[linux-2.6-block.git] / arch / x86 / kernel / io_delay.c

/*
 * 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		= "HP Pavilion dv9000z",
		.matches	= {
			DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
			DMI_MATCH(DMI_BOARD_NAME, "30B9")
		}
	},
	{ }
};

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);
Commit	Line	Data
b02aae9c RH	1	/*
b02aae9c RH	2	* I/O delay strategies for inb_p/outb_p
6e7c4025 IM	3	*
	4	* Allow for a DMI based override of port 0x80, needed for certain HP laptops
	5	* and possibly other systems. Also allow for the gradual elimination of
	6	* outb_p/inb_p API uses.
b02aae9c RH	7	*/
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/init.h>
	11	#include <linux/delay.h>
	12	#include <linux/dmi.h>
	13	#include <asm/io.h>
	14
6e7c4025 IM	15	int io_delay_type __read_mostly = CONFIG_DEFAULT_IO_DELAY_TYPE;
6e7c4025 IM	16	EXPORT_SYMBOL_GPL(io_delay_type);
b02aae9c	17
6e7c4025	18	static int __initdata io_delay_override;
b02aae9c RH	19
	20	/*
	21	* Paravirt wants native_io_delay to be a constant.
	22	*/
	23	void native_io_delay(void)
	24	{
6e7c4025 IM	25	switch (io_delay_type) {
	26	default:
	27	case CONFIG_IO_DELAY_TYPE_0X80:
	28	asm volatile ("outb %al, $0x80");
	29	break;
	30	case CONFIG_IO_DELAY_TYPE_0XED:
	31	asm volatile ("outb %al, $0xed");
	32	break;
	33	case CONFIG_IO_DELAY_TYPE_UDELAY:
	34	/*
	35	* 2 usecs is an upper-bound for the outb delay but
	36	* note that udelay doesn't have the bus-level
	37	* side-effects that outb does, nor does udelay() have
	38	* precise timings during very early bootup (the delays
	39	* are shorter until calibrated):
	40	*/
	41	udelay(2);
	42	case CONFIG_IO_DELAY_TYPE_NONE:
	43	break;
	44	}
b02aae9c RH	45	}
	46	EXPORT_SYMBOL(native_io_delay);
	47
6e7c4025	48	static int __init dmi_io_delay_0xed_port(const struct dmi_system_id *id)
b02aae9c	49	{
6e7c4025 IM	50	if (io_delay_type == CONFIG_IO_DELAY_TYPE_0X80) {
	51	printk(KERN_NOTICE "%s: using 0xed I/O delay port\n",
	52	id->ident);
	53	io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
	54	}
	55
b02aae9c RH	56	return 0;
	57	}
	58
6e7c4025 IM	59	/*
	60	* Quirk table for systems that misbehave (lock up, etc.) if port
	61	* 0x80 is used:
	62	*/
	63	static struct dmi_system_id __initdata io_delay_0xed_port_dmi_table[] = {
b02aae9c	64	{
6e7c4025	65	.callback = dmi_io_delay_0xed_port,
b02aae9c RH	66	.ident = "HP Pavilion dv9000z",
	67	.matches = {
	68	DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
	69	DMI_MATCH(DMI_BOARD_NAME, "30B9")
	70	}
	71	},
6e7c4025	72	{ }
b02aae9c RH	73	};
b02aae9c RH	74
b02aae9c RH	75	void __init io_delay_init(void)
	76	{
	77	if (!io_delay_override)
6e7c4025	78	dmi_check_system(io_delay_0xed_port_dmi_table);
b02aae9c	79	}
b02aae9c RH	80
	81	static int __init io_delay_param(char *s)
	82	{
6e7c4025 IM	83	if (!strcmp(s, "0x80"))
	84	io_delay_type = CONFIG_IO_DELAY_TYPE_0X80;
	85	else if (!strcmp(s, "0xed"))
	86	io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
b02aae9c	87	else if (!strcmp(s, "udelay"))
6e7c4025 IM	88	io_delay_type = CONFIG_IO_DELAY_TYPE_UDELAY;
	89	else if (!strcmp(s, "none"))
	90	io_delay_type = CONFIG_IO_DELAY_TYPE_NONE;
b02aae9c RH	91	else
	92	return -EINVAL;
	93
b02aae9c	94	io_delay_override = 1;
b02aae9c RH	95	return 0;
	96	}
	97
	98	early_param("io_delay", io_delay_param);