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/bootmem.h>
12 #include <linux/acpi.h>
13 #include <linux/dmi.h>
15 #include <asm/e820/api.h>
17 #include <asm/uv/uv.h>
18 #include <asm/cpu_device_id.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 size += addr % EFI_PAGE_SIZE;
263 size = round_up(size, EFI_PAGE_SIZE);
264 addr = round_down(addr, EFI_PAGE_SIZE);
266 mr.range.start = addr;
267 mr.range.end = addr + size - 1;
268 mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
270 num_entries = efi_memmap_split_count(&md, &mr.range);
271 num_entries += efi.memmap.nr_map;
273 new_size = efi.memmap.desc_size * num_entries;
275 new_phys = efi_memmap_alloc(num_entries);
277 pr_err("Could not allocate boot services memmap\n");
281 new = early_memremap(new_phys, new_size);
283 pr_err("Failed to map new boot services memmap\n");
287 efi_memmap_insert(&efi.memmap, new, &mr);
288 early_memunmap(new, new_size);
290 efi_memmap_install(new_phys, num_entries);
291 e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
292 e820__update_table(e820_table);
296 * Helper function for efi_reserve_boot_services() to figure out if we
297 * can free regions in efi_free_boot_services().
299 * Use this function to ensure we do not free regions owned by somebody
300 * else. We must only reserve (and then free) regions:
302 * - Not within any part of the kernel
303 * - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc)
305 static bool can_free_region(u64 start, u64 size)
307 if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
310 if (!e820__mapped_all(start, start+size, E820_TYPE_RAM))
316 void __init efi_reserve_boot_services(void)
318 efi_memory_desc_t *md;
320 for_each_efi_memory_desc(md) {
321 u64 start = md->phys_addr;
322 u64 size = md->num_pages << EFI_PAGE_SHIFT;
323 bool already_reserved;
325 if (md->type != EFI_BOOT_SERVICES_CODE &&
326 md->type != EFI_BOOT_SERVICES_DATA)
329 already_reserved = memblock_is_region_reserved(start, size);
332 * Because the following memblock_reserve() is paired
333 * with free_bootmem_late() for this region in
334 * efi_free_boot_services(), we must be extremely
335 * careful not to reserve, and subsequently free,
336 * critical regions of memory (like the kernel image) or
337 * those regions that somebody else has already
340 * A good example of a critical region that must not be
341 * freed is page zero (first 4Kb of memory), which may
342 * contain boot services code/data but is marked
343 * E820_TYPE_RESERVED by trim_bios_range().
345 if (!already_reserved) {
346 memblock_reserve(start, size);
349 * If we are the first to reserve the region, no
350 * one else cares about it. We own it and can
353 if (can_free_region(start, size))
358 * We don't own the region. We must not free it.
360 * Setting this bit for a boot services region really
361 * doesn't make sense as far as the firmware is
362 * concerned, but it does provide us with a way to tag
363 * those regions that must not be paired with
364 * free_bootmem_late().
366 md->attribute |= EFI_MEMORY_RUNTIME;
370 void __init efi_free_boot_services(void)
372 phys_addr_t new_phys, new_size;
373 efi_memory_desc_t *md;
377 for_each_efi_memory_desc(md) {
378 unsigned long long start = md->phys_addr;
379 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
382 if (md->type != EFI_BOOT_SERVICES_CODE &&
383 md->type != EFI_BOOT_SERVICES_DATA) {
388 /* Do not free, someone else owns it: */
389 if (md->attribute & EFI_MEMORY_RUNTIME) {
395 * Nasty quirk: if all sub-1MB memory is used for boot
396 * services, we can get here without having allocated the
397 * real mode trampoline. It's too late to hand boot services
398 * memory back to the memblock allocator, so instead
399 * try to manually allocate the trampoline if needed.
401 * I've seen this on a Dell XPS 13 9350 with firmware
402 * 1.4.4 with SGX enabled booting Linux via Fedora 24's
403 * grub2-efi on a hard disk. (And no, I don't know why
404 * this happened, but Linux should still try to boot rather
407 rm_size = real_mode_size_needed();
408 if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
409 set_real_mode_mem(start, rm_size);
414 free_bootmem_late(start, size);
420 new_size = efi.memmap.desc_size * num_entries;
421 new_phys = efi_memmap_alloc(num_entries);
423 pr_err("Failed to allocate new EFI memmap\n");
427 new = memremap(new_phys, new_size, MEMREMAP_WB);
429 pr_err("Failed to map new EFI memmap\n");
434 * Build a new EFI memmap that excludes any boot services
435 * regions that are not tagged EFI_MEMORY_RUNTIME, since those
436 * regions have now been freed.
439 for_each_efi_memory_desc(md) {
440 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
441 (md->type == EFI_BOOT_SERVICES_CODE ||
442 md->type == EFI_BOOT_SERVICES_DATA))
445 memcpy(new_md, md, efi.memmap.desc_size);
446 new_md += efi.memmap.desc_size;
451 if (efi_memmap_install(new_phys, num_entries)) {
452 pr_err("Could not install new EFI memmap\n");
458 * A number of config table entries get remapped to virtual addresses
459 * after entering EFI virtual mode. However, the kexec kernel requires
460 * their physical addresses therefore we pass them via setup_data and
461 * correct those entries to their respective physical addresses here.
463 * Currently only handles smbios which is necessary for some firmware
466 int __init efi_reuse_config(u64 tables, int nr_tables)
470 struct efi_setup_data *data;
475 if (!efi_enabled(EFI_64BIT))
478 data = early_memremap(efi_setup, sizeof(*data));
487 sz = sizeof(efi_config_table_64_t);
489 p = tablep = early_memremap(tables, nr_tables * sz);
491 pr_err("Could not map Configuration table!\n");
496 for (i = 0; i < efi.systab->nr_tables; i++) {
499 guid = ((efi_config_table_64_t *)p)->guid;
501 if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
502 ((efi_config_table_64_t *)p)->table = data->smbios;
505 early_memunmap(tablep, nr_tables * sz);
508 early_memunmap(data, sizeof(*data));
513 static const struct dmi_system_id sgi_uv1_dmi[] = {
515 { DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"),
516 DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"),
517 DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"),
520 { } /* NULL entry stops DMI scanning */
523 void __init efi_apply_memmap_quirks(void)
526 * Once setup is done earlier, unmap the EFI memory map on mismatched
527 * firmware/kernel architectures since there is no support for runtime
530 if (!efi_runtime_supported()) {
531 pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
535 /* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */
536 if (dmi_check_system(sgi_uv1_dmi))
537 set_bit(EFI_OLD_MEMMAP, &efi.flags);
541 * For most modern platforms the preferred method of powering off is via
542 * ACPI. However, there are some that are known to require the use of
543 * EFI runtime services and for which ACPI does not work at all.
545 * Using EFI is a last resort, to be used only if no other option
548 bool efi_reboot_required(void)
550 if (!acpi_gbl_reduced_hardware)
553 efi_reboot_quirk_mode = EFI_RESET_WARM;
557 bool efi_poweroff_required(void)
559 return acpi_gbl_reduced_hardware || acpi_no_s5;
562 #ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
564 static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
567 struct quark_security_header *csh = *pkbuff;
569 /* Only process data block that is larger than the security header */
570 if (hdr_bytes < sizeof(struct quark_security_header))
573 if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
574 csh->headersize != QUARK_SECURITY_HEADER_SIZE)
577 /* Only process data block if EFI header is included */
578 if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
579 sizeof(efi_capsule_header_t))
582 pr_debug("Quark security header detected\n");
584 if (csh->rsvd_next_header != 0) {
585 pr_err("multiple Quark security headers not supported\n");
589 *pkbuff += csh->headersize;
590 cap_info->total_size = csh->headersize;
593 * Update the first page pointer to skip over the CSH header.
595 cap_info->phys[0] += csh->headersize;
598 * cap_info->capsule should point at a virtual mapping of the entire
599 * capsule, starting at the capsule header. Our image has the Quark
600 * security header prepended, so we cannot rely on the default vmap()
601 * mapping created by the generic capsule code.
602 * Given that the Quark firmware does not appear to care about the
603 * virtual mapping, let's just point cap_info->capsule at our copy
604 * of the capsule header.
606 cap_info->capsule = &cap_info->header;
611 #define ICPU(family, model, quirk_handler) \
612 { X86_VENDOR_INTEL, family, model, X86_FEATURE_ANY, \
613 (unsigned long)&quirk_handler }
615 static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
616 ICPU(5, 9, qrk_capsule_setup_info), /* Intel Quark X1000 */
620 int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
623 int (*quirk_handler)(struct capsule_info *, void **, size_t);
624 const struct x86_cpu_id *id;
627 if (hdr_bytes < sizeof(efi_capsule_header_t))
630 cap_info->total_size = 0;
632 id = x86_match_cpu(efi_capsule_quirk_ids);
635 * The quirk handler is supposed to return
636 * - a value > 0 if the setup should continue, after advancing
638 * - 0 if not enough hdr_bytes are available yet
639 * - a negative error code otherwise
641 quirk_handler = (typeof(quirk_handler))id->driver_data;
642 ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
647 memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
649 cap_info->total_size += cap_info->header.imagesize;
651 return __efi_capsule_setup_info(cap_info);