[PATCH v6 16/29] x86/hpet: Prepare IRQ assignments to use the X86_ALLOC_AS_NMI flag

[Ricardo Neri]

The flag X86_ALLOC_AS_NMI indicates that the IRQs to be allocated in an
IRQ domain need to be configured as NMIs.  Add an as_nmi argument to
hpet_assign_irq(). Even though the HPET clock events do not need NMI
IRQs, the HPET hardlockup detector does. A subsequent changeset will
implement the reservation of a channel for it.

Cc: Andi Kleen <ak at linux.intel.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar at intel.com>
Cc: Stephane Eranian <eranian at google.com>
Cc: iommu at lists.linux-foundation.org
Cc: linuxppc-dev at lists.ozlabs.org
Cc: x86 at kernel.org
Suggested-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Tony Luck <tony.luck at intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon at linux.intel.com>
---
Changes since v5:
 * Introduced this patch.

Changes since v4:
 * N/A

Changes since v3:
 * N/A

Changes since v2:
 * N/A

Changes since v1:
 * N/A
---
 arch/x86/kernel/hpet.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 2c6713b40921..02d25e00e93f 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -618,7 +618,7 @@ static inline int hpet_dev_id(struct irq_domain *domain)
 }
 
 static int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
-			   int dev_num)
+			   int dev_num, bool as_nmi)
 {
 	struct irq_alloc_info info;
 
@@ -627,6 +627,8 @@ static int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
 	info.data = hc;
 	info.devid = hpet_dev_id(domain);
 	info.hwirq = dev_num;
+	if (as_nmi)
+		info.flags |= X86_IRQ_ALLOC_AS_NMI;
 
 	return irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &info);
 }
@@ -755,7 +757,7 @@ static void __init hpet_select_clockevents(void)
 
 		sprintf(hc->name, "hpet%d", i);
 
-		irq = hpet_assign_irq(hpet_domain, hc, hc->num);
+		irq = hpet_assign_irq(hpet_domain, hc, hc->num, false);
 		if (irq <= 0)
 			continue;
 
-- 
2.17.1