1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Hibernation support for x86 4 * 5 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl> 6 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz> 7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org> 8 */ 9 #include <linux/gfp.h> 10 #include <linux/smp.h> 11 #include <linux/suspend.h> 12 #include <linux/scatterlist.h> 13 #include <linux/kdebug.h> 14 #include <linux/cpu.h> 15 #include <linux/pgtable.h> 16 #include <linux/types.h> 17 #include <linux/crc32.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/mtrr.h> 24 #include <asm/sections.h> 25 #include <asm/suspend.h> 26 #include <asm/tlbflush.h> 27 28 /* 29 * Address to jump to in the last phase of restore in order to get to the image 30 * kernel's text (this value is passed in the image header). 31 */ 32 unsigned long restore_jump_address __visible; 33 unsigned long jump_address_phys; 34 35 /* 36 * Value of the cr3 register from before the hibernation (this value is passed 37 * in the image header). 38 */ 39 unsigned long restore_cr3 __visible; 40 unsigned long temp_pgt __visible; 41 unsigned long relocated_restore_code __visible; 42 43 /** 44 * pfn_is_nosave - check if given pfn is in the 'nosave' section 45 * @pfn: the page frame number to check. 46 */ 47 int pfn_is_nosave(unsigned long pfn) 48 { 49 unsigned long nosave_begin_pfn; 50 unsigned long nosave_end_pfn; 51 52 nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT; 53 nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT; 54 55 return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn; 56 } 57 58 struct restore_data_record { 59 unsigned long jump_address; 60 unsigned long jump_address_phys; 61 unsigned long cr3; 62 unsigned long magic; 63 unsigned long e820_checksum; 64 }; 65 66 /** 67 * compute_e820_crc32 - calculate crc32 of a given e820 table 68 * 69 * @table: the e820 table to be calculated 70 * 71 * Return: the resulting checksum 72 */ 73 static inline u32 compute_e820_crc32(struct e820_table *table) 74 { 75 int size = offsetof(struct e820_table, entries) + 76 sizeof(struct e820_entry) * table->nr_entries; 77 78 return ~crc32_le(~0, (unsigned char const *)table, size); 79 } 80 81 #ifdef CONFIG_X86_64 82 #define RESTORE_MAGIC 0x23456789ABCDEF02UL 83 #else 84 #define RESTORE_MAGIC 0x12345679UL 85 #endif 86 87 /** 88 * arch_hibernation_header_save - populate the architecture specific part 89 * of a hibernation image header 90 * @addr: address where architecture specific header data will be saved. 91 * @max_size: maximum size of architecture specific data in hibernation header. 92 * 93 * Return: 0 on success, -EOVERFLOW if max_size is insufficient. 94 */ 95 int arch_hibernation_header_save(void *addr, unsigned int max_size) 96 { 97 struct restore_data_record *rdr = addr; 98 99 if (max_size < sizeof(struct restore_data_record)) 100 return -EOVERFLOW; 101 rdr->magic = RESTORE_MAGIC; 102 rdr->jump_address = (unsigned long)restore_registers; 103 rdr->jump_address_phys = __pa_symbol(restore_registers); 104 105 /* 106 * The restore code fixes up CR3 and CR4 in the following sequence: 107 * 108 * [in hibernation asm] 109 * 1. CR3 <= temporary page tables 110 * 2. CR4 <= mmu_cr4_features (from the kernel that restores us) 111 * 3. CR3 <= rdr->cr3 112 * 4. CR4 <= mmu_cr4_features (from us, i.e. the image kernel) 113 * [in restore_processor_state()] 114 * 5. CR4 <= saved CR4 115 * 6. CR3 <= saved CR3 116 * 117 * Our mmu_cr4_features has CR4.PCIDE=0, and toggling 118 * CR4.PCIDE while CR3's PCID bits are nonzero is illegal, so 119 * rdr->cr3 needs to point to valid page tables but must not 120 * have any of the PCID bits set. 121 */ 122 rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK; 123 124 rdr->e820_checksum = compute_e820_crc32(e820_table_firmware); 125 return 0; 126 } 127 128 /** 129 * arch_hibernation_header_restore - read the architecture specific data 130 * from the hibernation image header 131 * @addr: address to read the data from 132 */ 133 int arch_hibernation_header_restore(void *addr) 134 { 135 struct restore_data_record *rdr = addr; 136 137 if (rdr->magic != RESTORE_MAGIC) { 138 pr_crit("Unrecognized hibernate image header format!\n"); 139 return -EINVAL; 140 } 141 142 restore_jump_address = rdr->jump_address; 143 jump_address_phys = rdr->jump_address_phys; 144 restore_cr3 = rdr->cr3; 145 146 if (rdr->e820_checksum != compute_e820_crc32(e820_table_firmware)) { 147 pr_crit("Hibernate inconsistent memory map detected!\n"); 148 return -ENODEV; 149 } 150 151 return 0; 152 } 153 154 int relocate_restore_code(void) 155 { 156 pgd_t *pgd; 157 p4d_t *p4d; 158 pud_t *pud; 159 pmd_t *pmd; 160 pte_t *pte; 161 162 relocated_restore_code = get_safe_page(GFP_ATOMIC); 163 if (!relocated_restore_code) 164 return -ENOMEM; 165 166 __memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE); 167 168 /* Make the page containing the relocated code executable */ 169 pgd = (pgd_t *)__va(read_cr3_pa()) + 170 pgd_index(relocated_restore_code); 171 p4d = p4d_offset(pgd, relocated_restore_code); 172 if (p4d_leaf(*p4d)) { 173 set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX)); 174 goto out; 175 } 176 pud = pud_offset(p4d, relocated_restore_code); 177 if (pud_leaf(*pud)) { 178 set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX)); 179 goto out; 180 } 181 pmd = pmd_offset(pud, relocated_restore_code); 182 if (pmd_leaf(*pmd)) { 183 set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX)); 184 goto out; 185 } 186 pte = pte_offset_kernel(pmd, relocated_restore_code); 187 set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX)); 188 out: 189 __flush_tlb_all(); 190 return 0; 191 } 192 193 int arch_resume_nosmt(void) 194 { 195 int ret; 196 197 /* 198 * We reached this while coming out of hibernation. This means 199 * that SMT siblings are sleeping in hlt, as mwait is not safe 200 * against control transition during resume (see comment in 201 * hibernate_resume_nonboot_cpu_disable()). 202 * 203 * If the resumed kernel has SMT disabled, we have to take all the 204 * SMT siblings out of hlt, and offline them again so that they 205 * end up in mwait proper. 206 * 207 * Called with hotplug disabled. 208 */ 209 cpu_hotplug_enable(); 210 211 ret = arch_cpu_rescan_dead_smt_siblings(); 212 213 cpu_hotplug_disable(); 214 215 return ret; 216 } 217