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/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 79583ba..01860c0 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -7,6 +7,7 @@
  * Author : K. Y. Srinivasan <kys@microsoft.com>
  */
 
+#include <linux/acpi.h>
 #include <linux/efi.h>
 #include <linux/types.h>
 #include <asm/apic.h>
@@ -14,6 +15,8 @@
 #include <asm/hypervisor.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/mshyperv.h>
+#include <asm/idtentry.h>
+#include <linux/kexec.h>
 #include <linux/version.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
@@ -21,11 +24,17 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/cpuhotplug.h>
+#include <linux/syscore_ops.h>
 #include <clocksource/hyperv_timer.h>
 
+int hyperv_init_cpuhp;
+
 void *hv_hypercall_pg;
 EXPORT_SYMBOL_GPL(hv_hypercall_pg);
 
+/* Storage to save the hypercall page temporarily for hibernation */
+static void *hv_hypercall_pg_saved;
+
 u32 *hv_vp_index;
 EXPORT_SYMBOL_GPL(hv_vp_index);
 
@@ -46,6 +55,14 @@
 }
 EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
 
+void *hv_alloc_hyperv_zeroed_page(void)
+{
+        BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
+
+        return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_zeroed_page);
+
 void hv_free_hyperv_page(unsigned long addr)
 {
 	free_page(addr);
@@ -60,7 +77,8 @@
 	struct page *pg;
 
 	input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
-	pg = alloc_page(GFP_KERNEL);
+	/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
+	pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
 	if (unlikely(!pg))
 		return -ENOMEM;
 	*input_arg = page_address(pg);
@@ -83,8 +101,7 @@
 	 * not be stopped in the case of CPU offlining and the VM will hang.
 	 */
 	if (!*hvp) {
-		*hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO,
-				 PAGE_KERNEL);
+		*hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO);
 	}
 
 	if (*hvp) {
@@ -134,20 +151,16 @@
 	 * Check for required features and priviliges to make TSC frequency
 	 * change notifications work.
 	 */
-	return ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
+	return ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
 		ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE &&
-		ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT;
+		ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT;
 }
 
-__visible void __irq_entry hyperv_reenlightenment_intr(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_reenlightenment)
 {
-	entering_ack_irq();
-
+	ack_APIC_irq();
 	inc_irq_stat(irq_hv_reenlightenment_count);
-
 	schedule_delayed_work(&hv_reenlightenment_work, HZ/10);
-
-	exiting_irq();
 }
 
 void set_hv_tscchange_cb(void (*cb)(void))
@@ -155,7 +168,6 @@
 	struct hv_reenlightenment_control re_ctrl = {
 		.vector = HYPERV_REENLIGHTENMENT_VECTOR,
 		.enabled = 1,
-		.target_vp = hv_vp_index[smp_processor_id()]
 	};
 	struct hv_tsc_emulation_control emu_ctrl = {.enabled = 1};
 
@@ -164,13 +176,20 @@
 		return;
 	}
 
+	if (!hv_vp_index)
+		return;
+
 	hv_reenlightenment_cb = cb;
 
 	/* Make sure callback is registered before we write to MSRs */
 	wmb();
 
+	re_ctrl.target_vp = hv_vp_index[get_cpu()];
+
 	wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
 	wrmsrl(HV_X64_MSR_TSC_EMULATION_CONTROL, *((u64 *)&emu_ctrl));
+
+	put_cpu();
 }
 EXPORT_SYMBOL_GPL(set_hv_tscchange_cb);
 
@@ -212,10 +231,18 @@
 
 	rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
 	if (re_ctrl.target_vp == hv_vp_index[cpu]) {
-		/* Reassign to some other online CPU */
+		/*
+		 * Reassign reenlightenment notifications to some other online
+		 * CPU or just disable the feature if there are no online CPUs
+		 * left (happens on hibernation).
+		 */
 		new_cpu = cpumask_any_but(cpu_online_mask, cpu);
 
-		re_ctrl.target_vp = hv_vp_index[new_cpu];
+		if (new_cpu < nr_cpu_ids)
+			re_ctrl.target_vp = hv_vp_index[new_cpu];
+		else
+			re_ctrl.enabled = 0;
+
 		wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
 	}
 
@@ -238,6 +265,81 @@
 	return 1;
 }
 
+static int hv_suspend(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+	int ret;
+
+	/*
+	 * Reset the hypercall page as it is going to be invalidated
+	 * accross hibernation. Setting hv_hypercall_pg to NULL ensures
+	 * that any subsequent hypercall operation fails safely instead of
+	 * crashing due to an access of an invalid page. The hypercall page
+	 * pointer is restored on resume.
+	 */
+	hv_hypercall_pg_saved = hv_hypercall_pg;
+	hv_hypercall_pg = NULL;
+
+	/* Disable the hypercall page in the hypervisor */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 0;
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	ret = hv_cpu_die(0);
+	return ret;
+}
+
+static void hv_resume(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+	int ret;
+
+	ret = hv_cpu_init(0);
+	WARN_ON(ret);
+
+	/* Re-enable the hypercall page */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 1;
+	hypercall_msr.guest_physical_address =
+		vmalloc_to_pfn(hv_hypercall_pg_saved);
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	hv_hypercall_pg = hv_hypercall_pg_saved;
+	hv_hypercall_pg_saved = NULL;
+
+	/*
+	 * Reenlightenment notifications are disabled by hv_cpu_die(0),
+	 * reenable them here if hv_reenlightenment_cb was previously set.
+	 */
+	if (hv_reenlightenment_cb)
+		set_hv_tscchange_cb(hv_reenlightenment_cb);
+}
+
+/* Note: when the ops are called, only CPU0 is online and IRQs are disabled. */
+static struct syscore_ops hv_syscore_ops = {
+	.suspend	= hv_suspend,
+	.resume		= hv_resume,
+};
+
+static void (* __initdata old_setup_percpu_clockev)(void);
+
+static void __init hv_stimer_setup_percpu_clockev(void)
+{
+	/*
+	 * Ignore any errors in setting up stimer clockevents
+	 * as we can run with the LAPIC timer as a fallback.
+	 */
+	(void)hv_stimer_alloc();
+
+	/*
+	 * Still register the LAPIC timer, because the direct-mode STIMER is
+	 * not supported by old versions of Hyper-V. This also allows users
+	 * to switch to LAPIC timer via /sys, if they want to.
+	 */
+	if (old_setup_percpu_clockev)
+		old_setup_percpu_clockev();
+}
+
 /*
  * This function is to be invoked early in the boot sequence after the
  * hypervisor has been detected.
@@ -256,8 +358,8 @@
 		return;
 
 	/* Absolutely required MSRs */
-	required_msrs = HV_X64_MSR_HYPERCALL_AVAILABLE |
-		HV_X64_MSR_VP_INDEX_AVAILABLE;
+	required_msrs = HV_MSR_HYPERCALL_AVAILABLE |
+		HV_MSR_VP_INDEX_AVAILABLE;
 
 	if ((ms_hyperv.features & required_msrs) != required_msrs)
 		return;
@@ -301,7 +403,10 @@
 	guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
 
-	hv_hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
+	hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
+			VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
+			VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
+			__builtin_return_address(0));
 	if (hv_hypercall_pg == NULL) {
 		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 		goto remove_cpuhp_state;
@@ -312,10 +417,23 @@
 	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
+	/*
+	 * hyperv_init() is called before LAPIC is initialized: see
+	 * apic_intr_mode_init() -> x86_platform.apic_post_init() and
+	 * apic_bsp_setup() -> setup_local_APIC(). The direct-mode STIMER
+	 * depends on LAPIC, so hv_stimer_alloc() should be called from
+	 * x86_init.timers.setup_percpu_clockev.
+	 */
+	old_setup_percpu_clockev = x86_init.timers.setup_percpu_clockev;
+	x86_init.timers.setup_percpu_clockev = hv_stimer_setup_percpu_clockev;
+
 	hv_apic_init();
 
 	x86_init.pci.arch_init = hv_pci_init;
 
+	register_syscore_ops(&hv_syscore_ops);
+
+	hyperv_init_cpuhp = cpuhp;
 	return;
 
 remove_cpuhp_state:
@@ -335,6 +453,8 @@
 {
 	union hv_x64_msr_hypercall_contents hypercall_msr;
 
+	unregister_syscore_ops(&hv_syscore_ops);
+
 	/* Reset our OS id */
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 
@@ -435,3 +555,9 @@
 	return hypercall_msr.enable;
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
+
+bool hv_is_hibernation_supported(void)
+{
+	return acpi_sleep_state_supported(ACPI_STATE_S4);
+}
+EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);