[PATCH v4.7 1/7] net/ncsi: Avoid unused-value warning
Gavin Shan
gwshan at linux.vnet.ibm.com
Wed Sep 28 12:48:29 AEST 2016
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 avoids the build warning by replacing xchg() with atomic_set()
and atomic_xchg(). atomic_read() is used to retrieve the NCSI channel's
state. No functional change introduced.
Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
net/ncsi/internal.h | 2 +-
net/ncsi/ncsi-aen.c | 17 ++++++++++-------
net/ncsi/ncsi-manage.c | 36 ++++++++++++++++++++----------------
net/ncsi/ncsi-rsp.c | 4 ++--
4 files changed, 33 insertions(+), 26 deletions(-)
diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
index 33738c0..549846b 100644
--- a/net/ncsi/internal.h
+++ b/net/ncsi/internal.h
@@ -175,7 +175,7 @@ struct ncsi_package;
struct ncsi_channel {
unsigned char id;
- int state;
+ atomic_t state;
#define NCSI_CHANNEL_INACTIVE 1
#define NCSI_CHANNEL_ACTIVE 2
#define NCSI_CHANNEL_INVISIBLE 3
diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
index d463468..77303da 100644
--- a/net/ncsi/ncsi-aen.c
+++ b/net/ncsi/ncsi-aen.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/atomic.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
@@ -55,6 +56,7 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
struct ncsi_channel_mode *ncm;
unsigned long old_data;
unsigned long flags;
+ int state;
/* Find the NCSI channel */
ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
@@ -70,12 +72,13 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
if (!((old_data ^ ncm->data[2]) & 0x1) ||
!list_empty(&nc->link))
return 0;
- if (!(nc->state == NCSI_CHANNEL_INACTIVE && (ncm->data[2] & 0x1)) &&
- !(nc->state == NCSI_CHANNEL_ACTIVE && !(ncm->data[2] & 0x1)))
+
+ state = atomic_read(&nc->state);
+ if (!(state == NCSI_CHANNEL_INACTIVE && (ncm->data[2] & 0x1)) &&
+ !(state == NCSI_CHANNEL_ACTIVE && !(ncm->data[2] & 0x1)))
return 0;
- if (!(ndp->flags & NCSI_DEV_HWA) &&
- nc->state == NCSI_CHANNEL_ACTIVE)
+ if (!(ndp->flags & NCSI_DEV_HWA) && state == NCSI_CHANNEL_ACTIVE)
ndp->flags |= NCSI_DEV_RESHUFFLE;
ncsi_stop_channel_monitor(nc);
@@ -98,12 +101,12 @@ static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
return -ENODEV;
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_ACTIVE)
+ atomic_read(&nc->state) != NCSI_CHANNEL_ACTIVE)
return 0;
ncsi_stop_channel_monitor(nc);
spin_lock_irqsave(&ndp->lock, flags);
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
list_add_tail_rcu(&nc->link, &ndp->channel_queue);
spin_unlock_irqrestore(&ndp->lock, flags);
@@ -128,7 +131,7 @@ static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
ncm->data[3] = ntohl(hncdsc->status);
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_ACTIVE ||
+ atomic_read(&nc->state) != NCSI_CHANNEL_ACTIVE ||
(ncm->data[3] & 0x1))
return 0;
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index ef017b8..b325c1d 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/atomic.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
@@ -143,7 +144,7 @@ static void ncsi_report_link(struct ncsi_dev_priv *ndp, bool force_down)
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_ACTIVE)
+ atomic_read(&nc->state) != NCSI_CHANNEL_ACTIVE)
continue;
if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1) {
@@ -166,7 +167,7 @@ static void ncsi_channel_monitor(unsigned long data)
bool enabled;
unsigned int timeout;
unsigned long flags;
- int ret;
+ int state, ret;
spin_lock_irqsave(&nc->lock, flags);
timeout = nc->timeout;
@@ -175,8 +176,9 @@ static void ncsi_channel_monitor(unsigned long data)
if (!enabled || !list_empty(&nc->link))
return;
- if (nc->state != NCSI_CHANNEL_INACTIVE &&
- nc->state != NCSI_CHANNEL_ACTIVE)
+
+ state = atomic_read(&nc->state);
+ if (state != NCSI_CHANNEL_INACTIVE && state != NCSI_CHANNEL_ACTIVE)
return;
if (!(timeout % 2)) {
@@ -195,11 +197,11 @@ static void ncsi_channel_monitor(unsigned long data)
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(&ndp->lock, flags);
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ atomic_set(&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);
@@ -266,7 +268,7 @@ struct ncsi_channel *ncsi_add_channel(struct ncsi_package *np, unsigned char id)
nc->id = id;
nc->package = np;
- nc->state = NCSI_CHANNEL_INACTIVE;
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
nc->enabled = false;
setup_timer(&nc->timer, ncsi_channel_monitor, (unsigned long)nc);
spin_lock_init(&nc->lock);
@@ -309,7 +311,7 @@ static void ncsi_remove_channel(struct ncsi_channel *nc)
kfree(ncf);
}
- nc->state = NCSI_CHANNEL_INACTIVE;
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
spin_unlock_irqrestore(&nc->lock, flags);
ncsi_stop_channel_monitor(nc);
@@ -556,7 +558,7 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
break;
case ncsi_dev_state_suspend_done:
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
ncsi_process_next_channel(ndp);
break;
@@ -676,9 +678,9 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
break;
case ncsi_dev_state_config_done:
if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1)
- xchg(&nc->state, NCSI_CHANNEL_ACTIVE);
+ atomic_set(&nc->state, NCSI_CHANNEL_ACTIVE);
else
- xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
ncsi_start_channel_monitor(nc);
ncsi_process_next_channel(ndp);
@@ -708,7 +710,7 @@ static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
if (!list_empty(&nc->link) ||
- nc->state != NCSI_CHANNEL_INACTIVE)
+ atomic_read(&nc->state) != NCSI_CHANNEL_INACTIVE)
continue;
if (!found)
@@ -770,7 +772,8 @@ static int ncsi_enable_hwa(struct ncsi_dev_priv *ndp)
spin_lock_irqsave(&ndp->lock, flags);
NCSI_FOR_EACH_PACKAGE(ndp, np) {
NCSI_FOR_EACH_CHANNEL(np, nc) {
- WARN_ON_ONCE(nc->state != NCSI_CHANNEL_INACTIVE ||
+ WARN_ON_ONCE(atomic_read(&nc->state) !=
+ NCSI_CHANNEL_INACTIVE ||
!list_empty(&nc->link));
ncsi_stop_channel_monitor(nc);
list_add_tail_rcu(&nc->link, &ndp->channel_queue);
@@ -987,7 +990,7 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp)
goto out;
}
- old_state = xchg(&nc->state, NCSI_CHANNEL_INVISIBLE);
+ old_state = atomic_xchg(&nc->state, NCSI_CHANNEL_INVISIBLE);
list_del_init(&nc->link);
spin_unlock_irqrestore(&ndp->lock, flags);
@@ -1006,7 +1009,7 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp)
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;
}
@@ -1166,7 +1169,8 @@ int ncsi_start_dev(struct ncsi_dev *nd)
/* 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);
+ old_state = atomic_xchg(&nc->state,
+ NCSI_CHANNEL_INACTIVE);
WARN_ON_ONCE(!list_empty(&nc->link) ||
old_state == NCSI_CHANNEL_INVISIBLE);
}
diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index af84389..54f7eed 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -123,7 +123,7 @@ static int ncsi_rsp_handler_dp(struct ncsi_request *nr)
/* Change state of all channels attached to the package */
NCSI_FOR_EACH_CHANNEL(np, nc) {
spin_lock_irqsave(&nc->lock, flags);
- nc->state = NCSI_CHANNEL_INACTIVE;
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
spin_unlock_irqrestore(&nc->lock, flags);
}
@@ -195,7 +195,7 @@ static int ncsi_rsp_handler_rc(struct ncsi_request *nr)
/* Update state for the specified channel */
spin_lock_irqsave(&nc->lock, flags);
- nc->state = NCSI_CHANNEL_INACTIVE;
+ atomic_set(&nc->state, NCSI_CHANNEL_INACTIVE);
spin_unlock_irqrestore(&nc->lock, flags);
return 0;
--
2.1.0
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