diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/kernel/bootflag.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/kernel/bootflag.c')
-rw-r--r-- | kernel/arch/x86/kernel/bootflag.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/kernel/arch/x86/kernel/bootflag.c b/kernel/arch/x86/kernel/bootflag.c new file mode 100644 index 000000000..5de7f4c56 --- /dev/null +++ b/kernel/arch/x86/kernel/bootflag.c @@ -0,0 +1,101 @@ +/* + * 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; +} +module_init(sbf_init); |