1 files changed, 114 insertions, 0 deletions

diff --git a/arch/x86/kernel/io_delay.c b/arch/x86/kernel/io_delay.c
new file mode 100644
index 000000000000..bd49321034db
--- /dev/null
+++ b/arch/x86/kernel/io_delay.c
@@ -0,0 +1,114 @@
+/*
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/dmi.h>
+#include <asm/io.h>
+
+int io_delay_type __read_mostly = CONFIG_DEFAULT_IO_DELAY_TYPE;
+EXPORT_SYMBOL_GPL(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) {
+                printk(KERN_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 struct dmi_system_id __initdata io_delay_0xed_port_dmi_table[] = {
+        {
+                .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 tx1000",
+                .matches        = {
+                        DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
+                        DMI_MATCH(DMI_BOARD_NAME, "30BF")
+                }
+        },
+        { }
+};
+
+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 (!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);