mirror of
https://github.com/torvalds/linux.git
synced 2024-12-11 21:52:04 +00:00
1206f53589
The bootflag.o is obj-y (always built in). It will never be modular, so using module_init as an alias for __initcall is somewhat misleading. Fix this up now, so that we can relocate module_init from init.h into module.h in the future. If we don't do this, we'd have to add module.h to obviously non-modular code, and that would be a worse thing. Note that direct use of __initcall is discouraged, vs. one of the priority categorized subgroups. As __initcall gets mapped onto device_initcall, our use of arch_initcall (which makes sense for arch code) will thus change this registration from level 6-device to level 3-arch (i.e. slightly earlier). However no observable impact of that small difference has been observed during testing, or is expected. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
102 lines
1.6 KiB
C
102 lines
1.6 KiB
C
/*
|
|
* Implement 'Simple Boot Flag Specification 2.0'
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/string.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/acpi.h>
|
|
#include <asm/io.h>
|
|
|
|
#include <linux/mc146818rtc.h>
|
|
|
|
#define SBF_RESERVED (0x78)
|
|
#define SBF_PNPOS (1<<0)
|
|
#define SBF_BOOTING (1<<1)
|
|
#define SBF_DIAG (1<<2)
|
|
#define SBF_PARITY (1<<7)
|
|
|
|
int sbf_port __initdata = -1; /* set via acpi_boot_init() */
|
|
|
|
static int __init parity(u8 v)
|
|
{
|
|
int x = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
x ^= (v & 1);
|
|
v >>= 1;
|
|
}
|
|
|
|
return x;
|
|
}
|
|
|
|
static void __init sbf_write(u8 v)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (sbf_port != -1) {
|
|
v &= ~SBF_PARITY;
|
|
if (!parity(v))
|
|
v |= SBF_PARITY;
|
|
|
|
printk(KERN_INFO "Simple Boot Flag at 0x%x set to 0x%x\n",
|
|
sbf_port, v);
|
|
|
|
spin_lock_irqsave(&rtc_lock, flags);
|
|
CMOS_WRITE(v, sbf_port);
|
|
spin_unlock_irqrestore(&rtc_lock, flags);
|
|
}
|
|
}
|
|
|
|
static u8 __init sbf_read(void)
|
|
{
|
|
unsigned long flags;
|
|
u8 v;
|
|
|
|
if (sbf_port == -1)
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&rtc_lock, flags);
|
|
v = CMOS_READ(sbf_port);
|
|
spin_unlock_irqrestore(&rtc_lock, flags);
|
|
|
|
return v;
|
|
}
|
|
|
|
static int __init sbf_value_valid(u8 v)
|
|
{
|
|
if (v & SBF_RESERVED) /* Reserved bits */
|
|
return 0;
|
|
if (!parity(v))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int __init sbf_init(void)
|
|
{
|
|
u8 v;
|
|
|
|
if (sbf_port == -1)
|
|
return 0;
|
|
|
|
v = sbf_read();
|
|
if (!sbf_value_valid(v)) {
|
|
printk(KERN_WARNING "Simple Boot Flag value 0x%x read from "
|
|
"CMOS RAM was invalid\n", v);
|
|
}
|
|
|
|
v &= ~SBF_RESERVED;
|
|
v &= ~SBF_BOOTING;
|
|
v &= ~SBF_DIAG;
|
|
#if defined(CONFIG_ISAPNP)
|
|
v |= SBF_PNPOS;
|
|
#endif
|
|
sbf_write(v);
|
|
|
|
return 0;
|
|
}
|
|
arch_initcall(sbf_init);
|