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 #include <linux/slab.h> 31 32 #include <asm/setup.h> 33 #include <asm/page.h> 34 #include <asm/e820.h> 35 #include <asm/pgtable.h> 36 #include <asm/tlbflush.h> 37 #include <asm/proto.h> 38 #include <asm/efi.h> 39 #include <asm/cacheflush.h> 40 #include <asm/fixmap.h> 41 42 static pgd_t *save_pgd __initdata; 43 static unsigned long efi_flags __initdata; 44 45 static void __init early_code_mapping_set_exec(int executable) 46 { 47 efi_memory_desc_t *md; 48 void *p; 49 50 if (!(__supported_pte_mask & _PAGE_NX)) 51 return; 52 53 /* Make EFI service code area executable */ 54 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 55 md = p; 56 if (md->type == EFI_RUNTIME_SERVICES_CODE || 57 md->type == EFI_BOOT_SERVICES_CODE) 58 efi_set_executable(md, executable); 59 } 60 } 61 62 void __init efi_call_phys_prelog(void) 63 { 64 unsigned long vaddress; 65 int pgd; 66 int n_pgds; 67 68 early_code_mapping_set_exec(1); 69 local_irq_save(efi_flags); 70 71 n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE); 72 save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL); 73 74 for (pgd = 0; pgd < n_pgds; pgd++) { 75 save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE); 76 vaddress = (unsigned long)__va(pgd * PGDIR_SIZE); 77 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress)); 78 } 79 __flush_tlb_all(); 80 } 81 82 void __init efi_call_phys_epilog(void) 83 { 84 /* 85 * After the lock is released, the original page table is restored. 86 */ 87 int pgd; 88 int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE); 89 for (pgd = 0; pgd < n_pgds; pgd++) 90 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]); 91 kfree(save_pgd); 92 __flush_tlb_all(); 93 local_irq_restore(efi_flags); 94 early_code_mapping_set_exec(0); 95 } 96 97 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size, 98 u32 type, u64 attribute) 99 { 100 unsigned long last_map_pfn; 101 102 if (type == EFI_MEMORY_MAPPED_IO) 103 return ioremap(phys_addr, size); 104 105 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size); 106 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) { 107 unsigned long top = last_map_pfn << PAGE_SHIFT; 108 efi_ioremap(top, size - (top - phys_addr), type, attribute); 109 } 110 111 if (!(attribute & EFI_MEMORY_WB)) 112 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size); 113 114 return (void __iomem *)__va(phys_addr); 115 } 116