text: /*
   * irq_comm.c: Common API for in kernel interrupt controller
   * Copyright (c) 2007, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
   * Place - Suite 330, Boston, MA 02111-1307 USA.
   * Authors:
   *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
   *
   * Copyright 2010 Red Hat, Inc. and/or its affiliates.
   */
  
  #include <linux/kvm_host.h>
  #include <linux/slab.h>
  #include <linux/export.h>
  #include <linux/rculist.h>
  
  #include <trace/events/kvm.h>
  
  #include <asm/msidef.h>
  
  #include "irq.h"
  
  #include "ioapic.h"
  
  #include "lapic.h"
  
  #include "hyperv.h"
  #include "x86.h"
  
  static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  			   struct kvm *kvm, int irq_source_id, int level,
  			   bool line_status)
  {
  	struct kvm_pic *pic = kvm->arch.vpic;
  	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  }
  
  static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  			      struct kvm *kvm, int irq_source_id, int level,
  			      bool line_status)
  {
  	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  				line_status);
  }
  
  int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  		struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  {
  	int i, r = -1;
  	struct kvm_vcpu *vcpu, *lowest = NULL;
  	unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  	unsigned int dest_vcpus = 0;
  
  	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  			kvm_lowest_prio_delivery(irq)) {
  		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  		irq->delivery_mode = APIC_DM_FIXED;
  	}
  
  	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  		return r;
  
  	memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  
  	kvm_for_each_vcpu(i, vcpu, kvm) {
  		if (!kvm_apic_present(vcpu))
  			continue;
  
  		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  					irq->dest_id, irq->dest_mode))
  			continue;
  
  		if (!kvm_lowest_prio_delivery(irq)) {
  			if (r < 0)
  				r = 0;
  			r += kvm_apic_set_irq(vcpu, irq, dest_map);
  		} else if (kvm_lapic_enabled(vcpu)) {
  			if (!kvm_vector_hashing_enabled()) {
  				if (!lowest)
  					lowest = vcpu;
  				else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  					lowest = vcpu;
  			} else {
  				__set_bit(i, dest_vcpu_bitmap);
  				dest_vcpus++;
  			}
  		}
  	}
  
  	if (dest_vcpus != 0) {
  		int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
  					dest_vcpu_bitmap, KVM_MAX_VCPUS);
  
  		lowest = kvm_get_vcpu(kvm, idx);
  	}
  
  	if (lowest)
  		r = kvm_apic_set_irq(lowest, irq, dest_map);
  
  	return r;
  }
  
  void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
  		     struct kvm_lapic_irq *irq)
  {
  	trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
  	                                     (u64)e->msi.address_hi << 32 : 0),
  	                      e->msi.data);
  
  	irq->dest_id = (e->msi.address_lo &
  			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
  	if (kvm->arch.x2apic_format)
  		irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
  	irq->vector = (e->msi.data &
  			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
  	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
  	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
  	irq->delivery_mode = e->msi.data & 0x700;
  	irq->msi_redir_hint = ((e->msi.address_lo
  		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
  	irq->level = 1;
  	irq->shorthand = 0;
  }
  EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
  
  static inline bool kvm_msi_route_invalid(struct kvm *kvm,
  		struct kvm_kernel_irq_routing_entry *e)
  {
  	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
  }
  
  int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
  		struct kvm *kvm, int irq_source_id, int level, bool line_status)
  {
  	struct kvm_lapic_irq irq;
  
  	if (kvm_msi_route_invalid(kvm, e))
  		return -EINVAL;
  
  	if (!level)
  		return -1;
  
  	kvm_set_msi_irq(kvm, e, &irq);
  
  	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
  }
  
  
  static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
  		    struct kvm *kvm, int irq_source_id, int level,
  		    bool line_status)
  {
  	if (!level)
  		return -1;
  
  	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
  }
  
  int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
  			      struct kvm *kvm, int irq_source_id, int level,
  			      bool line_status)
  {
  	struct kvm_lapic_irq irq;
  	int r;
  
  	switch (e->type) {
  	case KVM_IRQ_ROUTING_HV_SINT:
  		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
  				       line_status);
  
  	case KVM_IRQ_ROUTING_MSI:
  		if (kvm_msi_route_invalid(kvm, e))
  			return -EINVAL;
  
  		kvm_set_msi_irq(kvm, e, &irq);
  
  		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
  			return r;
  		break;
  
  	default:
  		break;
  	}
  
  	return -EWOULDBLOCK;
  }
  
  int kvm_request_irq_source_id(struct kvm *kvm)
  {
  	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
  	int irq_source_id;
  
  	mutex_lock(&kvm->irq_lock);
  	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
  
  	if (irq_source_id >= BITS_PER_LONG) {
  		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
  		irq_source_id = -EFAULT;
  		goto unlock;
  	}
  
  	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
  	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
  	set_bit(irq_source_id, bitmap);
  unlock:
  	mutex_unlock(&kvm->irq_lock);
  
  	return irq_source_id;
  }
  
  void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
  {
  	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
  	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
  
  	mutex_lock(&kvm->irq_lock);
  	if (irq_source_id < 0 ||
  	    irq_source_id >= BITS_PER_LONG) {
  		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
  		goto unlock;
  	}
  	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
  	if (!irqchip_kernel(kvm))
  		goto unlock;
  
  	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
  	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
  unlock:
  	mutex_unlock(&kvm->irq_lock);
  }
  
  void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
  				    struct kvm_irq_mask_notifier *kimn)
  {
  	mutex_lock(&kvm->irq_lock);
  	kimn->irq = irq;
  	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
  	mutex_unlock(&kvm->irq_lock);
  }
  
  void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
  				      struct kvm_irq_mask_notifier *kimn)
  {
  	mutex_lock(&kvm->irq_lock);
  	hlist_del_rcu(&kimn->link);
  	mutex_unlock(&kvm->irq_lock);
  	synchronize_srcu(&kvm->irq_srcu);
  }
  
  void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
  			     bool mask)
  {
  	struct kvm_irq_mask_notifier *kimn;
  	int idx, gsi;
  
  	idx = srcu_read_lock(&kvm->irq_srcu);
  	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
  	if (gsi != -1)
  		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
  			if (kimn->irq == gsi)
  				kimn->func(kimn, mask);
  	srcu_read_unlock(&kvm->irq_srcu, idx);
  }
  
  bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
  {
  	return irqchip_in_kernel(kvm);
  }
  
  int kvm_set_routing_entry(struct kvm *kvm,
  			  struct kvm_kernel_irq_routing_entry *e,
  			  const struct kvm_irq_routing_entry *ue)
  {
  	/* We can't check irqchip_in_kernel() here as some callers are
  	 * currently inititalizing the irqchip. Other callers should therefore
  	 * check kvm_arch_can_set_irq_routing() before calling this function.
  	 */
  	switch (ue->type) {
  	case KVM_IRQ_ROUTING_IRQCHIP:
  		if (irqchip_split(kvm))
  			return -EINVAL;
  		e->irqchip.pin = ue->u.irqchip.pin;
  		switch (ue->u.irqchip.irqchip) {
  		case KVM_IRQCHIP_PIC_SLAVE:
  			e->irqchip.pin += PIC_NUM_PINS / 2;
  			/* fall through */
  		case KVM_IRQCHIP_PIC_MASTER:
  			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
  				return -EINVAL;
  			e->set = kvm_set_pic_irq;
  			break;
  		case KVM_IRQCHIP_IOAPIC:
  			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
  				return -EINVAL;
  			e->set = kvm_set_ioapic_irq;
  			break;
  		default:
  			return -EINVAL;
  		}
  		e->irqchip.irqchip = ue->u.irqchip.irqchip;
  		break;
  	case KVM_IRQ_ROUTING_MSI:
  		e->set = kvm_set_msi;
  		e->msi.address_lo = ue->u.msi.address_lo;
  		e->msi.address_hi = ue->u.msi.address_hi;
  		e->msi.data = ue->u.msi.data;
  
  		if (kvm_msi_route_invalid(kvm, e))
  			return -EINVAL;
  		break;
  	case KVM_IRQ_ROUTING_HV_SINT:
  		e->set = kvm_hv_set_sint;
  		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
  		e->hv_sint.sint = ue->u.hv_sint.sint;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
  			     struct kvm_vcpu **dest_vcpu)
  {
  	int i, r = 0;
  	struct kvm_vcpu *vcpu;
  
  	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
  		return true;
  
  	kvm_for_each_vcpu(i, vcpu, kvm) {
  		if (!kvm_apic_present(vcpu))
  			continue;
  
  		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
  					irq->dest_id, irq->dest_mode))
  			continue;
  
  		if (++r == 2)
  			return false;
  
  		*dest_vcpu = vcpu;
  	}
  
  	return r == 1;
  }
  EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
  
  #define IOAPIC_ROUTING_ENTRY(irq) \
  	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
  	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
  #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
  
  #define PIC_ROUTING_ENTRY(irq) \
  	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
  	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
  #define ROUTING_ENTRY2(irq) \
  	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
  
  static const struct kvm_irq_routing_entry default_routing[] = {
  	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
  	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
  	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
  	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
  	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
  	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
  	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
  	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
  	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
  	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
  	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
  	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
  };
  
  int kvm_setup_default_irq_routing(struct kvm *kvm)
  {
  	return kvm_set_irq_routing(kvm, default_routing,
  				   ARRAY_SIZE(default_routing), 0);
  }
  
  static const struct kvm_irq_routing_entry empty_routing[] = {};
  
  int kvm_setup_empty_irq_routing(struct kvm *kvm)
  {
  	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
  }
  
  void kvm_arch_post_irq_routing_update(struct kvm *kvm)
  {
  	if (!irqchip_split(kvm))
  		return;
  	kvm_make_scan_ioapic_request(kvm);
  }
  
  void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
  			    ulong *ioapic_handled_vectors)
  {
  	struct kvm *kvm = vcpu->kvm;
  	struct kvm_kernel_irq_routing_entry *entry;
  	struct kvm_irq_routing_table *table;
  	u32 i, nr_ioapic_pins;
  	int idx;
  
  	idx = srcu_read_lock(&kvm->irq_srcu);
  	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
  	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
  			       kvm->arch.nr_reserved_ioapic_pins);
  	for (i = 0; i < nr_ioapic_pins; ++i) {
  		hlist_for_each_entry(entry, &table->map[i], link) {
  			struct kvm_lapic_irq irq;
  
  			if (entry->type != KVM_IRQ_ROUTING_MSI)
  				continue;
  
  			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
  
  			if (irq.trig_mode && kvm_apic_match_dest(vcpu, NULL, 0,
  						irq.dest_id, irq.dest_mode))
  				__set_bit(irq.vector, ioapic_handled_vectors);
  		}
  	}
  	srcu_read_unlock(&kvm->irq_srcu, idx);
  }
  
  void kvm_arch_irq_routing_update(struct kvm *kvm)
  {
  	kvm_hv_irq_routing_update(kvm);
  }
  