net: dsa: ocelot: consistently use devres in felix_pci_probe()

Russell King suggested that felix_vsc9959, seville_vsc9953 and
ocelot_ext have a large portion of duplicated init and teardown code,
which could be made common [1]. The teardown code could even be
simplified away if we made use of devres, something which is used here
and there in the felix driver, just not very consistently.

[1] https://lore.kernel.org/all/Zh1GvcOTXqb7CpQt@shell.armlinux.org.uk/

Prepare the ground in the felix_vsc9959 driver, by allocating the data
structures using devres and deleting the kfree() calls. This also
deletes the "Failed to allocate ..." message, since memory allocation
errors are extremely loud anyway, and it's hard to miss them.
Suggested-by: "Russell King (Oracle)" <linux@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/ocelot/felix_vsc9959.c

@@ -2663,6 +2663,7 @@ static irqreturn_t felix_irq_handler(int irq, void *data)
 static int felix_pci_probe(struct pci_dev *pdev,
 			   const struct pci_device_id *id)
 {
+	struct device *dev = &pdev->dev;
 	struct dsa_switch *ds;
 	struct ocelot *ocelot;
 	struct felix *felix;
@@ -2670,45 +2671,43 @@ static int felix_pci_probe(struct pci_dev *pdev,
 
 	err = pci_enable_device(pdev);
 	if (err) {
-		dev_err(&pdev->dev, "device enable failed\n");
-		goto err_pci_enable;
+		dev_err(dev, "device enable failed: %pe\n", ERR_PTR(err));
+		return err;
 	}
 
-	felix = kzalloc(sizeof(struct felix), GFP_KERNEL);
+	felix = devm_kzalloc(dev, sizeof(struct felix), GFP_KERNEL);
 	if (!felix) {
 		err = -ENOMEM;
-		dev_err(&pdev->dev, "Failed to allocate driver memory\n");
-		goto err_alloc_felix;
+		goto out_disable;
 	}
 
 	pci_set_drvdata(pdev, felix);
 	ocelot = &felix->ocelot;
-	ocelot->dev = &pdev->dev;
+	ocelot->dev = dev;
 	ocelot->num_flooding_pgids = OCELOT_NUM_TC;
 	felix->info = &felix_info_vsc9959;
 	felix->switch_base = pci_resource_start(pdev, VSC9959_SWITCH_PCI_BAR);
 
 	pci_set_master(pdev);
 
-	err = devm_request_threaded_irq(&pdev->dev, pdev->irq, NULL,
+	err = devm_request_threaded_irq(dev, pdev->irq, NULL,
 					&felix_irq_handler, IRQF_ONESHOT,
 					"felix-intb", ocelot);
 	if (err) {
-		dev_err(&pdev->dev, "Failed to request irq\n");
-		goto err_alloc_irq;
+		dev_err(dev, "Failed to request irq: %pe\n", ERR_PTR(err));
+		goto out_disable;
 	}
 
 	ocelot->ptp = 1;
 	ocelot->mm_supported = true;
 
-	ds = kzalloc(sizeof(struct dsa_switch), GFP_KERNEL);
+	ds = devm_kzalloc(dev, sizeof(struct dsa_switch), GFP_KERNEL);
 	if (!ds) {
 		err = -ENOMEM;
-		dev_err(&pdev->dev, "Failed to allocate DSA switch\n");
-		goto err_alloc_ds;
+		goto out_disable;
 	}
 
-	ds->dev = &pdev->dev;
+	ds->dev = dev;
 	ds->num_ports = felix->info->num_ports;
 	ds->num_tx_queues = felix->info->num_tx_queues;
 	ds->ops = &felix_switch_ops;
@@ -2719,20 +2718,14 @@ static int felix_pci_probe(struct pci_dev *pdev,
 
 	err = dsa_register_switch(ds);
 	if (err) {
-		dev_err_probe(&pdev->dev, err, "Failed to register DSA switch\n");
-		goto err_register_ds;
+		dev_err_probe(dev, err, "Failed to register DSA switch\n");
+		goto out_disable;
 	}
 
 	return 0;
 
-err_register_ds:
-	kfree(ds);
-err_alloc_ds:
-err_alloc_irq:
-	kfree(felix);
-err_alloc_felix:
+out_disable:
 	pci_disable_device(pdev);
-err_pci_enable:
 	return err;
 }
 
@@ -2745,9 +2738,6 @@ static void felix_pci_remove(struct pci_dev *pdev)
 
 	dsa_unregister_switch(felix->ds);
 
-	kfree(felix->ds);
-	kfree(felix);
-
 	pci_disable_device(pdev);
 }