summaryrefslogtreecommitdiffstats
path: root/arch/x86/power/hibernate.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--arch/x86/power/hibernate.c219
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;
+}