linux-kernel - [PATCH 1/1] Drivers: hv: vmbus: Use get

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Message-Id: <1418628891-31546-1-git-send-email-kys@microsoft.com>
Date:	Sun, 14 Dec 2014 23:34:51 -0800
From:	"K. Y. Srinivasan" <kys@...rosoft.com>
To:	gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
	devel@...uxdriverproject.org, olaf@...fle.de, apw@...onical.com,
	jasowang@...hat.com
Cc:	"K. Y. Srinivasan" <kys@...rosoft.com>
Subject: [PATCH 1/1] Drivers: hv: vmbus: Use get_cpu() to get the current CPU

Replace calls for smp_processor_id() to get_cpu() to get the CPU ID of
the current CPU. In these instances, there is no correctness issue with
regards to preemption, we just need the current CPU ID.

Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
---
 drivers/hv/channel_mgmt.c |    4 +++-
 drivers/hv/connection.c   |    6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index d36ce68..a205246 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -813,7 +813,7 @@ cleanup:
 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
 {
 	struct list_head *cur, *tmp;
-	int cur_cpu = hv_context.vp_index[smp_processor_id()];
+	int cur_cpu;
 	struct vmbus_channel *cur_channel;
 	struct vmbus_channel *outgoing_channel = primary;
 	int cpu_distance, new_cpu_distance;
@@ -821,6 +821,8 @@ struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
 	if (list_empty(&primary->sc_list))
 		return outgoing_channel;
 
+	cur_cpu = hv_context.vp_index[get_cpu()];
+	put_cpu();
 	list_for_each_safe(cur, tmp, &primary->sc_list) {
 		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 		if (cur_channel->state != CHANNEL_OPENED_STATE)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index e206619..a63a795 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -80,8 +80,10 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
 	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
 	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
-	if (version == VERSION_WIN8_1)
-		msg->target_vcpu = hv_context.vp_index[smp_processor_id()];
+	if (version == VERSION_WIN8_1) {
+		msg->target_vcpu = hv_context.vp_index[get_cpu()];
+		put_cpu();
+	}
 
 	/*
 	 * Add to list before we send the request since we may
-- 
1.7.4.1

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