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Message-ID: <1389089261-25714-1-git-send-email-yuvalmin@broadcom.com>
Date: Tue, 7 Jan 2014 12:07:41 +0200
From: Yuval Mintz <yuvalmin@...adcom.com>
To: <davem@...emloft.net>, <netdev@...r.kernel.org>
CC: Yuval Mintz <yuvalmin@...adcom.com>,
Dmitry Kravkov <dmitry@...adcom.com>,
Ariel Elior <ariele@...adcom.com>
Subject: [PATCH net] bnx2x: prevent WARN during driver unload
Starting with commit 80c33dd "net: add might_sleep() call to napi_disable"
bnx2x fails the might_sleep tests causing a stack trace to appear whenever
the driver is unloaded, as local_bh_disable() is being called before
napi_disable().
This changes the locking schematics related to CONFIG_NET_RX_BUSY_POLL,
preventing the need for calling local_bh_disable() and thus eliminating
the issue.
Signed-off-by: Yuval Mintz <yuvalmin@...adcom.com>
Signed-off-by: Dmitry Kravkov <dmitry@...adcom.com>
Signed-off-by: Ariel Elior <ariele@...adcom.com>
---
Hi Dave,
Please apply this to `net'.
Thanks,
Yuval Mintz
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 44 +++++++++++++++++++------
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 12 +++----
2 files changed, 38 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index a1f66e2..46eeace 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -520,10 +520,12 @@ struct bnx2x_fastpath {
#define BNX2X_FP_STATE_IDLE 0
#define BNX2X_FP_STATE_NAPI (1 << 0) /* NAPI owns this FP */
#define BNX2X_FP_STATE_POLL (1 << 1) /* poll owns this FP */
-#define BNX2X_FP_STATE_NAPI_YIELD (1 << 2) /* NAPI yielded this FP */
-#define BNX2X_FP_STATE_POLL_YIELD (1 << 3) /* poll yielded this FP */
+#define BNX2X_FP_STATE_DISABLED (1 << 2)
+#define BNX2X_FP_STATE_NAPI_YIELD (1 << 3) /* NAPI yielded this FP */
+#define BNX2X_FP_STATE_POLL_YIELD (1 << 4) /* poll yielded this FP */
+#define BNX2X_FP_OWNED (BNX2X_FP_STATE_NAPI | BNX2X_FP_STATE_POLL)
#define BNX2X_FP_YIELD (BNX2X_FP_STATE_NAPI_YIELD | BNX2X_FP_STATE_POLL_YIELD)
-#define BNX2X_FP_LOCKED (BNX2X_FP_STATE_NAPI | BNX2X_FP_STATE_POLL)
+#define BNX2X_FP_LOCKED (BNX2X_FP_OWNED | BNX2X_FP_STATE_DISABLED)
#define BNX2X_FP_USER_PEND (BNX2X_FP_STATE_POLL | BNX2X_FP_STATE_POLL_YIELD)
/* protect state */
spinlock_t lock;
@@ -613,7 +615,7 @@ static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
{
bool rc = true;
- spin_lock(&fp->lock);
+ spin_lock_bh(&fp->lock);
if (fp->state & BNX2X_FP_LOCKED) {
WARN_ON(fp->state & BNX2X_FP_STATE_NAPI);
fp->state |= BNX2X_FP_STATE_NAPI_YIELD;
@@ -622,7 +624,7 @@ static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
/* we don't care if someone yielded */
fp->state = BNX2X_FP_STATE_NAPI;
}
- spin_unlock(&fp->lock);
+ spin_unlock_bh(&fp->lock);
return rc;
}
@@ -631,14 +633,16 @@ static inline bool bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
{
bool rc = false;
- spin_lock(&fp->lock);
+ spin_lock_bh(&fp->lock);
WARN_ON(fp->state &
(BNX2X_FP_STATE_POLL | BNX2X_FP_STATE_NAPI_YIELD));
if (fp->state & BNX2X_FP_STATE_POLL_YIELD)
rc = true;
- fp->state = BNX2X_FP_STATE_IDLE;
- spin_unlock(&fp->lock);
+
+ /* state ==> idle, unless currently disabled */
+ fp->state &= BNX2X_FP_STATE_DISABLED;
+ spin_unlock_bh(&fp->lock);
return rc;
}
@@ -669,7 +673,9 @@ static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
if (fp->state & BNX2X_FP_STATE_POLL_YIELD)
rc = true;
- fp->state = BNX2X_FP_STATE_IDLE;
+
+ /* state ==> idle, unless currently disabled */
+ fp->state &= BNX2X_FP_STATE_DISABLED;
spin_unlock_bh(&fp->lock);
return rc;
}
@@ -677,9 +683,23 @@ static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
/* true if a socket is polling, even if it did not get the lock */
static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
{
- WARN_ON(!(fp->state & BNX2X_FP_LOCKED));
+ WARN_ON(!(fp->state & BNX2X_FP_OWNED));
return fp->state & BNX2X_FP_USER_PEND;
}
+
+/* false if fp is currently owned */
+static inline bool bnx2x_fp_ll_disable(struct bnx2x_fastpath *fp)
+{
+ int rc = true;
+
+ spin_lock_bh(&fp->lock);
+ if (fp->state & BNX2X_FP_OWNED)
+ rc = false;
+ fp->state |= BNX2X_FP_STATE_DISABLED;
+ spin_unlock_bh(&fp->lock);
+
+ return rc;
+}
#else
static inline void bnx2x_fp_init_lock(struct bnx2x_fastpath *fp)
{
@@ -709,6 +729,10 @@ static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
{
return false;
}
+static inline bool bnx2x_fp_ll_disable(struct bnx2x_fastpath *fp)
+{
+ return true;
+}
#endif /* CONFIG_NET_RX_BUSY_POLL */
/* Use 2500 as a mini-jumbo MTU for FCoE */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index ec96130..c6745d7 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -1790,26 +1790,22 @@ static void bnx2x_napi_disable_cnic(struct bnx2x *bp)
{
int i;
- local_bh_disable();
for_each_rx_queue_cnic(bp, i) {
napi_disable(&bnx2x_fp(bp, i, napi));
- while (!bnx2x_fp_lock_napi(&bp->fp[i]))
- mdelay(1);
+ while (!bnx2x_fp_ll_disable(&bp->fp[i]))
+ usleep_range(1000, 2000);
}
- local_bh_enable();
}
static void bnx2x_napi_disable(struct bnx2x *bp)
{
int i;
- local_bh_disable();
for_each_eth_queue(bp, i) {
napi_disable(&bnx2x_fp(bp, i, napi));
- while (!bnx2x_fp_lock_napi(&bp->fp[i]))
- mdelay(1);
+ while (!bnx2x_fp_ll_disable(&bp->fp[i]))
+ usleep_range(1000, 2000);
}
- local_bh_enable();
}
void bnx2x_netif_start(struct bnx2x *bp)
--
1.8.1.227.g44fe835
--
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