Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 161 insertions, 25 deletions

diff --git a/drivers/net/ethernet/freescale/enetc/Kconfig b/drivers/net/ethernet/freescale/enetc/Kconfig
index 0fa18b00c49b..d99ea0f4e4a6 100644
--- a/drivers/net/ethernet/freescale/enetc/Kconfig
+++ b/drivers/net/ethernet/freescale/enetc/Kconfig
@@ -16,6 +16,7 @@ config FSL_ENETC
 config FSL_ENETC_VF
 	tristate "ENETC VF driver"
 	depends on PCI && PCI_MSI
+	select FSL_ENETC_MDIO
 	select PHYLINK
 	select DIMLIB
 	help
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 01089c30b462..c78d12229730 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -33,7 +33,10 @@ netdev_tx_t enetc_xmit(struct sk_buff *skb, struct net_device *ndev)
 		return NETDEV_TX_BUSY;
 	}
 
+	enetc_lock_mdio();
 	count = enetc_map_tx_buffs(tx_ring, skb, priv->active_offloads);
+	enetc_unlock_mdio();
+
 	if (unlikely(!count))
 		goto drop_packet_err;
 
@@ -199,7 +202,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb,
 	skb_tx_timestamp(skb);
 
 	/* let H/W know BD ring has been updated */
-	enetc_wr_reg(tx_ring->tpir, i); /* includes wmb() */
+	enetc_wr_reg_hot(tx_ring->tpir, i); /* includes wmb() */
 
 	return count;
 
@@ -222,12 +225,16 @@ static irqreturn_t enetc_msix(int irq, void *data)
 	struct enetc_int_vector	*v = data;
 	int i;
 
+	enetc_lock_mdio();
+
 	/* disable interrupts */
-	enetc_wr_reg(v->rbier, 0);
-	enetc_wr_reg(v->ricr1, v->rx_ictt);
+	enetc_wr_reg_hot(v->rbier, 0);
+	enetc_wr_reg_hot(v->ricr1, v->rx_ictt);
 
 	for_each_set_bit(i, &v->tx_rings_map, ENETC_MAX_NUM_TXQS)
-		enetc_wr_reg(v->tbier_base + ENETC_BDR_OFF(i), 0);
+		enetc_wr_reg_hot(v->tbier_base + ENETC_BDR_OFF(i), 0);
+
+	enetc_unlock_mdio();
 
 	napi_schedule(&v->napi);
 
@@ -294,19 +301,23 @@ static int enetc_poll(struct napi_struct *napi, int budget)
 
 	v->rx_napi_work = false;
 
+	enetc_lock_mdio();
+
 	/* enable interrupts */
-	enetc_wr_reg(v->rbier, ENETC_RBIER_RXTIE);
+	enetc_wr_reg_hot(v->rbier, ENETC_RBIER_RXTIE);
 
 	for_each_set_bit(i, &v->tx_rings_map, ENETC_MAX_NUM_TXQS)
-		enetc_wr_reg(v->tbier_base + ENETC_BDR_OFF(i),
-			     ENETC_TBIER_TXTIE);
+		enetc_wr_reg_hot(v->tbier_base + ENETC_BDR_OFF(i),
+				 ENETC_TBIER_TXTIE);
+
+	enetc_unlock_mdio();
 
 	return work_done;
 }
 
 static int enetc_bd_ready_count(struct enetc_bdr *tx_ring, int ci)
 {
-	int pi = enetc_rd_reg(tx_ring->tcir) & ENETC_TBCIR_IDX_MASK;
+	int pi = enetc_rd_reg_hot(tx_ring->tcir) & ENETC_TBCIR_IDX_MASK;
 
 	return pi >= ci ? pi - ci : tx_ring->bd_count - ci + pi;
 }
@@ -346,7 +357,10 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
 
 	i = tx_ring->next_to_clean;
 	tx_swbd = &tx_ring->tx_swbd[i];
+
+	enetc_lock_mdio();
 	bds_to_clean = enetc_bd_ready_count(tx_ring, i);
+	enetc_unlock_mdio();
 
 	do_tstamp = false;
 
@@ -389,16 +403,20 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
 			tx_swbd = tx_ring->tx_swbd;
 		}
 
+		enetc_lock_mdio();
+
 		/* BD iteration loop end */
 		if (is_eof) {
 			tx_frm_cnt++;
 			/* re-arm interrupt source */
-			enetc_wr_reg(tx_ring->idr, BIT(tx_ring->index) |
-				     BIT(16 + tx_ring->index));
+			enetc_wr_reg_hot(tx_ring->idr, BIT(tx_ring->index) |
+					 BIT(16 + tx_ring->index));
 		}
 
 		if (unlikely(!bds_to_clean))
 			bds_to_clean = enetc_bd_ready_count(tx_ring, i);
+
+		enetc_unlock_mdio();
 	}
 
 	tx_ring->next_to_clean = i;
@@ -475,8 +493,6 @@ static int enetc_refill_rx_ring(struct enetc_bdr *rx_ring, const int buff_cnt)
 	if (likely(j)) {
 		rx_ring->next_to_alloc = i; /* keep track from page reuse */
 		rx_ring->next_to_use = i;
-		/* update ENETC's consumer index */
-		enetc_wr_reg(rx_ring->rcir, i);
 	}
 
 	return j;
@@ -494,8 +510,8 @@ static void enetc_get_rx_tstamp(struct net_device *ndev,
 	u64 tstamp;
 
 	if (le16_to_cpu(rxbd->r.flags) & ENETC_RXBD_FLAG_TSTMP) {
-		lo = enetc_rd(hw, ENETC_SICTR0);
-		hi = enetc_rd(hw, ENETC_SICTR1);
+		lo = enetc_rd_reg_hot(hw->reg + ENETC_SICTR0);
+		hi = enetc_rd_reg_hot(hw->reg + ENETC_SICTR1);
 		rxbd = enetc_rxbd_ext(rxbd);
 		tstamp_lo = le32_to_cpu(rxbd->ext.tstamp);
 		if (lo <= tstamp_lo)
@@ -644,23 +660,31 @@ static int enetc_clean_rx_ring(struct enetc_bdr *rx_ring,
 		u32 bd_status;
 		u16 size;
 
+		enetc_lock_mdio();
+
 		if (cleaned_cnt >= ENETC_RXBD_BUNDLE) {
 			int count = enetc_refill_rx_ring(rx_ring, cleaned_cnt);
 
+			/* update ENETC's consumer index */
+			enetc_wr_reg_hot(rx_ring->rcir, rx_ring->next_to_use);
 			cleaned_cnt -= count;
 		}
 
 		rxbd = enetc_rxbd(rx_ring, i);
 		bd_status = le32_to_cpu(rxbd->r.lstatus);
-		if (!bd_status)
+		if (!bd_status) {
+			enetc_unlock_mdio();
 			break;
+		}
 
-		enetc_wr_reg(rx_ring->idr, BIT(rx_ring->index));
+		enetc_wr_reg_hot(rx_ring->idr, BIT(rx_ring->index));
 		dma_rmb(); /* for reading other rxbd fields */
 		size = le16_to_cpu(rxbd->r.buf_len);
 		skb = enetc_map_rx_buff_to_skb(rx_ring, i, size);
-		if (!skb)
+		if (!skb) {
+			enetc_unlock_mdio();
 			break;
+		}
 
 		enetc_get_offloads(rx_ring, rxbd, skb);
 
@@ -672,6 +696,7 @@ static int enetc_clean_rx_ring(struct enetc_bdr *rx_ring,
 
 		if (unlikely(bd_status &
 			     ENETC_RXBD_LSTATUS(ENETC_RXBD_ERR_MASK))) {
+			enetc_unlock_mdio();
 			dev_kfree_skb(skb);
 			while (!(bd_status & ENETC_RXBD_LSTATUS_F)) {
 				dma_rmb();
@@ -711,6 +736,8 @@ static int enetc_clean_rx_ring(struct enetc_bdr *rx_ring,
 
 		enetc_process_skb(rx_ring, skb);
 
+		enetc_unlock_mdio();
+
 		napi_gro_receive(napi, skb);
 
 		rx_frm_cnt++;
@@ -1185,6 +1212,7 @@ static void enetc_setup_rxbdr(struct enetc_hw *hw, struct enetc_bdr *rx_ring)
 	rx_ring->idr = hw->reg + ENETC_SIRXIDR;
 
 	enetc_refill_rx_ring(rx_ring, enetc_bd_unused(rx_ring));
+	enetc_wr(hw, ENETC_SIRXIDR, rx_ring->next_to_use);
 
 	/* enable ring */
 	enetc_rxbdr_wr(hw, idx, ENETC_RBMR, rbmr);
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 68ef4f959982..861bd04638e0 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -324,14 +324,100 @@ struct enetc_hw {
 	void __iomem *global;
 };
 
-/* general register accessors */
-#define enetc_rd_reg(reg)	ioread32((reg))
-#define enetc_wr_reg(reg, val)	iowrite32((val), (reg))
+/* ENETC register accessors */
+
+/* MDIO issue workaround (on LS1028A) -
+ * Due to a hardware issue, an access to MDIO registers
+ * that is concurrent with other ENETC register accesses
+ * may lead to the MDIO access being dropped or corrupted.
+ * To protect the MDIO accesses a readers-writers locking
+ * scheme is used, where the MDIO register accesses are
+ * protected by write locks to insure exclusivity, while
+ * the remaining ENETC registers are accessed under read
+ * locks since they only compete with MDIO accesses.
+ */
+extern rwlock_t enetc_mdio_lock;
+
+/* use this locking primitive only on the fast datapath to
+ * group together multiple non-MDIO register accesses to
+ * minimize the overhead of the lock
+ */
+static inline void enetc_lock_mdio(void)
+{
+	read_lock(&enetc_mdio_lock);
+}
+
+static inline void enetc_unlock_mdio(void)
+{
+	read_unlock(&enetc_mdio_lock);
+}
+
+/* use these accessors only on the fast datapath under
+ * the enetc_lock_mdio() locking primitive to minimize
+ * the overhead of the lock
+ */
+static inline u32 enetc_rd_reg_hot(void __iomem *reg)
+{
+	lockdep_assert_held(&enetc_mdio_lock);
+
+	return ioread32(reg);
+}
+
+static inline void enetc_wr_reg_hot(void __iomem *reg, u32 val)
+{
+	lockdep_assert_held(&enetc_mdio_lock);
+
+	iowrite32(val, reg);
+}
+
+/* internal helpers for the MDIO w/a */
+static inline u32 _enetc_rd_reg_wa(void __iomem *reg)
+{
+	u32 val;
+
+	enetc_lock_mdio();
+	val = ioread32(reg);
+	enetc_unlock_mdio();
+
+	return val;
+}
+
+static inline void _enetc_wr_reg_wa(void __iomem *reg, u32 val)
+{
+	enetc_lock_mdio();
+	iowrite32(val, reg);
+	enetc_unlock_mdio();
+}
+
+static inline u32 _enetc_rd_mdio_reg_wa(void __iomem *reg)
+{
+	unsigned long flags;
+	u32 val;
+
+	write_lock_irqsave(&enetc_mdio_lock, flags);
+	val = ioread32(reg);
+	write_unlock_irqrestore(&enetc_mdio_lock, flags);
+
+	return val;
+}
+
+static inline void _enetc_wr_mdio_reg_wa(void __iomem *reg, u32 val)
+{
+	unsigned long flags;
+
+	write_lock_irqsave(&enetc_mdio_lock, flags);
+	iowrite32(val, reg);
+	write_unlock_irqrestore(&enetc_mdio_lock, flags);
+}
+
 #ifdef ioread64
-#define enetc_rd_reg64(reg)	ioread64((reg))
+static inline u64 _enetc_rd_reg64(void __iomem *reg)
+{
+	return ioread64(reg);
+}
 #else
 /* using this to read out stats on 32b systems */
-static inline u64 enetc_rd_reg64(void __iomem *reg)
+static inline u64 _enetc_rd_reg64(void __iomem *reg)
 {
 	u32 low, high, tmp;
 
@@ -345,12 +431,29 @@ static inline u64 enetc_rd_reg64(void __iomem *reg)
 }
 #endif
 
+static inline u64 _enetc_rd_reg64_wa(void __iomem *reg)
+{
+	u64 val;
+
+	enetc_lock_mdio();
+	val = _enetc_rd_reg64(reg);
+	enetc_unlock_mdio();
+
+	return val;
+}
+
+/* general register accessors */
+#define enetc_rd_reg(reg)		_enetc_rd_reg_wa((reg))
+#define enetc_wr_reg(reg, val)		_enetc_wr_reg_wa((reg), (val))
 #define enetc_rd(hw, off)		enetc_rd_reg((hw)->reg + (off))
 #define enetc_wr(hw, off, val)		enetc_wr_reg((hw)->reg + (off), val)
-#define enetc_rd64(hw, off)		enetc_rd_reg64((hw)->reg + (off))
+#define enetc_rd64(hw, off)		_enetc_rd_reg64_wa((hw)->reg + (off))
 /* port register accessors - PF only */
 #define enetc_port_rd(hw, off)		enetc_rd_reg((hw)->port + (off))
 #define enetc_port_wr(hw, off, val)	enetc_wr_reg((hw)->port + (off), val)
+#define enetc_port_rd_mdio(hw, off)	_enetc_rd_mdio_reg_wa((hw)->port + (off))
+#define enetc_port_wr_mdio(hw, off, val)	_enetc_wr_mdio_reg_wa(\
+							(hw)->port + (off), val)
 /* global register accessors - PF only */
 #define enetc_global_rd(hw, off)	enetc_rd_reg((hw)->global + (off))
 #define enetc_global_wr(hw, off, val)	enetc_wr_reg((hw)->global + (off), val)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
index 48c32a171afa..ee0116ed4738 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
@@ -16,13 +16,13 @@
 
 static inline u32 _enetc_mdio_rd(struct enetc_mdio_priv *mdio_priv, int off)
 {
-	return enetc_port_rd(mdio_priv->hw, mdio_priv->mdio_base + off);
+	return enetc_port_rd_mdio(mdio_priv->hw, mdio_priv->mdio_base + off);
 }
 
 static inline void _enetc_mdio_wr(struct enetc_mdio_priv *mdio_priv, int off,
 				  u32 val)
 {
-	enetc_port_wr(mdio_priv->hw, mdio_priv->mdio_base + off, val);
+	enetc_port_wr_mdio(mdio_priv->hw, mdio_priv->mdio_base + off, val);
 }
 
 #define enetc_mdio_rd(mdio_priv, off) \
@@ -174,3 +174,7 @@ struct enetc_hw *enetc_hw_alloc(struct device *dev, void __iomem *port_regs)
 	return hw;
 }
 EXPORT_SYMBOL_GPL(enetc_hw_alloc);
+
+/* Lock for MDIO access errata on LS1028A */
+DEFINE_RWLOCK(enetc_mdio_lock);
+EXPORT_SYMBOL_GPL(enetc_mdio_lock);