irq_poll: make blk-iopoll available outside the block layer

The new name is irq_poll as iopoll is already taken.  Better suggestions
welcome.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/linux/irq_poll.h b/include/linux/irq_poll.h
new file mode 100644
index 000000000000..50c39dcd2cba
--- /dev/null
+++ b/include/linux/irq_poll.h
@@ -0,0 +1,46 @@
+#ifndef IRQ_POLL_H
+#define IRQ_POLL_H
+
+struct irq_poll;
+typedef int (irq_poll_fn)(struct irq_poll *, int);
+
+struct irq_poll {
+	struct list_head list;
+	unsigned long state;
+	unsigned long data;
+	int weight;
+	int max;
+	irq_poll_fn *poll;
+};
+
+enum {
+	IRQ_POLL_F_SCHED	= 0,
+	IRQ_POLL_F_DISABLE	= 1,
+};
+
+/*
+ * Returns 0 if we successfully set the IRQ_POLL_F_SCHED bit, indicating
+ * that we were the first to acquire this iop for scheduling. If this iop
+ * is currently disabled, return "failure".
+ */
+static inline int irq_poll_sched_prep(struct irq_poll *iop)
+{
+	if (!test_bit(IRQ_POLL_F_DISABLE, &iop->state))
+		return test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state);
+
+	return 1;
+}
+
+static inline int irq_poll_disable_pending(struct irq_poll *iop)
+{
+	return test_bit(IRQ_POLL_F_DISABLE, &iop->state);
+}
+
+extern void irq_poll_sched(struct irq_poll *);
+extern void irq_poll_init(struct irq_poll *, int, irq_poll_fn *);
+extern void irq_poll_complete(struct irq_poll *);
+extern void __irq_poll_complete(struct irq_poll *);
+extern void irq_poll_enable(struct irq_poll *);
+extern void irq_poll_disable(struct irq_poll *);
+
+#endif