v4.19.13 snapshot.
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
new file mode 100644
index 0000000..07060e5
--- /dev/null
+++ b/arch/arm/xen/enlighten.c
@@ -0,0 +1,477 @@
+#include <xen/xen.h>
+#include <xen/events.h>
+#include <xen/grant_table.h>
+#include <xen/hvm.h>
+#include <xen/interface/vcpu.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/interface/hvm/params.h>
+#include <xen/features.h>
+#include <xen/platform_pci.h>
+#include <xen/xenbus.h>
+#include <xen/page.h>
+#include <xen/interface/sched.h>
+#include <xen/xen-ops.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/xen-ops.h>
+#include <asm/system_misc.h>
+#include <asm/efi.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/cpuidle.h>
+#include <linux/cpufreq.h>
+#include <linux/cpu.h>
+#include <linux/console.h>
+#include <linux/pvclock_gtod.h>
+#include <linux/time64.h>
+#include <linux/timekeeping.h>
+#include <linux/timekeeper_internal.h>
+#include <linux/acpi.h>
+
+#include <linux/mm.h>
+
+struct start_info _xen_start_info;
+struct start_info *xen_start_info = &_xen_start_info;
+EXPORT_SYMBOL(xen_start_info);
+
+enum xen_domain_type xen_domain_type = XEN_NATIVE;
+EXPORT_SYMBOL(xen_domain_type);
+
+struct shared_info xen_dummy_shared_info;
+struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
+
+DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
+static struct vcpu_info __percpu *xen_vcpu_info;
+
+/* Linux <-> Xen vCPU id mapping */
+DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
+EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
+
+/* These are unused until we support booting "pre-ballooned" */
+unsigned long xen_released_pages;
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
+static __read_mostly unsigned int xen_events_irq;
+
+uint32_t xen_start_flags;
+EXPORT_SYMBOL(xen_start_flags);
+
+int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
+			       unsigned long addr,
+			       xen_pfn_t *gfn, int nr,
+			       int *err_ptr, pgprot_t prot,
+			       unsigned domid,
+			       struct page **pages)
+{
+	return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
+					 prot, domid, pages);
+}
+EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
+
+/* Not used by XENFEAT_auto_translated guests. */
+int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
+                              unsigned long addr,
+                              xen_pfn_t gfn, int nr,
+                              pgprot_t prot, unsigned domid,
+                              struct page **pages)
+{
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
+
+int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
+			       int nr, struct page **pages)
+{
+	return xen_xlate_unmap_gfn_range(vma, nr, pages);
+}
+EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
+
+/* Not used by XENFEAT_auto_translated guests. */
+int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
+			       unsigned long addr,
+			       xen_pfn_t *mfn, int nr,
+			       int *err_ptr, pgprot_t prot,
+			       unsigned int domid, struct page **pages)
+{
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_array);
+
+static void xen_read_wallclock(struct timespec64 *ts)
+{
+	u32 version;
+	struct timespec64 now, ts_monotonic;
+	struct shared_info *s = HYPERVISOR_shared_info;
+	struct pvclock_wall_clock *wall_clock = &(s->wc);
+
+	/* get wallclock at system boot */
+	do {
+		version = wall_clock->version;
+		rmb();		/* fetch version before time */
+		now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
+		now.tv_nsec = wall_clock->nsec;
+		rmb();		/* fetch time before checking version */
+	} while ((wall_clock->version & 1) || (version != wall_clock->version));
+
+	/* time since system boot */
+	ktime_get_ts64(&ts_monotonic);
+	*ts = timespec64_add(now, ts_monotonic);
+}
+
+static int xen_pvclock_gtod_notify(struct notifier_block *nb,
+				   unsigned long was_set, void *priv)
+{
+	/* Protected by the calling core code serialization */
+	static struct timespec64 next_sync;
+
+	struct xen_platform_op op;
+	struct timespec64 now, system_time;
+	struct timekeeper *tk = priv;
+
+	now.tv_sec = tk->xtime_sec;
+	now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
+	system_time = timespec64_add(now, tk->wall_to_monotonic);
+
+	/*
+	 * We only take the expensive HV call when the clock was set
+	 * or when the 11 minutes RTC synchronization time elapsed.
+	 */
+	if (!was_set && timespec64_compare(&now, &next_sync) < 0)
+		return NOTIFY_OK;
+
+	op.cmd = XENPF_settime64;
+	op.u.settime64.mbz = 0;
+	op.u.settime64.secs = now.tv_sec;
+	op.u.settime64.nsecs = now.tv_nsec;
+	op.u.settime64.system_time = timespec64_to_ns(&system_time);
+	(void)HYPERVISOR_platform_op(&op);
+
+	/*
+	 * Move the next drift compensation time 11 minutes
+	 * ahead. That's emulating the sync_cmos_clock() update for
+	 * the hardware RTC.
+	 */
+	next_sync = now;
+	next_sync.tv_sec += 11 * 60;
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block xen_pvclock_gtod_notifier = {
+	.notifier_call = xen_pvclock_gtod_notify,
+};
+
+static int xen_starting_cpu(unsigned int cpu)
+{
+	struct vcpu_register_vcpu_info info;
+	struct vcpu_info *vcpup;
+	int err;
+
+	/* 
+	 * VCPUOP_register_vcpu_info cannot be called twice for the same
+	 * vcpu, so if vcpu_info is already registered, just get out. This
+	 * can happen with cpu-hotplug.
+	 */
+	if (per_cpu(xen_vcpu, cpu) != NULL)
+		goto after_register_vcpu_info;
+
+	pr_info("Xen: initializing cpu%d\n", cpu);
+	vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
+
+	info.mfn = virt_to_gfn(vcpup);
+	info.offset = xen_offset_in_page(vcpup);
+
+	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+				 &info);
+	BUG_ON(err);
+	per_cpu(xen_vcpu, cpu) = vcpup;
+
+	xen_setup_runstate_info(cpu);
+
+after_register_vcpu_info:
+	enable_percpu_irq(xen_events_irq, 0);
+	return 0;
+}
+
+static int xen_dying_cpu(unsigned int cpu)
+{
+	disable_percpu_irq(xen_events_irq);
+	return 0;
+}
+
+void xen_reboot(int reason)
+{
+	struct sched_shutdown r = { .reason = reason };
+	int rc;
+
+	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
+	BUG_ON(rc);
+}
+
+static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+	xen_reboot(SHUTDOWN_reboot);
+}
+
+
+static void xen_power_off(void)
+{
+	xen_reboot(SHUTDOWN_poweroff);
+}
+
+static irqreturn_t xen_arm_callback(int irq, void *arg)
+{
+	xen_hvm_evtchn_do_upcall();
+	return IRQ_HANDLED;
+}
+
+static __initdata struct {
+	const char *compat;
+	const char *prefix;
+	const char *version;
+	bool found;
+} hyper_node = {"xen,xen", "xen,xen-", NULL, false};
+
+static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
+				      int depth, void *data)
+{
+	const void *s = NULL;
+	int len;
+
+	if (depth != 1 || strcmp(uname, "hypervisor") != 0)
+		return 0;
+
+	if (of_flat_dt_is_compatible(node, hyper_node.compat))
+		hyper_node.found = true;
+
+	s = of_get_flat_dt_prop(node, "compatible", &len);
+	if (strlen(hyper_node.prefix) + 3  < len &&
+	    !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
+		hyper_node.version = s + strlen(hyper_node.prefix);
+
+	/*
+	 * Check if Xen supports EFI by checking whether there is the
+	 * "/hypervisor/uefi" node in DT. If so, runtime services are available
+	 * through proxy functions (e.g. in case of Xen dom0 EFI implementation
+	 * they call special hypercall which executes relevant EFI functions)
+	 * and that is why they are always enabled.
+	 */
+	if (IS_ENABLED(CONFIG_XEN_EFI)) {
+		if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
+		    !efi_runtime_disabled())
+			set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+	}
+
+	return 0;
+}
+
+/*
+ * see Documentation/devicetree/bindings/arm/xen.txt for the
+ * documentation of the Xen Device Tree format.
+ */
+#define GRANT_TABLE_PHYSADDR 0
+void __init xen_early_init(void)
+{
+	of_scan_flat_dt(fdt_find_hyper_node, NULL);
+	if (!hyper_node.found) {
+		pr_debug("No Xen support\n");
+		return;
+	}
+
+	if (hyper_node.version == NULL) {
+		pr_debug("Xen version not found\n");
+		return;
+	}
+
+	pr_info("Xen %s support found\n", hyper_node.version);
+
+	xen_domain_type = XEN_HVM_DOMAIN;
+
+	xen_setup_features();
+
+	if (xen_feature(XENFEAT_dom0))
+		xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
+
+	if (!console_set_on_cmdline && !xen_initial_domain())
+		add_preferred_console("hvc", 0, NULL);
+}
+
+static void __init xen_acpi_guest_init(void)
+{
+#ifdef CONFIG_ACPI
+	struct xen_hvm_param a;
+	int interrupt, trigger, polarity;
+
+	a.domid = DOMID_SELF;
+	a.index = HVM_PARAM_CALLBACK_IRQ;
+
+	if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
+	    || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
+		xen_events_irq = 0;
+		return;
+	}
+
+	interrupt = a.value & 0xff;
+	trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
+					 : ACPI_LEVEL_SENSITIVE;
+	polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
+					  : ACPI_ACTIVE_HIGH;
+	xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
+#endif
+}
+
+static void __init xen_dt_guest_init(void)
+{
+	struct device_node *xen_node;
+
+	xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
+	if (!xen_node) {
+		pr_err("Xen support was detected before, but it has disappeared\n");
+		return;
+	}
+
+	xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+}
+
+static int __init xen_guest_init(void)
+{
+	struct xen_add_to_physmap xatp;
+	struct shared_info *shared_info_page = NULL;
+	int cpu;
+
+	if (!xen_domain())
+		return 0;
+
+	if (!acpi_disabled)
+		xen_acpi_guest_init();
+	else
+		xen_dt_guest_init();
+
+	if (!xen_events_irq) {
+		pr_err("Xen event channel interrupt not found\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
+	 * parameters are found. Force enable runtime services.
+	 */
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		xen_efi_runtime_setup();
+
+	shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
+
+	if (!shared_info_page) {
+		pr_err("not enough memory\n");
+		return -ENOMEM;
+	}
+	xatp.domid = DOMID_SELF;
+	xatp.idx = 0;
+	xatp.space = XENMAPSPACE_shared_info;
+	xatp.gpfn = virt_to_gfn(shared_info_page);
+	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+		BUG();
+
+	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
+
+	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions. 
+	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
+	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
+	 * for secondary CPUs as they are brought up.
+	 * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
+	 */
+	xen_vcpu_info = alloc_percpu(struct vcpu_info);
+	if (xen_vcpu_info == NULL)
+		return -ENOMEM;
+
+	/* Direct vCPU id mapping for ARM guests. */
+	for_each_possible_cpu(cpu)
+		per_cpu(xen_vcpu_id, cpu) = cpu;
+
+	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
+	if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
+					  &xen_auto_xlat_grant_frames.vaddr,
+					  xen_auto_xlat_grant_frames.count)) {
+		free_percpu(xen_vcpu_info);
+		return -ENOMEM;
+	}
+	gnttab_init();
+	if (!xen_initial_domain())
+		xenbus_probe(NULL);
+
+	/*
+	 * Making sure board specific code will not set up ops for
+	 * cpu idle and cpu freq.
+	 */
+	disable_cpuidle();
+	disable_cpufreq();
+
+	xen_init_IRQ();
+
+	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
+			       "events", &xen_vcpu)) {
+		pr_err("Error request IRQ %d\n", xen_events_irq);
+		return -EINVAL;
+	}
+
+	xen_time_setup_guest();
+
+	if (xen_initial_domain())
+		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
+
+	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
+				 "arm/xen:starting", xen_starting_cpu,
+				 xen_dying_cpu);
+}
+early_initcall(xen_guest_init);
+
+static int __init xen_pm_init(void)
+{
+	if (!xen_domain())
+		return -ENODEV;
+
+	pm_power_off = xen_power_off;
+	arm_pm_restart = xen_restart;
+	if (!xen_initial_domain()) {
+		struct timespec64 ts;
+		xen_read_wallclock(&ts);
+		do_settimeofday64(&ts);
+	}
+
+	return 0;
+}
+late_initcall(xen_pm_init);
+
+
+/* empty stubs */
+void xen_arch_pre_suspend(void) { }
+void xen_arch_post_suspend(int suspend_cancelled) { }
+void xen_timer_resume(void) { }
+void xen_arch_resume(void) { }
+void xen_arch_suspend(void) { }
+
+
+/* In the hypercall.S file. */
+EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
+EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
+EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
+EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
+EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
+EXPORT_SYMBOL_GPL(privcmd_call);