Initial import

1 files changed, 153 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
new file mode 100644
index 000000000..939155ffd
--- /dev/null
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -0,0 +1,153 @@
+/*
+ * HyperV  Detection code.
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/clocksource.h>
+#include <linux/module.h>
+#include <linux/hardirq.h>
+#include <linux/efi.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/processor.h>
+#include <asm/hypervisor.h>
+#include <asm/hyperv.h>
+#include <asm/mshyperv.h>
+#include <asm/desc.h>
+#include <asm/idle.h>
+#include <asm/irq_regs.h>
+#include <asm/i8259.h>
+#include <asm/apic.h>
+#include <asm/timer.h>
+
+struct ms_hyperv_info ms_hyperv;
+EXPORT_SYMBOL_GPL(ms_hyperv);
+
+#if IS_ENABLED(CONFIG_HYPERV)
+static void (*vmbus_handler)(void);
+
+void hyperv_vector_handler(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	irq_enter();
+	exit_idle();
+
+	inc_irq_stat(irq_hv_callback_count);
+	if (vmbus_handler)
+		vmbus_handler();
+
+	irq_exit();
+	set_irq_regs(old_regs);
+}
+
+void hv_setup_vmbus_irq(void (*handler)(void))
+{
+	vmbus_handler = handler;
+	/*
+	 * Setup the IDT for hypervisor callback. Prevent reallocation
+	 * at module reload.
+	 */
+	if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
+		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
+				hyperv_callback_vector);
+}
+
+void hv_remove_vmbus_irq(void)
+{
+	/* We have no way to deallocate the interrupt gate */
+	vmbus_handler = NULL;
+}
+EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
+EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
+#endif
+
+static uint32_t  __init ms_hyperv_platform(void)
+{
+	u32 eax;
+	u32 hyp_signature[3];
+
+	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
+		return 0;
+
+	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
+	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
+
+	if (eax >= HYPERV_CPUID_MIN &&
+	    eax <= HYPERV_CPUID_MAX &&
+	    !memcmp("Microsoft Hv", hyp_signature, 12))
+		return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
+
+	return 0;
+}
+
+static cycle_t read_hv_clock(struct clocksource *arg)
+{
+	cycle_t current_tick;
+	/*
+	 * Read the partition counter to get the current tick count. This count
+	 * is set to 0 when the partition is created and is incremented in
+	 * 100 nanosecond units.
+	 */
+	rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
+	return current_tick;
+}
+
+static struct clocksource hyperv_cs = {
+	.name		= "hyperv_clocksource",
+	.rating		= 400, /* use this when running on Hyperv*/
+	.read		= read_hv_clock,
+	.mask		= CLOCKSOURCE_MASK(64),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init ms_hyperv_init_platform(void)
+{
+	/*
+	 * Extract the features and hints
+	 */
+	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
+	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
+
+	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);
+	}
+#endif
+
+	if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
+		clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
+
+#ifdef CONFIG_X86_IO_APIC
+	no_timer_check = 1;
+#endif
+
+}
+
+const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
+	.name			= "Microsoft HyperV",
+	.detect			= ms_hyperv_platform,
+	.init_platform		= ms_hyperv_init_platform,
+};
+EXPORT_SYMBOL(x86_hyper_ms_hyperv);