From: kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Date: Thu, 29 Sep 2005 14:14:03 +0000 (+0100)
Subject: Change semantics of bind_evtchn_to_xxx and
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~16769^2~11
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=eb3abaa7a237c5df141f7ad82831f0a1bc9d43fb;p=xen.git

Change semantics of bind_evtchn_to_xxx and
unbind_evtchn_from_xxx. The bind now returns the IRQ
number on success. The unbind takes this as a parameter
instead of the event-channel port. Also, unbind closes
down the underlying event-channel port if it is still
live.

Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/evtchn.c b/linux-2.6-xen-sparse/arch/xen/kernel/evtchn.c
index 1f94775476..32294c7bcd 100644
--- a/linux-2.6-xen-sparse/arch/xen/kernel/evtchn.c
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/evtchn.c
@@ -320,13 +320,19 @@ int bind_evtchn_to_irq(unsigned int evtchn)
 }
 EXPORT_SYMBOL(bind_evtchn_to_irq);
 
-void unbind_evtchn_from_irq(unsigned int evtchn)
+void unbind_evtchn_from_irq(unsigned int irq)
 {
-	int irq = evtchn_to_irq[evtchn];
+	evtchn_op_t op;
+	int evtchn = irq_to_evtchn[irq];
 
 	spin_lock(&irq_mapping_update_lock);
 
-	if (--irq_bindcount[irq] == 0) {
+	if ((--irq_bindcount[irq] == 0) && (evtchn != -1)) {
+		op.cmd          = EVTCHNOP_close;
+		op.u.close.dom  = DOMID_SELF;
+		op.u.close.port = evtchn;
+		BUG_ON(HYPERVISOR_event_channel_op(&op) != 0);
+
 		evtchn_to_irq[evtchn] = -1;
 		irq_to_evtchn[irq]    = -1;
 	}
@@ -348,17 +354,16 @@ int bind_evtchn_to_irqhandler(
 	irq = bind_evtchn_to_irq(evtchn);
 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
 	if (retval != 0)
-		unbind_evtchn_from_irq(evtchn);
+		unbind_evtchn_from_irq(irq);
 
-	return retval;
+	return irq;
 }
 EXPORT_SYMBOL(bind_evtchn_to_irqhandler);
 
-void unbind_evtchn_from_irqhandler(unsigned int evtchn, void *dev_id)
+void unbind_evtchn_from_irqhandler(unsigned int irq, void *dev_id)
 {
-	unsigned int irq = evtchn_to_irq[evtchn];
 	free_irq(irq, dev_id);
-	unbind_evtchn_from_irq(evtchn);
+	unbind_evtchn_from_irq(irq);
 }
 EXPORT_SYMBOL(unbind_evtchn_from_irqhandler);
 
@@ -425,9 +430,8 @@ static unsigned int startup_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	if (!VALID_EVTCHN(evtchn))
-		return 0;
-	unmask_evtchn(evtchn);
+	if (VALID_EVTCHN(evtchn))
+		unmask_evtchn(evtchn);
 	return 0;
 }
 
@@ -435,38 +439,41 @@ static void shutdown_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	if (!VALID_EVTCHN(evtchn))
-		return;
-	mask_evtchn(evtchn);
+	if (VALID_EVTCHN(evtchn))
+		mask_evtchn(evtchn);
 }
 
 static void enable_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	unmask_evtchn(evtchn);
+	if (VALID_EVTCHN(evtchn))
+		unmask_evtchn(evtchn);
 }
 
 static void disable_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	mask_evtchn(evtchn);
+	if (VALID_EVTCHN(evtchn))
+		mask_evtchn(evtchn);
 }
 
 static void ack_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	mask_evtchn(evtchn);
-	clear_evtchn(evtchn);
+	if (VALID_EVTCHN(evtchn)) {
+		mask_evtchn(evtchn);
+		clear_evtchn(evtchn);
+	}
 }
 
 static void end_dynirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
 
-	if (!(irq_desc[irq].status & IRQ_DISABLED))
+	if (VALID_EVTCHN(evtchn) && !(irq_desc[irq].status & IRQ_DISABLED))
 		unmask_evtchn(evtchn);
 }
 
@@ -559,35 +566,36 @@ static void shutdown_pirq(unsigned int irq)
 static void enable_pirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
-	if (!VALID_EVTCHN(evtchn))
-		return;
-	unmask_evtchn(evtchn);
-	pirq_unmask_notify(irq_to_pirq(irq));
+
+	if (VALID_EVTCHN(evtchn)) {
+		unmask_evtchn(evtchn);
+		pirq_unmask_notify(irq_to_pirq(irq));
+	}
 }
 
 static void disable_pirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
-	if (!VALID_EVTCHN(evtchn))
-		return;
-	mask_evtchn(evtchn);
+
+	if (VALID_EVTCHN(evtchn))
+		mask_evtchn(evtchn);
 }
 
 static void ack_pirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
-	if (!VALID_EVTCHN(evtchn))
-		return;
-	mask_evtchn(evtchn);
-	clear_evtchn(evtchn);
+
+	if (VALID_EVTCHN(evtchn)) {
+		mask_evtchn(evtchn);
+		clear_evtchn(evtchn);
+	}
 }
 
 static void end_pirq(unsigned int irq)
 {
 	int evtchn = irq_to_evtchn[irq];
-	if (!VALID_EVTCHN(evtchn))
-		return;
-	if (!(irq_desc[irq].status & IRQ_DISABLED)) {
+
+	if (VALID_EVTCHN(evtchn) && !(irq_desc[irq].status & IRQ_DISABLED)) {
 		unmask_evtchn(evtchn);
 		pirq_unmask_notify(irq_to_pirq(irq));
 	}
@@ -637,6 +645,10 @@ void irq_resume(void)
 			BUG_ON(per_cpu(ipi_to_evtchn, cpu)[ipi] != -1);
 	}
 
+	/* No IRQ -> event-channel mappings. */
+	for (irq = 0; irq < NR_IRQS; irq++)
+		irq_to_evtchn[irq] = -1;
+
 	/* Primary CPU: rebind VIRQs automatically. */
 	for (virq = 0; virq < NR_VIRQS; virq++) {
 		if ((irq = per_cpu(virq_to_irq, 0)[virq]) == -1)
@@ -676,6 +688,13 @@ void irq_resume(void)
 		/* Ready for use. */
 		unmask_evtchn(evtchn);
 	}
+
+	/* Remove defunct event-channel -> IRQ mappings. */
+	for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++) {
+		if ((evtchn_to_irq[evtchn] != -1) &&
+		    (irq_to_evtchn[evtchn_to_irq[evtchn]] == -1))
+			evtchn_to_irq[evtchn] = -1;
+	}
 }
 
 void __init init_IRQ(void)
@@ -689,11 +708,10 @@ void __init init_IRQ(void)
 
 	init_evtchn_cpu_bindings();
 
+	/* No VIRQ or IPI bindings. */
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		/* No VIRQ -> IRQ mappings. */
 		for (i = 0; i < NR_VIRQS; i++)
 			per_cpu(virq_to_irq, cpu)[i] = -1;
-		/* No VIRQ -> IRQ mappings. */
 		for (i = 0; i < NR_IPIS; i++)
 			per_cpu(ipi_to_evtchn, cpu)[i] = -1;
 	}
diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c b/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
index 03fff886aa..ab8f32e531 100644
--- a/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
@@ -65,12 +65,6 @@ static int __do_suspend(void *ignore)
 {
 	int i, j, k, fpp;
 
-#ifdef CONFIG_XEN_USB_FRONTEND
-	extern void usbif_resume();
-#else
-#define usbif_resume() do{}while(0)
-#endif
-
 	extern int gnttab_suspend(void);
 	extern int gnttab_resume(void);
 
@@ -87,7 +81,6 @@ static int __do_suspend(void *ignore)
 	int restore_vcpu_context(int vcpu, vcpu_guest_context_t *ctxt);
 #endif
 
-	extern void xencons_suspend(void);
 	extern void xencons_resume(void);
 
 	int err = 0;
@@ -147,17 +140,15 @@ static int __do_suspend(void *ignore)
 	}
 #endif
 
+	xenbus_suspend();
+
+	gnttab_suspend();
+
 #ifdef __i386__
 	mm_pin_all();
 	kmem_cache_shrink(pgd_cache);
 #endif
 
-	xenbus_suspend();
-
-	xencons_suspend();
-
-	gnttab_suspend();
-
 	HYPERVISOR_shared_info = (shared_info_t *)empty_zero_page;
 	clear_fixmap(FIX_SHARED_INFO);
 
@@ -202,8 +193,6 @@ static int __do_suspend(void *ignore)
 
 	time_resume();
 
-	usbif_resume();
-
 #ifdef CONFIG_SMP
 	for_each_cpu_mask(i, prev_present_cpus)
 		restore_vcpu_context(i, &suspended_cpu_records[i]);
diff --git a/linux-2.6-xen-sparse/drivers/xen/blkback/common.h b/linux-2.6-xen-sparse/drivers/xen/blkback/common.h
index ffc168d0a0..4235d3f4fe 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkback/common.h
+++ b/linux-2.6-xen-sparse/drivers/xen/blkback/common.h
@@ -44,7 +44,7 @@ typedef struct blkif_st {
 	unsigned int      handle;
 	/* Physical parameters of the comms window. */
 	unsigned int      evtchn;
-	unsigned int      remote_evtchn;
+	unsigned int      irq;
 	/* Comms information. */
 	blkif_back_ring_t blk_ring;
 	struct vm_struct *blk_ring_area;
diff --git a/linux-2.6-xen-sparse/drivers/xen/blkback/interface.c b/linux-2.6-xen-sparse/drivers/xen/blkback/interface.c
index 15649685d5..92e37850b3 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkback/interface.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blkback/interface.c
@@ -71,8 +71,6 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
 	evtchn_op_t op = { .cmd = EVTCHNOP_bind_interdomain };
 	int err;
 
-	BUG_ON(blkif->remote_evtchn);
-
 	if ( (blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL )
 		return -ENOMEM;
 
@@ -94,13 +92,12 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
 	}
 
 	blkif->evtchn = op.u.bind_interdomain.port1;
-	blkif->remote_evtchn = evtchn;
 
 	sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
 	SHARED_RING_INIT(sring);
 	BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
 
-	bind_evtchn_to_irqhandler(
+	blkif->irq = bind_evtchn_to_irqhandler(
 		blkif->evtchn, blkif_be_int, 0, "blkif-backend", blkif);
 	blkif->status = CONNECTED;
 
@@ -109,21 +106,13 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
 
 static void free_blkif(void *arg)
 {
-	evtchn_op_t op = { .cmd = EVTCHNOP_close };
 	blkif_t *blkif = (blkif_t *)arg;
 
-	op.u.close.port = blkif->evtchn;
-	op.u.close.dom = DOMID_SELF;
-	HYPERVISOR_event_channel_op(&op);
-	op.u.close.port = blkif->remote_evtchn;
-	op.u.close.dom = blkif->domid;
-	HYPERVISOR_event_channel_op(&op);
+	if (blkif->irq)
+		unbind_evtchn_from_irqhandler(blkif->irq, blkif);
 
 	vbd_free(&blkif->vbd);
 
-	if (blkif->evtchn)
-		unbind_evtchn_from_irqhandler(blkif->evtchn, blkif);
-
 	if (blkif->blk_ring.sring) {
 		unmap_frontend_page(blkif);
 		free_vm_area(blkif->blk_ring_area);
diff --git a/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c b/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
index 8c1db775ff..209cd6b101 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
@@ -357,8 +357,9 @@ static void blkif_free(struct blkfront_info *info)
 	if (info->ring_ref != GRANT_INVALID_REF)
 		gnttab_end_foreign_access(info->ring_ref, 0);
 	info->ring_ref = GRANT_INVALID_REF;
-	unbind_evtchn_from_irqhandler(info->evtchn, info); 
-	info->evtchn = 0;
+	if (info->irq)
+		unbind_evtchn_from_irqhandler(info->irq, info); 
+	info->evtchn = info->irq = 0;
 }
 
 static void blkif_recover(struct blkfront_info *info)
@@ -429,10 +430,12 @@ static void blkif_connect(struct blkfront_info *info, u16 evtchn)
 
 	err = bind_evtchn_to_irqhandler(
 		info->evtchn, blkif_int, SA_SAMPLE_RANDOM, "blkif", info);
-	if (err != 0) {
+	if (err <= 0) {
 		WPRINTK("bind_evtchn_to_irqhandler failed (err=%d)\n", err);
 		return;
 	}
+
+	info->irq = err;
 }
 
 
diff --git a/linux-2.6-xen-sparse/drivers/xen/blkfront/block.h b/linux-2.6-xen-sparse/drivers/xen/blkfront/block.h
index 9dc7a54379..24388e84e5 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkfront/block.h
+++ b/linux-2.6-xen-sparse/drivers/xen/blkfront/block.h
@@ -123,7 +123,7 @@ struct blkfront_info
 	int backend_id;
 	int ring_ref;
 	blkif_front_ring_t ring;
-	unsigned int evtchn;
+	unsigned int evtchn, irq;
 	struct xlbd_major_info *mi;
 	request_queue_t *rq;
 	struct work_struct work;
diff --git a/linux-2.6-xen-sparse/drivers/xen/blktap/common.h b/linux-2.6-xen-sparse/drivers/xen/blktap/common.h
index 3caae4654f..38fa80b557 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/common.h
+++ b/linux-2.6-xen-sparse/drivers/xen/blktap/common.h
@@ -46,7 +46,7 @@ typedef struct blkif_st {
 	unsigned int      handle;
 	/* Physical parameters of the comms window. */
 	unsigned int      evtchn;
-	unsigned int      remote_evtchn;
+	unsigned int      irq;
 	/* Comms information. */
 	blkif_back_ring_t blk_ring;
 	struct vm_struct *blk_ring_area;
diff --git a/linux-2.6-xen-sparse/drivers/xen/blktap/interface.c b/linux-2.6-xen-sparse/drivers/xen/blktap/interface.c
index 7719b76acc..85cf5d7362 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blktap/interface.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blktap/interface.c
@@ -71,8 +71,6 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
 	evtchn_op_t op = { .cmd = EVTCHNOP_bind_interdomain };
 	int err;
 
-	BUG_ON(blkif->remote_evtchn);
-
 	if ((blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL)
 		return -ENOMEM;
 
@@ -93,35 +91,26 @@ int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
 		return err;
 	}
 
-
 	blkif->evtchn = op.u.bind_interdomain.port1;
-	blkif->remote_evtchn = evtchn;
 
 	sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
 	SHARED_RING_INIT(sring);
 	BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
 
-	bind_evtchn_to_irqhandler(
+	blkif->irq = bind_evtchn_to_irqhandler(
 		blkif->evtchn, blkif_be_int, 0, "blkif-backend", blkif);
-	blkif->status        = CONNECTED;
+
+	blkif->status = CONNECTED;
 
 	return 0;
 }
 
 static void free_blkif(void *arg)
 {
-	evtchn_op_t op = { .cmd = EVTCHNOP_close };
 	blkif_t *blkif = (blkif_t *)arg;
 
-	op.u.close.port = blkif->evtchn;
-	op.u.close.dom = DOMID_SELF;
-	HYPERVISOR_event_channel_op(&op);
-	op.u.close.port = blkif->remote_evtchn;
-	op.u.close.dom = blkif->domid;
-	HYPERVISOR_event_channel_op(&op);
-
-	if (blkif->evtchn)
-		unbind_evtchn_from_irqhandler(blkif->evtchn, blkif);
+	if (blkif->irq)
+		unbind_evtchn_from_irqhandler(blkif->irq, blkif);
 
 	if (blkif->blk_ring.sring) {
 		unmap_frontend_page(blkif);
diff --git a/linux-2.6-xen-sparse/drivers/xen/console/xencons_ring.c b/linux-2.6-xen-sparse/drivers/xen/console/xencons_ring.c
index 40d4da5349..2402a76ea4 100644
--- a/linux-2.6-xen-sparse/drivers/xen/console/xencons_ring.c
+++ b/linux-2.6-xen-sparse/drivers/xen/console/xencons_ring.c
@@ -21,7 +21,6 @@
 #include <linux/err.h>
 #include "xencons_ring.h"
 
-
 struct ring_head
 {
 	u32 cons;
@@ -29,6 +28,7 @@ struct ring_head
 	char buf[0];
 } __attribute__((packed));
 
+static int xencons_irq;
 
 #define XENCONS_RING_SIZE (PAGE_SIZE/2 - sizeof (struct ring_head))
 #define XENCONS_IDX(cnt) ((cnt) % XENCONS_RING_SIZE)
@@ -97,32 +97,28 @@ int xencons_ring_init(void)
 {
 	int err;
 
+	if (xencons_irq)
+		unbind_evtchn_from_irqhandler(xencons_irq, inring());
+	xencons_irq = 0;
+
 	if (!xen_start_info->console_evtchn)
 		return 0;
 
-	err = bind_evtchn_to_irqhandler(xen_start_info->console_evtchn,
-					handle_input, 0, "xencons", inring());
-	if (err) {
+	err = bind_evtchn_to_irqhandler(
+		xen_start_info->console_evtchn,
+		handle_input, 0, "xencons", inring());
+	if (err <= 0) {
 		xprintk("XEN console request irq failed %i\n", err);
 		return err;
 	}
 
-	return 0;
-}
-
-void xencons_suspend(void)
-{
-
-	if (!xen_start_info->console_evtchn)
-		return;
+	xencons_irq = err;
 
-	unbind_evtchn_from_irqhandler(xen_start_info->console_evtchn,
-				      inring());
+	return 0;
 }
 
 void xencons_resume(void)
 {
-
 	(void)xencons_ring_init();
 }
 
diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/common.h b/linux-2.6-xen-sparse/drivers/xen/netback/common.h
index 1c907cff9c..5150cb8844 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/common.h
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/common.h
@@ -50,7 +50,7 @@ typedef struct netif_st {
 	u16              rx_shmem_handle;
 	grant_ref_t      rx_shmem_ref; 
 	unsigned int     evtchn;
-	unsigned int     remote_evtchn;
+	unsigned int     irq;
 
 	/* The shared rings and indexes. */
 	netif_tx_interface_t *tx;
diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/interface.c b/linux-2.6-xen-sparse/drivers/xen/netback/interface.c
index c3d525c3f4..b8b495ecb3 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/interface.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/interface.c
@@ -15,18 +15,17 @@ static void __netif_up(netif_t *netif)
 	spin_lock_bh(&dev->xmit_lock);
 	netif->active = 1;
 	spin_unlock_bh(&dev->xmit_lock);
-	(void)bind_evtchn_to_irqhandler(
-		netif->evtchn, netif_be_int, 0, dev->name, netif);
+	enable_irq(netif->irq);
 	netif_schedule_work(netif);
 }
 
 static void __netif_down(netif_t *netif)
 {
 	struct net_device *dev = netif->dev;
+	disable_irq(netif->irq);
 	spin_lock_bh(&dev->xmit_lock);
 	netif->active = 0;
 	spin_unlock_bh(&dev->xmit_lock);
-	unbind_evtchn_from_irqhandler(netif->evtchn, netif);
 	netif_deschedule_work(netif);
 }
 
@@ -203,7 +202,10 @@ int netif_map(netif_t *netif, unsigned long tx_ring_ref,
 	}
 
 	netif->evtchn = op.u.bind_interdomain.port1;
-	netif->remote_evtchn = evtchn;
+
+	netif->irq = bind_evtchn_to_irqhandler(
+		netif->evtchn, netif_be_int, 0, netif->dev->name, netif);
+	disable_irq(netif->irq);
 
 	netif->tx = (netif_tx_interface_t *)netif->comms_area->addr;
 	netif->rx = (netif_rx_interface_t *)
@@ -224,21 +226,15 @@ int netif_map(netif_t *netif, unsigned long tx_ring_ref,
 
 static void free_netif_callback(void *arg)
 {
-	evtchn_op_t op = { .cmd = EVTCHNOP_close };
 	netif_t *netif = (netif_t *)arg;
 
 	/*
-	 * These can't be done in netif_disconnect() because at that point
+	 * This can't be done in netif_disconnect() because at that point
 	 * there may be outstanding requests in the network stack whose
 	 * asynchronous responses must still be notified to the remote driver.
 	 */
-
-	op.u.close.port = netif->evtchn;
-	op.u.close.dom = DOMID_SELF;
-	HYPERVISOR_event_channel_op(&op);
-	op.u.close.port = netif->remote_evtchn;
-	op.u.close.dom = netif->domid;
-	HYPERVISOR_event_channel_op(&op);
+	if (netif->irq)
+		unbind_evtchn_from_irqhandler(netif->irq, netif);
 
 	unregister_netdev(netif->dev);
 
diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 732e0d818e..abb4524dca 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -127,7 +127,7 @@ struct net_private
 	spinlock_t   rx_lock;
 
 	unsigned int handle;
-	unsigned int evtchn;
+	unsigned int evtchn, irq;
 
 	/* What is the status of our connection to the remote backend? */
 #define BEST_CLOSED       0
@@ -815,7 +815,7 @@ connect_device(struct net_private *np, unsigned int evtchn)
 	memcpy(dev->dev_addr, np->mac, ETH_ALEN);
 	np->evtchn = evtchn;
 	network_connect(dev);
-	(void)bind_evtchn_to_irqhandler(
+	np->irq = bind_evtchn_to_irqhandler(
 		np->evtchn, netif_int, SA_SAMPLE_RANDOM, dev->name, dev);
 	(void)send_fake_arp(dev);
 	show_device(np);
@@ -1055,8 +1055,9 @@ static void netif_free(struct netfront_info *info)
 		gnttab_end_foreign_access(info->rx_ring_ref, 0);
 	info->rx_ring_ref = GRANT_INVALID_REF;
 
-	unbind_evtchn_from_irqhandler(info->evtchn, info->netdev);
-	info->evtchn = 0;
+	if (info->irq)
+		unbind_evtchn_from_irqhandler(info->irq, info->netdev);
+	info->evtchn = info->irq = 0;
 }
 
 /* Stop network device and free tx/rx queues and irq. */
diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h b/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
index d447c873fa..25a1bbea25 100644
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
@@ -35,7 +35,7 @@ typedef struct tpmif_st {
 
 	/* Physical parameters of the comms window. */
 	unsigned int evtchn;
-	unsigned int remote_evtchn;
+	unsigned int irq;
 
 	/* The shared rings and indexes. */
 	tpmif_tx_interface_t *tx;
diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c b/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
index af93a6bdd4..43c6f6e0cc 100644
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
@@ -120,8 +120,6 @@ tpmif_map(tpmif_t *tpmif, unsigned long shared_page, unsigned int evtchn)
 	evtchn_op_t op = {.cmd = EVTCHNOP_bind_interdomain };
 	int err;
 
-	BUG_ON(tpmif->remote_evtchn);
-
 	if ((tpmif->tx_area = alloc_vm_area(PAGE_SIZE)) == NULL)
 		return -ENOMEM;
 
@@ -143,12 +141,11 @@ tpmif_map(tpmif_t *tpmif, unsigned long shared_page, unsigned int evtchn)
 	}
 
 	tpmif->evtchn = op.u.bind_interdomain.port1;
-	tpmif->remote_evtchn = evtchn;
 
 	tpmif->tx = (tpmif_tx_interface_t *)tpmif->tx_area->addr;
 
-	bind_evtchn_to_irqhandler(tpmif->evtchn,
-				  tpmif_be_int, 0, "tpmif-backend", tpmif);
+	tpmif->irq = bind_evtchn_to_irqhandler(
+		tpmif->evtchn, tpmif_be_int, 0, "tpmif-backend", tpmif);
 	tpmif->status = CONNECTED;
 	tpmif->shmem_ref = shared_page;
 	tpmif->active = 1;
@@ -159,18 +156,10 @@ tpmif_map(tpmif_t *tpmif, unsigned long shared_page, unsigned int evtchn)
 static void
 __tpmif_disconnect_complete(void *arg)
 {
-	evtchn_op_t op = {.cmd = EVTCHNOP_close };
 	tpmif_t *tpmif = (tpmif_t *) arg;
 
-	op.u.close.port = tpmif->evtchn;
-	op.u.close.dom = DOMID_SELF;
-	HYPERVISOR_event_channel_op(&op);
-	op.u.close.port = tpmif->remote_evtchn;
-	op.u.close.dom = tpmif->domid;
-	HYPERVISOR_event_channel_op(&op);
-
-	if (tpmif->evtchn)
-		unbind_evtchn_from_irqhandler(tpmif->evtchn, tpmif);
+	if (tpmif->irq)
+		unbind_evtchn_from_irqhandler(tpmif->irq, tpmif);
 
 	if (tpmif->tx) {
 		unmap_frontend_page(tpmif);
diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c b/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c
index 0bd6114f43..516aae330d 100644
--- a/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c
@@ -292,8 +292,10 @@ static void destroy_tpmring(struct tpmfront_info *info, struct tpm_private *tp)
 		free_page((unsigned long)tp->tx);
 		tp->tx = NULL;
 	}
-	unbind_evtchn_from_irqhandler(tp->evtchn, NULL);
-	tp->evtchn = 0;
+
+	if (tpm->irq)
+		unbind_evtchn_from_irqhandler(tp->irq, NULL);
+	tp->evtchn = tpm->irq = 0;
 }
 
 
@@ -501,10 +503,12 @@ static void tpmif_connect(u16 evtchn, domid_t domid)
 	err = bind_evtchn_to_irqhandler(
 		tp->evtchn,
 		tpmif_int, SA_SAMPLE_RANDOM, "tpmif", tp);
-	if ( err != 0 ) {
+	if ( err <= 0 ) {
 		WPRINTK("bind_evtchn_to_irqhandler failed (err=%d)\n", err);
 		return;
 	}
+
+	tp->irq = err;
 }
 
 static struct xenbus_device_id tpmfront_ids[] = {
diff --git a/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.h b/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.h
index 9c7f51a2bc..f5ddea0cbf 100644
--- a/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.h
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.h
@@ -5,7 +5,7 @@
 struct tpm_private
 {
 	tpmif_tx_interface_t *tx;
-	unsigned int evtchn;
+	unsigned int evtchn, irq;
 	int connected;
 
 	spinlock_t tx_lock;
diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.c b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.c
index e0052d7f48..972236d285 100644
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.c
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.c
@@ -44,6 +44,8 @@ struct ringbuf_head
 	char buf[0];
 } __attribute__((packed));
 
+static int xenbus_irq;
+
 DECLARE_WAIT_QUEUE_HEAD(xb_waitq);
 
 static inline struct ringbuf_head *outbuf(void)
@@ -205,33 +207,29 @@ int xb_init_comms(void)
 {
 	int err;
 
+	if (xenbus_irq)
+		unbind_evtchn_from_irqhandler(xenbus_irq, &xb_waitq);
+	xenbus_irq = 0;
+
 	if (!xen_start_info->store_evtchn)
 		return 0;
 
 	err = bind_evtchn_to_irqhandler(
 		xen_start_info->store_evtchn, wake_waiting,
 		0, "xenbus", &xb_waitq);
-	if (err) {
+	if (err <= 0) {
 		printk(KERN_ERR "XENBUS request irq failed %i\n", err);
-		unbind_evtchn_from_irq(xen_start_info->store_evtchn);
 		return err;
 	}
 
+	xenbus_irq = err;
+
 	/* FIXME zero out page -- domain builder should probably do this*/
 	memset(mfn_to_virt(xen_start_info->store_mfn), 0, PAGE_SIZE);
 
 	return 0;
 }
 
-void xb_suspend_comms(void)
-{
-
-	if (!xen_start_info->store_evtchn)
-		return;
-
-	unbind_evtchn_from_irqhandler(xen_start_info->store_evtchn, &xb_waitq);
-}
-
 /*
  * Local variables:
  *  c-file-style: "linux"
diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.h b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.h
index 04500f4855..59ca0d3080 100644
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.h
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_comms.h
@@ -30,7 +30,6 @@
 
 int xs_init(void);
 int xb_init_comms(void);
-void xb_suspend_comms(void);
 
 /* Low level routines. */
 int xb_write(const void *data, unsigned len);
diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
index 094d81870e..1ac3f457bc 100644
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
@@ -607,7 +607,6 @@ void xenbus_suspend(void)
 	down(&xenbus_lock);
 	bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev);
 	bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, suspend_dev);
-	xb_suspend_comms();
 }
 
 void xenbus_resume(void)
diff --git a/linux-2.6-xen-sparse/include/asm-xen/evtchn.h b/linux-2.6-xen-sparse/include/asm-xen/evtchn.h
index d364b0a4b5..360388fec6 100644
--- a/linux-2.6-xen-sparse/include/asm-xen/evtchn.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/evtchn.h
@@ -51,14 +51,21 @@ extern void unbind_virq_from_irq(int virq);
 extern int  bind_ipi_to_irq(int ipi);
 extern void unbind_ipi_from_irq(int ipi);
 
-/* Dynamically bind an event-channel port to Linux IRQ space. */
+/*
+ * Dynamically bind an event-channel port to Linux IRQ space.
+ * BIND:   Returns IRQ or error.
+ * UNBIND: Takes IRQ to unbind from; automatically closes the event channel.
+ */
 extern int  bind_evtchn_to_irq(unsigned int evtchn);
-extern void unbind_evtchn_from_irq(unsigned int evtchn);
+extern void unbind_evtchn_from_irq(unsigned int irq);
 
 /*
  * Dynamically bind an event-channel port to an IRQ-like callback handler.
  * On some platforms this may not be implemented via the Linux IRQ subsystem.
- * You *cannot* trust the irq argument passed to the callback handler.
+ * The IRQ argument passed to the callback handler is the same as returned
+ * from the bind call. It may not correspond to a Linux IRQ number.
+ * BIND:   Returns IRQ or error.
+ * UNBIND: Takes IRQ to unbind from; automatically closes the event channel.
  */
 extern int  bind_evtchn_to_irqhandler(
 	unsigned int evtchn,
@@ -66,7 +73,7 @@ extern int  bind_evtchn_to_irqhandler(
 	unsigned long irqflags,
 	const char *devname,
 	void *dev_id);
-extern void unbind_evtchn_from_irqhandler(unsigned int evtchn, void *dev_id);
+extern void unbind_evtchn_from_irqhandler(unsigned int irq, void *dev_id);
 
 extern void irq_resume(void);