[patch v6 6/6] bus/vmbus: set event for channel without monitoring support

[longli at linuxonhyperv.com]

From: Long Li <longli at microsoft.com>

For vmbus channels without monitoring support, use kernel UIO interface
to indicate packet through interrupt page and UIO file handle.

Signed-off-by: Long Li <longli at microsoft.com>
---
Changes:
v4: replace RTE_ATOMIC(uint32_t) * with RTE_ATOMIC(uint32_t *) for declaring variable
v6: revert the v4 version back to v3 as it generates a warning under clang with enable_stdatomic=true

 drivers/bus/vmbus/vmbus_channel.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/vmbus/vmbus_channel.c b/drivers/bus/vmbus/vmbus_channel.c
index d066e3288d..6887fbad46 100644
--- a/drivers/bus/vmbus/vmbus_channel.c
+++ b/drivers/bus/vmbus/vmbus_channel.c
@@ -25,6 +25,19 @@ vmbus_sync_set_bit(volatile RTE_ATOMIC(uint32_t) *addr, uint32_t mask)
 	rte_atomic_fetch_or_explicit(addr, mask, rte_memory_order_seq_cst);
 }
 
+static inline void
+vmbus_send_interrupt(const struct rte_vmbus_device *dev, uint32_t relid)
+{
+	RTE_ATOMIC(uint32_t) *int_addr;
+	uint32_t int_mask;
+
+	int_addr = (RTE_ATOMIC(uint32_t) *) (dev->int_page + relid / 32);
+	int_mask = 1u << (relid % 32);
+	vmbus_sync_set_bit(int_addr, int_mask);
+
+	vmbus_uio_irq_control(dev, 1);
+}
+
 static inline void
 vmbus_set_monitor(const struct vmbus_channel *channel, uint32_t monitor_id)
 {
@@ -40,10 +53,13 @@ vmbus_set_monitor(const struct vmbus_channel *channel, uint32_t monitor_id)
 }
 
 static void
-vmbus_set_event(struct rte_vmbus_device *dev __rte_unused,
-		const struct vmbus_channel *chan)
+vmbus_set_event(struct rte_vmbus_device *dev, const struct vmbus_channel *chan)
 {
-	vmbus_set_monitor(chan, chan->monitor_id);
+	/* Use monitored bit if supported, otherwise use interrupt/Hypercall */
+	if (chan->monitor_id != UINT8_MAX)
+		vmbus_set_monitor(chan, chan->monitor_id);
+	else
+		vmbus_send_interrupt(dev, chan->relid);
 }
 
 /*
-- 
2.34.1