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>
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index ef017b8..a26ce51 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -132,6 +132,7 @@
struct ncsi_dev *nd = &ndp->ndev;
struct ncsi_package *np;
struct ncsi_channel *nc;
+ unsigned long flags;
nd->state = ncsi_dev_state_functional;
if (force_down) {
@@ -142,14 +143,21 @@
nd->link_up = 0;
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
+ 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);
continue;
+ }
if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1) {
+ spin_unlock_irqrestore(&nc->lock, flags);
nd->link_up = 1;
goto report;
}
+
+ spin_unlock_irqrestore(&nc->lock, flags);
}
}
@@ -163,20 +171,22 @@
struct ncsi_package *np = nc->package;
struct ncsi_dev_priv *ndp = np->ndp;
struct ncsi_cmd_arg nca;
- bool enabled;
+ bool enabled, chained;
unsigned int timeout;
unsigned long flags;
- int ret;
+ int state, ret;
spin_lock_irqsave(&nc->lock, flags);
+ state = nc->state;
+ chained = !list_empty(&nc->link);
timeout = nc->timeout;
enabled = nc->enabled;
spin_unlock_irqrestore(&nc->lock, flags);
- if (!enabled || !list_empty(&nc->link))
+ if (!enabled || chained)
return;
- if (nc->state != NCSI_CHANNEL_INACTIVE &&
- nc->state != NCSI_CHANNEL_ACTIVE)
+ if (state != NCSI_CHANNEL_INACTIVE &&
+ state != NCSI_CHANNEL_ACTIVE)
return;
if (!(timeout % 2)) {
@@ -195,11 +205,15 @@
if (timeout + 1 >= 3) {
if (!(ndp->flags & NCSI_DEV_HWA) &&
- nc->state == NCSI_CHANNEL_ACTIVE)
+ state == NCSI_CHANNEL_ACTIVE)
ncsi_report_link(ndp, true);
+ 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);
ncsi_process_next_channel(ndp);
@@ -508,6 +522,7 @@
struct ncsi_package *np = ndp->active_package;
struct ncsi_channel *nc = ndp->active_channel;
struct ncsi_cmd_arg nca;
+ unsigned long flags;
int ret;
nca.ndp = ndp;
@@ -556,7 +571,9 @@
break;
case ncsi_dev_state_suspend_done:
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ spin_lock_irqsave(&nc->lock, flags);
+ nc->state = NCSI_CHANNEL_INACTIVE;
+ spin_unlock_irqrestore(&nc->lock, flags);
ncsi_process_next_channel(ndp);
break;
@@ -574,6 +591,7 @@
struct ncsi_channel *nc = ndp->active_channel;
struct ncsi_cmd_arg nca;
unsigned char index;
+ unsigned long flags;
int ret;
nca.ndp = ndp;
@@ -675,10 +693,12 @@
goto error;
break;
case ncsi_dev_state_config_done:
+ spin_lock_irqsave(&nc->lock, flags);
if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1)
- xchg(&nc->state, NCSI_CHANNEL_ACTIVE);
+ nc->state = NCSI_CHANNEL_ACTIVE;
else
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ nc->state = NCSI_CHANNEL_INACTIVE;
+ spin_unlock_irqrestore(&nc->lock, flags);
ncsi_start_channel_monitor(nc);
ncsi_process_next_channel(ndp);
@@ -707,18 +727,25 @@
found = NULL;
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
+ spin_lock_irqsave(&nc->lock, flags);
+
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_INACTIVE)
+ nc->state != NCSI_CHANNEL_INACTIVE) {
+ spin_unlock_irqrestore(&nc->lock, flags);
continue;
+ }
if (!found)
found = nc;
ncm = &nc->modes[NCSI_MODE_LINK];
if (ncm->data[2] & 0x1) {
+ spin_unlock_irqrestore(&nc->lock, flags);
found = nc;
goto out;
}
+
+ spin_unlock_irqrestore(&nc->lock, flags);
}
}
@@ -987,11 +1014,14 @@
goto out;
}
- old_state = xchg(&nc->state, NCSI_CHANNEL_INVISIBLE);
list_del_init(&nc->link);
-
spin_unlock_irqrestore(&ndp->lock, flags);
+ spin_lock_irqsave(&nc->lock, flags);
+ old_state = nc->state;
+ nc->state = NCSI_CHANNEL_INVISIBLE;
+ spin_unlock_irqrestore(&nc->lock, flags);
+
ndp->active_channel = nc;
ndp->active_package = nc->package;
@@ -1006,7 +1036,7 @@
break;
default:
netdev_err(ndp->ndev.dev, "Invalid state 0x%x on %d:%d\n",
- nc->state, nc->package->id, nc->id);
+ old_state, nc->package->id, nc->id);
ncsi_report_link(ndp, false);
return -EINVAL;
}
@@ -1151,6 +1181,8 @@
struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
struct ncsi_package *np;
struct ncsi_channel *nc;
+ unsigned long flags;
+ bool chained;
int old_state, ret;
if (nd->state != ncsi_dev_state_registered &&
@@ -1166,8 +1198,13 @@
/* Reset channel's state and start over */
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
- old_state = xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
- WARN_ON_ONCE(!list_empty(&nc->link) ||
+ spin_lock_irqsave(&nc->lock, flags);
+ chained = !list_empty(&nc->link);
+ old_state = nc->state;
+ nc->state = NCSI_CHANNEL_INACTIVE;
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ WARN_ON_ONCE(chained ||
old_state == NCSI_CHANNEL_INVISIBLE);
}
}