Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 1c2f9ba..65d1171 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -23,6 +23,7 @@
 #include <asm/hyperv-tlfs.h>
 #include <asm/mshyperv.h>
 #include <asm/desc.h>
+#include <asm/idtentry.h>
 #include <asm/irq_regs.h>
 #include <asm/i8259.h>
 #include <asm/apic.h>
@@ -40,11 +41,10 @@
 static void (*hv_kexec_handler)(void);
 static void (*hv_crash_handler)(struct pt_regs *regs);
 
-__visible void __irq_entry hyperv_vector_handler(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
-	entering_irq();
 	inc_irq_stat(irq_hv_callback_count);
 	if (vmbus_handler)
 		vmbus_handler();
@@ -52,13 +52,17 @@
 	if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
 		ack_APIC_irq();
 
-	exiting_irq();
 	set_irq_regs(old_regs);
 }
 
-void hv_setup_vmbus_irq(void (*handler)(void))
+int hv_setup_vmbus_irq(int irq, void (*handler)(void))
 {
+	/*
+	 * The 'irq' argument is ignored on x86/x64 because a hard-coded
+	 * interrupt vector is used for Hyper-V interrupts.
+	 */
 	vmbus_handler = handler;
+	return 0;
 }
 
 void hv_remove_vmbus_irq(void)
@@ -73,19 +77,16 @@
  * Routines to do per-architecture handling of stimer0
  * interrupts when in Direct Mode
  */
-
-__visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
-	entering_irq();
 	inc_irq_stat(hyperv_stimer0_count);
 	if (hv_stimer0_handler)
 		hv_stimer0_handler();
 	add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
 	ack_APIC_irq();
 
-	exiting_irq();
 	set_irq_regs(old_regs);
 }
 
@@ -134,14 +135,32 @@
 {
 	if (kexec_in_progress && hv_kexec_handler)
 		hv_kexec_handler();
+
+	/*
+	 * Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor
+	 * corrupts the old VP Assist Pages and can crash the kexec kernel.
+	 */
+	if (kexec_in_progress && hyperv_init_cpuhp > 0)
+		cpuhp_remove_state(hyperv_init_cpuhp);
+
+	/* The function calls stop_other_cpus(). */
 	native_machine_shutdown();
+
+	/* Disable the hypercall page when there is only 1 active CPU. */
+	if (kexec_in_progress)
+		hyperv_cleanup();
 }
 
 static void hv_machine_crash_shutdown(struct pt_regs *regs)
 {
 	if (hv_crash_handler)
 		hv_crash_handler(regs);
+
+	/* The function calls crash_smp_send_stop(). */
 	native_machine_crash_shutdown(regs);
+
+	/* Disable the hypercall page when there is only 1 active CPU. */
+	hyperv_cleanup();
 }
 #endif /* CONFIG_KEXEC_CORE */
 #endif /* CONFIG_HYPERV */
@@ -252,7 +271,7 @@
 			hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF);
 	}
 
-	if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
+	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
 	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
 		x86_platform.calibrate_tsc = hv_get_tsc_khz;
 		x86_platform.calibrate_cpu = hv_get_tsc_khz;
@@ -274,7 +293,7 @@
 		crash_kexec_post_notifiers = true;
 
 #ifdef CONFIG_X86_LOCAL_APIC
-	if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
+	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
 	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
 		/*
 		 * Get the APIC frequency.
@@ -300,7 +319,10 @@
 	machine_ops.shutdown = hv_machine_shutdown;
 	machine_ops.crash_shutdown = hv_machine_crash_shutdown;
 #endif
-	mark_tsc_unstable("running on Hyper-V");
+	if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
+		wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
+		setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+	}
 
 	/*
 	 * Generation 2 instances don't support reading the NMI status from
@@ -326,17 +348,19 @@
 	x86_platform.apic_post_init = hyperv_init;
 	hyperv_setup_mmu_ops();
 	/* Setup the IDT for hypervisor callback */
-	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
+	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_hyperv_callback);
 
 	/* Setup the IDT for reenlightenment notifications */
-	if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT)
+	if (ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT) {
 		alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
-				hyperv_reenlightenment_vector);
+				asm_sysvec_hyperv_reenlightenment);
+	}
 
 	/* Setup the IDT for stimer0 */
-	if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE)
+	if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) {
 		alloc_intr_gate(HYPERV_STIMER0_VECTOR,
-				hv_stimer0_callback_vector);
+				asm_sysvec_hyperv_stimer0);
+	}
 
 # ifdef CONFIG_SMP
 	smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
@@ -356,13 +380,13 @@
 	/* Register Hyper-V specific clocksource */
 	hv_init_clocksource();
 #endif
-}
-
-void hv_setup_sched_clock(void *sched_clock)
-{
-#ifdef CONFIG_PARAVIRT
-	pv_ops.time.sched_clock = sched_clock;
-#endif
+	/*
+	 * TSC should be marked as unstable only after Hyper-V
+	 * clocksource has been initialized. This ensures that the
+	 * stability of the sched_clock is not altered.
+	 */
+	if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
+		mark_tsc_unstable("running on Hyper-V");
 }
 
 const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {