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 41static pgd_t save_pgd __initdata; 42static unsigned long efi_flags __initdata; 43 44static void __init early_mapping_set_exec(unsigned long start, 45 unsigned long end, 46 int executable) 47{ 48 unsigned long num_pages; 49 50 start &= PMD_MASK; 51 end = (end + PMD_SIZE - 1) & PMD_MASK; 52 num_pages = (end - start) >> PAGE_SHIFT; 53 if (executable) 54 set_memory_x((unsigned long)__va(start), num_pages); 55 else 56 set_memory_nx((unsigned long)__va(start), num_pages); 57} 58 59static void __init early_runtime_code_mapping_set_exec(int executable) 60{ 61 efi_memory_desc_t *md; 62 void *p; 63 64 if (!(__supported_pte_mask & _PAGE_NX)) 65 return; 66 67 /* Make EFI runtime service code area executable */ 68 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 69 md = p; 70 if (md->type == EFI_RUNTIME_SERVICES_CODE) { 71 unsigned long end; 72 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); 73 early_mapping_set_exec(md->phys_addr, end, executable); 74 } 75 } 76} 77 78void __init efi_call_phys_prelog(void) 79{ 80 unsigned long vaddress; 81 82 early_runtime_code_mapping_set_exec(1); 83 local_irq_save(efi_flags); 84 vaddress = (unsigned long)__va(0x0UL); 85 save_pgd = *pgd_offset_k(0x0UL); 86 set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress)); 87 __flush_tlb_all(); 88} 89 90void __init efi_call_phys_epilog(void) 91{ 92 /* 93 * After the lock is released, the original page table is restored. 94 */ 95 set_pgd(pgd_offset_k(0x0UL), save_pgd); 96 __flush_tlb_all(); 97 local_irq_restore(efi_flags); 98 early_runtime_code_mapping_set_exec(0); 99} 100 101void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size, 102 u32 type) 103{ 104 unsigned long last_map_pfn; 105 106 if (type == EFI_MEMORY_MAPPED_IO) 107 return ioremap(phys_addr, size); 108 109 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size); 110 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) 111 return NULL; 112 113 return (void __iomem *)__va(phys_addr); 114} 115