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;
+}