| 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 | |
| 40 | static pgd_t save_pgd __initdata; |
| 41 | static unsigned long efi_flags __initdata; |
| 42 | |
| 43 | static void __init early_mapping_set_exec(unsigned long start, |
| 44 | unsigned long end, |
| 45 | int executable) |
| 46 | { |
| 47 | unsigned long num_pages; |
| 48 | |
| 49 | start &= PMD_MASK; |
| 50 | end = (end + PMD_SIZE - 1) & PMD_MASK; |
| 51 | num_pages = (end - start) >> PAGE_SHIFT; |
| 52 | if (executable) |
| 53 | set_memory_x((unsigned long)__va(start), num_pages); |
| 54 | else |
| 55 | set_memory_nx((unsigned long)__va(start), num_pages); |
| 56 | } |
| 57 | |
| 58 | static void __init early_runtime_code_mapping_set_exec(int executable) |
| 59 | { |
| 60 | efi_memory_desc_t *md; |
| 61 | void *p; |
| 62 | |
| 63 | if (!(__supported_pte_mask & _PAGE_NX)) |
| 64 | return; |
| 65 | |
| 66 | /* Make EFI runtime service code area executable */ |
| 67 | for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { |
| 68 | md = p; |
| 69 | if (md->type == EFI_RUNTIME_SERVICES_CODE) { |
| 70 | unsigned long end; |
| 71 | end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); |
| 72 | early_mapping_set_exec(md->phys_addr, end, executable); |
| 73 | } |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | void __init efi_call_phys_prelog(void) |
| 78 | { |
| 79 | unsigned long vaddress; |
| 80 | |
| 81 | early_runtime_code_mapping_set_exec(1); |
| 82 | local_irq_save(efi_flags); |
| 83 | vaddress = (unsigned long)__va(0x0UL); |
| 84 | save_pgd = *pgd_offset_k(0x0UL); |
| 85 | set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress)); |
| 86 | __flush_tlb_all(); |
| 87 | } |
| 88 | |
| 89 | void __init efi_call_phys_epilog(void) |
| 90 | { |
| 91 | /* |
| 92 | * After the lock is released, the original page table is restored. |
| 93 | */ |
| 94 | set_pgd(pgd_offset_k(0x0UL), save_pgd); |
| 95 | __flush_tlb_all(); |
| 96 | local_irq_restore(efi_flags); |
| 97 | early_runtime_code_mapping_set_exec(0); |
| 98 | } |
| 99 | |
| 100 | void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size) |
| 101 | { |
| 102 | static unsigned pages_mapped __initdata; |
| 103 | unsigned i, pages; |
| 104 | unsigned long offset; |
| 105 | |
| 106 | pages = PFN_UP(phys_addr + size) - PFN_DOWN(phys_addr); |
| 107 | offset = phys_addr & ~PAGE_MASK; |
| 108 | phys_addr &= PAGE_MASK; |
| 109 | |
| 110 | if (pages_mapped + pages > MAX_EFI_IO_PAGES) |
| 111 | return NULL; |
| 112 | |
| 113 | for (i = 0; i < pages; i++) { |
| 114 | __set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped, |
| 115 | phys_addr, PAGE_KERNEL); |
| 116 | phys_addr += PAGE_SIZE; |
| 117 | pages_mapped++; |
| 118 | } |
| 119 | |
| 120 | return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \ |
| 121 | (pages_mapped - pages)) + offset; |
| 122 | } |