diff mbox

[2/6] KVM: irqchip: Provide and use accessors for irq routing table

Message ID 1404125474-18611-3-git-send-email-paulus@samba.org
State New, archived
Headers show

Commit Message

Paul Mackerras June 30, 2014, 10:51 a.m. UTC 
This provides accessor functions for the KVM interrupt mappings, in
order to reduce the amount of code that accesses the fields of the
kvm_irq_routing_table struct, and restrict that code to one file,
virt/kvm/irqchip.c.  The new functions are kvm_irq_map_gsi(), which
maps from a global interrupt number to a set of IRQ routing entries,
and kvm_irq_map_chip_pin, which maps from IRQ chip and pin numbers to
a global interrupt number.

This also moves the update of kvm_irq_routing_table::chip[][]
into irqchip.c, out of the various kvm_set_routing_entry
implementations.  That means that none of the kvm_set_routing_entry
implementations need the kvm_irq_routing_table argument anymore,
so this removes it.

This does not change any locking or data lifetime rules.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/mpic.c   |  4 +---
 arch/s390/kvm/interrupt.c |  3 +--
 include/linux/kvm_host.h  |  8 ++++++--
 virt/kvm/eventfd.c        | 10 ++++++----
 virt/kvm/irq_comm.c       | 20 +++++++++-----------
 virt/kvm/irqchip.c        | 42 ++++++++++++++++++++++++++++++++++--------
 6 files changed, 57 insertions(+), 30 deletions(-)
diff mbox

Patch

diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
index b68d0dc..39b3a8f 100644
--- a/arch/powerpc/kvm/mpic.c
+++ b/arch/powerpc/kvm/mpic.c
@@ -1826,8 +1826,7 @@  int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 	return 0;
 }
 
-int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
-			  struct kvm_kernel_irq_routing_entry *e,
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue)
 {
 	int r = -EINVAL;
@@ -1839,7 +1838,6 @@  int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
 		e->irqchip.pin = ue->u.irqchip.pin;
 		if (e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS)
 			goto out;
-		rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 		break;
 	case KVM_IRQ_ROUTING_MSI:
 		e->set = kvm_set_msi;
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 90c8de2..cd1e754 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1589,8 +1589,7 @@  static int set_adapter_int(struct kvm_kernel_irq_routing_entry *e,
 	return ret;
 }
 
-int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
-			  struct kvm_kernel_irq_routing_entry *e,
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue)
 {
 	int ret;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ec4e3bd..4530753 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -752,6 +752,11 @@  void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 			     bool mask);
 
+int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries,
+		    struct kvm_irq_routing_table *irq_rt, int gsi);
+int kvm_irq_map_chip_pin(struct kvm_irq_routing_table *irq_rt,
+			 unsigned irqchip, unsigned pin);
+
 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
 		bool line_status);
 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level);
@@ -942,8 +947,7 @@  int kvm_set_irq_routing(struct kvm *kvm,
 			const struct kvm_irq_routing_entry *entries,
 			unsigned nr,
 			unsigned flags);
-int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
-			  struct kvm_kernel_irq_routing_entry *e,
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue);
 void kvm_free_irq_routing(struct kvm *kvm);
 
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index bae593a..15fa948 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -282,20 +282,22 @@  static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,
 			 struct kvm_irq_routing_table *irq_rt)
 {
 	struct kvm_kernel_irq_routing_entry *e;
+	struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
+	int i, n_entries;
+
+	n_entries = kvm_irq_map_gsi(entries, irq_rt, irqfd->gsi);
 
 	write_seqcount_begin(&irqfd->irq_entry_sc);
 
 	irqfd->irq_entry.type = 0;
-	if (irqfd->gsi >= irq_rt->nr_rt_entries)
-		goto out;
 
-	hlist_for_each_entry(e, &irq_rt->map[irqfd->gsi], link) {
+	e = entries;
+	for (i = 0; i < n_entries; ++i, ++e) {
 		/* Only fast-path MSI. */
 		if (e->type == KVM_IRQ_ROUTING_MSI)
 			irqfd->irq_entry = *e;
 	}
 
- out:
 	write_seqcount_end(&irqfd->irq_entry_sc);
 }
 
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index ced4a54..6e73af2 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -160,6 +160,7 @@  static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
  */
 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 {
+	struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
 	struct kvm_kernel_irq_routing_entry *e;
 	int ret = -EINVAL;
 	struct kvm_irq_routing_table *irq_rt;
@@ -177,14 +178,13 @@  int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	 */
 	idx = srcu_read_lock(&kvm->irq_srcu);
 	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
-	if (irq < irq_rt->nr_rt_entries)
-		hlist_for_each_entry(e, &irq_rt->map[irq], link) {
-			if (likely(e->type == KVM_IRQ_ROUTING_MSI))
-				ret = kvm_set_msi_inatomic(e, kvm);
-			else
-				ret = -EWOULDBLOCK;
-			break;
-		}
+	if (kvm_irq_map_gsi(entries, irq_rt, irq) > 0) {
+		e = &entries[0];
+		if (likely(e->type == KVM_IRQ_ROUTING_MSI))
+			ret = kvm_set_msi_inatomic(e, kvm);
+		else
+			ret = -EWOULDBLOCK;
+	}
 	srcu_read_unlock(&kvm->irq_srcu, idx);
 	return ret;
 }
@@ -272,8 +272,7 @@  void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 	srcu_read_unlock(&kvm->irq_srcu, idx);
 }
 
-int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
-			  struct kvm_kernel_irq_routing_entry *e,
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue)
 {
 	int r = -EINVAL;
@@ -304,7 +303,6 @@  int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
 		e->irqchip.pin = ue->u.irqchip.pin + delta;
 		if (e->irqchip.pin >= max_pin)
 			goto out;
-		rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 		break;
 	case KVM_IRQ_ROUTING_MSI:
 		e->set = kvm_set_msi;
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index b43c275..f4648dd 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -31,13 +31,37 @@ 
 #include <trace/events/kvm.h>
 #include "irq.h"
 
+int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries,
+		    struct kvm_irq_routing_table *irq_rt, int gsi)
+{
+	struct kvm_kernel_irq_routing_entry *e;
+	int n = 0;
+
+	if (gsi < irq_rt->nr_rt_entries) {
+		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
+			entries[n] = *e;
+			++n;
+		}
+	}
+
+	return n;
+}
+
+int kvm_irq_map_chip_pin(struct kvm_irq_routing_table *irq_rt,
+			 unsigned irqchip, unsigned pin)
+{
+	return irq_rt->chip[irqchip][pin];
+}
+
 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
+	struct kvm_irq_routing_table *irq_rt;
 	struct kvm_irq_ack_notifier *kian;
 	int gsi, idx;
 
 	idx = srcu_read_lock(&kvm->irq_srcu);
-	gsi = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu)->chip[irqchip][pin];
+	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
+	gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);
 	if (gsi != -1)
 		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 					 link)
@@ -54,13 +78,15 @@  EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
 
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
+	struct kvm_irq_routing_table *irq_rt;
 	struct kvm_irq_ack_notifier *kian;
 	int gsi, idx;
 
 	trace_kvm_ack_irq(irqchip, pin);
 
 	idx = srcu_read_lock(&kvm->irq_srcu);
-	gsi = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu)->chip[irqchip][pin];
+	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
+	gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);
 	if (gsi != -1)
 		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 					 link)
@@ -115,8 +141,8 @@  int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
 		bool line_status)
 {
-	struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
-	int ret = -1, i = 0, idx;
+	struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
+	int ret = -1, i, idx;
 	struct kvm_irq_routing_table *irq_rt;
 
 	trace_kvm_set_irq(irq, level, irq_source_id);
@@ -127,9 +153,7 @@  int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
 	 */
 	idx = srcu_read_lock(&kvm->irq_srcu);
 	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
-	if (irq < irq_rt->nr_rt_entries)
-		hlist_for_each_entry(e, &irq_rt->map[irq], link)
-			irq_set[i++] = *e;
+	i = kvm_irq_map_gsi(irq_set, irq_rt, irq);
 	srcu_read_unlock(&kvm->irq_srcu, idx);
 
 	while(i--) {
@@ -171,9 +195,11 @@  static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 
 	e->gsi = ue->gsi;
 	e->type = ue->type;
-	r = kvm_set_routing_entry(rt, e, ue);
+	r = kvm_set_routing_entry(e, ue);
 	if (r)
 		goto out;
+	if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
+		rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
 
 	hlist_add_head(&e->link, &rt->map[e->gsi]);
 	r = 0;