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authorGavin Shan <gwshan@linux.vnet.ibm.com>2016-10-04 11:25:47 +1100
committerDavid S. Miller <davem@davemloft.net>2016-10-04 02:11:50 -0400
commitd8cedaabe71236d27da1ff03d32ab1da06ed041f (patch)
treee07609143c4bdacb750823c991578551b021d56c /net/ncsi/ncsi-aen.c
parent93409033ae653f1c9a949202fb537ab095b2092f (diff)
net/ncsi: Avoid unused-value build warning from ia64-linux-gcc
xchg() is used to set NCSI channel's state in order for consistent access to the state. xchg()'s return value should be used. Otherwise, one build warning will be raised (with -Wunused-value) as below message indicates. It is reported by ia64-linux-gcc (GCC) 4.9.0. net/ncsi/ncsi-manage.c: In function 'ncsi_channel_monitor': arch/ia64/include/uapi/asm/cmpxchg.h:56:2: warning: value computed is \ not used [-Wunused-value] ((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)))) ^ net/ncsi/ncsi-manage.c:202:3: note: in expansion of macro 'xchg' xchg(&nc->state, NCSI_CHANNEL_INACTIVE); This removes the atomic access to NCSI channel's state avoid the above build warning. We have to hold the channel's lock when its state is readed or updated. No functional changes introduced. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ncsi/ncsi-aen.c')
-rw-r--r--net/ncsi/ncsi-aen.c37
1 files changed, 27 insertions, 10 deletions
diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
index d463468442ae..b41a6617d498 100644
--- a/net/ncsi/ncsi-aen.c
+++ b/net/ncsi/ncsi-aen.c
@@ -53,7 +53,9 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
struct ncsi_aen_lsc_pkt *lsc;
struct ncsi_channel *nc;
struct ncsi_channel_mode *ncm;
- unsigned long old_data;
+ bool chained;
+ int state;
+ unsigned long old_data, data;
unsigned long flags;
/* Find the NCSI channel */
@@ -62,20 +64,27 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
return -ENODEV;
/* Update the link status */
- ncm = &nc->modes[NCSI_MODE_LINK];
lsc = (struct ncsi_aen_lsc_pkt *)h;
+
+ spin_lock_irqsave(&nc->lock, flags);
+ ncm = &nc->modes[NCSI_MODE_LINK];
old_data = ncm->data[2];
- ncm->data[2] = ntohl(lsc->status);
+ data = ntohl(lsc->status);
+ ncm->data[2] = data;
ncm->data[4] = ntohl(lsc->oem_status);
- if (!((old_data ^ ncm->data[2]) & 0x1) ||
- !list_empty(&nc->link))
+
+ chained = !list_empty(&nc->link);
+ state = nc->state;
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ if (!((old_data ^ data) & 0x1) || chained)
return 0;
- if (!(nc->state == NCSI_CHANNEL_INACTIVE && (ncm->data[2] & 0x1)) &&
- !(nc->state == NCSI_CHANNEL_ACTIVE && !(ncm->data[2] & 0x1)))
+ if (!(state == NCSI_CHANNEL_INACTIVE && (data & 0x1)) &&
+ !(state == NCSI_CHANNEL_ACTIVE && !(data & 0x1)))
return 0;
if (!(ndp->flags & NCSI_DEV_HWA) &&
- nc->state == NCSI_CHANNEL_ACTIVE)
+ state == NCSI_CHANNEL_ACTIVE)
ndp->flags |= NCSI_DEV_RESHUFFLE;
ncsi_stop_channel_monitor(nc);
@@ -97,13 +106,21 @@ static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
if (!nc)
return -ENODEV;
+ spin_lock_irqsave(&nc->lock, flags);
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_ACTIVE)
+ nc->state != NCSI_CHANNEL_ACTIVE) {
+ spin_unlock_irqrestore(&nc->lock, flags);
return 0;
+ }
+ spin_unlock_irqrestore(&nc->lock, flags);
ncsi_stop_channel_monitor(nc);
+ spin_lock_irqsave(&nc->lock, flags);
+ nc->state = NCSI_CHANNEL_INVISIBLE;
+ spin_unlock_irqrestore(&nc->lock, flags);
+
spin_lock_irqsave(&ndp->lock, flags);
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ nc->state = NCSI_CHANNEL_INACTIVE;
list_add_tail_rcu(&nc->link, &ndp->channel_queue);
spin_unlock_irqrestore(&ndp->lock, flags);