diff options
Diffstat (limited to 'arch/x86/power/hibernate.c')
| -rw-r--r-- | arch/x86/power/hibernate.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c new file mode 100644 index 000000000..e94e0050a --- /dev/null +++ b/arch/x86/power/hibernate.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hibernation support for x86 + * + * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl> + * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz> + * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org> + */ +#include <linux/gfp.h> +#include <linux/smp.h> +#include <linux/suspend.h> +#include <linux/scatterlist.h> +#include <linux/kdebug.h> +#include <linux/cpu.h> +#include <linux/pgtable.h> +#include <linux/types.h> +#include <linux/crc32.h> + +#include <asm/e820/api.h> +#include <asm/init.h> +#include <asm/proto.h> +#include <asm/page.h> +#include <asm/mtrr.h> +#include <asm/sections.h> +#include <asm/suspend.h> +#include <asm/tlbflush.h> + +/* + * Address to jump to in the last phase of restore in order to get to the image + * kernel's text (this value is passed in the image header). + */ +unsigned long restore_jump_address __visible; +unsigned long jump_address_phys; + +/* + * Value of the cr3 register from before the hibernation (this value is passed + * in the image header). + */ +unsigned long restore_cr3 __visible; +unsigned long temp_pgt __visible; +unsigned long relocated_restore_code __visible; + +/** + * pfn_is_nosave - check if given pfn is in the 'nosave' section + */ +int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn; + unsigned long nosave_end_pfn; + + nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT; + nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT; + + return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn; +} + +struct restore_data_record { + unsigned long jump_address; + unsigned long jump_address_phys; + unsigned long cr3; + unsigned long magic; + unsigned long e820_checksum; +}; + +/** + * compute_e820_crc32 - calculate crc32 of a given e820 table + * + * @table: the e820 table to be calculated + * + * Return: the resulting checksum + */ +static inline u32 compute_e820_crc32(struct e820_table *table) +{ + int size = offsetof(struct e820_table, entries) + + sizeof(struct e820_entry) * table->nr_entries; + + return ~crc32_le(~0, (unsigned char const *)table, size); +} + +#ifdef CONFIG_X86_64 +#define RESTORE_MAGIC 0x23456789ABCDEF02UL +#else +#define RESTORE_MAGIC 0x12345679UL +#endif + +/** + * arch_hibernation_header_save - populate the architecture specific part + * of a hibernation image header + * @addr: address to save the data at + */ +int arch_hibernation_header_save(void *addr, unsigned int max_size) +{ + struct restore_data_record *rdr = addr; + + if (max_size < sizeof(struct restore_data_record)) + return -EOVERFLOW; + rdr->magic = RESTORE_MAGIC; + rdr->jump_address = (unsigned long)restore_registers; + rdr->jump_address_phys = __pa_symbol(restore_registers); + + /* + * The restore code fixes up CR3 and CR4 in the following sequence: + * + * [in hibernation asm] + * 1. CR3 <= temporary page tables + * 2. CR4 <= mmu_cr4_features (from the kernel that restores us) + * 3. CR3 <= rdr->cr3 + * 4. CR4 <= mmu_cr4_features (from us, i.e. the image kernel) + * [in restore_processor_state()] + * 5. CR4 <= saved CR4 + * 6. CR3 <= saved CR3 + * + * Our mmu_cr4_features has CR4.PCIDE=0, and toggling + * CR4.PCIDE while CR3's PCID bits are nonzero is illegal, so + * rdr->cr3 needs to point to valid page tables but must not + * have any of the PCID bits set. + */ + rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK; + + rdr->e820_checksum = compute_e820_crc32(e820_table_firmware); + return 0; +} + +/** + * arch_hibernation_header_restore - read the architecture specific data + * from the hibernation image header + * @addr: address to read the data from + */ +int arch_hibernation_header_restore(void *addr) +{ + struct restore_data_record *rdr = addr; + + if (rdr->magic != RESTORE_MAGIC) { + pr_crit("Unrecognized hibernate image header format!\n"); + return -EINVAL; + } + + restore_jump_address = rdr->jump_address; + jump_address_phys = rdr->jump_address_phys; + restore_cr3 = rdr->cr3; + + if (rdr->e820_checksum != compute_e820_crc32(e820_table_firmware)) { + pr_crit("Hibernate inconsistent memory map detected!\n"); + return -ENODEV; + } + + return 0; +} + +int relocate_restore_code(void) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + relocated_restore_code = get_safe_page(GFP_ATOMIC); + if (!relocated_restore_code) + return -ENOMEM; + + memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE); + + /* Make the page containing the relocated code executable */ + pgd = (pgd_t *)__va(read_cr3_pa()) + + pgd_index(relocated_restore_code); + p4d = p4d_offset(pgd, relocated_restore_code); + if (p4d_large(*p4d)) { + set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX)); + goto out; + } + pud = pud_offset(p4d, relocated_restore_code); + if (pud_large(*pud)) { + set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX)); + goto out; + } + pmd = pmd_offset(pud, relocated_restore_code); + if (pmd_large(*pmd)) { + set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX)); + goto out; + } + pte = pte_offset_kernel(pmd, relocated_restore_code); + set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX)); +out: + __flush_tlb_all(); + return 0; +} + +int arch_resume_nosmt(void) +{ + int ret = 0; + /* + * We reached this while coming out of hibernation. This means + * that SMT siblings are sleeping in hlt, as mwait is not safe + * against control transition during resume (see comment in + * hibernate_resume_nonboot_cpu_disable()). + * + * If the resumed kernel has SMT disabled, we have to take all the + * SMT siblings out of hlt, and offline them again so that they + * end up in mwait proper. + * + * Called with hotplug disabled. + */ + cpu_hotplug_enable(); + if (cpu_smt_control == CPU_SMT_DISABLED || + cpu_smt_control == CPU_SMT_FORCE_DISABLED) { + enum cpuhp_smt_control old = cpu_smt_control; + + ret = cpuhp_smt_enable(); + if (ret) + goto out; + ret = cpuhp_smt_disable(old); + if (ret) + goto out; + } +out: + cpu_hotplug_disable(); + return ret; +} |