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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 11:07:49 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 11:07:49 +0900
commit2dc1733fd4ebd4a67c9312d85f1dbc2ac2ffeb26 (patch)
tree5443fedac650dfa11e15eee8e4295ad016e930e8
parent69019d77c71472428a5d67ab8bb7cfa9145000d0 (diff)
parent4c08edd305019061bf1ac95ce089497bdbb8b8ac (diff)
Merge branch 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/hyperv changes from Ingo Molnar: "These changes enable Linux guests to boot as 'Modern VM' guest kernels on MS-Hyperv hosts" * 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, hyperv: Move a variable to avoid an unused variable warning x86, hyperv: Fix build error due to missing <asm/apic.h> include x86, hyperv: Correctly guard the local APIC calibration code x86, hyperv: Get the local APIC timer frequency from the hypervisor
-rw-r--r--arch/x86/include/uapi/asm/hyperv.h19
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c27
2 files changed, 46 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index b80420bcd09..b8f1c0176cb 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -27,6 +27,19 @@
#define HV_X64_MSR_VP_RUNTIME_AVAILABLE (1 << 0)
/* Partition Reference Counter (HV_X64_MSR_TIME_REF_COUNT) available*/
#define HV_X64_MSR_TIME_REF_COUNT_AVAILABLE (1 << 1)
+
+/*
+ * There is a single feature flag that signifies the presence of the MSR
+ * that can be used to retrieve both the local APIC Timer frequency as
+ * well as the TSC frequency.
+ */
+
+/* Local APIC timer frequency MSR (HV_X64_MSR_APIC_FREQUENCY) is available */
+#define HV_X64_MSR_APIC_FREQUENCY_AVAILABLE (1 << 11)
+
+/* TSC frequency MSR (HV_X64_MSR_TSC_FREQUENCY) is available */
+#define HV_X64_MSR_TSC_FREQUENCY_AVAILABLE (1 << 11)
+
/*
* Basic SynIC MSRs (HV_X64_MSR_SCONTROL through HV_X64_MSR_EOM
* and HV_X64_MSR_SINT0 through HV_X64_MSR_SINT15) available
@@ -136,6 +149,12 @@
/* MSR used to read the per-partition time reference counter */
#define HV_X64_MSR_TIME_REF_COUNT 0x40000020
+/* MSR used to retrieve the TSC frequency */
+#define HV_X64_MSR_TSC_FREQUENCY 0x40000022
+
+/* MSR used to retrieve the local APIC timer frequency */
+#define HV_X64_MSR_APIC_FREQUENCY 0x40000023
+
/* Define the virtual APIC registers */
#define HV_X64_MSR_EOI 0x40000070
#define HV_X64_MSR_ICR 0x40000071
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 71a39f3621b..9f7ca266864 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -15,6 +15,7 @@
#include <linux/clocksource.h>
#include <linux/module.h>
#include <linux/hardirq.h>
+#include <linux/efi.h>
#include <linux/interrupt.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
@@ -23,6 +24,8 @@
#include <asm/desc.h>
#include <asm/idle.h>
#include <asm/irq_regs.h>
+#include <asm/i8259.h>
+#include <asm/apic.h>
struct ms_hyperv_info ms_hyperv;
EXPORT_SYMBOL_GPL(ms_hyperv);
@@ -76,6 +79,30 @@ static void __init ms_hyperv_init_platform(void)
printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
+#ifdef CONFIG_X86_LOCAL_APIC
+ if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
+ /*
+ * Get the APIC frequency.
+ */
+ u64 hv_lapic_frequency;
+
+ rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
+ hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
+ lapic_timer_frequency = hv_lapic_frequency;
+ printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n",
+ lapic_timer_frequency);
+
+ /*
+ * On Hyper-V, when we are booting off an EFI firmware stack,
+ * we do not have many legacy devices including PIC, PIT etc.
+ */
+ if (efi_enabled(EFI_BOOT)) {
+ printk(KERN_INFO "HyperV: Using null_legacy_pic\n");
+ legacy_pic = &null_legacy_pic;
+ }
+ }
+#endif
+
if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
}