linux-kernel - [PATCH 34 of 38] xen: remove irq bindcount

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <281cf0412d4ddaeb34b4.1226603432@abulafia.goop.org>
Date:	Thu, 13 Nov 2008 11:10:32 -0800
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	linux-kernel@...r.kernel.org,
	Xen-devel <xen-devel@...ts.xensource.com>,
	the arch/x86 maintainers <x86@...nel.org>,
	Ian Campbell <ian.campbell@...rix.com>
Subject: [PATCH 34 of 38] xen: remove irq bindcount

There should be no need for us to maintain our own bind count for
irqs, since the surrounding irq system should keep track of shared
irqs for us.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
---
 drivers/xen/events.c |   26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -53,7 +53,7 @@
 
 /* Interrupt types. */
 enum xen_irq_type {
-	IRQT_UNBOUND,
+	IRQT_UNBOUND = 0,
 	IRQT_PIRQ,
 	IRQT_VIRQ,
 	IRQT_IPI,
@@ -94,9 +94,6 @@
 };
 static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
 
-/* Reference counts for bindings to IRQs. */
-static int irq_bindcount[NR_IRQS];
-
 /* Xen will never allocate port zero for any purpose. */
 #define VALID_EVTCHN(chn)	((chn) != 0)
 
@@ -320,9 +317,8 @@
 {
 	int irq;
 
-	/* Only allocate from dynirq range */
 	for_each_irq_nr(irq)
-		if (irq_bindcount[irq] == 0)
+		if (irq_info[irq].type == IRQT_UNBOUND)
 			break;
 
 	if (irq == nr_irqs)
@@ -351,8 +347,6 @@
 		irq_info[irq] = mk_evtchn_info(evtchn);
 	}
 
-	irq_bindcount[irq]++;
-
 	spin_unlock(&irq_mapping_update_lock);
 
 	return irq;
@@ -389,8 +383,6 @@
 		bind_evtchn_to_cpu(evtchn, cpu);
 	}
 
-	irq_bindcount[irq]++;
-
  out:
 	spin_unlock(&irq_mapping_update_lock);
 	return irq;
@@ -427,8 +419,6 @@
 		bind_evtchn_to_cpu(evtchn, cpu);
 	}
 
-	irq_bindcount[irq]++;
-
 	spin_unlock(&irq_mapping_update_lock);
 
 	return irq;
@@ -441,7 +431,7 @@
 
 	spin_lock(&irq_mapping_update_lock);
 
-	if ((--irq_bindcount[irq] == 0) && VALID_EVTCHN(evtchn)) {
+	if (VALID_EVTCHN(evtchn)) {
 		close.port = evtchn;
 		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 			BUG();
@@ -667,6 +657,8 @@
 /* Rebind a new event channel to an existing irq. */
 void rebind_evtchn_irq(int evtchn, int irq)
 {
+	struct irq_info *info = info_for_irq(irq);
+
 	/* Make sure the irq is masked, since the new event channel
 	   will also be masked. */
 	disable_irq(irq);
@@ -676,8 +668,8 @@
 	/* After resume the irq<->evtchn mappings are all cleared out */
 	BUG_ON(evtchn_to_irq[evtchn] != -1);
 	/* Expect irq to have been bound before,
-	   so the bindcount should be non-0 */
-	BUG_ON(irq_bindcount[irq] == 0);
+	   so there should be a proper type */
+	BUG_ON(info->type != IRQT_UNBOUND);
 
 	evtchn_to_irq[evtchn] = irq;
 	irq_info[irq] = mk_evtchn_info(evtchn);
@@ -930,9 +922,5 @@
 	for (i = 0; i < NR_EVENT_CHANNELS; i++)
 		mask_evtchn(i);
 
-	/* Dynamic IRQ space is currently unbound. Zero the refcnts. */
-	for_each_irq_nr(i)
-		irq_bindcount[i] = 0;
-
 	irq_ctx_init(smp_processor_id());
 }


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/