1 #define pr_fmt(fmt) "efi: " fmt
3 #include <linux/init.h>
4 #include <linux/kernel.h>
5 #include <linux/string.h>
6 #include <linux/time.h>
7 #include <linux/types.h>
9 #include <linux/slab.h>
10 #include <linux/memblock.h>
11 #include <linux/acpi.h>
12 #include <linux/dmi.h>
14 #include <asm/e820/api.h>
16 #include <asm/uv/uv.h>
17 #include <asm/cpu_device_id.h>
18 #include <asm/reboot.h>
20 #define EFI_MIN_RESERVE 5120
22 #define EFI_DUMMY_GUID \
23 EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
25 #define QUARK_CSH_SIGNATURE 0x5f435348 /* _CSH */
26 #define QUARK_SECURITY_HEADER_SIZE 0x400
29 * Header prepended to the standard EFI capsule on Quark systems the are based
30 * on Intel firmware BSP.
31 * @csh_signature: Unique identifier to sanity check signed module
33 * @version: Current version of CSH used. Should be one for Quark A0.
34 * @modulesize: Size of the entire module including the module header
36 * @security_version_number_index: Index of SVN to use for validation of signed
38 * @security_version_number: Used to prevent against roll back of modules.
39 * @rsvd_module_id: Currently unused for Clanton (Quark).
40 * @rsvd_module_vendor: Vendor Identifier. For Intel products value is
42 * @rsvd_date: BCD representation of build date as yyyymmdd, where
43 * yyyy=4 digit year, mm=1-12, dd=1-31.
44 * @headersize: Total length of the header including including any
45 * padding optionally added by the signing tool.
46 * @hash_algo: What Hash is used in the module signing.
47 * @cryp_algo: What Crypto is used in the module signing.
48 * @keysize: Total length of the key data including including any
49 * padding optionally added by the signing tool.
50 * @signaturesize: Total length of the signature including including any
51 * padding optionally added by the signing tool.
52 * @rsvd_next_header: 32-bit pointer to the next Secure Boot Module in the
53 * chain, if there is a next header.
54 * @rsvd: Reserved, padding structure to required size.
56 * See also QuartSecurityHeader_t in
57 * Quark_EDKII_v1.2.1.1/QuarkPlatformPkg/Include/QuarkBootRom.h
58 * from https://downloadcenter.intel.com/download/23197/Intel-Quark-SoC-X1000-Board-Support-Package-BSP
60 struct quark_security_header {
64 u32 security_version_number_index;
65 u32 security_version_number;
67 u32 rsvd_module_vendor;
78 static const efi_char16_t efi_dummy_name[] = L"DUMMY";
80 static bool efi_no_storage_paranoia;
83 * Some firmware implementations refuse to boot if there's insufficient
84 * space in the variable store. The implementation of garbage collection
85 * in some FW versions causes stale (deleted) variables to take up space
86 * longer than intended and space is only freed once the store becomes
87 * almost completely full.
89 * Enabling this option disables the space checks in
90 * efi_query_variable_store() and forces garbage collection.
92 * Only enable this option if deleting EFI variables does not free up
93 * space in your variable store, e.g. if despite deleting variables
94 * you're unable to create new ones.
96 static int __init setup_storage_paranoia(char *arg)
98 efi_no_storage_paranoia = true;
101 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
104 * Deleting the dummy variable which kicks off garbage collection
106 void efi_delete_dummy_variable(void)
108 efi.set_variable_nonblocking((efi_char16_t *)efi_dummy_name,
110 EFI_VARIABLE_NON_VOLATILE |
111 EFI_VARIABLE_BOOTSERVICE_ACCESS |
112 EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
116 * In the nonblocking case we do not attempt to perform garbage
117 * collection if we do not have enough free space. Rather, we do the
118 * bare minimum check and give up immediately if the available space
119 * is below EFI_MIN_RESERVE.
121 * This function is intended to be small and simple because it is
122 * invoked from crash handler paths.
125 query_variable_store_nonblocking(u32 attributes, unsigned long size)
128 u64 storage_size, remaining_size, max_size;
130 status = efi.query_variable_info_nonblocking(attributes, &storage_size,
133 if (status != EFI_SUCCESS)
136 if (remaining_size - size < EFI_MIN_RESERVE)
137 return EFI_OUT_OF_RESOURCES;
143 * Some firmware implementations refuse to boot if there's insufficient space
144 * in the variable store. Ensure that we never use more than a safe limit.
146 * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
149 efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
153 u64 storage_size, remaining_size, max_size;
155 if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
159 return query_variable_store_nonblocking(attributes, size);
161 status = efi.query_variable_info(attributes, &storage_size,
162 &remaining_size, &max_size);
163 if (status != EFI_SUCCESS)
167 * We account for that by refusing the write if permitting it would
168 * reduce the available space to under 5KB. This figure was provided by
169 * Samsung, so should be safe.
171 if ((remaining_size - size < EFI_MIN_RESERVE) &&
172 !efi_no_storage_paranoia) {
175 * Triggering garbage collection may require that the firmware
176 * generate a real EFI_OUT_OF_RESOURCES error. We can force
177 * that by attempting to use more space than is available.
179 unsigned long dummy_size = remaining_size + 1024;
180 void *dummy = kzalloc(dummy_size, GFP_KERNEL);
183 return EFI_OUT_OF_RESOURCES;
185 status = efi.set_variable((efi_char16_t *)efi_dummy_name,
187 EFI_VARIABLE_NON_VOLATILE |
188 EFI_VARIABLE_BOOTSERVICE_ACCESS |
189 EFI_VARIABLE_RUNTIME_ACCESS,
192 if (status == EFI_SUCCESS) {
194 * This should have failed, so if it didn't make sure
195 * that we delete it...
197 efi_delete_dummy_variable();
203 * The runtime code may now have triggered a garbage collection
204 * run, so check the variable info again
206 status = efi.query_variable_info(attributes, &storage_size,
207 &remaining_size, &max_size);
209 if (status != EFI_SUCCESS)
213 * There still isn't enough room, so return an error
215 if (remaining_size - size < EFI_MIN_RESERVE)
216 return EFI_OUT_OF_RESOURCES;
221 EXPORT_SYMBOL_GPL(efi_query_variable_store);
224 * The UEFI specification makes it clear that the operating system is
225 * free to do whatever it wants with boot services code after
226 * ExitBootServices() has been called. Ignoring this recommendation a
227 * significant bunch of EFI implementations continue calling into boot
228 * services code (SetVirtualAddressMap). In order to work around such
229 * buggy implementations we reserve boot services region during EFI
230 * init and make sure it stays executable. Then, after
231 * SetVirtualAddressMap(), it is discarded.
233 * However, some boot services regions contain data that is required
234 * by drivers, so we need to track which memory ranges can never be
235 * freed. This is done by tagging those regions with the
236 * EFI_MEMORY_RUNTIME attribute.
238 * Any driver that wants to mark a region as reserved must use
239 * efi_mem_reserve() which will insert a new EFI memory descriptor
240 * into efi.memmap (splitting existing regions if necessary) and tag
241 * it with EFI_MEMORY_RUNTIME.
243 void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
245 phys_addr_t new_phys, new_size;
246 struct efi_mem_range mr;
247 efi_memory_desc_t md;
251 if (efi_mem_desc_lookup(addr, &md) ||
252 md.type != EFI_BOOT_SERVICES_DATA) {
253 pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
257 if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) {
258 pr_err("Region spans EFI memory descriptors, %pa\n", &addr);
262 /* No need to reserve regions that will never be freed. */
263 if (md.attribute & EFI_MEMORY_RUNTIME)
266 size += addr % EFI_PAGE_SIZE;
267 size = round_up(size, EFI_PAGE_SIZE);
268 addr = round_down(addr, EFI_PAGE_SIZE);
270 mr.range.start = addr;
271 mr.range.end = addr + size - 1;
272 mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
274 num_entries = efi_memmap_split_count(&md, &mr.range);
275 num_entries += efi.memmap.nr_map;
277 new_size = efi.memmap.desc_size * num_entries;
279 new_phys = efi_memmap_alloc(num_entries);
281 pr_err("Could not allocate boot services memmap\n");
285 new = early_memremap(new_phys, new_size);
287 pr_err("Failed to map new boot services memmap\n");
291 efi_memmap_insert(&efi.memmap, new, &mr);
292 early_memunmap(new, new_size);
294 efi_memmap_install(new_phys, num_entries);
298 * Helper function for efi_reserve_boot_services() to figure out if we
299 * can free regions in efi_free_boot_services().
301 * Use this function to ensure we do not free regions owned by somebody
302 * else. We must only reserve (and then free) regions:
304 * - Not within any part of the kernel
305 * - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc)
307 static __init bool can_free_region(u64 start, u64 size)
309 if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
312 if (!e820__mapped_all(start, start+size, E820_TYPE_RAM))
318 void __init efi_reserve_boot_services(void)
320 efi_memory_desc_t *md;
322 for_each_efi_memory_desc(md) {
323 u64 start = md->phys_addr;
324 u64 size = md->num_pages << EFI_PAGE_SHIFT;
325 bool already_reserved;
327 if (md->type != EFI_BOOT_SERVICES_CODE &&
328 md->type != EFI_BOOT_SERVICES_DATA)
331 already_reserved = memblock_is_region_reserved(start, size);
334 * Because the following memblock_reserve() is paired
335 * with memblock_free_late() for this region in
336 * efi_free_boot_services(), we must be extremely
337 * careful not to reserve, and subsequently free,
338 * critical regions of memory (like the kernel image) or
339 * those regions that somebody else has already
342 * A good example of a critical region that must not be
343 * freed is page zero (first 4Kb of memory), which may
344 * contain boot services code/data but is marked
345 * E820_TYPE_RESERVED by trim_bios_range().
347 if (!already_reserved) {
348 memblock_reserve(start, size);
351 * If we are the first to reserve the region, no
352 * one else cares about it. We own it and can
355 if (can_free_region(start, size))
360 * We don't own the region. We must not free it.
362 * Setting this bit for a boot services region really
363 * doesn't make sense as far as the firmware is
364 * concerned, but it does provide us with a way to tag
365 * those regions that must not be paired with
366 * memblock_free_late().
368 md->attribute |= EFI_MEMORY_RUNTIME;
373 * Apart from having VA mappings for EFI boot services code/data regions,
374 * (duplicate) 1:1 mappings were also created as a quirk for buggy firmware. So,
375 * unmap both 1:1 and VA mappings.
377 static void __init efi_unmap_pages(efi_memory_desc_t *md)
379 pgd_t *pgd = efi_mm.pgd;
380 u64 pa = md->phys_addr;
381 u64 va = md->virt_addr;
384 * To Do: Remove this check after adding functionality to unmap EFI boot
385 * services code/data regions from direct mapping area because
386 * "efi=old_map" maps EFI regions in swapper_pg_dir.
388 if (efi_enabled(EFI_OLD_MEMMAP))
392 * EFI mixed mode has all RAM mapped to access arguments while making
393 * EFI runtime calls, hence don't unmap EFI boot services code/data
396 if (!efi_is_native())
399 if (kernel_unmap_pages_in_pgd(pgd, pa, md->num_pages))
400 pr_err("Failed to unmap 1:1 mapping for 0x%llx\n", pa);
402 if (kernel_unmap_pages_in_pgd(pgd, va, md->num_pages))
403 pr_err("Failed to unmap VA mapping for 0x%llx\n", va);
406 void __init efi_free_boot_services(void)
408 phys_addr_t new_phys, new_size;
409 efi_memory_desc_t *md;
413 for_each_efi_memory_desc(md) {
414 unsigned long long start = md->phys_addr;
415 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
418 if (md->type != EFI_BOOT_SERVICES_CODE &&
419 md->type != EFI_BOOT_SERVICES_DATA) {
424 /* Do not free, someone else owns it: */
425 if (md->attribute & EFI_MEMORY_RUNTIME) {
431 * Before calling set_virtual_address_map(), EFI boot services
432 * code/data regions were mapped as a quirk for buggy firmware.
433 * Unmap them from efi_pgd before freeing them up.
438 * Nasty quirk: if all sub-1MB memory is used for boot
439 * services, we can get here without having allocated the
440 * real mode trampoline. It's too late to hand boot services
441 * memory back to the memblock allocator, so instead
442 * try to manually allocate the trampoline if needed.
444 * I've seen this on a Dell XPS 13 9350 with firmware
445 * 1.4.4 with SGX enabled booting Linux via Fedora 24's
446 * grub2-efi on a hard disk. (And no, I don't know why
447 * this happened, but Linux should still try to boot rather
450 rm_size = real_mode_size_needed();
451 if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
452 set_real_mode_mem(start);
457 memblock_free_late(start, size);
463 new_size = efi.memmap.desc_size * num_entries;
464 new_phys = efi_memmap_alloc(num_entries);
466 pr_err("Failed to allocate new EFI memmap\n");
470 new = memremap(new_phys, new_size, MEMREMAP_WB);
472 pr_err("Failed to map new EFI memmap\n");
477 * Build a new EFI memmap that excludes any boot services
478 * regions that are not tagged EFI_MEMORY_RUNTIME, since those
479 * regions have now been freed.
482 for_each_efi_memory_desc(md) {
483 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
484 (md->type == EFI_BOOT_SERVICES_CODE ||
485 md->type == EFI_BOOT_SERVICES_DATA))
488 memcpy(new_md, md, efi.memmap.desc_size);
489 new_md += efi.memmap.desc_size;
494 if (efi_memmap_install(new_phys, num_entries)) {
495 pr_err("Could not install new EFI memmap\n");
501 * A number of config table entries get remapped to virtual addresses
502 * after entering EFI virtual mode. However, the kexec kernel requires
503 * their physical addresses therefore we pass them via setup_data and
504 * correct those entries to their respective physical addresses here.
506 * Currently only handles smbios which is necessary for some firmware
509 int __init efi_reuse_config(u64 tables, int nr_tables)
513 struct efi_setup_data *data;
518 if (!efi_enabled(EFI_64BIT))
521 data = early_memremap(efi_setup, sizeof(*data));
530 sz = sizeof(efi_config_table_64_t);
532 p = tablep = early_memremap(tables, nr_tables * sz);
534 pr_err("Could not map Configuration table!\n");
539 for (i = 0; i < efi.systab->nr_tables; i++) {
542 guid = ((efi_config_table_64_t *)p)->guid;
544 if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
545 ((efi_config_table_64_t *)p)->table = data->smbios;
548 early_memunmap(tablep, nr_tables * sz);
551 early_memunmap(data, sizeof(*data));
556 static const struct dmi_system_id sgi_uv1_dmi[] = {
558 { DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"),
559 DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"),
560 DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"),
563 { } /* NULL entry stops DMI scanning */
566 void __init efi_apply_memmap_quirks(void)
569 * Once setup is done earlier, unmap the EFI memory map on mismatched
570 * firmware/kernel architectures since there is no support for runtime
573 if (!efi_runtime_supported()) {
574 pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
578 /* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */
579 if (dmi_check_system(sgi_uv1_dmi))
580 set_bit(EFI_OLD_MEMMAP, &efi.flags);
584 * For most modern platforms the preferred method of powering off is via
585 * ACPI. However, there are some that are known to require the use of
586 * EFI runtime services and for which ACPI does not work at all.
588 * Using EFI is a last resort, to be used only if no other option
591 bool efi_reboot_required(void)
593 if (!acpi_gbl_reduced_hardware)
596 efi_reboot_quirk_mode = EFI_RESET_WARM;
600 bool efi_poweroff_required(void)
602 return acpi_gbl_reduced_hardware || acpi_no_s5;
605 #ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
607 static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
610 struct quark_security_header *csh = *pkbuff;
612 /* Only process data block that is larger than the security header */
613 if (hdr_bytes < sizeof(struct quark_security_header))
616 if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
617 csh->headersize != QUARK_SECURITY_HEADER_SIZE)
620 /* Only process data block if EFI header is included */
621 if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
622 sizeof(efi_capsule_header_t))
625 pr_debug("Quark security header detected\n");
627 if (csh->rsvd_next_header != 0) {
628 pr_err("multiple Quark security headers not supported\n");
632 *pkbuff += csh->headersize;
633 cap_info->total_size = csh->headersize;
636 * Update the first page pointer to skip over the CSH header.
638 cap_info->phys[0] += csh->headersize;
641 * cap_info->capsule should point at a virtual mapping of the entire
642 * capsule, starting at the capsule header. Our image has the Quark
643 * security header prepended, so we cannot rely on the default vmap()
644 * mapping created by the generic capsule code.
645 * Given that the Quark firmware does not appear to care about the
646 * virtual mapping, let's just point cap_info->capsule at our copy
647 * of the capsule header.
649 cap_info->capsule = &cap_info->header;
654 #define ICPU(family, model, quirk_handler) \
655 { X86_VENDOR_INTEL, family, model, X86_FEATURE_ANY, \
656 (unsigned long)&quirk_handler }
658 static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
659 ICPU(5, 9, qrk_capsule_setup_info), /* Intel Quark X1000 */
663 int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
666 int (*quirk_handler)(struct capsule_info *, void **, size_t);
667 const struct x86_cpu_id *id;
670 if (hdr_bytes < sizeof(efi_capsule_header_t))
673 cap_info->total_size = 0;
675 id = x86_match_cpu(efi_capsule_quirk_ids);
678 * The quirk handler is supposed to return
679 * - a value > 0 if the setup should continue, after advancing
681 * - 0 if not enough hdr_bytes are available yet
682 * - a negative error code otherwise
684 quirk_handler = (typeof(quirk_handler))id->driver_data;
685 ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
690 memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
692 cap_info->total_size += cap_info->header.imagesize;
694 return __efi_capsule_setup_info(cap_info);
700 * If any access by any efi runtime service causes a page fault, then,
701 * 1. If it's efi_reset_system(), reboot through BIOS.
702 * 2. If any other efi runtime service, then
703 * a. Return error status to the efi caller process.
704 * b. Disable EFI Runtime Services forever and
705 * c. Freeze efi_rts_wq and schedule new process.
707 * @return: Returns, if the page fault is not handled. This function
708 * will never return if the page fault is handled successfully.
710 void efi_recover_from_page_fault(unsigned long phys_addr)
712 if (!IS_ENABLED(CONFIG_X86_64))
716 * Make sure that an efi runtime service caused the page fault.
717 * "efi_mm" cannot be used to check if the page fault had occurred
718 * in the firmware context because efi=old_map doesn't use efi_pgd.
720 if (efi_rts_work.efi_rts_id == EFI_NONE)
724 * Address range 0x0000 - 0x0fff is always mapped in the efi_pgd, so
725 * page faulting on these addresses isn't expected.
727 if (phys_addr >= 0x0000 && phys_addr <= 0x0fff)
731 * Print stack trace as it might be useful to know which EFI Runtime
734 WARN(1, FW_BUG "Page fault caused by firmware at PA: 0x%lx\n",
738 * Buggy efi_reset_system() is handled differently from other EFI
739 * Runtime Services as it doesn't use efi_rts_wq. Although,
740 * native_machine_emergency_restart() says that machine_real_restart()
741 * could fail, it's better not to compilcate this fault handler
742 * because this case occurs *very* rarely and hence could be improved
743 * on a need by basis.
745 if (efi_rts_work.efi_rts_id == EFI_RESET_SYSTEM) {
746 pr_info("efi_reset_system() buggy! Reboot through BIOS\n");
747 machine_real_restart(MRR_BIOS);
752 * Before calling EFI Runtime Service, the kernel has switched the
753 * calling process to efi_mm. Hence, switch back to task_mm.
755 arch_efi_call_virt_teardown();
757 /* Signal error status to the efi caller process */
758 efi_rts_work.status = EFI_ABORTED;
759 complete(&efi_rts_work.efi_rts_comp);
761 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
762 pr_info("Froze efi_rts_wq and disabled EFI Runtime Services\n");
765 * Call schedule() in an infinite loop, so that any spurious wake ups
766 * will never run efi_rts_wq again.
769 set_current_state(TASK_IDLE);