md->type != EFI_BOOT_SERVICES_CODE &&
303 md->type != EFI_RUNTIME_SERVICES_CODE)
304 flags |= _PAGE_NX;
305
306 if (!(md->attribute & EFI_MEMORY_WB))
307 flags |= _PAGE_PCD;
308
309 if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
310 flags |= _PAGE_ENC;
311
312 pfn = md->phys_addr >> PAGE_SHIFT;
313 if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
314 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
315 md->phys_addr, va);
316 }
317
efi_map_region(efi_memory_desc_t * md)318 void __init efi_map_region(efi_memory_desc_t *md)
319 {
320 unsigned long size = md->num_pages << PAGE_SHIFT;
321 u64 pa = md->phys_addr;
322
323 /*
324 * Make sure the 1:1 mappings are present as a catch-all for b0rked
325 * firmware which doesn't update all internal pointers after switching
326 * to virtual mode and would otherwise crap on us.
327 */
328 __map_region(md, md->phys_addr);
329
330 /*
331 * Enforce the 1:1 mapping as the default virtual address when
332 * booting in EFI mixed mode, because even though we may be
333 * running a 64-bit kernel, the firmware may only be 32-bit.
334 */
335 if (efi_is_mixed()) {
336 md->virt_addr = md->phys_addr;
337 return;
338 }
339
340 efi_va -= size;
341
342 /* Is PA 2M-aligned? */
343 if (!(pa & (PMD_SIZE - 1))) {
344 efi_va &= PMD_MASK;
345 } else {
346 u64 pa_offset = pa & (PMD_SIZE - 1);
347 u64 prev_va = efi_va;
348
349 /* get us the same offset within this 2M page */
350 efi_va = (efi_va & PMD_MASK) + pa_offset;
351
352 if (efi_va > prev_va)
353 efi_va -= PMD_SIZE;
354 }
355
356 if (efi_va < EFI_VA_END) {
357 pr_warn(FW_WARN "VA address range overflow!\n");
358 return;
359 }
360
361 /* Do the VA map */
362 __map_region(md, efi_va);
363 md->virt_addr = efi_va;
364 }
365
366 /*
367 * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
368 * md->virt_addr is the original virtual address which had been mapped in kexec
369 * 1st kernel.
370 */
efi_map_region_fixed(efi_memory_desc_t * md)371 void __init efi_map_region_fixed(efi_memory_desc_t *md)
372 {
373 __map_region(md, md->phys_addr);
374 __map_region(md, md->virt_addr);
375 }
376
parse_efi_setup(u64 phys_addr,u32 data_len)377 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
378 {
379 efi_setup = phys_addr + sizeof(struct setup_data);
380 }
381
efi_update_mappings(efi_memory_desc_t * md,unsigned long pf)382 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
383 {
384 unsigned long pfn;
385 pgd_t *pgd = efi_mm.pgd;
386 int err1, err2;
387
388 /* Update the 1:1 mapping */
389 pfn = md->phys_addr >> PAGE_SHIFT;
390 err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
391 if (err1) {
392 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
393 md->phys_addr, md->virt_addr);
394 }
395
396 err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
397 if (err2) {
398 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
399 md->phys_addr, md->virt_addr);
400 }
401
402 return err1 || err2;
403 }
404
efi_update_mem_attr(struct mm_struct * mm,efi_memory_desc_t * md)405 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
406 {
407 unsigned long pf = 0;
408
409 if (md->attribute & EFI_MEMORY_XP)
410 pf |= _PAGE_NX;
411
412 if (!(md->attribute & EFI_MEMORY_RO))
413 pf |= _PAGE_RW;
414
415 if (sev_active())
416 pf |= _PAGE_ENC;
417
418 return efi_update_mappings(md, pf);
419 }
420
efi_runtime_update_mappings(void)421 void __init efi_runtime_update_mappings(void)
422 {
423 efi_memory_desc_t *md;
424
425 /*
426 * Use the EFI Memory Attribute Table for mapping permissions if it
427 * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
428 */
429 if (efi_enabled(EFI_MEM_ATTR)) {
430 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
431 return;
432 }
433
434 /*
435 * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
436 * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
437 * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
438 * published by the firmware. Even if we find a buggy implementation of
439 * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
440 * EFI_PROPERTIES_TABLE, because of the same reason.
441 */
442
443 if (!efi_enabled(EFI_NX_PE_DATA))
444 return;
445
446 for_each_efi_memory_desc(md) {
447 unsigned long pf = 0;
448
449 if (!(md->attribute & EFI_MEMORY_RUNTIME))
450 continue;
451
452 if (!(md->attribute & EFI_MEMORY_WB))
453 pf |= _PAGE_PCD;
454
455 if ((md->attribute & EFI_MEMORY_XP) ||
456 (md->type == EFI_RUNTIME_SERVICES_DATA))
457 pf |= _PAGE_NX;
458
459 if (!(md->attribute & EFI_MEMORY_RO) &&
460 (md->type != EFI_RUNTIME_SERVICES_CODE))
461 pf |= _PAGE_RW;
462
463 if (sev_active())
464 pf |= _PAGE_ENC;
465
466 efi_update_mappings(md, pf);
467 }
468 }
469
efi_dump_pagetable(void)470 void __init efi_dump_pagetable(void)
471 {
472 #ifdef CONFIG_EFI_PGT_DUMP
473 ptdump_walk_pgd_level(NULL, &efi_mm);
474 #endif
475 }
476
477 /*
478 * Makes the calling thread switch to/from efi_mm context. Can be used
479 * in a kernel thread and user context. Preemption needs to remain disabled
480 * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
481 * can not change under us.
482 * It should be ensured that there are no concurent calls to this function.
483 */
efi_switch_mm(struct mm_struct * mm)484 void efi_switch_mm(struct mm_struct *mm)
485 {
486 efi_scratch.prev_mm = current->active_mm;
487 current->active_mm = mm;
488 switch_mm(efi_scratch.prev_mm, mm, NULL);
489 }
490
491 static DEFINE_SPINLOCK(efi_runtime_lock);
492
493 /*
494 * DS and ES contain user values. We need to save them.
495 * The 32-bit EFI code needs a valid DS, ES, and SS. There's no
496 * need to save the old SS: __KERNEL_DS is always acceptable.
497 */
498 #define __efi_thunk(func, ...) \
499 ({ \
500 unsigned short __ds, __es; \
501 efi_status_t ____s; \
502 \
503 savesegment(ds, __ds); \
504 savesegment(es, __es); \
505 \
506 loadsegment(ss, __KERNEL_DS); \
507 loadsegment(ds, __KERNEL_DS); \
508 loadsegment(es, __KERNEL_DS); \
509 \
510 ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
511 \
512 loadsegment(ds, __ds); \
513 loadsegment(es, __es); \
514 \
515 ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32; \
516 ____s; \
517 })
518
519 /*
520 * Switch to the EFI page tables early so that we can access the 1:1
521 * runtime services mappings which are not mapped in any other page
522 * tables.
523 *
524 * Also, disable interrupts because the IDT points to 64-bit handlers,
525 * which aren't going to function correctly when we switch to 32-bit.
526 */
527 #define efi_thunk(func...) \
528 ({ \
529 efi_status_t __s; \
530 \
531 arch_efi_call_virt_setup(); \
532 \
533 __s = __efi_thunk(func); \
534 \
535 arch_efi_call_virt_teardown(); \
536 \
537 __s; \
538 })
539
540 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)541 efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
542 unsigned long descriptor_size,
543 u32 descriptor_version,
544 efi_memory_desc_t *virtual_map)
545 {
546 efi_status_t status;
547 unsigned long flags;
548
549 efi_sync_low_kernel_mappings();
550 local_irq_save(flags);
551
552 efi_switch_mm(&efi_mm);
553
554 status = __efi_thunk(set_virtual_address_map, memory_map_size,
555 descriptor_size, descriptor_version, virtual_map);
556
557 efi_switch_mm(efi_scratch.prev_mm);
558 local_irq_restore(flags);
559
560 return status;
561 }
562
efi_thunk_get_time(efi_time_t * tm,efi_time_cap_t * tc)563 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
564 {
565 return EFI_UNSUPPORTED;
566 }
567
efi_thunk_set_time(efi_time_t * tm)568 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
569 {
570 return EFI_UNSUPPORTED;
571 }
572
573 static efi_status_t
efi_thunk_get_wakeup_time(efi_bool_t * enabled,efi_bool_t * pending,efi_time_t * tm)574 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
575 efi_time_t *tm)
576 {
577 return EFI_UNSUPPORTED;
578 }
579
580 static efi_status_t
efi_thunk_set_wakeup_time(efi_bool_t enabled,efi_time_t * tm)581 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
582 {
583 return EFI_UNSUPPORTED;
584 }
585
efi_name_size(efi_char16_t * name)586 static unsigned long efi_name_size(efi_char16_t *name)
587 {
588 return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
589 }
590
591 static efi_status_t
efi_thunk_get_variable(efi_char16_t * name,efi_guid_t * vendor,u32 * attr,unsigned long * data_size,void * data)592 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
593 u32 *attr, unsigned long *data_size, void *data)
594 {
595 u8 buf[24] __aligned(8);
596 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
597 efi_status_t status;
598 u32 phys_name, phys_vendor, phys_attr;
599 u32 phys_data_size, phys_data;
600 unsigned long flags;
601
602 spin_lock_irqsave(&efi_runtime_lock, flags);
603
604 *vnd = *vendor;
605
606 phys_data_size = virt_to_phys_or_null(data_size);
607 phys_vendor = virt_to_phys_or_null(vnd);
608 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
609 phys_attr = virt_to_phys_or_null(attr);
610 phys_data = virt_to_phys_or_null_size(data, *data_size);
611
612 if (!phys_name || (data && !phys_data))
613 status = EFI_INVALID_PARAMETER;
614 else
615 status = efi_thunk(get_variable, phys_name, phys_vendor,
616 phys_attr, phys_data_size, phys_data);
617
618 spin_unlock_irqrestore(&efi_runtime_lock, flags);
619
620 return status;
621 }
622
623 static efi_status_t
efi_thunk_set_variable(efi_char16_t * name,efi_guid_t * vendor,u32 attr,unsigned long data_size,void * data)624 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
625 u32 attr, unsigned long data_size, void *data)
626 {
627 u8 buf[24] __aligned(8);
628 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
629 u32 phys_name, phys_vendor, phys_data;
630 efi_status_t status;
631 unsigned long flags;
632
633 spin_lock_irqsave(&efi_runtime_lock, flags);
634
635 *vnd = *vendor;
636
637 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
638 phys_vendor = virt_to_phys_or_null(vnd);
639 phys_data = virt_to_phys_or_null_size(data, data_size);
640
641 if (!phys_name || (data && !phys_data))
642 status = EFI_INVALID_PARAMETER;
643 else
644 status = efi_thunk(set_variable, phys_name, phys_vendor,
645 attr, data_size, phys_data);
646
647 spin_unlock_irqrestore(&efi_runtime_lock, flags);
648
649 return status;
650 }
651
652 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)653 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
654 u32 attr, unsigned long data_size,
655 void *data)
656 {
657 u8 buf[24] __aligned(8);
658 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
659 u32 phys_name, phys_vendor, phys_data;
660 efi_status_t status;
661 unsigned long flags;
662
663 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
664 return EFI_NOT_READY;
665
666 *vnd = *vendor;
667
668 phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
669 phys_vendor = virt_to_phys_or_null(vnd);
670 phys_data = virt_to_phys_or_null_size(data, data_size);
671
672 if (!phys_name || (data && !phys_data))
673 status = EFI_INVALID_PARAMETER;
674 else
675 status = efi_thunk(set_variable, phys_name, phys_vendor,
676 attr, data_size, phys_data);
677
678 spin_unlock_irqrestore(&efi_runtime_lock, flags);
679
680 return status;
681 }
682
683 static efi_status_t
efi_thunk_get_next_variable(unsigned long * name_size,efi_char16_t * name,efi_guid_t * vendor)684 efi_thunk_get_next_variable(unsigned long *name_size,
685 efi_char16_t *name,
686 efi_guid_t *vendor)
687 {
688 u8 buf[24] __aligned(8);
689 efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
690 efi_status_t status;
691 u32 phys_name_size, phys_name, phys_vendor;
692 unsigned long flags;
693
694 spin_lock_irqsave(&efi_runtime_lock, flags);
695
696 *vnd = *vendor;
697
698 phys_name_size = virt_to_phys_or_null(name_size);
699 phys_vendor = virt_to_phys_or_null(vnd);
700 phys_name = virt_to_phys_or_null_size(name, *name_size);
701
702 if (!phys_name)
703 status = EFI_INVALID_PARAMETER;
704 else
705 status = efi_thunk(get_next_variable, phys_name_size,
706 phys_name, phys_vendor);
707
708 spin_unlock_irqrestore(&efi_runtime_lock, flags);
709
710 *vendor = *vnd;
711 return status;
712 }
713
714 static efi_status_t
efi_thunk_get_next_high_mono_count(u32 * count)715 efi_thunk_get_next_high_mono_count(u32 *count)
716 {
717 return EFI_UNSUPPORTED;
718 }
719
720 static void
efi_thunk_reset_system(int reset_type,efi_status_t status,unsigned long data_size,efi_char16_t * data)721 efi_thunk_reset_system(int reset_type, efi_status_t status,
722 unsigned long data_size, efi_char16_t *data)
723 {
724 u32 phys_data;
725 unsigned long flags;
726
727 spin_lock_irqsave(&efi_runtime_lock, flags);
728
729 phys_data = virt_to_phys_or_null_size(data, data_size);
730
731 efi_thunk(reset_system, reset_type, status, data_size, phys_data);
732
733 spin_unlock_irqrestore(&efi_runtime_lock, flags);
734 }
735
736 static efi_status_t
efi_thunk_update_capsule(efi_capsule_header_t ** capsules,unsigned long count,unsigned long sg_list)737 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
738 unsigned long count, unsigned long sg_list)
739 {
740 /*
741 * To properly support this function we would need to repackage
742 * 'capsules' because the firmware doesn't understand 64-bit
743 * pointers.
744 */
745 return EFI_UNSUPPORTED;
746 }
747
748 static efi_status_t
efi_thunk_query_variable_info(u32 attr,u64 * storage_space,u64 * remaining_space,u64 * max_variable_size)749 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
750 u64 *remaining_space,
751 u64 *max_variable_size)
752 {
753 efi_status_t status;
754 u32 phys_storage, phys_remaining, phys_max;
755 unsigned long flags;
756
757 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
758 return EFI_UNSUPPORTED;
759
760 spin_lock_irqsave(&efi_runtime_lock, flags);
761
762 phys_storage = virt_to_phys_or_null(storage_space);
763 phys_remaining = virt_to_phys_or_null(remaining_space);
764 phys_max = virt_to_phys_or_null(max_variable_size);
765
766 status = efi_thunk(query_variable_info, attr, phys_storage,
767 phys_remaining, phys_max);
768
769 spin_unlock_irqrestore(&efi_runtime_lock, flags);
770
771 return status;
772 }
773
774 static efi_status_t
efi_thunk_query_variable_info_nonblocking(u32 attr,u64 * storage_space,u64 * remaining_space,u64 * max_variable_size)775 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
776 u64 *remaining_space,
777 u64 *max_variable_size)
778 {
779 efi_status_t status;
780 u32 phys_storage, phys_remaining, phys_max;
781 unsigned long flags;
782
783 if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
784 return EFI_UNSUPPORTED;
785
786 if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
787 return EFI_NOT_READY;
788
789 phys_storage = virt_to_phys_or_null(storage_space);
790 phys_remaining = virt_to_phys_or_null(remaining_space);
791 phys_max = virt_to_phys_or_null(max_variable_size);
792
793 status = efi_thunk(query_variable_info, attr, phys_storage,
794 phys_remaining, phys_max);
795
796 spin_unlock_irqrestore(&efi_runtime_lock, flags);
797
798 return status;
799 }
800
801 static efi_status_t
efi_thunk_query_capsule_caps(efi_capsule_header_t ** capsules,unsigned long count,u64 * max_size,int * reset_type)802 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
803 unsigned long count, u64 *max_size,
804 int *reset_type)
805 {
806 /*
807 * To properly support this function we would need to repackage
808 * 'capsules' because the firmware doesn't understand 64-bit
809 * pointers.
810 */
811 return EFI_UNSUPPORTED;
812 }
813
efi_thunk_runtime_setup(void)814 void __init efi_thunk_runtime_setup(void)
815 {
816 if (!IS_ENABLED(CONFIG_EFI_MIXED))
817 return;
818
819 efi.get_time = efi_thunk_get_time;
820 efi.set_time = efi_thunk_set_time;
821 efi.get_wakeup_time = efi_thunk_get_wakeup_time;
822 efi.set_wakeup_time = efi_thunk_set_wakeup_time;
823 efi.get_variable = efi_thunk_get_variable;
824 efi.get_next_variable = efi_thunk_get_next_variable;
825 efi.set_variable = efi_thunk_set_variable;
826 efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
827 efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
828 efi.reset_system = efi_thunk_reset_system;
829 efi.query_variable_info = efi_thunk_query_variable_info;
830 efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
831 efi.update_capsule = efi_thunk_update_capsule;
832 efi.query_capsule_caps = efi_thunk_query_capsule_caps;
833 }
834
835 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)836 efi_set_virtual_address_map(unsigned long memory_map_size,
837 unsigned long descriptor_size,
838 u32 descriptor_version,
839 efi_memory_desc_t *virtual_map,
840 unsigned long systab_phys)
841 {
842 const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
843 efi_status_t status;
844 unsigned long flags;
845
846 if (efi_is_mixed())
847 return efi_thunk_set_virtual_address_map(memory_map_size,
848 descriptor_size,
849 descriptor_version,
850 virtual_map);
851 efi_switch_mm(&efi_mm);
852
853 kernel_fpu_begin();
854
855 /* Disable interrupts around EFI calls: */
856 local_irq_save(flags);
857 status = efi_call(efi.runtime->set_virtual_address_map,
858 memory_map_size, descriptor_size,
859 descriptor_version, virtual_map);
860 local_irq_restore(flags);
861
862 kernel_fpu_end();
863
864 /* grab the virtually remapped EFI runtime services table pointer */
865 efi.runtime = READ_ONCE(systab->runtime);
866
867 efi_switch_mm(efi_scratch.prev_mm);
868
869 return status;
870 }
871
