[PATCH net-next v5 05/19] net: stmmac: embed struct stmmac_est in stmmac_priv struct

[James Hilliard <james.hilliard1@gmail.com>]

From: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>

This is a preliminary change to fix EST reconfiguration in the open
and resume paths: the taprio offload must be re-applied after the DMA
soft reset clears the MTL_EST registers, but the current layout makes
that fragile.
priv->est is currently a pointer allocated with devm_kzalloc() on the
first taprio REPLACE, and the mutex guarding it (priv->est_lock) is
initialized at the same time. That ties the lock's validity to whether
taprio has ever been configured, so the EST parameters can not be
read under the lock (e.g. to check priv->est->enable in the open and
resume paths) before the first offload setup.
Embed struct stmmac_est into struct stmmac_priv and initialize the mutex
in probe(). This makes the code simpler (no logical changes added).
Moreover, the lock is now unconditionally valid, so the enable flag can
be inspected under the lock from any control path.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h      |  2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 17 +++----
 drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c  | 22 ++++----
 drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c   | 61 ++++++++++-------------
 4 files changed, 45 insertions(+), 57 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 83c30b39f704..c65d95fc4760 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -300,7 +300,7 @@ struct stmmac_priv {
 	struct plat_stmmacenet_data *plat;
 	/* Protect est parameters */
 	struct mutex est_lock;
-	struct stmmac_est *est;
+	struct stmmac_est est;
 	struct dma_features dma_cap;
 	struct stmmac_counters mmc;
 	int hw_cap_support;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 894de213b92f..b233105cb449 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2745,9 +2745,8 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
 		if (!xsk_tx_peek_desc(pool, &xdp_desc))
 			break;
 
-		if (priv->est && priv->est->enable &&
-		    priv->est->max_sdu[queue] &&
-		    xdp_desc.len > priv->est->max_sdu[queue]) {
+		if (priv->est.enable && priv->est.max_sdu[queue] &&
+		    xdp_desc.len > priv->est.max_sdu[queue]) {
 			priv->xstats.max_sdu_txq_drop[queue]++;
 			continue;
 		}
@@ -4843,13 +4842,12 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (skb_is_gso(skb))
 		return stmmac_tso_xmit(skb, dev);
 
-	if (priv->est && priv->est->enable &&
-	    priv->est->max_sdu[queue]) {
+	if (priv->est.enable && priv->est.max_sdu[queue]) {
 		sdu_len = skb->len;
 		/* Add VLAN tag length if VLAN tag insertion offload is requested */
 		if (priv->dma_cap.vlins && skb_vlan_tag_present(skb))
 			sdu_len += VLAN_HLEN;
-		if (sdu_len > priv->est->max_sdu[queue]) {
+		if (sdu_len > priv->est.max_sdu[queue]) {
 			priv->xstats.max_sdu_txq_drop[queue]++;
 			goto max_sdu_err;
 		}
@@ -5253,9 +5251,8 @@ static int stmmac_xdp_xmit_xdpf(struct stmmac_priv *priv, int queue,
 	if (stmmac_tx_avail(priv, queue) < STMMAC_TX_THRESH(priv))
 		return STMMAC_XDP_CONSUMED;
 
-	if (priv->est && priv->est->enable &&
-	    priv->est->max_sdu[queue] &&
-	    xdpf->len > priv->est->max_sdu[queue]) {
+	if (priv->est.enable && priv->est.max_sdu[queue] &&
+	    xdpf->len > priv->est.max_sdu[queue]) {
 		priv->xstats.max_sdu_txq_drop[queue]++;
 		return STMMAC_XDP_CONSUMED;
 	}
@@ -8106,6 +8103,7 @@ static int __stmmac_dvr_probe(struct device *device,
 	stmmac_napi_add(ndev);
 
 	mutex_init(&priv->lock);
+	mutex_init(&priv->est_lock);
 	rwlock_init(&priv->ptp_lock);
 
 	stmmac_fpe_init(priv);
@@ -8238,6 +8236,7 @@ void stmmac_dvr_remove(struct device *dev)
 	stmmac_mdio_unregister(ndev);
 
 	destroy_workqueue(priv->wq);
+	mutex_destroy(&priv->est_lock);
 	mutex_destroy(&priv->lock);
 	bitmap_free(priv->af_xdp_zc_qps);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index 3bfcc9760dce..2a4099fe470c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -69,11 +69,11 @@ static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
 	nsec = reminder;
 
 	/* If EST is enabled, disabled it before adjust ptp time. */
-	if (priv->est && priv->est->enable) {
+	if (priv->est.enable) {
 		est_rst = true;
 		mutex_lock(&priv->est_lock);
-		priv->est->enable = false;
-		stmmac_est_configure(priv, priv, priv->est,
+		priv->est.enable = false;
+		stmmac_est_configure(priv, priv, &priv->est,
 				     priv->plat->clk_ptp_rate);
 		mutex_unlock(&priv->est_lock);
 	}
@@ -91,19 +91,19 @@ static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
 		mutex_lock(&priv->est_lock);
 		priv->ptp_clock_ops.gettime64(&priv->ptp_clock_ops, &current_time);
 		current_time_ns = timespec64_to_ktime(current_time);
-		time.tv_nsec = priv->est->btr_reserve[0];
-		time.tv_sec = priv->est->btr_reserve[1];
+		time.tv_nsec = priv->est.btr_reserve[0];
+		time.tv_sec = priv->est.btr_reserve[1];
 		basetime = timespec64_to_ktime(time);
-		cycle_time = (u64)priv->est->ctr[1] * NSEC_PER_SEC +
-			     priv->est->ctr[0];
+		cycle_time = (u64)priv->est.ctr[1] * NSEC_PER_SEC +
+			     priv->est.ctr[0];
 		time = stmmac_calc_tas_basetime(basetime,
 						current_time_ns,
 						cycle_time);
 
-		priv->est->btr[0] = (u32)time.tv_nsec;
-		priv->est->btr[1] = (u32)time.tv_sec;
-		priv->est->enable = true;
-		ret = stmmac_est_configure(priv, priv, priv->est,
+		priv->est.btr[0] = (u32)time.tv_nsec;
+		priv->est.btr[1] = (u32)time.tv_sec;
+		priv->est.enable = true;
+		ret = stmmac_est_configure(priv, priv, &priv->est,
 					   priv->plat->clk_ptp_rate);
 		mutex_unlock(&priv->est_lock);
 		if (ret)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 42a00446e9b4..357d1eaf0d7d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -959,7 +959,7 @@ static void tc_taprio_map_maxsdu_txq(struct stmmac_priv *priv,
 		count = qopt->mqprio.qopt.count[i];
 
 		for (j = offset; j < offset + count; j++)
-			priv->est->max_sdu[j] = qopt->max_sdu[i] + ETH_HLEN - ETH_TLEN;
+			priv->est.max_sdu[j] = qopt->max_sdu[i] + ETH_HLEN - ETH_TLEN;
 	}
 }
 
@@ -1023,24 +1023,15 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
 	if (qopt->cycle_time_extension >= BIT(wid + 7))
 		return -ERANGE;
 
-	if (!priv->est) {
-		priv->est = devm_kzalloc(priv->device, sizeof(*priv->est),
-					 GFP_KERNEL);
-		if (!priv->est)
-			return -ENOMEM;
-
-		mutex_init(&priv->est_lock);
-	} else {
-		mutex_lock(&priv->est_lock);
-		memset(priv->est, 0, sizeof(*priv->est));
-		mutex_unlock(&priv->est_lock);
-	}
+	mutex_lock(&priv->est_lock);
+	memset(&priv->est, 0, sizeof(priv->est));
+	mutex_unlock(&priv->est_lock);
 
 	size = qopt->num_entries;
 
 	mutex_lock(&priv->est_lock);
-	priv->est->gcl_size = size;
-	priv->est->enable = qopt->cmd == TAPRIO_CMD_REPLACE;
+	priv->est.gcl_size = size;
+	priv->est.enable = qopt->cmd == TAPRIO_CMD_REPLACE;
 	mutex_unlock(&priv->est_lock);
 
 	for (i = 0; i < size; i++) {
@@ -1065,7 +1056,7 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
 			return -EOPNOTSUPP;
 		}
 
-		priv->est->gcl[i] = delta_ns | (gates << wid);
+		priv->est.gcl[i] = delta_ns | (gates << wid);
 	}
 
 	mutex_lock(&priv->est_lock);
@@ -1075,22 +1066,22 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
 	time = stmmac_calc_tas_basetime(qopt->base_time, current_time_ns,
 					qopt->cycle_time);
 
-	priv->est->btr[0] = (u32)time.tv_nsec;
-	priv->est->btr[1] = (u32)time.tv_sec;
+	priv->est.btr[0] = (u32)time.tv_nsec;
+	priv->est.btr[1] = (u32)time.tv_sec;
 
 	qopt_time = ktime_to_timespec64(qopt->base_time);
-	priv->est->btr_reserve[0] = (u32)qopt_time.tv_nsec;
-	priv->est->btr_reserve[1] = (u32)qopt_time.tv_sec;
+	priv->est.btr_reserve[0] = (u32)qopt_time.tv_nsec;
+	priv->est.btr_reserve[1] = (u32)qopt_time.tv_sec;
 
 	ctr = qopt->cycle_time;
-	priv->est->ctr[0] = do_div(ctr, NSEC_PER_SEC);
-	priv->est->ctr[1] = (u32)ctr;
+	priv->est.ctr[0] = do_div(ctr, NSEC_PER_SEC);
+	priv->est.ctr[1] = (u32)ctr;
 
-	priv->est->ter = qopt->cycle_time_extension;
+	priv->est.ter = qopt->cycle_time_extension;
 
 	tc_taprio_map_maxsdu_txq(priv, qopt);
 
-	ret = stmmac_est_configure(priv, priv, priv->est,
+	ret = stmmac_est_configure(priv, priv, &priv->est,
 				   priv->plat->clk_ptp_rate);
 	mutex_unlock(&priv->est_lock);
 	if (ret) {
@@ -1106,19 +1097,17 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
 	return 0;
 
 disable:
-	if (priv->est) {
-		mutex_lock(&priv->est_lock);
-		priv->est->enable = false;
-		stmmac_est_configure(priv, priv, priv->est,
-				     priv->plat->clk_ptp_rate);
-		/* Reset taprio status */
-		for (i = 0; i < priv->plat->tx_queues_to_use; i++) {
-			priv->xstats.max_sdu_txq_drop[i] = 0;
-			priv->xstats.mtl_est_txq_hlbf[i] = 0;
-			priv->xstats.mtl_est_txq_hlbs[i] = 0;
-		}
-		mutex_unlock(&priv->est_lock);
+	mutex_lock(&priv->est_lock);
+	priv->est.enable = false;
+	stmmac_est_configure(priv, priv, &priv->est,
+			     priv->plat->clk_ptp_rate);
+	/* Reset taprio status */
+	for (i = 0; i < priv->plat->tx_queues_to_use; i++) {
+		priv->xstats.max_sdu_txq_drop[i] = 0;
+		priv->xstats.mtl_est_txq_hlbf[i] = 0;
+		priv->xstats.mtl_est_txq_hlbs[i] = 0;
 	}
+	mutex_unlock(&priv->est_lock);
 
 	err = stmmac_fpe_map_preemption_class(priv, priv->dev, extack, 0);
 

-- 
2.53.0