alistair23-linux/arch/x86/kernel/io_delay.c
Paul Gortmaker 186f43608a x86/kernel: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 15:06:41 +02:00

132 lines
3 KiB
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/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 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 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);