v4.19.13 snapshot.
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
new file mode 100644
index 0000000..f1915b7
--- /dev/null
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sleep.c - x86-specific ACPI sleep support.
+ *
+ *  Copyright (C) 2001-2003 Patrick Mochel
+ *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
+ */
+
+#include <linux/acpi.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/dmi.h>
+#include <linux/cpumask.h>
+#include <asm/segment.h>
+#include <asm/desc.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+#include <asm/realmode.h>
+
+#include <linux/ftrace.h>
+#include "../../realmode/rm/wakeup.h"
+#include "sleep.h"
+
+unsigned long acpi_realmode_flags;
+
+#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
+static char temp_stack[4096];
+#endif
+
+/**
+ * x86_acpi_enter_sleep_state - enter sleep state
+ * @state: Sleep state to enter.
+ *
+ * Wrapper around acpi_enter_sleep_state() to be called by assmebly.
+ */
+acpi_status asmlinkage __visible x86_acpi_enter_sleep_state(u8 state)
+{
+	return acpi_enter_sleep_state(state);
+}
+
+/**
+ * x86_acpi_suspend_lowlevel - save kernel state
+ *
+ * Create an identity mapped page table and copy the wakeup routine to
+ * low memory.
+ */
+int x86_acpi_suspend_lowlevel(void)
+{
+	struct wakeup_header *header =
+		(struct wakeup_header *) __va(real_mode_header->wakeup_header);
+
+	if (header->signature != WAKEUP_HEADER_SIGNATURE) {
+		printk(KERN_ERR "wakeup header does not match\n");
+		return -EINVAL;
+	}
+
+	header->video_mode = saved_video_mode;
+
+	header->pmode_behavior = 0;
+
+#ifndef CONFIG_64BIT
+	native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
+
+	/*
+	 * We have to check that we can write back the value, and not
+	 * just read it.  At least on 90 nm Pentium M (Family 6, Model
+	 * 13), reading an invalid MSR is not guaranteed to trap, see
+	 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
+	 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
+	 * nm process with 512-KB L2 Cache Specification Update".
+	 */
+	if (!rdmsr_safe(MSR_EFER,
+			&header->pmode_efer_low,
+			&header->pmode_efer_high) &&
+	    !wrmsr_safe(MSR_EFER,
+			header->pmode_efer_low,
+			header->pmode_efer_high))
+		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
+#endif /* !CONFIG_64BIT */
+
+	header->pmode_cr0 = read_cr0();
+	if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
+		header->pmode_cr4 = __read_cr4();
+		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
+	}
+	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
+			&header->pmode_misc_en_low,
+			&header->pmode_misc_en_high) &&
+	    !wrmsr_safe(MSR_IA32_MISC_ENABLE,
+			header->pmode_misc_en_low,
+			header->pmode_misc_en_high))
+		header->pmode_behavior |=
+			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
+	header->realmode_flags = acpi_realmode_flags;
+	header->real_magic = 0x12345678;
+
+#ifndef CONFIG_64BIT
+	header->pmode_entry = (u32)&wakeup_pmode_return;
+	header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
+	saved_magic = 0x12345678;
+#else /* CONFIG_64BIT */
+#ifdef CONFIG_SMP
+	initial_stack = (unsigned long)temp_stack + sizeof(temp_stack);
+	early_gdt_descr.address =
+			(unsigned long)get_cpu_gdt_rw(smp_processor_id());
+	initial_gs = per_cpu_offset(smp_processor_id());
+#endif
+	initial_code = (unsigned long)wakeup_long64;
+       saved_magic = 0x123456789abcdef0L;
+#endif /* CONFIG_64BIT */
+
+	/*
+	 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
+	 * inconsistent call/return info after it jumps to the wakeup vector.
+	 */
+	pause_graph_tracing();
+	do_suspend_lowlevel();
+	unpause_graph_tracing();
+	return 0;
+}
+
+static int __init acpi_sleep_setup(char *str)
+{
+	while ((str != NULL) && (*str != '\0')) {
+		if (strncmp(str, "s3_bios", 7) == 0)
+			acpi_realmode_flags |= 1;
+		if (strncmp(str, "s3_mode", 7) == 0)
+			acpi_realmode_flags |= 2;
+		if (strncmp(str, "s3_beep", 7) == 0)
+			acpi_realmode_flags |= 4;
+#ifdef CONFIG_HIBERNATION
+		if (strncmp(str, "s4_nohwsig", 10) == 0)
+			acpi_no_s4_hw_signature();
+#endif
+		if (strncmp(str, "nonvs", 5) == 0)
+			acpi_nvs_nosave();
+		if (strncmp(str, "nonvs_s3", 8) == 0)
+			acpi_nvs_nosave_s3();
+		if (strncmp(str, "old_ordering", 12) == 0)
+			acpi_old_suspend_ordering();
+		if (strncmp(str, "nobl", 4) == 0)
+			acpi_sleep_no_blacklist();
+		str = strchr(str, ',');
+		if (str != NULL)
+			str += strspn(str, ", \t");
+	}
+	return 1;
+}
+
+__setup("acpi_sleep=", acpi_sleep_setup);