of: net: pass the dst buffer to of_get_mac_address()

of_get_mac_address() returns a "const void*" pointer to a MAC address.
Lately, support to fetch the MAC address by an NVMEM provider was added.
But this will only work with platform devices. It will not work with
PCI devices (e.g. of an integrated root complex) and esp. not with DSA
ports.

There is an of_* variant of the nvmem binding which works without
devices. The returned data of a nvmem_cell_read() has to be freed after
use. On the other hand the return of_get_mac_address() points to some
static data without a lifetime. The trick for now, was to allocate a
device resource managed buffer which is then returned. This will only
work if we have an actual device.

Change it, so that the caller of of_get_mac_address() has to supply a
buffer where the MAC address is written to. Unfortunately, this will
touch all drivers which use the of_get_mac_address().

Usually the code looks like:

  const char *addr;
  addr = of_get_mac_address(np);
  if (!IS_ERR(addr))
    ether_addr_copy(ndev->dev_addr, addr);

This can then be simply rewritten as:

  of_get_mac_address(np, ndev->dev_addr);

Sometimes is_valid_ether_addr() is used to test the MAC address.
of_get_mac_address() already makes sure, it just returns a valid MAC
address. Thus we can just test its return code. But we have to be
careful if there are still other sources for the MAC address before the
of_get_mac_address(). In this case we have to keep the
is_valid_ether_addr() call.

The following coccinelle patch was used to convert common cases to the
new style. Afterwards, I've manually gone over the drivers and fixed the
return code variable: either used a new one or if one was already
available use that. Mansour Moufid, thanks for that coccinelle patch!

<spml>
@a@
identifier x;
expression y, z;
@@
- x = of_get_mac_address(y);
+ x = of_get_mac_address(y, z);
  <...
- ether_addr_copy(z, x);
  ...>

@@
identifier a.x;
@@
- if (<+... x ...+>) {}

@@
identifier a.x;
@@
  if (<+... x ...+>) {
      ...
  }
- else {}

@@
identifier a.x;
expression e;
@@
- if (<+... x ...+>@e)
-     {}
- else
+ if (!(e))
      {...}

@@
expression x, y, z;
@@
- x = of_get_mac_address(y, z);
+ of_get_mac_address(y, z);
  ... when != x
</spml>

All drivers, except drivers/net/ethernet/aeroflex/greth.c, were
compile-time tested.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

23 files changed, 29 insertions, 29 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-anarion.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-anarion.c
index 08c76636c164..dfbaea06d108 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-anarion.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-anarion.c
@@ -115,7 +115,7 @@ static int anarion_dwmac_probe(struct platform_device *pdev)
 	if (IS_ERR(gmac))
 		return PTR_ERR(gmac);
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
index 27254b27d7ed..bc91fd867dcd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
@@ -438,7 +438,7 @@ static int dwc_eth_dwmac_probe(struct platform_device *pdev)
 	if (IS_ERR(stmmac_res.addr))
 		return PTR_ERR(stmmac_res.addr);
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-generic.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-generic.c
index fad503820e04..fbfda55b4c52 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-generic.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-generic.c
@@ -27,7 +27,7 @@ static int dwmac_generic_probe(struct platform_device *pdev)
 		return ret;
 
 	if (pdev->dev.of_node) {
-		plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+		plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 		if (IS_ERR(plat_dat)) {
 			dev_err(&pdev->dev, "dt configuration failed\n");
 			return PTR_ERR(plat_dat);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
index c1a361305a5a..84651207a1de 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
@@ -231,7 +231,7 @@ static int imx_dwmac_probe(struct platform_device *pdev)
 	if (!dwmac)
 		return -ENOMEM;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
index 6c19fcc76c6f..06d287f104be 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
@@ -85,7 +85,7 @@ static int intel_eth_plat_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat)) {
 		dev_err(&pdev->dev, "dt configuration failed\n");
 		return PTR_ERR(plat_dat);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
index 749585fe6fc9..28dd0ed85a82 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -255,7 +255,7 @@ static int ipq806x_gmac_probe(struct platform_device *pdev)
 	if (val)
 		return val;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-lpc18xx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-lpc18xx.c
index 3d3f43d91b98..9d77c647badd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-lpc18xx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-lpc18xx.c
@@ -37,7 +37,7 @@ static int lpc18xx_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
index 9e4b83832938..58c0feaa8131 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -407,7 +407,7 @@ static int mediatek_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson.c
index bbc16b5a410a..16fb66a0ca72 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson.c
@@ -52,7 +52,7 @@ static int meson6_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
index 848e5c37746b..c7a6588d9398 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
@@ -398,7 +398,7 @@ static int meson8b_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
index 8551ea878ba5..adfeb8d3293d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
@@ -118,7 +118,7 @@ static int oxnas_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index a674b7d6b49a..84382fc5cc4d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
@@ -461,7 +461,7 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat)) {
 		dev_err(&pdev->dev, "dt configuration failed\n");
 		return PTR_ERR(plat_dat);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
index 6ef30252bfe0..8d28a536e1bb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
@@ -1396,7 +1396,7 @@ static int rk_gmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 70d41783329d..85208128f135 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -398,7 +398,7 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
index e1b63df6f96f..710d7435733e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
@@ -325,7 +325,7 @@ static int sti_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index 5d4df4c5254e..2b38a499a404 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -371,7 +371,7 @@ static int stm32_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 19e7ec30af4c..4422baeed3d8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -1221,7 +1221,7 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return -EINVAL;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sunxi.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sunxi.c
index 0e1ca2cba3c7..527077c98ebc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sunxi.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sunxi.c
@@ -108,7 +108,7 @@ static int sun7i_gmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
index d23be45a64e5..d046e33b8a29 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
@@ -208,7 +208,7 @@ static int visconti_eth_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
 	if (IS_ERR(plat_dat))
 		return PTR_ERR(plat_dat);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index c49debb62b05..8b4ff9c189a1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -26,7 +26,7 @@
 
 struct stmmac_resources {
 	void __iomem *addr;
-	const char *mac;
+	u8 mac[ETH_ALEN];
 	int wol_irq;
 	int lpi_irq;
 	int irq;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 77285646c5fc..328aeb2cd276 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6016,7 +6016,7 @@ int stmmac_dvr_probe(struct device *device,
 	for (i = 0; i < MTL_MAX_TX_QUEUES; i++)
 		priv->tx_irq[i] = res->tx_irq[i];
 
-	if (!IS_ERR_OR_NULL(res->mac))
+	if (!is_zero_ether_addr(res->mac))
 		memcpy(priv->dev->dev_addr, res->mac, ETH_ALEN);
 
 	dev_set_drvdata(device, priv->dev);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 5a1e018884e6..1e17a23d9118 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -394,7 +394,7 @@ static int stmmac_of_get_mac_mode(struct device_node *np)
  * set some private fields that will be used by the main at runtime.
  */
 struct plat_stmmacenet_data *
-stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
+stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct plat_stmmacenet_data *plat;
@@ -406,12 +406,12 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	if (!plat)
 		return ERR_PTR(-ENOMEM);
 
-	*mac = of_get_mac_address(np);
-	if (IS_ERR(*mac)) {
-		if (PTR_ERR(*mac) == -EPROBE_DEFER)
-			return ERR_CAST(*mac);
+	rc = of_get_mac_address(np, mac);
+	if (rc) {
+		if (rc == -EPROBE_DEFER)
+			return ERR_PTR(rc);
 
-		*mac = NULL;
+		eth_zero_addr(mac);
 	}
 
 	plat->phy_interface = device_get_phy_mode(&pdev->dev);
@@ -627,7 +627,7 @@ void stmmac_remove_config_dt(struct platform_device *pdev,
 }
 #else
 struct plat_stmmacenet_data *
-stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
+stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 {
 	return ERR_PTR(-EINVAL);
 }
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h
index 3a4663b7b460..3fff3f59d73d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h
@@ -12,7 +12,7 @@
 #include "stmmac.h"
 
 struct plat_stmmacenet_data *
-stmmac_probe_config_dt(struct platform_device *pdev, const char **mac);
+stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac);
 void stmmac_remove_config_dt(struct platform_device *pdev,
 			     struct plat_stmmacenet_data *plat);