Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct

The field is read only in numa_node_show() and it is already stored twice
(after a call to cpu_to_node()) in target_cpu_store() and init_vp_index();
there is no need to "cache" its value in the channel data structure.
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-3-parri.andrea@gmail.comReviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/channel_mgmt.c

@@ -702,7 +702,6 @@ static void init_vp_index(struct vmbus_channel *channel)
 		 * In case alloc_cpumask_var() fails, bind it to
 		 * VMBUS_CONNECT_CPU.
 		 */
-		channel->numa_node = cpu_to_node(VMBUS_CONNECT_CPU);
 		channel->target_cpu = VMBUS_CONNECT_CPU;
 		if (perf_chn)
 			hv_set_alloced_cpu(VMBUS_CONNECT_CPU);
@@ -719,7 +718,6 @@ static void init_vp_index(struct vmbus_channel *channel)
 			continue;
 		break;
 	}
-	channel->numa_node = numa_node;
 	alloced_mask = &hv_context.hv_numa_map[numa_node];
 
 	if (cpumask_weight(alloced_mask) ==

drivers/hv/vmbus_drv.c

@@ -226,7 +226,7 @@ static ssize_t numa_node_show(struct device *dev,
 	if (!hv_dev->channel)
 		return -ENODEV;
 
-	return sprintf(buf, "%d\n", hv_dev->channel->numa_node);
+	return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
 }
 static DEVICE_ATTR_RO(numa_node);
 #endif
@@ -1778,7 +1778,6 @@ static ssize_t target_cpu_store(struct vmbus_channel *channel,
 	 */
 
 	channel->target_cpu = target_cpu;
-	channel->numa_node = cpu_to_node(target_cpu);
 
 	/* See init_vp_index(). */
 	if (hv_is_perf_channel(channel))

include/linux/hyperv.h

@@ -812,7 +812,6 @@ struct vmbus_channel {
 	 * the earlier behavior.
 	 */
 	u32 target_cpu;
-	int numa_node;
 	/*
 	 * Support for sub-channels. For high performance devices,
 	 * it will be useful to have multiple sub-channels to support