1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Extensible Firmware Interface 4 * 5 * Based on Extensible Firmware Interface Specification version 1.0 6 * 7 * Copyright (C) 1999 VA Linux Systems 8 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> 9 * Copyright (C) 1999-2002 Hewlett-Packard Co. 10 * David Mosberger-Tang <davidm@hpl.hp.com> 11 * Stephane Eranian <eranian@hpl.hp.com> 12 * 13 * All EFI Runtime Services are not implemented yet as EFI only 14 * supports physical mode addressing on SoftSDV. This is to be fixed 15 * in a future version. --drummond 1999-07-20 16 * 17 * Implemented EFI runtime services and virtual mode calls. --davidm 18 * 19 * Goutham Rao: <goutham.rao@intel.com> 20 * Skip non-WB memory and ignore empty memory ranges. 21 */ 22 23 #include <linux/kernel.h> 24 #include <linux/types.h> 25 #include <linux/ioport.h> 26 #include <linux/efi.h> 27 #include <linux/pgtable.h> 28 29 #include <asm/io.h> 30 #include <asm/desc.h> 31 #include <asm/page.h> 32 #include <asm/set_memory.h> 33 #include <asm/tlbflush.h> 34 #include <asm/efi.h> 35 36 void __init efi_map_region(efi_memory_desc_t *md) 37 { 38 u64 start_pfn, end_pfn, end; 39 unsigned long size; 40 void *va; 41 42 start_pfn = PFN_DOWN(md->phys_addr); 43 size = md->num_pages << PAGE_SHIFT; 44 end = md->phys_addr + size; 45 end_pfn = PFN_UP(end); 46 47 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 48 va = __va(md->phys_addr); 49 50 if (!(md->attribute & EFI_MEMORY_WB)) 51 set_memory_uc((unsigned long)va, md->num_pages); 52 } else { 53 va = ioremap_cache(md->phys_addr, size); 54 } 55 56 md->virt_addr = (unsigned long)va; 57 if (!va) 58 pr_err("ioremap of 0x%llX failed!\n", md->phys_addr); 59 } 60 61 /* 62 * To make EFI call EFI runtime service in physical addressing mode we need 63 * prolog/epilog before/after the invocation to claim the EFI runtime service 64 * handler exclusively and to duplicate a memory mapping in low memory space, 65 * say 0 - 3G. 66 */ 67 68 int __init efi_alloc_page_tables(void) 69 { 70 return 0; 71 } 72 73 void efi_sync_low_kernel_mappings(void) {} 74 75 void __init efi_dump_pagetable(void) 76 { 77 #ifdef CONFIG_EFI_PGT_DUMP 78 ptdump_walk_pgd_level(NULL, &init_mm); 79 #endif 80 } 81 82 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) 83 { 84 return 0; 85 } 86 87 void __init efi_map_region_fixed(efi_memory_desc_t *md) {} 88 void __init parse_efi_setup(u64 phys_addr, u32 data_len) {} 89 90 efi_status_t efi_call_svam(efi_runtime_services_t * const *, 91 u32, u32, u32, void *, u32); 92 93 efi_status_t __init efi_set_virtual_address_map(unsigned long memory_map_size, 94 unsigned long descriptor_size, 95 u32 descriptor_version, 96 efi_memory_desc_t *virtual_map, 97 unsigned long systab_phys) 98 { 99 const efi_system_table_t *systab = (efi_system_table_t *)systab_phys; 100 struct desc_ptr gdt_descr; 101 efi_status_t status; 102 unsigned long flags; 103 pgd_t *save_pgd; 104 105 /* Current pgd is swapper_pg_dir, we'll restore it later: */ 106 save_pgd = swapper_pg_dir; 107 load_cr3(initial_page_table); 108 __flush_tlb_all(); 109 110 gdt_descr.address = get_cpu_gdt_paddr(0); 111 gdt_descr.size = GDT_SIZE - 1; 112 load_gdt(&gdt_descr); 113 114 /* Disable interrupts around EFI calls: */ 115 local_irq_save(flags); 116 status = efi_call_svam(&systab->runtime, 117 memory_map_size, descriptor_size, 118 descriptor_version, virtual_map, 119 __pa(&efi.runtime)); 120 local_irq_restore(flags); 121 122 load_fixmap_gdt(0); 123 load_cr3(save_pgd); 124 __flush_tlb_all(); 125 126 return status; 127 } 128 129 void __init efi_runtime_update_mappings(void) 130 { 131 if (__supported_pte_mask & _PAGE_NX) { 132 efi_memory_desc_t *md; 133 134 /* Make EFI runtime service code area executable */ 135 for_each_efi_memory_desc(md) { 136 if (md->type != EFI_RUNTIME_SERVICES_CODE) 137 continue; 138 139 set_memory_x(md->virt_addr, md->num_pages); 140 } 141 } 142 } 143 144 void arch_efi_call_virt_setup(void) 145 { 146 efi_fpu_begin(); 147 firmware_restrict_branch_speculation_start(); 148 } 149 150 void arch_efi_call_virt_teardown(void) 151 { 152 firmware_restrict_branch_speculation_end(); 153 efi_fpu_end(); 154 } 155