genirq: Introduce IRQD_AFFINITY_MANAGED flag
Interupts marked with this flag are excluded from user space interrupt
affinity changes. Contrary to the IRQ_NO_BALANCING flag, the kernel internal
affinity mechanism is not blocked.
This flag will be used for multi-queue device interrupts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: axboe@fb.com
Cc: agordeev@redhat.com
Link: http://lkml.kernel.org/r/1467621574-8277-3-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ef0bc02..30658e9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -115,12 +115,12 @@
#ifdef CONFIG_SMP
cpumask_var_t irq_default_affinity;
-static int __irq_can_set_affinity(struct irq_desc *desc)
+static bool __irq_can_set_affinity(struct irq_desc *desc)
{
if (!desc || !irqd_can_balance(&desc->irq_data) ||
!desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
- return 0;
- return 1;
+ return false;
+ return true;
}
/**
@@ -134,6 +134,21 @@
}
/**
+ * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
+ * @irq: Interrupt to check
+ *
+ * Like irq_can_set_affinity() above, but additionally checks for the
+ * AFFINITY_MANAGED flag.
+ */
+bool irq_can_set_affinity_usr(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ return __irq_can_set_affinity(desc) &&
+ !irqd_affinity_is_managed(&desc->irq_data);
+}
+
+/**
* irq_set_thread_affinity - Notify irq threads to adjust affinity
* @desc: irq descriptor which has affitnity changed
*
