From: Kan Liang <kan.li...@intel.com>
Having msr_set/clear_bit on many cpus or given CPU can avoid extra
unnecessory IPIs and simplify MSR content manipulation, when it only
needs to flip a bit.
There is already msr_set/clear_bit, but missing the _on_cpu and _on_cpus
version.
Signed-off-by: Kan Liang <kan.li...@intel.com>
---
arch/x86/include/asm/msr.h | 29 ++++++++++++++++++
arch/x86/lib/msr-smp.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+)
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 898dba2..9bc999b 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -20,6 +20,11 @@ struct msr {
};
};
+struct msr_bit_info {
+ u32 msr_no;
+ u8 bit;
+};
+
struct msr_info {
u32 msr_no;
struct msr reg;
@@ -314,6 +319,10 @@ int msr_set_bit(u32 msr, u8 bit);
int msr_clear_bit(u32 msr, u8 bit);
#ifdef CONFIG_SMP
+int msr_set_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit);
+int msr_clear_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit);
+void msr_set_bit_on_cpus(const struct cpumask *mask, u32 msr, u8 bit);
+void msr_clear_bit_on_cpus(const struct cpumask *mask, u32 msr, u8 bit);
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
@@ -327,6 +336,26 @@ int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64
q);
int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
#else /* CONFIG_SMP */
+static inline int msr_set_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit)
+{
+ return msr_set_bit(msr, bit);
+}
+
+static inline int msr_clear_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit)
+{
+ return msr_clear_bit(msr, bit);
+}
+
+static inline void msr_set_bit_on_cpus(const struct cpumask *mask, u32 msr, u8
bit)
+{
+ msr_set_bit(msr, bit);
+}
+
+static inline void msr_clear_bit_on_cpus(const struct cpumask *mask, u32 msr,
u8 bit)
+{
+ msr_clear_bit(msr, bit);
+}
+
static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
rdmsr(msr_no, *l, *h);
diff --git a/arch/x86/lib/msr-smp.c b/arch/x86/lib/msr-smp.c
index ce68b6a..100b3cb 100644
--- a/arch/x86/lib/msr-smp.c
+++ b/arch/x86/lib/msr-smp.c
@@ -3,6 +3,82 @@
#include <linux/smp.h>
#include <asm/msr.h>
+static void __msr_set_bit_on_cpu(void *info)
+{
+ struct msr_bit_info *bit_info = info;
+
+ msr_set_bit(bit_info->msr_no, bit_info->bit);
+}
+
+static void __msr_clear_bit_on_cpu(void *info)
+{
+ struct msr_bit_info *bit_info = info;
+
+ msr_clear_bit(bit_info->msr_no, bit_info->bit);
+}
+
+int msr_set_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit)
+{
+ struct msr_bit_info info;
+ int err;
+
+ info.msr_no = msr;
+ info.bit = bit;
+
+ err = smp_call_function_single(cpu, __msr_set_bit_on_cpu, &info, 1);
+
+ return err;
+}
+EXPORT_SYMBOL(msr_set_bit_on_cpu);
+
+int msr_clear_bit_on_cpu(unsigned int cpu, u32 msr, u8 bit)
+{
+ struct msr_bit_info info;
+ int err;
+
+ info.msr_no = msr;
+ info.bit = bit;
+
+ err = smp_call_function_single(cpu, __msr_clear_bit_on_cpu, &info, 1);
+
+ return err;
+}
+EXPORT_SYMBOL(msr_clear_bit_on_cpu);
+
+void msr_set_bit_on_cpus(const struct cpumask *mask, u32 msr, u8 bit)
+{
+ struct msr_bit_info info;
+ int this_cpu;
+
+ info.msr_no = msr;
+ info.bit = bit;
+
+ this_cpu = get_cpu();
+ if (cpumask_test_cpu(this_cpu, mask))
+ __msr_set_bit_on_cpu(&info);
+
+ smp_call_function_many(mask, __msr_set_bit_on_cpu, &info, 1);
+ put_cpu();
+}
+EXPORT_SYMBOL(msr_set_bit_on_cpus);
+
+void msr_clear_bit_on_cpus(const struct cpumask *mask, u32 msr, u8 bit)
+{
+ struct msr_bit_info info;
+ int this_cpu;
+
+ info.msr_no = msr;
+ info.bit = bit;
+
+ this_cpu = get_cpu();
+ if (cpumask_test_cpu(this_cpu, mask))
+ __msr_clear_bit_on_cpu(&info);
+
+ smp_call_function_many(mask, __msr_clear_bit_on_cpu, &info, 1);
+ put_cpu();
+}
+EXPORT_SYMBOL(msr_clear_bit_on_cpus);
+
static void __rdmsr_on_cpu(void *info)
{
struct msr_info *rv = info;
--
2.7.4
