v4.19.13 snapshot.
diff --git a/arch/x86/kernel/io_delay.c b/arch/x86/kernel/io_delay.c
new file mode 100644
index 0000000..805b7a3
--- /dev/null
+++ b/arch/x86/kernel/io_delay.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * I/O delay strategies for inb_p/outb_p
+ *
+ * Allow for a DMI based override of port 0x80, needed for certain HP laptops
+ * and possibly other systems. Also allow for the gradual elimination of
+ * outb_p/inb_p API uses.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/dmi.h>
+#include <linux/io.h>
+
+int io_delay_type __read_mostly = CONFIG_DEFAULT_IO_DELAY_TYPE;
+
+static int __initdata io_delay_override;
+
+/*
+ * Paravirt wants native_io_delay to be a constant.
+ */
+void native_io_delay(void)
+{
+ switch (io_delay_type) {
+ default:
+ case CONFIG_IO_DELAY_TYPE_0X80:
+ asm volatile ("outb %al, $0x80");
+ break;
+ case CONFIG_IO_DELAY_TYPE_0XED:
+ asm volatile ("outb %al, $0xed");
+ break;
+ case CONFIG_IO_DELAY_TYPE_UDELAY:
+ /*
+ * 2 usecs is an upper-bound for the outb delay but
+ * note that udelay doesn't have the bus-level
+ * side-effects that outb does, nor does udelay() have
+ * precise timings during very early bootup (the delays
+ * are shorter until calibrated):
+ */
+ udelay(2);
+ case CONFIG_IO_DELAY_TYPE_NONE:
+ break;
+ }
+}
+EXPORT_SYMBOL(native_io_delay);
+
+static int __init dmi_io_delay_0xed_port(const struct dmi_system_id *id)
+{
+ if (io_delay_type == CONFIG_IO_DELAY_TYPE_0X80) {
+ pr_notice("%s: using 0xed I/O delay port\n", id->ident);
+ io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
+ }
+
+ return 0;
+}
+
+/*
+ * Quirk table for systems that misbehave (lock up, etc.) if port
+ * 0x80 is used:
+ */
+static const struct dmi_system_id io_delay_0xed_port_dmi_table[] __initconst = {
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "Compaq Presario V6000",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30B7")
+ }
+ },
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "HP Pavilion dv9000z",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30B9")
+ }
+ },
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "HP Pavilion dv6000",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30B8")
+ }
+ },
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "HP Pavilion tx1000",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30BF")
+ }
+ },
+ {
+ .callback = dmi_io_delay_0xed_port,
+ .ident = "Presario F700",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+ DMI_MATCH(DMI_BOARD_NAME, "30D3")
+ }
+ },
+ { }
+};
+
+void __init io_delay_init(void)
+{
+ if (!io_delay_override)
+ dmi_check_system(io_delay_0xed_port_dmi_table);
+}
+
+static int __init io_delay_param(char *s)
+{
+ if (!s)
+ return -EINVAL;
+
+ if (!strcmp(s, "0x80"))
+ io_delay_type = CONFIG_IO_DELAY_TYPE_0X80;
+ else if (!strcmp(s, "0xed"))
+ io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
+ else if (!strcmp(s, "udelay"))
+ io_delay_type = CONFIG_IO_DELAY_TYPE_UDELAY;
+ else if (!strcmp(s, "none"))
+ io_delay_type = CONFIG_IO_DELAY_TYPE_NONE;
+ else
+ return -EINVAL;
+
+ io_delay_override = 1;
+ return 0;
+}
+
+early_param("io_delay", io_delay_param);