staging: hv: use sync_bitops when interacting with the hypervisor

Locking is required when tweaking bits located in a shared page, use the
sync_ version of bitops. Without this change vmbus_on_event() will miss
events and as a result, vmbus_isr() will not schedule the receive tasklet.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: stable <stable@kernel.org>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Acked-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 8 insertions, 7 deletions

diff --git a/drivers/staging/hv/channel.c b/drivers/staging/hv/channel.c
index 775a52a91222..f7ce7d2494b3 100644
--- a/drivers/staging/hv/channel.c
+++ b/drivers/staging/hv/channel.c
@@ -81,14 +81,14 @@ static void vmbus_setevent(struct vmbus_channel *channel)
 
         if (channel->offermsg.monitor_allocated) {
                 /* Each u32 represents 32 channels */
-                set_bit(channel->offermsg.child_relid & 31,
+                sync_set_bit(channel->offermsg.child_relid & 31,
                         (unsigned long *) vmbus_connection.send_int_page +
                         (channel->offermsg.child_relid >> 5));
 
                 monitorpage = vmbus_connection.monitor_pages;
                 monitorpage++; /* Get the child to parent monitor page */
 
-                set_bit(channel->monitor_bit,
+                sync_set_bit(channel->monitor_bit,
                         (unsigned long *)&monitorpage->trigger_group
                                         [channel->monitor_grp].pending);
 
@@ -104,7 +104,7 @@ static void VmbusChannelClearEvent(struct vmbus_channel *channel)
 
         if (Channel->offermsg.monitor_allocated) {
                 /* Each u32 represents 32 channels */
-                clear_bit(Channel->offermsg.child_relid & 31,
+                sync_clear_bit(Channel->offermsg.child_relid & 31,
                           (unsigned long *)vmbus_connection.send_int_page +
                           (Channel->offermsg.child_relid >> 5));
 
@@ -112,7 +112,7 @@ static void VmbusChannelClearEvent(struct vmbus_channel *channel)
                         vmbus_connection.monitor_pages;
                 monitorPage++; /* Get the child to parent monitor page */
 
-                clear_bit(Channel->monitor_bit,
+                sync_clear_bit(Channel->monitor_bit,
                           (unsigned long *)&monitorPage->trigger_group
                                         [Channel->monitor_grp].Pending);
         }
diff --git a/drivers/staging/hv/connection.c b/drivers/staging/hv/connection.c
index 44b203b95a22..afc8116e7aa4 100644
--- a/drivers/staging/hv/connection.c
+++ b/drivers/staging/hv/connection.c
@@ -296,7 +296,7 @@ void vmbus_on_event(unsigned long data)
                 for (dword = 0; dword < maxdword; dword++) {
                         if (recv_int_page[dword]) {
                                 for (bit = 0; bit < 32; bit++) {
-                                        if (test_and_clear_bit(bit,
+                                        if (sync_test_and_clear_bit(bit,
                                                 (unsigned long *)
                                                 &recv_int_page[dword])) {
                                                 relid = (dword << 5) + bit;
@@ -338,7 +338,7 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 int vmbus_set_event(u32 child_relid)
 {
         /* Each u32 represents 32 channels */
-        set_bit(child_relid & 31,
+        sync_set_bit(child_relid & 31,
                 (unsigned long *)vmbus_connection.send_int_page +
                 (child_relid >> 5));
 
diff --git a/drivers/staging/hv/vmbus_drv.c b/drivers/staging/hv/vmbus_drv.c
index b473f468dd83..79089f85d903 100644
--- a/drivers/staging/hv/vmbus_drv.c
+++ b/drivers/staging/hv/vmbus_drv.c
@@ -254,7 +254,7 @@ static int vmbus_on_isr(void)
         event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
 
         /* Since we are a child, we only need to check bit 0 */
-        if (test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
+        if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
                 DPRINT_DBG(VMBUS, "received event %d", event->flags32[0]);
                 ret |= 0x2;
         }
diff --git a/drivers/staging/hv/vmbus_private.h b/drivers/staging/hv/vmbus_private.h
index ca050a499b99..6f0d8df5e178 100644
--- a/drivers/staging/hv/vmbus_private.h
+++ b/drivers/staging/hv/vmbus_private.h
@@ -31,6 +31,7 @@
 #include "channel_mgmt.h"
 #include "ring_buffer.h"
 #include <linux/list.h>
+#include <asm/sync_bitops.h>
 
 
 /*