[PATCH net-next 06/10] eth: fbnic: store NAPIs in an array instead of the list

[Jakub Kicinski <kuba@kernel.org>]

We will need an array for storing NAPIs in the upcoming IRQ handler
reuse rework. Replace the current list we have, so that we are able
to reuse it later.

In a few places replace i as the iterator with t when we iterate
over triads, this seems slightly less confusing than having
i, j, k variables.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../net/ethernet/meta/fbnic/fbnic_netdev.c    |   1 -
 .../net/ethernet/meta/fbnic/fbnic_netdev.h    |   6 +-
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 117 ++++++++++--------
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |   7 +-
 4 files changed, 71 insertions(+), 60 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
index fc7d80db5fa6..558644c49a4b 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
@@ -615,7 +615,6 @@ struct net_device *fbnic_netdev_alloc(struct fbnic_dev *fbd)
 
 	fbn->netdev = netdev;
 	fbn->fbd = fbd;
-	INIT_LIST_HEAD(&fbn->napis);
 
 	fbn->txq_size = FBNIC_TXQ_SIZE_DEFAULT;
 	fbn->hpq_size = FBNIC_HPQ_SIZE_DEFAULT;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
index b8417b300778..0986c8f120a8 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
@@ -11,10 +11,14 @@
 #include "fbnic_rpc.h"
 #include "fbnic_txrx.h"
 
+#define FBNIC_MAX_NAPI_VECTORS		128u
+
 struct fbnic_net {
 	struct fbnic_ring *tx[FBNIC_MAX_TXQS];
 	struct fbnic_ring *rx[FBNIC_MAX_RXQS];
 
+	struct fbnic_napi_vector *napi[FBNIC_MAX_NAPI_VECTORS];
+
 	struct net_device *netdev;
 	struct fbnic_dev *fbd;
 
@@ -56,8 +60,6 @@ struct fbnic_net {
 
 	/* Time stampinn filter config */
 	struct kernel_hwtstamp_config hwtstamp_config;
-
-	struct list_head napis;
 };
 
 int __fbnic_open(struct fbnic_net *fbn);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index b5050fabe8fe..87e4eb03d991 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -1116,16 +1116,17 @@ static void fbnic_free_napi_vector(struct fbnic_net *fbn,
 	fbnic_free_irq(fbd, v_idx, nv);
 	page_pool_destroy(nv->page_pool);
 	netif_napi_del(&nv->napi);
-	list_del(&nv->napis);
+	fbn->napi[fbnic_napi_idx(nv)] = NULL;
 	kfree(nv);
 }
 
 void fbnic_free_napi_vectors(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv, *temp;
+	int i;
 
-	list_for_each_entry_safe(nv, temp, &fbn->napis, napis)
-		fbnic_free_napi_vector(fbn, nv);
+	for (i = 0; i < fbn->num_napi; i++)
+		if (fbn->napi[i])
+			fbnic_free_napi_vector(fbn, fbn->napi[i]);
 }
 
 static void fbnic_name_napi_vector(struct fbnic_napi_vector *nv)
@@ -1222,7 +1223,7 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 	nv->v_idx = v_idx;
 
 	/* Tie napi to netdev */
-	list_add(&nv->napis, &fbn->napis);
+	fbn->napi[fbnic_napi_idx(nv)] = nv;
 	netif_napi_add(fbn->netdev, &nv->napi, fbnic_poll);
 
 	/* Record IRQ to NAPI struct */
@@ -1307,7 +1308,7 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 	page_pool_destroy(nv->page_pool);
 napi_del:
 	netif_napi_del(&nv->napi);
-	list_del(&nv->napis);
+	fbn->napi[fbnic_napi_idx(nv)] = NULL;
 	kfree(nv);
 	return err;
 }
@@ -1612,19 +1613,18 @@ static int fbnic_alloc_nv_resources(struct fbnic_net *fbn,
 
 void fbnic_free_resources(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv;
+	int i;
 
-	list_for_each_entry(nv, &fbn->napis, napis)
-		fbnic_free_nv_resources(fbn, nv);
+	for (i = 0; i < fbn->num_napi; i++)
+		fbnic_free_nv_resources(fbn, fbn->napi[i]);
 }
 
 int fbnic_alloc_resources(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv;
-	int err = -ENODEV;
+	int i, err = -ENODEV;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
-		err = fbnic_alloc_nv_resources(fbn, nv);
+	for (i = 0; i < fbn->num_napi; i++) {
+		err = fbnic_alloc_nv_resources(fbn, fbn->napi[i]);
 		if (err)
 			goto free_resources;
 	}
@@ -1632,8 +1632,8 @@ int fbnic_alloc_resources(struct fbnic_net *fbn)
 	return 0;
 
 free_resources:
-	list_for_each_entry_continue_reverse(nv, &fbn->napis, napis)
-		fbnic_free_nv_resources(fbn, nv);
+	while (i--)
+		fbnic_free_nv_resources(fbn, fbn->napi[i]);
 
 	return err;
 }
@@ -1670,33 +1670,34 @@ static void fbnic_disable_rcq(struct fbnic_ring *rxr)
 
 void fbnic_napi_disable(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv;
+	int i;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
-		napi_disable(&nv->napi);
+	for (i = 0; i < fbn->num_napi; i++) {
+		napi_disable(&fbn->napi[i]->napi);
 
-		fbnic_nv_irq_disable(nv);
+		fbnic_nv_irq_disable(fbn->napi[i]);
 	}
 }
 
 void fbnic_disable(struct fbnic_net *fbn)
 {
 	struct fbnic_dev *fbd = fbn->fbd;
-	struct fbnic_napi_vector *nv;
-	int i, j;
+	int i, j, t;
+
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
 		/* Disable Tx queue triads */
-		for (i = 0; i < nv->txt_count; i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (t = 0; t < nv->txt_count; t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_disable_twq0(&qt->sub0);
 			fbnic_disable_tcq(&qt->cmpl);
 		}
 
 		/* Disable Rx queue triads */
-		for (j = 0; j < nv->rxt_count; j++, i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (j = 0; j < nv->rxt_count; j++, t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_disable_bdq(&qt->sub0, &qt->sub1);
 			fbnic_disable_rcq(&qt->cmpl);
@@ -1792,14 +1793,15 @@ int fbnic_wait_all_queues_idle(struct fbnic_dev *fbd, bool may_fail)
 
 void fbnic_flush(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv;
+	int i;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
-		int i, j;
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
+		int j, t;
 
 		/* Flush any processed Tx Queue Triads and drop the rest */
-		for (i = 0; i < nv->txt_count; i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (t = 0; t < nv->txt_count; t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 			struct netdev_queue *tx_queue;
 
 			/* Clean the work queues of unprocessed work */
@@ -1823,8 +1825,8 @@ void fbnic_flush(struct fbnic_net *fbn)
 		}
 
 		/* Flush any processed Rx Queue Triads and drop the rest */
-		for (j = 0; j < nv->rxt_count; j++, i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (j = 0; j < nv->rxt_count; j++, t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			/* Clean the work queues of unprocessed work */
 			fbnic_clean_bdq(nv, 0, &qt->sub0, qt->sub0.tail);
@@ -1845,14 +1847,15 @@ void fbnic_flush(struct fbnic_net *fbn)
 
 void fbnic_fill(struct fbnic_net *fbn)
 {
-	struct fbnic_napi_vector *nv;
+	int i;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
-		int i, j;
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
+		int j, t;
 
 		/* Configure NAPI mapping for Tx */
-		for (i = 0; i < nv->txt_count; i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (t = 0; t < nv->txt_count; t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			/* Nothing to do if Tx queue is disabled */
 			if (qt->sub0.flags & FBNIC_RING_F_DISABLED)
@@ -1866,8 +1869,8 @@ void fbnic_fill(struct fbnic_net *fbn)
 		/* Configure NAPI mapping and populate pages
 		 * in the BDQ rings to use for Rx
 		 */
-		for (j = 0; j < nv->rxt_count; j++, i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (j = 0; j < nv->rxt_count; j++, t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			/* Associate Rx queue with NAPI */
 			netif_queue_set_napi(nv->napi.dev, qt->cmpl.q_idx,
@@ -2025,21 +2028,23 @@ static void fbnic_enable_rcq(struct fbnic_napi_vector *nv,
 void fbnic_enable(struct fbnic_net *fbn)
 {
 	struct fbnic_dev *fbd = fbn->fbd;
-	struct fbnic_napi_vector *nv;
-	int i, j;
+	int i;
+
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
+		int j, t;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
 		/* Setup Tx Queue Triads */
-		for (i = 0; i < nv->txt_count; i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (t = 0; t < nv->txt_count; t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_enable_twq0(&qt->sub0);
 			fbnic_enable_tcq(nv, &qt->cmpl);
 		}
 
 		/* Setup Rx Queue Triads */
-		for (j = 0; j < nv->rxt_count; j++, i++) {
-			struct fbnic_q_triad *qt = &nv->qt[i];
+		for (j = 0; j < nv->rxt_count; j++, t++) {
+			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_enable_bdq(&qt->sub0, &qt->sub1);
 			fbnic_config_drop_mode_rcq(nv, &qt->cmpl);
@@ -2064,10 +2069,11 @@ void fbnic_napi_enable(struct fbnic_net *fbn)
 {
 	u32 irqs[FBNIC_MAX_MSIX_VECS / 32] = {};
 	struct fbnic_dev *fbd = fbn->fbd;
-	struct fbnic_napi_vector *nv;
 	int i;
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
+
 		napi_enable(&nv->napi);
 
 		fbnic_nv_irq_enable(nv);
@@ -2096,17 +2102,18 @@ void fbnic_napi_depletion_check(struct net_device *netdev)
 	struct fbnic_net *fbn = netdev_priv(netdev);
 	u32 irqs[FBNIC_MAX_MSIX_VECS / 32] = {};
 	struct fbnic_dev *fbd = fbn->fbd;
-	struct fbnic_napi_vector *nv;
-	int i, j;
+	int i, j, t;
+
+	for (i = 0; i < fbn->num_napi; i++) {
+		struct fbnic_napi_vector *nv = fbn->napi[i];
 
-	list_for_each_entry(nv, &fbn->napis, napis) {
 		/* Find RQs which are completely out of pages */
-		for (i = nv->txt_count, j = 0; j < nv->rxt_count; j++, i++) {
+		for (t = nv->txt_count, j = 0; j < nv->rxt_count; j++, t++) {
 			/* Assume 4 pages is always enough to fit a packet
 			 * and therefore generate a completion and an IRQ.
 			 */
-			if (fbnic_desc_used(&nv->qt[i].sub0) < 4 ||
-			    fbnic_desc_used(&nv->qt[i].sub1) < 4)
+			if (fbnic_desc_used(&nv->qt[t].sub0) < 4 ||
+			    fbnic_desc_used(&nv->qt[t].sub1) < 4)
 				irqs[nv->v_idx / 32] |= BIT(nv->v_idx % 32);
 		}
 	}
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 8d626287c3f4..1965d1fa38a2 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -110,8 +110,6 @@ struct fbnic_napi_vector {
 	u8 txt_count;
 	u8 rxt_count;
 
-	struct list_head napis;
-
 	struct fbnic_q_triad qt[];
 };
 
@@ -137,4 +135,9 @@ void fbnic_fill(struct fbnic_net *fbn);
 void fbnic_napi_depletion_check(struct net_device *netdev);
 int fbnic_wait_all_queues_idle(struct fbnic_dev *fbd, bool may_fail);
 
+static inline int fbnic_napi_idx(const struct fbnic_napi_vector *nv)
+{
+	return nv->v_idx - FBNIC_NON_NAPI_VECTORS;
+}
+
 #endif /* _FBNIC_TXRX_H_ */
-- 
2.47.1