be2net: add support for ndo_busy_poll
Includes:
- ndo_busy_poll implementation
- Locking between napi and busy_poll
- Fix rx_post_starvation (replenish rx-queues in out-of-mememory scenario)
logic to accomodate busy_poll.
v2 changes:
[Eric D.'s comment] call alloc_pages() with GFP_ATOMIC even in ndo_busy_poll
context as it is not allowed to sleep.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index 1bce77f..b2765eb 100644
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -199,6 +199,19 @@
u16 spurious_intr;
struct napi_struct napi;
struct be_adapter *adapter;
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+#define BE_EQ_IDLE 0
+#define BE_EQ_NAPI 1 /* napi owns this EQ */
+#define BE_EQ_POLL 2 /* poll owns this EQ */
+#define BE_EQ_LOCKED (BE_EQ_NAPI | BE_EQ_POLL)
+#define BE_EQ_NAPI_YIELD 4 /* napi yielded this EQ */
+#define BE_EQ_POLL_YIELD 8 /* poll yielded this EQ */
+#define BE_EQ_YIELD (BE_EQ_NAPI_YIELD | BE_EQ_POLL_YIELD)
+#define BE_EQ_USER_PEND (BE_EQ_POLL | BE_EQ_POLL_YIELD)
+ unsigned int state;
+ spinlock_t lock; /* lock to serialize napi and busy-poll */
+#endif /* CONFIG_NET_RX_BUSY_POLL */
} ____cacheline_aligned_in_smp;
struct be_aic_obj { /* Adaptive interrupt coalescing (AIC) info */
@@ -212,6 +225,11 @@
u64 tx_reqs_prev; /* Used to calculate TX pps */
};
+enum {
+ NAPI_POLLING,
+ BUSY_POLLING
+};
+
struct be_mcc_obj {
struct be_queue_info q;
struct be_queue_info cq;
@@ -561,6 +579,10 @@
for (i = 0, eqo = &adapter->eq_obj[i]; i < adapter->num_evt_qs; \
i++, eqo++)
+#define for_all_rx_queues_on_eq(adapter, eqo, rxo, i) \
+ for (i = eqo->idx, rxo = &adapter->rx_obj[i]; i < adapter->num_rx_qs;\
+ i += adapter->num_evt_qs, rxo += adapter->num_evt_qs)
+
#define is_mcc_eqo(eqo) (eqo->idx == 0)
#define mcc_eqo(adapter) (&adapter->eq_obj[0])
@@ -711,6 +733,106 @@
return adapter->flags & BE_FLAGS_QNQ_ASYNC_EVT_RCVD;
}
+#ifdef CONFIG_NET_RX_BUSY_POLL
+static inline bool be_lock_napi(struct be_eq_obj *eqo)
+{
+ bool status = true;
+
+ spin_lock(&eqo->lock); /* BH is already disabled */
+ if (eqo->state & BE_EQ_LOCKED) {
+ WARN_ON(eqo->state & BE_EQ_NAPI);
+ eqo->state |= BE_EQ_NAPI_YIELD;
+ status = false;
+ } else {
+ eqo->state = BE_EQ_NAPI;
+ }
+ spin_unlock(&eqo->lock);
+ return status;
+}
+
+static inline void be_unlock_napi(struct be_eq_obj *eqo)
+{
+ spin_lock(&eqo->lock); /* BH is already disabled */
+
+ WARN_ON(eqo->state & (BE_EQ_POLL | BE_EQ_NAPI_YIELD));
+ eqo->state = BE_EQ_IDLE;
+
+ spin_unlock(&eqo->lock);
+}
+
+static inline bool be_lock_busy_poll(struct be_eq_obj *eqo)
+{
+ bool status = true;
+
+ spin_lock_bh(&eqo->lock);
+ if (eqo->state & BE_EQ_LOCKED) {
+ eqo->state |= BE_EQ_POLL_YIELD;
+ status = false;
+ } else {
+ eqo->state |= BE_EQ_POLL;
+ }
+ spin_unlock_bh(&eqo->lock);
+ return status;
+}
+
+static inline void be_unlock_busy_poll(struct be_eq_obj *eqo)
+{
+ spin_lock_bh(&eqo->lock);
+
+ WARN_ON(eqo->state & (BE_EQ_NAPI));
+ eqo->state = BE_EQ_IDLE;
+
+ spin_unlock_bh(&eqo->lock);
+}
+
+static inline void be_enable_busy_poll(struct be_eq_obj *eqo)
+{
+ spin_lock_init(&eqo->lock);
+ eqo->state = BE_EQ_IDLE;
+}
+
+static inline void be_disable_busy_poll(struct be_eq_obj *eqo)
+{
+ local_bh_disable();
+
+ /* It's enough to just acquire napi lock on the eqo to stop
+ * be_busy_poll() from processing any queueus.
+ */
+ while (!be_lock_napi(eqo))
+ mdelay(1);
+
+ local_bh_enable();
+}
+
+#else /* CONFIG_NET_RX_BUSY_POLL */
+
+static inline bool be_lock_napi(struct be_eq_obj *eqo)
+{
+ return true;
+}
+
+static inline void be_unlock_napi(struct be_eq_obj *eqo)
+{
+}
+
+static inline bool be_lock_busy_poll(struct be_eq_obj *eqo)
+{
+ return false;
+}
+
+static inline void be_unlock_busy_poll(struct be_eq_obj *eqo)
+{
+}
+
+static inline void be_enable_busy_poll(struct be_eq_obj *eqo)
+{
+}
+
+static inline void be_disable_busy_poll(struct be_eq_obj *eqo)
+{
+}
+#endif /* CONFIG_NET_RX_BUSY_POLL */
+
void be_cq_notify(struct be_adapter *adapter, u16 qid, bool arm,
u16 num_popped);
void be_link_status_update(struct be_adapter *adapter, u8 link_status);