mlxsw: pci: Utilize MRSR register to perform FW reset

So far, the PCI BAR0 register is used for triggering FW reset. However,
that is a legacy attitude and it is recommended to use MRSR to perform
reset instead. So do that. Move the reset into init() function as
the cmd interface needs to be used. With that, IRQ initialization needs
to be moved as well. As a side effect, the reset move simplifies
the devlink reload flow.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -966,14 +966,12 @@ mlxsw_devlink_sb_occ_tc_port_bind_get(struct devlink_port *devlink_port,
 static int mlxsw_devlink_core_bus_device_reload(struct devlink *devlink)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
-	const struct mlxsw_bus *mlxsw_bus = mlxsw_core->bus;
 	int err;
 
-	if (!mlxsw_bus->reset)
+	if (!(mlxsw_core->bus->features & MLXSW_BUS_F_RESET))
 		return -EOPNOTSUPP;
 
 	mlxsw_core_bus_device_unregister(mlxsw_core, true);
-	mlxsw_bus->reset(mlxsw_core->bus_priv);
 	err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
 					     mlxsw_core->bus,
 					     mlxsw_core->bus_priv, true,

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -337,6 +337,7 @@ u64 mlxsw_core_res_get(struct mlxsw_core *mlxsw_core,
 	mlxsw_core_res_get(mlxsw_core, MLXSW_RES_ID_##short_res_id)
 
 #define MLXSW_BUS_F_TXRX	BIT(0)
+#define MLXSW_BUS_F_RESET	BIT(1)
 
 struct mlxsw_bus {
 	const char *kind;
@@ -344,7 +345,6 @@ struct mlxsw_bus {
 		    const struct mlxsw_config_profile *profile,
 		    struct mlxsw_res *res);
 	void (*fini)(void *bus_priv);
-	void (*reset)(void *bus_priv);
 	bool (*skb_transmit_busy)(void *bus_priv,
 				  const struct mlxsw_tx_info *tx_info);
 	int (*skb_transmit)(void *bus_priv, struct sk_buff *skb,

drivers/net/ethernet/mellanox/mlxsw/pci.c

@@ -1371,6 +1371,51 @@ static void mlxsw_pci_mbox_free(struct mlxsw_pci *mlxsw_pci,
 			    mbox->mapaddr);
 }
 
+static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci,
+			      const struct pci_device_id *id)
+{
+	unsigned long end;
+	char mrsr_pl[MLXSW_REG_MRSR_LEN];
+	int err;
+
+	mlxsw_reg_mrsr_pack(mrsr_pl);
+	err = mlxsw_reg_write(mlxsw_pci->core, MLXSW_REG(mrsr), mrsr_pl);
+	if (err)
+		return err;
+	if (id->device == PCI_DEVICE_ID_MELLANOX_SWITCHX2) {
+		msleep(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
+		return 0;
+	}
+
+	/* We must wait for the HW to become responsive once again. */
+	msleep(MLXSW_PCI_SW_RESET_WAIT_MSECS);
+
+	end = jiffies + msecs_to_jiffies(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
+	do {
+		u32 val = mlxsw_pci_read32(mlxsw_pci, FW_READY);
+
+		if ((val & MLXSW_PCI_FW_READY_MASK) == MLXSW_PCI_FW_READY_MAGIC)
+			break;
+		cond_resched();
+	} while (time_before(jiffies, end));
+	return 0;
+}
+
+static int mlxsw_pci_alloc_irq_vectors(struct mlxsw_pci *mlxsw_pci)
+{
+	int err;
+
+	err = pci_alloc_irq_vectors(mlxsw_pci->pdev, 1, 1, PCI_IRQ_MSIX);
+	if (err < 0)
+		dev_err(&mlxsw_pci->pdev->dev, "MSI-X init failed\n");
+	return err;
+}
+
+static void mlxsw_pci_free_irq_vectors(struct mlxsw_pci *mlxsw_pci)
+{
+	pci_free_irq_vectors(mlxsw_pci->pdev);
+}
+
 static int mlxsw_pci_init(void *bus_priv, struct mlxsw_core *mlxsw_core,
 			  const struct mlxsw_config_profile *profile,
 			  struct mlxsw_res *res)
@@ -1398,6 +1443,16 @@ static int mlxsw_pci_init(void *bus_priv, struct mlxsw_core *mlxsw_core,
 	if (err)
 		goto err_out_mbox_alloc;
 
+	err = mlxsw_pci_sw_reset(mlxsw_pci, mlxsw_pci->id);
+	if (err)
+		goto err_sw_reset;
+
+	err = mlxsw_pci_alloc_irq_vectors(mlxsw_pci);
+	if (err < 0) {
+		dev_err(&pdev->dev, "MSI-X init failed\n");
+		goto err_alloc_irq;
+	}
+
 	err = mlxsw_cmd_query_fw(mlxsw_core, mbox);
 	if (err)
 		goto err_query_fw;
@@ -1481,6 +1536,9 @@ static int mlxsw_pci_init(void *bus_priv, struct mlxsw_core *mlxsw_core,
 err_doorbell_page_bar:
 err_iface_rev:
 err_query_fw:
+	mlxsw_pci_free_irq_vectors(mlxsw_pci);
+err_alloc_irq:
+err_sw_reset:
 	mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.out_mbox);
 err_out_mbox_alloc:
 	mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox);
@@ -1496,6 +1554,7 @@ static void mlxsw_pci_fini(void *bus_priv)
 	free_irq(pci_irq_vector(mlxsw_pci->pdev, 0), mlxsw_pci);
 	mlxsw_pci_aqs_fini(mlxsw_pci);
 	mlxsw_pci_fw_area_fini(mlxsw_pci);
+	mlxsw_pci_free_irq_vectors(mlxsw_pci);
 	mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.out_mbox);
 	mlxsw_pci_mbox_free(mlxsw_pci, &mlxsw_pci->cmd.in_mbox);
 }
@@ -1677,58 +1736,6 @@ static int mlxsw_pci_cmd_exec(void *bus_priv, u16 opcode, u8 opcode_mod,
 	return err;
 }
 
-static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci,
-			      const struct pci_device_id *id)
-{
-	unsigned long end;
-
-	mlxsw_pci_write32(mlxsw_pci, SW_RESET, MLXSW_PCI_SW_RESET_RST_BIT);
-	if (id->device == PCI_DEVICE_ID_MELLANOX_SWITCHX2) {
-		msleep(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
-		return 0;
-	}
-
-	/* Reset needs to be written before we read control register, and
-	 * we must wait for the HW to become responsive once again
-	 */
-	wmb();
-	msleep(MLXSW_PCI_SW_RESET_WAIT_MSECS);
-
-	end = jiffies + msecs_to_jiffies(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
-	do {
-		u32 val = mlxsw_pci_read32(mlxsw_pci, FW_READY);
-
-		if ((val & MLXSW_PCI_FW_READY_MASK) == MLXSW_PCI_FW_READY_MAGIC)
-			break;
-		cond_resched();
-	} while (time_before(jiffies, end));
-	return 0;
-}
-
-static void mlxsw_pci_free_irq_vectors(struct mlxsw_pci *mlxsw_pci)
-{
-	pci_free_irq_vectors(mlxsw_pci->pdev);
-}
-
-static int mlxsw_pci_alloc_irq_vectors(struct mlxsw_pci *mlxsw_pci)
-{
-	int err;
-
-	err = pci_alloc_irq_vectors(mlxsw_pci->pdev, 1, 1, PCI_IRQ_MSIX);
-	if (err < 0)
-		dev_err(&mlxsw_pci->pdev->dev, "MSI-X init failed\n");
-	return err;
-}
-
-static void mlxsw_pci_reset(void *bus_priv)
-{
-	struct mlxsw_pci *mlxsw_pci = bus_priv;
-
-	mlxsw_pci_free_irq_vectors(mlxsw_pci);
-	mlxsw_pci_sw_reset(mlxsw_pci, mlxsw_pci->id);
-	mlxsw_pci_alloc_irq_vectors(mlxsw_pci);
-}
-
 static const struct mlxsw_bus mlxsw_pci_bus = {
 	.kind			= "pci",
 	.init			= mlxsw_pci_init,
@@ -1736,8 +1743,7 @@ static const struct mlxsw_bus mlxsw_pci_bus = {
 	.skb_transmit_busy	= mlxsw_pci_skb_transmit_busy,
 	.skb_transmit		= mlxsw_pci_skb_transmit,
 	.cmd_exec		= mlxsw_pci_cmd_exec,
-	.features		= MLXSW_BUS_F_TXRX,
-	.reset			= mlxsw_pci_reset,
+	.features		= MLXSW_BUS_F_TXRX | MLXSW_BUS_F_RESET,
 };
 
 static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -1795,18 +1801,6 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	mlxsw_pci->pdev = pdev;
 	pci_set_drvdata(pdev, mlxsw_pci);
 
-	err = mlxsw_pci_sw_reset(mlxsw_pci, id);
-	if (err) {
-		dev_err(&pdev->dev, "Software reset failed\n");
-		goto err_sw_reset;
-	}
-
-	err = mlxsw_pci_alloc_irq_vectors(mlxsw_pci);
-	if (err < 0) {
-		dev_err(&pdev->dev, "MSI-X init failed\n");
-		goto err_msix_init;
-	}
-
 	mlxsw_pci->bus_info.device_kind = driver_name;
 	mlxsw_pci->bus_info.device_name = pci_name(mlxsw_pci->pdev);
 	mlxsw_pci->bus_info.dev = &pdev->dev;
@@ -1823,9 +1817,6 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return 0;
 
 err_bus_device_register:
-	mlxsw_pci_free_irq_vectors(mlxsw_pci);
-err_msix_init:
-err_sw_reset:
 	iounmap(mlxsw_pci->hw_addr);
 err_ioremap:
 err_pci_resource_len_check:
@@ -1843,7 +1834,6 @@ static void mlxsw_pci_remove(struct pci_dev *pdev)
 	struct mlxsw_pci *mlxsw_pci = pci_get_drvdata(pdev);
 
 	mlxsw_core_bus_device_unregister(mlxsw_pci->core, false);
-	mlxsw_pci_free_irq_vectors(mlxsw_pci);
 	iounmap(mlxsw_pci->hw_addr);
 	pci_release_regions(mlxsw_pci->pdev);
 	pci_disable_device(mlxsw_pci->pdev);