be2net: Add MCC queue mechanism for BE cmds

Currenlty all cmds use the blocking MCC mbox to post cmds. An mbox cmd is protected
via a spin_lock(cmd_lock) and not spin_lock_bh() as it is undesirable
to disable BHs while a blocking mbox cmd is in progress (and take long to finish.)
This can lockup a cmd in progress in process context. Instead cmds that may be
called in BH context must use the MCC queue to post cmds. The cmd completions
are rcvd in a separate completion queue and the events are placed in the tx-event
queue.

Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 64 insertions, 31 deletions

diff --git a/drivers/net/benet/be.h b/drivers/net/benet/be.h
index b4bb06f..ef5be13 100644
--- a/drivers/net/benet/be.h
+++ b/drivers/net/benet/be.h
@@ -65,7 +65,7 @@ static inline char *nic_name(struct pci_dev *pdev)
 #define TX_CQ_LEN		1024
 #define RX_Q_LEN		1024	/* Does not support any other value */
 #define RX_CQ_LEN		1024
-#define MCC_Q_LEN		64	/* total size not to exceed 8 pages */
+#define MCC_Q_LEN		128	/* total size not to exceed 8 pages */
 #define MCC_CQ_LEN		256
 
 #define BE_NAPI_WEIGHT		64
@@ -91,6 +91,61 @@ struct be_queue_info {
 	atomic_t used;	/* Number of valid elements in the queue */
 };
 
+static inline u32 MODULO(u16 val, u16 limit)
+{
+	BUG_ON(limit & (limit - 1));
+	return val & (limit - 1);
+}
+
+static inline void index_adv(u16 *index, u16 val, u16 limit)
+{
+	*index = MODULO((*index + val), limit);
+}
+
+static inline void index_inc(u16 *index, u16 limit)
+{
+	*index = MODULO((*index + 1), limit);
+}
+
+static inline void *queue_head_node(struct be_queue_info *q)
+{
+	return q->dma_mem.va + q->head * q->entry_size;
+}
+
+static inline void *queue_tail_node(struct be_queue_info *q)
+{
+	return q->dma_mem.va + q->tail * q->entry_size;
+}
+
+static inline void queue_head_inc(struct be_queue_info *q)
+{
+	index_inc(&q->head, q->len);
+}
+
+static inline void queue_tail_inc(struct be_queue_info *q)
+{
+	index_inc(&q->tail, q->len);
+}
+
+
+struct be_eq_obj {
+	struct be_queue_info q;
+	char desc[32];
+
+	/* Adaptive interrupt coalescing (AIC) info */
+	bool enable_aic;
+	u16 min_eqd;		/* in usecs */
+	u16 max_eqd;		/* in usecs */
+	u16 cur_eqd;		/* in usecs */
+
+	struct napi_struct napi;
+};
+
+struct be_mcc_obj {
+	struct be_queue_info q;
+	struct be_queue_info cq;
+};
+
 struct be_ctrl_info {
 	u8 __iomem *csr;
 	u8 __iomem *db;		/* Door Bell */
@@ -98,11 +153,16 @@ struct be_ctrl_info {
 	int pci_func;
 
 	/* Mbox used for cmd request/response */
-	spinlock_t cmd_lock;	/* For serializing cmds to BE card */
+	spinlock_t mbox_lock;	/* For serializing mbox cmds to BE card */
 	struct be_dma_mem mbox_mem;
 	/* Mbox mem is adjusted to align to 16 bytes. The allocated addr
 	 * is stored for freeing purpose */
 	struct be_dma_mem mbox_mem_alloced;
+
+	/* MCC Rings */
+	struct be_mcc_obj mcc_obj;
+	spinlock_t mcc_lock;	/* For serializing mcc cmds to BE card */
+	spinlock_t mcc_cq_lock;
 };
 
 #include "be_cmds.h"
@@ -150,19 +210,6 @@ struct be_stats_obj {
 	struct be_dma_mem cmd;
 };
 
-struct be_eq_obj {
-	struct be_queue_info q;
-	char desc[32];
-
-	/* Adaptive interrupt coalescing (AIC) info */
-	bool enable_aic;
-	u16 min_eqd;		/* in usecs */
-	u16 max_eqd;		/* in usecs */
-	u16 cur_eqd;		/* in usecs */
-
-	struct napi_struct napi;
-};
-
 struct be_tx_obj {
 	struct be_queue_info q;
 	struct be_queue_info cq;
@@ -235,22 +282,6 @@ extern struct ethtool_ops be_ethtool_ops;
 
 #define BE_SET_NETDEV_OPS(netdev, ops)	(netdev->netdev_ops = ops)
 
-static inline u32 MODULO(u16 val, u16 limit)
-{
-	BUG_ON(limit & (limit - 1));
-	return val & (limit - 1);
-}
-
-static inline void index_adv(u16 *index, u16 val, u16 limit)
-{
-	*index = MODULO((*index + val), limit);
-}
-
-static inline void index_inc(u16 *index, u16 limit)
-{
-	*index = MODULO((*index + 1), limit);
-}
-
 #define PAGE_SHIFT_4K		12
 #define PAGE_SIZE_4K		(1 << PAGE_SHIFT_4K)
 
@@ -339,4 +370,6 @@ static inline u8 is_udp_pkt(struct sk_buff *skb)
 	return val;
 }
 
+extern void be_cq_notify(struct be_ctrl_info *ctrl, u16 qid, bool arm,
+		u16 num_popped);
 #endif				/* BE_H */