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/lib/msr.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/lib/msr.c')
-rw-r--r-- | kernel/arch/x86/lib/msr.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/kernel/arch/x86/lib/msr.c b/kernel/arch/x86/lib/msr.c new file mode 100644 index 000000000..43623739c --- /dev/null +++ b/kernel/arch/x86/lib/msr.c @@ -0,0 +1,110 @@ +#include <linux/module.h> +#include <linux/preempt.h> +#include <asm/msr.h> + +struct msr *msrs_alloc(void) +{ + struct msr *msrs = NULL; + + msrs = alloc_percpu(struct msr); + if (!msrs) { + pr_warn("%s: error allocating msrs\n", __func__); + return NULL; + } + + return msrs; +} +EXPORT_SYMBOL(msrs_alloc); + +void msrs_free(struct msr *msrs) +{ + free_percpu(msrs); +} +EXPORT_SYMBOL(msrs_free); + +/** + * Read an MSR with error handling + * + * @msr: MSR to read + * @m: value to read into + * + * It returns read data only on success, otherwise it doesn't change the output + * argument @m. + * + */ +int msr_read(u32 msr, struct msr *m) +{ + int err; + u64 val; + + err = rdmsrl_safe(msr, &val); + if (!err) + m->q = val; + + return err; +} + +/** + * Write an MSR with error handling + * + * @msr: MSR to write + * @m: value to write + */ +int msr_write(u32 msr, struct msr *m) +{ + return wrmsrl_safe(msr, m->q); +} + +static inline int __flip_bit(u32 msr, u8 bit, bool set) +{ + struct msr m, m1; + int err = -EINVAL; + + if (bit > 63) + return err; + + err = msr_read(msr, &m); + if (err) + return err; + + m1 = m; + if (set) + m1.q |= BIT_64(bit); + else + m1.q &= ~BIT_64(bit); + + if (m1.q == m.q) + return 0; + + err = msr_write(msr, &m1); + if (err) + return err; + + return 1; +} + +/** + * Set @bit in a MSR @msr. + * + * Retval: + * < 0: An error was encountered. + * = 0: Bit was already set. + * > 0: Hardware accepted the MSR write. + */ +int msr_set_bit(u32 msr, u8 bit) +{ + return __flip_bit(msr, bit, true); +} + +/** + * Clear @bit in a MSR @msr. + * + * Retval: + * < 0: An error was encountered. + * = 0: Bit was already cleared. + * > 0: Hardware accepted the MSR write. + */ +int msr_clear_bit(u32 msr, u8 bit) +{ + return __flip_bit(msr, bit, false); +} |