[PATCH] stmmac: fix memory barriers

From: Pavel Machek
Date: Sun Dec 18 2016 - 15:38:29 EST



Fix up memory barriers in stmmac driver. They are meant to protect
against DMA engine, so smp_ variants are certainly wrong, and dma_
variants are preferable.

Signed-off-by: Pavel Machek <pavel@xxxxxxx>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index a340fc8..8816515 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -334,7 +334,7 @@ static void dwmac4_rd_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
* descriptors for the same frame has to be set before, to
* avoid race condition.
*/
- wmb();
+ dma_wmb();

p->des3 = cpu_to_le32(tdes3);
}
@@ -377,7 +377,7 @@ static void dwmac4_rd_prepare_tso_tx_desc(struct dma_desc *p, int is_fs,
* descriptors for the same frame has to be set before, to
* avoid race condition.
*/
- wmb();
+ dma_wmb();

p->des3 = cpu_to_le32(tdes3);
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
index ce97e52..f0d8632 100644
--- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
@@ -350,7 +350,7 @@ static void enh_desc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
* descriptors for the same frame has to be set before, to
* avoid race condition.
*/
- wmb();
+ dma_wmb();

p->des0 = cpu_to_le32(tdes0);
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3e40578..bb40382 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2125,7 +2125,7 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
* descriptor and then barrier is needed to make sure that
* all is coherent before granting the DMA engine.
*/
- smp_wmb();
+ dma_wmb();

if (netif_msg_pktdata(priv)) {
pr_info("%s: curr=%d dirty=%d f=%d, e=%d, f_p=%p, nfrags %d\n",
@@ -2338,7 +2338,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
* descriptor and then barrier is needed to make sure that
* all is coherent before granting the DMA engine.
*/
- smp_wmb();
+ dma_wmb();
}

netdev_sent_queue(dev, skb->len);
@@ -2443,14 +2443,14 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
netif_dbg(priv, rx_status, priv->dev,
"refill entry #%d\n", entry);
}
- wmb();
+ dma_wmb();

if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00))
priv->hw->desc->init_rx_desc(p, priv->use_riwt, 0, 0);
else
priv->hw->desc->set_rx_owner(p);

- wmb();
+ dma_wmb();

entry = STMMAC_GET_ENTRY(entry, DMA_RX_SIZE);
}

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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