net: ll_temac: Support indirect_mutex share within TEMAC IP

Indirect register access goes through a DCR bus bridge, which
allows only one outstanding transaction.  And to make matters
worse, each TEMAC IP block contains two Ethernet interfaces, and
although they seem to have separate registers for indirect access,
they actually share the registers.  Or to be more specific, MSW, LSW
and CTL registers are physically shared between Ethernet interfaces
in same TEMAC IP, with RDY register being (almost) specificic to
the Ethernet interface.  The 0x10000 bit in RDY reflects combined
bus ready state though.

So we need to take care to synchronize not only within a single
device, but also between devices in same TEMAC IP.

This commit allows to do that with legacy platform devices.

For OF devices, the xlnx,compound parent of the temac node should be
used to find siblings, and setup a shared indirect_mutex between them.
I will leave this work to somebody else, as I don't have hardware to
test that.  No regression is introduced by that, as before this commit
using two Ethernet interfaces in same TEMAC block is simply broken.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 11 deletions

diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 179a9984bc64..d3899e7efd45 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -344,7 +344,7 @@ static void temac_do_set_mac_address(struct net_device *ndev)
 	struct temac_local *lp = netdev_priv(ndev);
 
 	/* set up unicast MAC address filter set its mac address */
-	mutex_lock(&lp->indirect_mutex);
+	mutex_lock(lp->indirect_mutex);
 	temac_indirect_out32(lp, XTE_UAW0_OFFSET,
 			     (ndev->dev_addr[0]) |
 			     (ndev->dev_addr[1] << 8) |
@@ -355,7 +355,7 @@ static void temac_do_set_mac_address(struct net_device *ndev)
 	temac_indirect_out32(lp, XTE_UAW1_OFFSET,
 			     (ndev->dev_addr[4] & 0x000000ff) |
 			     (ndev->dev_addr[5] << 8));
-	mutex_unlock(&lp->indirect_mutex);
+	mutex_unlock(lp->indirect_mutex);
 }
 
 static int temac_init_mac_address(struct net_device *ndev, const void *address)
@@ -384,7 +384,7 @@ static void temac_set_multicast_list(struct net_device *ndev)
 	u32 multi_addr_msw, multi_addr_lsw, val;
 	int i;
 
-	mutex_lock(&lp->indirect_mutex);
+	mutex_lock(lp->indirect_mutex);
 	if (ndev->flags & (IFF_ALLMULTI | IFF_PROMISC) ||
 	    netdev_mc_count(ndev) > MULTICAST_CAM_TABLE_NUM) {
 		/*
@@ -423,7 +423,7 @@ static void temac_set_multicast_list(struct net_device *ndev)
 		temac_indirect_out32(lp, XTE_MAW1_OFFSET, 0);
 		dev_info(&ndev->dev, "Promiscuous mode disabled.\n");
 	}
-	mutex_unlock(&lp->indirect_mutex);
+	mutex_unlock(lp->indirect_mutex);
 }
 
 static struct temac_option {
@@ -515,7 +515,7 @@ static u32 temac_setoptions(struct net_device *ndev, u32 options)
 	struct temac_option *tp = &temac_options[0];
 	int reg;
 
-	mutex_lock(&lp->indirect_mutex);
+	mutex_lock(lp->indirect_mutex);
 	while (tp->opt) {
 		reg = temac_indirect_in32(lp, tp->reg) & ~tp->m_or;
 		if (options & tp->opt)
@@ -524,7 +524,7 @@ static u32 temac_setoptions(struct net_device *ndev, u32 options)
 		tp++;
 	}
 	lp->options |= options;
-	mutex_unlock(&lp->indirect_mutex);
+	mutex_unlock(lp->indirect_mutex);
 
 	return 0;
 }
@@ -543,7 +543,7 @@ static void temac_device_reset(struct net_device *ndev)
 
 	dev_dbg(&ndev->dev, "%s()\n", __func__);
 
-	mutex_lock(&lp->indirect_mutex);
+	mutex_lock(lp->indirect_mutex);
 	/* Reset the receiver and wait for it to finish reset */
 	temac_indirect_out32(lp, XTE_RXC1_OFFSET, XTE_RXC1_RXRST_MASK);
 	timeout = 1000;
@@ -595,7 +595,7 @@ static void temac_device_reset(struct net_device *ndev)
 	temac_indirect_out32(lp, XTE_TXC_OFFSET, 0);
 	temac_indirect_out32(lp, XTE_FCC_OFFSET, XTE_FCC_RXFLO_MASK);
 
-	mutex_unlock(&lp->indirect_mutex);
+	mutex_unlock(lp->indirect_mutex);
 
 	/* Sync default options with HW
 	 * but leave receiver and transmitter disabled.  */
@@ -623,7 +623,7 @@ static void temac_adjust_link(struct net_device *ndev)
 	/* hash together the state values to decide if something has changed */
 	link_state = phy->speed | (phy->duplex << 1) | phy->link;
 
-	mutex_lock(&lp->indirect_mutex);
+	mutex_lock(lp->indirect_mutex);
 	if (lp->last_link != link_state) {
 		mii_speed = temac_indirect_in32(lp, XTE_EMCFG_OFFSET);
 		mii_speed &= ~XTE_EMCFG_LINKSPD_MASK;
@@ -639,7 +639,7 @@ static void temac_adjust_link(struct net_device *ndev)
 		lp->last_link = link_state;
 		phy_print_status(phy);
 	}
-	mutex_unlock(&lp->indirect_mutex);
+	mutex_unlock(lp->indirect_mutex);
 }
 
 #ifdef CONFIG_64BIT
@@ -1091,7 +1091,21 @@ static int temac_probe(struct platform_device *pdev)
 	lp->dev = &pdev->dev;
 	lp->options = XTE_OPTION_DEFAULTS;
 	spin_lock_init(&lp->rx_lock);
-	mutex_init(&lp->indirect_mutex);
+
+	/* Setup mutex for synchronization of indirect register access */
+	if (pdata) {
+		if (!pdata->indirect_mutex) {
+			dev_err(&pdev->dev,
+				"indirect_mutex missing in platform_data\n");
+			return -EINVAL;
+		}
+		lp->indirect_mutex = pdata->indirect_mutex;
+	} else {
+		lp->indirect_mutex = devm_kmalloc(&pdev->dev,
+						  sizeof(*lp->indirect_mutex),
+						  GFP_KERNEL);
+		mutex_init(lp->indirect_mutex);
+	}
 
 	/* map device registers */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);