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Date: Tue, 14 Apr 2015 16:35:13 +0300
From: Yuval Mintz <Yuval.Mintz@...gic.com>
To: <davem@...emloft.net>, <netdev@...r.kernel.org>
CC: <bind@...s.net>, <peter@...leysoftware.com>,
Yuval Mintz <Yuval.Mintz@...gic.com>,
Ariel Elior <Ariel.Elior@...gic.com>
Subject: [PATCH net] bnx2x: Fix netpoll interoperability
Commit 9a2620c877454 ("bnx2x: prevent WARN during driver unload") switched
the napi/busy_lock locking mechanism from spin_lock() into spin_lock_bh(),
breaking inter-operability with netconsole, as netpoll disables interrupts
prior to calling our napi mechanism.
This switches the driver into using atomic assignments instead of the spinlock
mechanisms previously employed.
Signed-off-by: Yuval Mintz <Yuval.Mintz@...gic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@...gic.com>
---
Hi Dave,
Please consider applying this to 'net'.
Thanks,
Yuval
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 116 +++++++-----------------
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 5 +-
2 files changed, 34 insertions(+), 87 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index 4085c4b..d8b87a7 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -525,26 +525,23 @@ enum bnx2x_tpa_mode_t {
TPA_MODE_GRO
};
+#ifdef CONFIG_NET_RX_BUSY_POLL
+enum bnx2x_fp_state {
+ BNX2X_STATE_FP_IDLE,
+ BNX2X_STATE_FP_NAPI,
+ BNX2X_STATE_FP_POLL,
+ BNX2X_STATE_FP_DISABLE,
+};
+#endif
+
struct bnx2x_fastpath {
struct bnx2x *bp; /* parent */
struct napi_struct napi;
#ifdef CONFIG_NET_RX_BUSY_POLL
- unsigned int state;
-#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_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_OWNED | BNX2X_FP_STATE_DISABLED)
-#define BNX2X_FP_USER_PEND (BNX2X_FP_STATE_POLL | BNX2X_FP_STATE_POLL_YIELD)
- /* protect state */
- spinlock_t lock;
-#endif /* CONFIG_NET_RX_BUSY_POLL */
+ atomic_t state;
+#endif
union host_hc_status_block status_blk;
/* chip independent shortcuts into sb structure */
@@ -621,99 +618,50 @@ struct bnx2x_fastpath {
#ifdef CONFIG_NET_RX_BUSY_POLL
static inline void bnx2x_fp_init_lock(struct bnx2x_fastpath *fp)
{
- spin_lock_init(&fp->lock);
- fp->state = BNX2X_FP_STATE_IDLE;
+ atomic_set(&fp->state, BNX2X_STATE_FP_IDLE);
}
/* called from the device poll routine to get ownership of a FP */
static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
{
- bool rc = true;
-
- 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;
- rc = false;
- } else {
- /* we don't care if someone yielded */
- fp->state = BNX2X_FP_STATE_NAPI;
- }
- spin_unlock_bh(&fp->lock);
- return rc;
+ int rc = atomic_cmpxchg(&fp->state, BNX2X_STATE_FP_IDLE,
+ BNX2X_STATE_FP_NAPI);
+ return rc == BNX2X_STATE_FP_IDLE;
}
-/* returns true is someone tried to get the FP while napi had it */
-static inline bool bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
+static inline void bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
{
- bool rc = false;
-
- 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;
-
- /* state ==> idle, unless currently disabled */
- fp->state &= BNX2X_FP_STATE_DISABLED;
- spin_unlock_bh(&fp->lock);
- return rc;
+ WARN_ON(atomic_read(&fp->state) != BNX2X_STATE_FP_NAPI);
+ atomic_set(&fp->state, BNX2X_STATE_FP_IDLE);
}
/* called from bnx2x_low_latency_poll() */
static inline bool bnx2x_fp_lock_poll(struct bnx2x_fastpath *fp)
{
- bool rc = true;
-
- spin_lock_bh(&fp->lock);
- if ((fp->state & BNX2X_FP_LOCKED)) {
- fp->state |= BNX2X_FP_STATE_POLL_YIELD;
- rc = false;
- } else {
- /* preserve yield marks */
- fp->state |= BNX2X_FP_STATE_POLL;
- }
- spin_unlock_bh(&fp->lock);
- return rc;
+ int rc = atomic_cmpxchg(&fp->state, BNX2X_STATE_FP_IDLE,
+ BNX2X_STATE_FP_POLL);
+ return rc == BNX2X_STATE_FP_IDLE;
}
-/* returns true if someone tried to get the FP while it was locked */
-static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
+static inline void bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
{
- bool rc = false;
-
- spin_lock_bh(&fp->lock);
- WARN_ON(fp->state & BNX2X_FP_STATE_NAPI);
-
- if (fp->state & BNX2X_FP_STATE_POLL_YIELD)
- rc = true;
-
- /* state ==> idle, unless currently disabled */
- fp->state &= BNX2X_FP_STATE_DISABLED;
- spin_unlock_bh(&fp->lock);
- return rc;
+ WARN_ON(atomic_read(&fp->state) != BNX2X_STATE_FP_POLL);
+ atomic_set(&fp->state, BNX2X_STATE_FP_IDLE);
}
-/* true if a socket is polling, even if it did not get the lock */
+/* true if a socket is polling */
static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
{
- WARN_ON(!(fp->state & BNX2X_FP_OWNED));
- return fp->state & BNX2X_FP_USER_PEND;
+ return atomic_read(&fp->state) == BNX2X_STATE_FP_POLL;
}
/* false if fp is currently owned */
static inline bool bnx2x_fp_ll_disable(struct bnx2x_fastpath *fp)
{
- int rc = true;
+ int rc = atomic_cmpxchg(&fp->state, BNX2X_STATE_FP_IDLE,
+ BNX2X_STATE_FP_DISABLE);
+ return rc == BNX2X_STATE_FP_IDLE;
- 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)
@@ -725,9 +673,8 @@ static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
return true;
}
-static inline bool bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
+static inline void bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
{
- return false;
}
static inline bool bnx2x_fp_lock_poll(struct bnx2x_fastpath *fp)
@@ -735,9 +682,8 @@ static inline bool bnx2x_fp_lock_poll(struct bnx2x_fastpath *fp)
return false;
}
-static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
+static inline void bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
{
- return false;
}
static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 0a9faa1..f7c0375 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -3191,9 +3191,10 @@ static int bnx2x_poll(struct napi_struct *napi, int budget)
}
}
+ bnx2x_fp_unlock_napi(fp);
+
/* Fall out from the NAPI loop if needed */
- if (!bnx2x_fp_unlock_napi(fp) &&
- !(bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))) {
+ if (!(bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))) {
/* No need to update SB for FCoE L2 ring as long as
* it's connected to the default SB and the SB
--
1.9.3
--
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