[64/67] irq: Add new IRQ flag IRQF_NO_SUSPEND

[64/67] irq: Add new IRQ flag IRQF_NO_SUSPEND

[Greg KH]

2.6.35-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Ian Campbell <ian.campbell@citrix.com>

commit 685fd0b4ea3f0f1d5385610b0d5b57775a8d5842 upstream.

A small number of users of IRQF_TIMER are using it for the implied no
suspend behaviour on interrupts which are not timer interrupts.

Therefore add a new IRQF_NO_SUSPEND flag, rename IRQF_TIMER to
__IRQF_TIMER and redefine IRQF_TIMER in terms of these new flags.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: xen-devel@lists.xensource.com
Cc: linux-input@vger.kernel.org
Cc: linuxppc-dev@ozlabs.org
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1280398595-29708-1-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 include/linux/interrupt.h |    7 ++++++-
 kernel/irq/manage.c       |    2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -53,16 +53,21 @@
  * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
  *                Used by threaded interrupts which need to keep the
  *                irq line disabled until the threaded handler has been run.
+ * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
+ *
  */
 #define IRQF_DISABLED		0x00000020
 #define IRQF_SAMPLE_RANDOM	0x00000040
 #define IRQF_SHARED		0x00000080
 #define IRQF_PROBE_SHARED	0x00000100
-#define IRQF_TIMER		0x00000200
+#define __IRQF_TIMER		0x00000200
 #define IRQF_PERCPU		0x00000400
 #define IRQF_NOBALANCING	0x00000800
 #define IRQF_IRQPOLL		0x00001000
 #define IRQF_ONESHOT		0x00002000
+#define IRQF_NO_SUSPEND		0x00004000
+
+#define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND)
 
 /*
  * Bits used by threaded handlers:
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -216,7 +216,7 @@ static inline int setup_affinity(unsigne
 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
 {
 	if (suspend) {
-		if (!desc->action || (desc->action->flags & IRQF_TIMER))
+		if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
 			return;
 		desc->status |= IRQ_SUSPENDED;
 	}

[65/67] xen: Do not suspend IPI IRQs.

[Greg KH]

2.6.35-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Ian Campbell <ian.campbell@citrix.com>

commit 4877c737283813bdb4bebfa3168c1585f6e3a8ca upstream.

In general the semantics of IPIs are that they are are expected to
continue functioning after dpm_suspend_noirq().

Specifically I have seen a deadlock between the callfunc IPI and the
stop machine used by xen's do_suspend() routine. If one CPU has already
called dpm_suspend_noirq() then there is a window where it can be sent
a callfunc IPI before all the other CPUs have entered stop_cpu().

If this happens then the first CPU ends up spinning in stop_cpu()
waiting for the other to rendezvous in state STOPMACHINE_PREPARE while
the other is spinning in csd_lock_wait().

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/xen/events.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -536,6 +536,7 @@ int bind_ipi_to_irqhandler(enum ipi_vect
 	if (irq < 0)
 		return irq;
 
+	irqflags |= IRQF_NO_SUSPEND;
 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
 	if (retval != 0) {
 		unbind_from_irq(irq);