#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/system_misc.h>
  #include <linux/interrupt.h>
  #include <linux/irqreturn.h>
  #include <linux/module.h>
  #include <linux/of.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/mm.h>
  
  struct start_info _xen_start_info;
  struct start_info *xen_start_info = &_xen_start_info;
  EXPORT_SYMBOL_GPL(xen_start_info);
  
  enum xen_domain_type xen_domain_type = XEN_NATIVE;
  EXPORT_SYMBOL_GPL(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;
  
  /* 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;
  
  /* TODO: to be removed */
  __read_mostly int xen_have_vector_callback;
  EXPORT_SYMBOL_GPL(xen_have_vector_callback);
  
  int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
  EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
  
  static __read_mostly int xen_events_irq = -1;
  
  /* map fgmfn of domid to lpfn in the current domain */
  static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
  			    unsigned int domid)
  {
  	int rc;
  	struct xen_add_to_physmap_range xatp = {
  		.domid = DOMID_SELF,
  		.foreign_domid = domid,
  		.size = 1,
  		.space = XENMAPSPACE_gmfn_foreign,
  	};
  	xen_ulong_t idx = fgmfn;
  	xen_pfn_t gpfn = lpfn;
  	int err = 0;
  
  	set_xen_guest_handle(xatp.idxs, &idx);
  	set_xen_guest_handle(xatp.gpfns, &gpfn);
  	set_xen_guest_handle(xatp.errs, &err);
  
  	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
  	if (rc || err) {
  		pr_warn("Failed to map pfn to mfn rc:%d:%d pfn:%lx mfn:%lx
  ",
  			rc, err, lpfn, fgmfn);
  		return 1;
  	}
  	return 0;
  }
  
  struct remap_data {
  	xen_pfn_t fgmfn; /* foreign domain's gmfn */
  	pgprot_t prot;
  	domid_t  domid;
  	struct vm_area_struct *vma;
  	int index;
  	struct page **pages;
  	struct xen_remap_mfn_info *info;
  };
  
  static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
  			void *data)
  {
  	struct remap_data *info = data;
  	struct page *page = info->pages[info->index++];
  	unsigned long pfn = page_to_pfn(page);
  	pte_t pte = pte_mkspecial(pfn_pte(pfn, info->prot));
  
  	if (map_foreign_page(pfn, info->fgmfn, info->domid))
  		return -EFAULT;
  	set_pte_at(info->vma->vm_mm, addr, ptep, pte);
  
  	return 0;
  }
  
  int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
  			       unsigned long addr,
  			       xen_pfn_t mfn, int nr,
  			       pgprot_t prot, unsigned domid,
  			       struct page **pages)
  {
  	int err;
  	struct remap_data data;
  
  	/* TBD: Batching, current sole caller only does page at a time */
  	if (nr > 1)
  		return -EINVAL;
  
  	data.fgmfn = mfn;
  	data.prot = prot;
  	data.domid = domid;
  	data.vma = vma;
  	data.index = 0;
  	data.pages = pages;
  	err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
  				  remap_pte_fn, &data);
  	return err;
  }
  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
  
  int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
  			       int nr, struct page **pages)
  {
  	int i;
  
  	for (i = 0; i < nr; i++) {
  		struct xen_remove_from_physmap xrp;
  		unsigned long rc, pfn;
  
  		pfn = page_to_pfn(pages[i]);
  
  		xrp.domid = DOMID_SELF;
  		xrp.gpfn = pfn;
  		rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
  		if (rc) {
  			pr_warn("Failed to unmap pfn:%lx rc:%ld
  ",
  				pfn, rc);
  			return rc;
  		}
  	}
  	return 0;
  }
  EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);
  
  static void xen_percpu_init(void)
  {
  	struct vcpu_register_vcpu_info info;
  	struct vcpu_info *vcpup;
  	int err;
  	int cpu = get_cpu();
  
  	pr_info("Xen: initializing cpu%d
  ", cpu);
  	vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
  
  	info.mfn = __pa(vcpup) >> PAGE_SHIFT;
  	info.offset = offset_in_page(vcpup);
  
  	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
  	BUG_ON(err);
  	per_cpu(xen_vcpu, cpu) = vcpup;
  
  	enable_percpu_irq(xen_events_irq, 0);
  	put_cpu();
  }
  
  static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
  {
  	struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
  	int rc;
  	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
  	if (rc)
  		BUG();
  }
  
  static void xen_power_off(void)
  {
  	struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
  	int rc;
  	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
  	if (rc)
  		BUG();
  }
  
  static int xen_cpu_notification(struct notifier_block *self,
  				unsigned long action,
  				void *hcpu)
  {
  	switch (action) {
  	case CPU_STARTING:
  		xen_percpu_init();
  		break;
  	default:
  		break;
  	}
  
  	return NOTIFY_OK;
  }
  
  static struct notifier_block xen_cpu_notifier = {
  	.notifier_call = xen_cpu_notification,
  };
  
  static irqreturn_t xen_arm_callback(int irq, void *arg)
  {
  	xen_hvm_evtchn_do_upcall();
  	return IRQ_HANDLED;
  }
  
  /*
   * see Documentation/devicetree/bindings/arm/xen.txt for the
   * documentation of the Xen Device Tree format.
   */
  #define GRANT_TABLE_PHYSADDR 0
  static int __init xen_guest_init(void)
  {
  	struct xen_add_to_physmap xatp;
  	static struct shared_info *shared_info_page = 0;
  	struct device_node *node;
  	int len;
  	const char *s = NULL;
  	const char *version = NULL;
  	const char *xen_prefix = "xen,xen-";
  	struct resource res;
  	phys_addr_t grant_frames;
  
  	node = of_find_compatible_node(NULL, NULL, "xen,xen");
  	if (!node) {
  		pr_debug("No Xen support
  ");
  		return 0;
  	}
  	s = of_get_property(node, "compatible", &len);
  	if (strlen(xen_prefix) + 3  < len &&
  			!strncmp(xen_prefix, s, strlen(xen_prefix)))
  		version = s + strlen(xen_prefix);
  	if (version == NULL) {
  		pr_debug("Xen version not found
  ");
  		return 0;
  	}
  	if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
  		return 0;
  	grant_frames = res.start;
  	xen_events_irq = irq_of_parse_and_map(node, 0);
  	pr_info("Xen %s support found, events_irq=%d gnttab_frame=%pa
  ",
  			version, xen_events_irq, &grant_frames);
  
  	if (xen_events_irq < 0)
  		return -ENODEV;
  
  	xen_domain_type = XEN_HVM_DOMAIN;
  
  	xen_setup_features();
  	if (xen_feature(XENFEAT_dom0))
  		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
  	else
  		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
  
  	if (!shared_info_page)
  		shared_info_page = (struct shared_info *)
  			get_zeroed_page(GFP_KERNEL);
  	if (!shared_info_page) {
  		pr_err("not enough memory
  ");
  		return -ENOMEM;
  	}
  	xatp.domid = DOMID_SELF;
  	xatp.idx = 0;
  	xatp.space = XENMAPSPACE_shared_info;
  	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
  	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(sizeof(struct vcpu_info),
  			                       sizeof(struct vcpu_info));
  	if (xen_vcpu_info == NULL)
  		return -ENOMEM;
  
  	if (gnttab_setup_auto_xlat_frames(grant_frames)) {
  		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
  ", xen_events_irq);
  		return -EINVAL;
  	}
  
  	xen_percpu_init();
  
  	register_cpu_notifier(&xen_cpu_notifier);
  
  	return 0;
  }
  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;
  
  	return 0;
  }
  late_initcall(xen_pm_init);
  
  /* In the hypervisor.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(privcmd_call);