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 efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
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(efi_dummy_name, &EFI_DUMMY_GUID,
109 EFI_VARIABLE_NON_VOLATILE |
110 EFI_VARIABLE_BOOTSERVICE_ACCESS |
111 EFI_VARIABLE_RUNTIME_ACCESS,
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_ATOMIC);
183 return EFI_OUT_OF_RESOURCES;
185 status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
186 EFI_VARIABLE_NON_VOLATILE |
187 EFI_VARIABLE_BOOTSERVICE_ACCESS |
188 EFI_VARIABLE_RUNTIME_ACCESS,
191 if (status == EFI_SUCCESS) {
193 * This should have failed, so if it didn't make sure
194 * that we delete it...
196 efi_delete_dummy_variable();
202 * The runtime code may now have triggered a garbage collection
203 * run, so check the variable info again
205 status = efi.query_variable_info(attributes, &storage_size,
206 &remaining_size, &max_size);
208 if (status != EFI_SUCCESS)
212 * There still isn't enough room, so return an error
214 if (remaining_size - size < EFI_MIN_RESERVE)
215 return EFI_OUT_OF_RESOURCES;
220 EXPORT_SYMBOL_GPL(efi_query_variable_store);
223 * The UEFI specification makes it clear that the operating system is
224 * free to do whatever it wants with boot services code after
225 * ExitBootServices() has been called. Ignoring this recommendation a
226 * significant bunch of EFI implementations continue calling into boot
227 * services code (SetVirtualAddressMap). In order to work around such
228 * buggy implementations we reserve boot services region during EFI
229 * init and make sure it stays executable. Then, after
230 * SetVirtualAddressMap(), it is discarded.
232 * However, some boot services regions contain data that is required
233 * by drivers, so we need to track which memory ranges can never be
234 * freed. This is done by tagging those regions with the
235 * EFI_MEMORY_RUNTIME attribute.
237 * Any driver that wants to mark a region as reserved must use
238 * efi_mem_reserve() which will insert a new EFI memory descriptor
239 * into efi.memmap (splitting existing regions if necessary) and tag
240 * it with EFI_MEMORY_RUNTIME.
242 void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
244 phys_addr_t new_phys, new_size;
245 struct efi_mem_range mr;
246 efi_memory_desc_t md;
250 if (efi_mem_desc_lookup(addr, &md)) {
251 pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
255 if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) {
256 pr_err("Region spans EFI memory descriptors, %pa\n", &addr);
260 size += addr % EFI_PAGE_SIZE;
261 size = round_up(size, EFI_PAGE_SIZE);
262 addr = round_down(addr, EFI_PAGE_SIZE);
264 mr.range.start = addr;
265 mr.range.end = addr + size - 1;
266 mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
268 num_entries = efi_memmap_split_count(&md, &mr.range);
269 num_entries += efi.memmap.nr_map;
271 new_size = efi.memmap.desc_size * num_entries;
273 new_phys = efi_memmap_alloc(num_entries);
275 pr_err("Could not allocate boot services memmap\n");
279 new = early_memremap_prot(new_phys, new_size,
280 pgprot_val(pgprot_encrypted(FIXMAP_PAGE_NORMAL)));
282 pr_err("Failed to map new boot services memmap\n");
286 efi_memmap_insert(&efi.memmap, new, &mr);
287 early_memunmap(new, new_size);
289 efi_memmap_install(new_phys, num_entries);
290 e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
291 e820__update_table(e820_table);
295 * Helper function for efi_reserve_boot_services() to figure out if we
296 * can free regions in efi_free_boot_services().
298 * Use this function to ensure we do not free regions owned by somebody
299 * else. We must only reserve (and then free) regions:
301 * - Not within any part of the kernel
302 * - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc)
304 static bool can_free_region(u64 start, u64 size)
306 if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
309 if (!e820__mapped_all(start, start+size, E820_TYPE_RAM))
315 void __init efi_reserve_boot_services(void)
317 efi_memory_desc_t *md;
319 for_each_efi_memory_desc(md) {
320 u64 start = md->phys_addr;
321 u64 size = md->num_pages << EFI_PAGE_SHIFT;
322 bool already_reserved;
324 if (md->type != EFI_BOOT_SERVICES_CODE &&
325 md->type != EFI_BOOT_SERVICES_DATA)
328 already_reserved = memblock_is_region_reserved(start, size);
331 * Because the following memblock_reserve() is paired
332 * with free_bootmem_late() for this region in
333 * efi_free_boot_services(), we must be extremely
334 * careful not to reserve, and subsequently free,
335 * critical regions of memory (like the kernel image) or
336 * those regions that somebody else has already
339 * A good example of a critical region that must not be
340 * freed is page zero (first 4Kb of memory), which may
341 * contain boot services code/data but is marked
342 * E820_TYPE_RESERVED by trim_bios_range().
344 if (!already_reserved) {
345 memblock_reserve(start, size);
348 * If we are the first to reserve the region, no
349 * one else cares about it. We own it and can
352 if (can_free_region(start, size))
357 * We don't own the region. We must not free it.
359 * Setting this bit for a boot services region really
360 * doesn't make sense as far as the firmware is
361 * concerned, but it does provide us with a way to tag
362 * those regions that must not be paired with
363 * free_bootmem_late().
365 md->attribute |= EFI_MEMORY_RUNTIME;
369 void __init efi_free_boot_services(void)
371 phys_addr_t new_phys, new_size;
372 efi_memory_desc_t *md;
376 for_each_efi_memory_desc(md) {
377 unsigned long long start = md->phys_addr;
378 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
381 if (md->type != EFI_BOOT_SERVICES_CODE &&
382 md->type != EFI_BOOT_SERVICES_DATA) {
387 /* Do not free, someone else owns it: */
388 if (md->attribute & EFI_MEMORY_RUNTIME) {
394 * Nasty quirk: if all sub-1MB memory is used for boot
395 * services, we can get here without having allocated the
396 * real mode trampoline. It's too late to hand boot services
397 * memory back to the memblock allocator, so instead
398 * try to manually allocate the trampoline if needed.
400 * I've seen this on a Dell XPS 13 9350 with firmware
401 * 1.4.4 with SGX enabled booting Linux via Fedora 24's
402 * grub2-efi on a hard disk. (And no, I don't know why
403 * this happened, but Linux should still try to boot rather
406 rm_size = real_mode_size_needed();
407 if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
408 set_real_mode_mem(start, rm_size);
413 free_bootmem_late(start, size);
419 new_size = efi.memmap.desc_size * num_entries;
420 new_phys = efi_memmap_alloc(num_entries);
422 pr_err("Failed to allocate new EFI memmap\n");
426 new = memremap(new_phys, new_size, MEMREMAP_WB);
428 pr_err("Failed to map new EFI memmap\n");
433 * Build a new EFI memmap that excludes any boot services
434 * regions that are not tagged EFI_MEMORY_RUNTIME, since those
435 * regions have now been freed.
438 for_each_efi_memory_desc(md) {
439 if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
440 (md->type == EFI_BOOT_SERVICES_CODE ||
441 md->type == EFI_BOOT_SERVICES_DATA))
444 memcpy(new_md, md, efi.memmap.desc_size);
445 new_md += efi.memmap.desc_size;
450 if (efi_memmap_install(new_phys, num_entries)) {
451 pr_err("Could not install new EFI memmap\n");
457 * A number of config table entries get remapped to virtual addresses
458 * after entering EFI virtual mode. However, the kexec kernel requires
459 * their physical addresses therefore we pass them via setup_data and
460 * correct those entries to their respective physical addresses here.
462 * Currently only handles smbios which is necessary for some firmware
465 int __init efi_reuse_config(u64 tables, int nr_tables)
469 struct efi_setup_data *data;
474 if (!efi_enabled(EFI_64BIT))
477 data = early_memremap(efi_setup, sizeof(*data));
486 sz = sizeof(efi_config_table_64_t);
488 p = tablep = early_memremap(tables, nr_tables * sz);
490 pr_err("Could not map Configuration table!\n");
495 for (i = 0; i < efi.systab->nr_tables; i++) {
498 guid = ((efi_config_table_64_t *)p)->guid;
500 if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
501 ((efi_config_table_64_t *)p)->table = data->smbios;
504 early_memunmap(tablep, nr_tables * sz);
507 early_memunmap(data, sizeof(*data));
512 static const struct dmi_system_id sgi_uv1_dmi[] = {
514 { DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"),
515 DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"),
516 DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"),
519 { } /* NULL entry stops DMI scanning */
522 void __init efi_apply_memmap_quirks(void)
525 * Once setup is done earlier, unmap the EFI memory map on mismatched
526 * firmware/kernel architectures since there is no support for runtime
529 if (!efi_runtime_supported()) {
530 pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
534 /* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */
535 if (dmi_check_system(sgi_uv1_dmi))
536 set_bit(EFI_OLD_MEMMAP, &efi.flags);
540 * For most modern platforms the preferred method of powering off is via
541 * ACPI. However, there are some that are known to require the use of
542 * EFI runtime services and for which ACPI does not work at all.
544 * Using EFI is a last resort, to be used only if no other option
547 bool efi_reboot_required(void)
549 if (!acpi_gbl_reduced_hardware)
552 efi_reboot_quirk_mode = EFI_RESET_WARM;
556 bool efi_poweroff_required(void)
558 return acpi_gbl_reduced_hardware || acpi_no_s5;
561 #ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
563 static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
566 struct quark_security_header *csh = *pkbuff;
568 /* Only process data block that is larger than the security header */
569 if (hdr_bytes < sizeof(struct quark_security_header))
572 if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
573 csh->headersize != QUARK_SECURITY_HEADER_SIZE)
576 /* Only process data block if EFI header is included */
577 if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
578 sizeof(efi_capsule_header_t))
581 pr_debug("Quark security header detected\n");
583 if (csh->rsvd_next_header != 0) {
584 pr_err("multiple Quark security headers not supported\n");
588 *pkbuff += csh->headersize;
589 cap_info->total_size = csh->headersize;
592 * Update the first page pointer to skip over the CSH header.
594 cap_info->phys[0] += csh->headersize;
597 * cap_info->capsule should point at a virtual mapping of the entire
598 * capsule, starting at the capsule header. Our image has the Quark
599 * security header prepended, so we cannot rely on the default vmap()
600 * mapping created by the generic capsule code.
601 * Given that the Quark firmware does not appear to care about the
602 * virtual mapping, let's just point cap_info->capsule at our copy
603 * of the capsule header.
605 cap_info->capsule = &cap_info->header;
610 #define ICPU(family, model, quirk_handler) \
611 { X86_VENDOR_INTEL, family, model, X86_FEATURE_ANY, \
612 (unsigned long)&quirk_handler }
614 static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
615 ICPU(5, 9, qrk_capsule_setup_info), /* Intel Quark X1000 */
619 int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
622 int (*quirk_handler)(struct capsule_info *, void **, size_t);
623 const struct x86_cpu_id *id;
626 if (hdr_bytes < sizeof(efi_capsule_header_t))
629 cap_info->total_size = 0;
631 id = x86_match_cpu(efi_capsule_quirk_ids);
634 * The quirk handler is supposed to return
635 * - a value > 0 if the setup should continue, after advancing
637 * - 0 if not enough hdr_bytes are available yet
638 * - a negative error code otherwise
640 quirk_handler = (typeof(quirk_handler))id->driver_data;
641 ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
646 memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
648 cap_info->total_size += cap_info->header.imagesize;
650 return __efi_capsule_setup_info(cap_info);