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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Hibernation support for x86
- *
- * Copyright (c) 2007 Rafael J. Wysocki <[email protected]>
- * Copyright (c) 2002 Pavel Machek <[email protected]>
- * Copyright (c) 2001 Patrick Mochel <[email protected]>
- */
- #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;
- }
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