| #define pr_fmt(fmt) "efi: " fmt |
| |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/time.h> |
| #include <linux/types.h> |
| #include <linux/efi.h> |
| #include <linux/slab.h> |
| #include <linux/memblock.h> |
| #include <linux/bootmem.h> |
| #include <linux/acpi.h> |
| #include <linux/dmi.h> |
| #include <asm/efi.h> |
| #include <asm/uv/uv.h> |
| |
| #define EFI_MIN_RESERVE 5120 |
| |
| #define EFI_DUMMY_GUID \ |
| EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9) |
| |
| static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 }; |
| |
| static bool efi_no_storage_paranoia; |
| |
| /* |
| * Some firmware implementations refuse to boot if there's insufficient |
| * space in the variable store. The implementation of garbage collection |
| * in some FW versions causes stale (deleted) variables to take up space |
| * longer than intended and space is only freed once the store becomes |
| * almost completely full. |
| * |
| * Enabling this option disables the space checks in |
| * efi_query_variable_store() and forces garbage collection. |
| * |
| * Only enable this option if deleting EFI variables does not free up |
| * space in your variable store, e.g. if despite deleting variables |
| * you're unable to create new ones. |
| */ |
| static int __init setup_storage_paranoia(char *arg) |
| { |
| efi_no_storage_paranoia = true; |
| return 0; |
| } |
| early_param("efi_no_storage_paranoia", setup_storage_paranoia); |
| |
| /* |
| * Deleting the dummy variable which kicks off garbage collection |
| */ |
| void efi_delete_dummy_variable(void) |
| { |
| efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID, |
| EFI_VARIABLE_NON_VOLATILE | |
| EFI_VARIABLE_BOOTSERVICE_ACCESS | |
| EFI_VARIABLE_RUNTIME_ACCESS, |
| 0, NULL); |
| } |
| |
| /* |
| * Some firmware implementations refuse to boot if there's insufficient space |
| * in the variable store. Ensure that we never use more than a safe limit. |
| * |
| * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable |
| * store. |
| */ |
| efi_status_t efi_query_variable_store(u32 attributes, unsigned long size) |
| { |
| efi_status_t status; |
| u64 storage_size, remaining_size, max_size; |
| |
| if (!(attributes & EFI_VARIABLE_NON_VOLATILE)) |
| return 0; |
| |
| status = efi.query_variable_info(attributes, &storage_size, |
| &remaining_size, &max_size); |
| if (status != EFI_SUCCESS) |
| return status; |
| |
| /* |
| * We account for that by refusing the write if permitting it would |
| * reduce the available space to under 5KB. This figure was provided by |
| * Samsung, so should be safe. |
| */ |
| if ((remaining_size - size < EFI_MIN_RESERVE) && |
| !efi_no_storage_paranoia) { |
| |
| /* |
| * Triggering garbage collection may require that the firmware |
| * generate a real EFI_OUT_OF_RESOURCES error. We can force |
| * that by attempting to use more space than is available. |
| */ |
| unsigned long dummy_size = remaining_size + 1024; |
| void *dummy = kzalloc(dummy_size, GFP_ATOMIC); |
| |
| if (!dummy) |
| return EFI_OUT_OF_RESOURCES; |
| |
| status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID, |
| EFI_VARIABLE_NON_VOLATILE | |
| EFI_VARIABLE_BOOTSERVICE_ACCESS | |
| EFI_VARIABLE_RUNTIME_ACCESS, |
| dummy_size, dummy); |
| |
| if (status == EFI_SUCCESS) { |
| /* |
| * This should have failed, so if it didn't make sure |
| * that we delete it... |
| */ |
| efi_delete_dummy_variable(); |
| } |
| |
| kfree(dummy); |
| |
| /* |
| * The runtime code may now have triggered a garbage collection |
| * run, so check the variable info again |
| */ |
| status = efi.query_variable_info(attributes, &storage_size, |
| &remaining_size, &max_size); |
| |
| if (status != EFI_SUCCESS) |
| return status; |
| |
| /* |
| * There still isn't enough room, so return an error |
| */ |
| if (remaining_size - size < EFI_MIN_RESERVE) |
| return EFI_OUT_OF_RESOURCES; |
| } |
| |
| return EFI_SUCCESS; |
| } |
| EXPORT_SYMBOL_GPL(efi_query_variable_store); |
| |
| /* |
| * The UEFI specification makes it clear that the operating system is free to do |
| * whatever it wants with boot services code after ExitBootServices() has been |
| * called. Ignoring this recommendation a significant bunch of EFI implementations |
| * continue calling into boot services code (SetVirtualAddressMap). In order to |
| * work around such buggy implementations we reserve boot services region during |
| * EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it |
| * is discarded. |
| */ |
| void __init efi_reserve_boot_services(void) |
| { |
| void *p; |
| |
| for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { |
| efi_memory_desc_t *md = p; |
| u64 start = md->phys_addr; |
| u64 size = md->num_pages << EFI_PAGE_SHIFT; |
| |
| if (md->type != EFI_BOOT_SERVICES_CODE && |
| md->type != EFI_BOOT_SERVICES_DATA) |
| continue; |
| /* Only reserve where possible: |
| * - Not within any already allocated areas |
| * - Not over any memory area (really needed, if above?) |
| * - Not within any part of the kernel |
| * - Not the bios reserved area |
| */ |
| if ((start + size > __pa_symbol(_text) |
| && start <= __pa_symbol(_end)) || |
| !e820_all_mapped(start, start+size, E820_RAM) || |
| memblock_is_region_reserved(start, size)) { |
| /* Could not reserve, skip it */ |
| md->num_pages = 0; |
| memblock_dbg("Could not reserve boot range [0x%010llx-0x%010llx]\n", |
| start, start+size-1); |
| } else |
| memblock_reserve(start, size); |
| } |
| } |
| |
| void __init efi_free_boot_services(void) |
| { |
| void *p; |
| |
| for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { |
| efi_memory_desc_t *md = p; |
| unsigned long long start = md->phys_addr; |
| unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; |
| |
| if (md->type != EFI_BOOT_SERVICES_CODE && |
| md->type != EFI_BOOT_SERVICES_DATA) |
| continue; |
| |
| /* Could not reserve boot area */ |
| if (!size) |
| continue; |
| |
| free_bootmem_late(start, size); |
| } |
| |
| efi_unmap_memmap(); |
| } |
| |
| /* |
| * A number of config table entries get remapped to virtual addresses |
| * after entering EFI virtual mode. However, the kexec kernel requires |
| * their physical addresses therefore we pass them via setup_data and |
| * correct those entries to their respective physical addresses here. |
| * |
| * Currently only handles smbios which is necessary for some firmware |
| * implementation. |
| */ |
| int __init efi_reuse_config(u64 tables, int nr_tables) |
| { |
| int i, sz, ret = 0; |
| void *p, *tablep; |
| struct efi_setup_data *data; |
| |
| if (!efi_setup) |
| return 0; |
| |
| if (!efi_enabled(EFI_64BIT)) |
| return 0; |
| |
| data = early_memremap(efi_setup, sizeof(*data)); |
| if (!data) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| if (!data->smbios) |
| goto out_memremap; |
| |
| sz = sizeof(efi_config_table_64_t); |
| |
| p = tablep = early_memremap(tables, nr_tables * sz); |
| if (!p) { |
| pr_err("Could not map Configuration table!\n"); |
| ret = -ENOMEM; |
| goto out_memremap; |
| } |
| |
| for (i = 0; i < efi.systab->nr_tables; i++) { |
| efi_guid_t guid; |
| |
| guid = ((efi_config_table_64_t *)p)->guid; |
| |
| if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID)) |
| ((efi_config_table_64_t *)p)->table = data->smbios; |
| p += sz; |
| } |
| early_memunmap(tablep, nr_tables * sz); |
| |
| out_memremap: |
| early_memunmap(data, sizeof(*data)); |
| out: |
| return ret; |
| } |
| |
| static const struct dmi_system_id sgi_uv1_dmi[] = { |
| { NULL, "SGI UV1", |
| { DMI_MATCH(DMI_PRODUCT_NAME, "Stoutland Platform"), |
| DMI_MATCH(DMI_PRODUCT_VERSION, "1.0"), |
| DMI_MATCH(DMI_BIOS_VENDOR, "SGI.COM"), |
| } |
| }, |
| { } /* NULL entry stops DMI scanning */ |
| }; |
| |
| void __init efi_apply_memmap_quirks(void) |
| { |
| /* |
| * Once setup is done earlier, unmap the EFI memory map on mismatched |
| * firmware/kernel architectures since there is no support for runtime |
| * services. |
| */ |
| if (!efi_runtime_supported()) { |
| pr_info("Setup done, disabling due to 32/64-bit mismatch\n"); |
| efi_unmap_memmap(); |
| } |
| |
| /* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */ |
| if (dmi_check_system(sgi_uv1_dmi)) |
| set_bit(EFI_OLD_MEMMAP, &efi.flags); |
| } |
| |
| /* |
| * For most modern platforms the preferred method of powering off is via |
| * ACPI. However, there are some that are known to require the use of |
| * EFI runtime services and for which ACPI does not work at all. |
| * |
| * Using EFI is a last resort, to be used only if no other option |
| * exists. |
| */ |
| bool efi_reboot_required(void) |
| { |
| if (!acpi_gbl_reduced_hardware) |
| return false; |
| |
| efi_reboot_quirk_mode = EFI_RESET_WARM; |
| return true; |
| } |
| |
| bool efi_poweroff_required(void) |
| { |
| return !!acpi_gbl_reduced_hardware; |
| } |