1 /* 2 * Hibernation support for x86-64 3 * 4 * Distribute under GPLv2 5 * 6 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl> 7 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz> 8 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org> 9 */ 10 11 #include <linux/gfp.h> 12 #include <linux/smp.h> 13 #include <linux/suspend.h> 14 #include <linux/scatterlist.h> 15 #include <linux/kdebug.h> 16 17 #include <crypto/hash.h> 18 19 #include <asm/e820/api.h> 20 #include <asm/init.h> 21 #include <asm/proto.h> 22 #include <asm/page.h> 23 #include <asm/pgtable.h> 24 #include <asm/mtrr.h> 25 #include <asm/sections.h> 26 #include <asm/suspend.h> 27 #include <asm/tlbflush.h> 28 29 static int set_up_temporary_text_mapping(pgd_t *pgd) 30 { 31 pmd_t *pmd; 32 pud_t *pud; 33 p4d_t *p4d = NULL; 34 pgprot_t pgtable_prot = __pgprot(_KERNPG_TABLE); 35 pgprot_t pmd_text_prot = __pgprot(__PAGE_KERNEL_LARGE_EXEC); 36 37 /* Filter out unsupported __PAGE_KERNEL* bits: */ 38 pgprot_val(pmd_text_prot) &= __default_kernel_pte_mask; 39 pgprot_val(pgtable_prot) &= __default_kernel_pte_mask; 40 41 /* 42 * The new mapping only has to cover the page containing the image 43 * kernel's entry point (jump_address_phys), because the switch over to 44 * it is carried out by relocated code running from a page allocated 45 * specifically for this purpose and covered by the identity mapping, so 46 * the temporary kernel text mapping is only needed for the final jump. 47 * Moreover, in that mapping the virtual address of the image kernel's 48 * entry point must be the same as its virtual address in the image 49 * kernel (restore_jump_address), so the image kernel's 50 * restore_registers() code doesn't find itself in a different area of 51 * the virtual address space after switching over to the original page 52 * tables used by the image kernel. 53 */ 54 55 if (pgtable_l5_enabled()) { 56 p4d = (p4d_t *)get_safe_page(GFP_ATOMIC); 57 if (!p4d) 58 return -ENOMEM; 59 } 60 61 pud = (pud_t *)get_safe_page(GFP_ATOMIC); 62 if (!pud) 63 return -ENOMEM; 64 65 pmd = (pmd_t *)get_safe_page(GFP_ATOMIC); 66 if (!pmd) 67 return -ENOMEM; 68 69 set_pmd(pmd + pmd_index(restore_jump_address), 70 __pmd((jump_address_phys & PMD_MASK) | pgprot_val(pmd_text_prot))); 71 set_pud(pud + pud_index(restore_jump_address), 72 __pud(__pa(pmd) | pgprot_val(pgtable_prot))); 73 if (p4d) { 74 p4d_t new_p4d = __p4d(__pa(pud) | pgprot_val(pgtable_prot)); 75 pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot)); 76 77 set_p4d(p4d + p4d_index(restore_jump_address), new_p4d); 78 set_pgd(pgd + pgd_index(restore_jump_address), new_pgd); 79 } else { 80 /* No p4d for 4-level paging: point the pgd to the pud page table */ 81 pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot)); 82 set_pgd(pgd + pgd_index(restore_jump_address), new_pgd); 83 } 84 85 return 0; 86 } 87 88 static void *alloc_pgt_page(void *context) 89 { 90 return (void *)get_safe_page(GFP_ATOMIC); 91 } 92 93 static int set_up_temporary_mappings(void) 94 { 95 struct x86_mapping_info info = { 96 .alloc_pgt_page = alloc_pgt_page, 97 .page_flag = __PAGE_KERNEL_LARGE_EXEC, 98 .offset = __PAGE_OFFSET, 99 }; 100 unsigned long mstart, mend; 101 pgd_t *pgd; 102 int result; 103 int i; 104 105 pgd = (pgd_t *)get_safe_page(GFP_ATOMIC); 106 if (!pgd) 107 return -ENOMEM; 108 109 /* Prepare a temporary mapping for the kernel text */ 110 result = set_up_temporary_text_mapping(pgd); 111 if (result) 112 return result; 113 114 /* Set up the direct mapping from scratch */ 115 for (i = 0; i < nr_pfn_mapped; i++) { 116 mstart = pfn_mapped[i].start << PAGE_SHIFT; 117 mend = pfn_mapped[i].end << PAGE_SHIFT; 118 119 result = kernel_ident_mapping_init(&info, pgd, mstart, mend); 120 if (result) 121 return result; 122 } 123 124 temp_pgt = __pa(pgd); 125 return 0; 126 } 127 128 asmlinkage int swsusp_arch_resume(void) 129 { 130 int error; 131 132 /* We have got enough memory and from now on we cannot recover */ 133 error = set_up_temporary_mappings(); 134 if (error) 135 return error; 136 137 error = relocate_restore_code(); 138 if (error) 139 return error; 140 141 restore_image(); 142 return 0; 143 } 144