1 /* 2 * x86_64 specific EFI support functions 3 * Based on Extensible Firmware Interface Specification version 1.0 4 * 5 * Copyright (C) 2005-2008 Intel Co. 6 * Fenghua Yu <fenghua.yu@intel.com> 7 * Bibo Mao <bibo.mao@intel.com> 8 * Chandramouli Narayanan <mouli@linux.intel.com> 9 * Huang Ying <ying.huang@intel.com> 10 * 11 * Code to convert EFI to E820 map has been implemented in elilo bootloader 12 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table 13 * is setup appropriately for EFI runtime code. 14 * - mouli 06/14/2007. 15 * 16 */ 17 18 #include <linux/kernel.h> 19 #include <linux/init.h> 20 #include <linux/mm.h> 21 #include <linux/types.h> 22 #include <linux/spinlock.h> 23 #include <linux/bootmem.h> 24 #include <linux/ioport.h> 25 #include <linux/module.h> 26 #include <linux/efi.h> 27 #include <linux/uaccess.h> 28 #include <linux/io.h> 29 #include <linux/reboot.h> 30 31 #include <asm/setup.h> 32 #include <asm/page.h> 33 #include <asm/e820.h> 34 #include <asm/pgtable.h> 35 #include <asm/tlbflush.h> 36 #include <asm/proto.h> 37 #include <asm/efi.h> 38 #include <asm/cacheflush.h> 39 #include <asm/fixmap.h> 40 41 static pgd_t save_pgd __initdata; 42 static unsigned long efi_flags __initdata; 43 44 static void __init early_code_mapping_set_exec(int executable) 45 { 46 efi_memory_desc_t *md; 47 void *p; 48 49 if (!(__supported_pte_mask & _PAGE_NX)) 50 return; 51 52 /* Make EFI service code area executable */ 53 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 54 md = p; 55 if (md->type == EFI_RUNTIME_SERVICES_CODE || 56 md->type == EFI_BOOT_SERVICES_CODE) 57 efi_set_executable(md, executable); 58 } 59 } 60 61 void __init efi_call_phys_prelog(void) 62 { 63 unsigned long vaddress; 64 65 early_code_mapping_set_exec(1); 66 local_irq_save(efi_flags); 67 vaddress = (unsigned long)__va(0x0UL); 68 save_pgd = *pgd_offset_k(0x0UL); 69 set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress)); 70 __flush_tlb_all(); 71 } 72 73 void __init efi_call_phys_epilog(void) 74 { 75 /* 76 * After the lock is released, the original page table is restored. 77 */ 78 set_pgd(pgd_offset_k(0x0UL), save_pgd); 79 __flush_tlb_all(); 80 local_irq_restore(efi_flags); 81 early_code_mapping_set_exec(0); 82 } 83 84 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size, 85 u32 type) 86 { 87 unsigned long last_map_pfn; 88 89 if (type == EFI_MEMORY_MAPPED_IO) 90 return ioremap(phys_addr, size); 91 92 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size); 93 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) { 94 unsigned long top = last_map_pfn << PAGE_SHIFT; 95 efi_ioremap(top, size - (top - phys_addr), type); 96 } 97 98 return (void __iomem *)__va(phys_addr); 99 } 100