Merge branch 'thunderx-perf'

Sunil Goutham says:

====================
net: thunderx: Performance enhancement changes

Below patches attempts to improve performance by reducing
no of atomic operations while allocating new receive buffers
and reducing cache misses by adjusting nicvf structure elements.

Changes from v1:
 No changes, resubmitting a fresh as per David's suggestion.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/thunder/nic.h

@@ -272,45 +272,54 @@ struct nicvf {
 	struct nicvf		*pnicvf;
 	struct net_device	*netdev;
 	struct pci_dev		*pdev;
+	void __iomem		*reg_base;
+	struct queue_set	*qs;
+	struct nicvf_cq_poll	*napi[8];
 	u8			vf_id;
-	u8			node;
-	u8			tns_mode:1;
-	u8			sqs_mode:1;
-	u8			loopback_supported:1;
+	u8			sqs_id;
+	bool                    sqs_mode;
 	bool			hw_tso;
-	u16			mtu;
-	struct queue_set	*qs;
+
+	/* Receive buffer alloc */
+	u32			rb_page_offset;
+	u16			rb_pageref;
+	bool			rb_alloc_fail;
+	bool			rb_work_scheduled;
+	struct page		*rb_page;
+	struct delayed_work	rbdr_work;
+	struct tasklet_struct	rbdr_task;
+
+	/* Secondary Qset */
+	u8			sqs_count;
 #define	MAX_SQS_PER_VF_SINGLE_NODE		5
 #define	MAX_SQS_PER_VF				11
-	u8			sqs_id;
-	u8			sqs_count; /* Secondary Qset count */
 	struct nicvf		*snicvf[MAX_SQS_PER_VF];
+
+	/* Queue count */
 	u8			rx_queues;
 	u8			tx_queues;
 	u8			max_queues;
-	void __iomem		*reg_base;
+
+	u8			node;
+	u8			cpi_alg;
+	u16			mtu;
 	bool			link_up;
 	u8			duplex;
 	u32			speed;
-	struct page		*rb_page;
-	u32			rb_page_offset;
-	bool			rb_alloc_fail;
-	bool			rb_work_scheduled;
-	struct delayed_work	rbdr_work;
-	struct tasklet_struct	rbdr_task;
-	struct tasklet_struct	qs_err_task;
-	struct tasklet_struct	cq_task;
-	struct nicvf_cq_poll	*napi[8];
+	bool			tns_mode;
+	bool			loopback_supported;
 	struct nicvf_rss_info	rss_info;
-	u8			cpi_alg;
+	struct tasklet_struct	qs_err_task;
+	struct work_struct	reset_task;
+
 	/* Interrupt coalescing settings */
 	u32			cq_coalesce_usecs;
-
 	u32			msg_enable;
+
+	/* Stats */
 	struct nicvf_hw_stats   hw_stats;
 	struct nicvf_drv_stats  drv_stats;
 	struct bgx_stats	bgx_stats;
-	struct work_struct	reset_task;
 
 	/* MSI-X  */
 	bool			msix_enabled;

drivers/net/ethernet/cavium/thunder/nicvf_queues.c

@@ -18,6 +18,15 @@
 #include "q_struct.h"
 #include "nicvf_queues.h"
 
+static void nicvf_get_page(struct nicvf *nic)
+{
+	if (!nic->rb_pageref || !nic->rb_page)
+		return;
+
+	atomic_add(nic->rb_pageref, &nic->rb_page->_count);
+	nic->rb_pageref = 0;
+}
+
 /* Poll a register for a specific value */
 static int nicvf_poll_reg(struct nicvf *nic, int qidx,
 			  u64 reg, int bit_pos, int bits, int val)
@@ -81,16 +90,15 @@ static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
 	int order = (PAGE_SIZE <= 4096) ?  PAGE_ALLOC_COSTLY_ORDER : 0;
 
 	/* Check if request can be accomodated in previous allocated page */
-	if (nic->rb_page) {
-		if ((nic->rb_page_offset + buf_len + buf_len) >
-		    (PAGE_SIZE << order)) {
-			nic->rb_page = NULL;
-		} else {
-			nic->rb_page_offset += buf_len;
-			get_page(nic->rb_page);
-		}
+	if (nic->rb_page &&
+	    ((nic->rb_page_offset + buf_len) < (PAGE_SIZE << order))) {
+		nic->rb_pageref++;
+		goto ret;
 	}
 
+	nicvf_get_page(nic);
+	nic->rb_page = NULL;
+
 	/* Allocate a new page */
 	if (!nic->rb_page) {
 		nic->rb_page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN,
@@ -102,7 +110,9 @@ static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
 		nic->rb_page_offset = 0;
 	}
 
+ret:
 	*rbuf = (u64 *)((u64)page_address(nic->rb_page) + nic->rb_page_offset);
+	nic->rb_page_offset += buf_len;
 
 	return 0;
 }
@@ -158,6 +168,9 @@ static int  nicvf_init_rbdr(struct nicvf *nic, struct rbdr *rbdr,
 		desc = GET_RBDR_DESC(rbdr, idx);
 		desc->buf_addr = virt_to_phys(rbuf) >> NICVF_RCV_BUF_ALIGN;
 	}
+
+	nicvf_get_page(nic);
+
 	return 0;
 }
 
@@ -241,6 +254,8 @@ static void nicvf_refill_rbdr(struct nicvf *nic, gfp_t gfp)
 		new_rb++;
 	}
 
+	nicvf_get_page(nic);
+
 	/* make sure all memory stores are done before ringing doorbell */
 	smp_wmb();