1 /* 2 * Extensible Firmware Interface 3 * 4 * Based on Extensible Firmware Interface Specification version 2.4 5 * 6 * Copyright (C) 2013, 2014 Linaro Ltd. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 14 #include <linux/dmi.h> 15 #include <linux/efi.h> 16 #include <linux/init.h> 17 18 #include <asm/efi.h> 19 20 int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) 21 { 22 pteval_t prot_val; 23 24 /* 25 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be 26 * executable, everything else can be mapped with the XN bits 27 * set. 28 */ 29 if ((md->attribute & EFI_MEMORY_WB) == 0) 30 prot_val = PROT_DEVICE_nGnRE; 31 else if (md->type == EFI_RUNTIME_SERVICES_CODE || 32 !PAGE_ALIGNED(md->phys_addr)) 33 prot_val = pgprot_val(PAGE_KERNEL_EXEC); 34 else 35 prot_val = pgprot_val(PAGE_KERNEL); 36 37 create_pgd_mapping(mm, md->phys_addr, md->virt_addr, 38 md->num_pages << EFI_PAGE_SHIFT, 39 __pgprot(prot_val | PTE_NG)); 40 return 0; 41 } 42 43 static int __init arm64_dmi_init(void) 44 { 45 /* 46 * On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to 47 * be called early because dmi_id_init(), which is an arch_initcall 48 * itself, depends on dmi_scan_machine() having been called already. 49 */ 50 dmi_scan_machine(); 51 if (dmi_available) 52 dmi_set_dump_stack_arch_desc(); 53 return 0; 54 } 55 core_initcall(arm64_dmi_init); 56 57 /* 58 * UpdateCapsule() depends on the system being shutdown via 59 * ResetSystem(). 60 */ 61 bool efi_poweroff_required(void) 62 { 63 return efi_enabled(EFI_RUNTIME_SERVICES); 64 } 65