PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers

Currently, dw_pcie_ep_init_registers() API is directly called by the glue
drivers requiring active refclk from host. But for the other drivers, it is
getting called implicitly by dw_pcie_ep_init(). This is due to the fact
that this API initializes DWC EP specific registers and that requires an
active refclk (either from host or generated locally by endpoint itsef).

But, this causes a discrepancy among the glue drivers. So to avoid this
confusion, let's call this API directly from all glue drivers irrespective
of refclk dependency. Only difference here is that the drivers requiring
refclk from host will call this API only after the refclk is received and
other drivers without refclk dependency will call this API right after
dw_pcie_ep_init().

With this change, the check for 'core_init_notifier' flag can now be
dropped from dw_pcie_ep_init() API. This will also allow us to remove the
'core_init_notifier' flag completely in the later commits.

Link: https://lore.kernel.org/linux-pci/20240327-pci-dbi-rework-v12-7-082625472414@linaro.orgSigned-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

drivers/pci/controller/dwc/pci-dra7xx.c

@@ -467,6 +467,13 @@ static int dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
 		return ret;
 	}
 
+	ret = dw_pcie_ep_init_registers(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(ep);
+		return ret;
+	}
+
 	return 0;
 }
 

drivers/pci/controller/dwc/pci-imx6.c

@@ -1123,6 +1123,14 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
 		dev_err(dev, "failed to initialize endpoint\n");
 		return ret;
 	}
+
+	ret = dw_pcie_ep_init_registers(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(ep);
+		return ret;
+	}
+
 	/* Start LTSSM. */
 	imx6_pcie_ltssm_enable(dev);
 

drivers/pci/controller/dwc/pci-keystone.c

@@ -1286,6 +1286,13 @@ static int ks_pcie_probe(struct platform_device *pdev)
 		ret = dw_pcie_ep_init(&pci->ep);
 		if (ret < 0)
 			goto err_get_sync;
+
+		ret = dw_pcie_ep_init_registers(&pci->ep);
+		if (ret) {
+			dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+			goto err_ep_init;
+		}
+
 		break;
 	default:
 		dev_err(dev, "INVALID device type %d\n", mode);
@@ -1295,6 +1302,8 @@ static int ks_pcie_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_ep_init:
+	dw_pcie_ep_deinit(&pci->ep);
 err_get_sync:
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);

drivers/pci/controller/dwc/pci-layerscape-ep.c

@@ -279,6 +279,13 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = dw_pcie_ep_init_registers(&pci->ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(&pci->ep);
+		return ret;
+	}
+
 	return ls_pcie_ep_interrupt_init(pcie, pdev);
 }
 

drivers/pci/controller/dwc/pcie-artpec6.c

@@ -441,7 +441,18 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
 
 		pci->ep.ops = &pcie_ep_ops;
 
-		return dw_pcie_ep_init(&pci->ep);
+		ret = dw_pcie_ep_init(&pci->ep);
+		if (ret)
+			return ret;
+
+		ret = dw_pcie_ep_init_registers(&pci->ep);
+		if (ret) {
+			dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+			dw_pcie_ep_deinit(&pci->ep);
+			return ret;
+		}
+
+		break;
 	default:
 		dev_err(dev, "INVALID device type %d\n", artpec6_pcie->mode);
 	}

drivers/pci/controller/dwc/pcie-designware-ep.c

@@ -821,7 +821,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	struct device *dev = pci->dev;
 	struct platform_device *pdev = to_platform_device(dev);
 	struct device_node *np = dev->of_node;
-	const struct pci_epc_features *epc_features;
 
 	INIT_LIST_HEAD(&ep->func_list);
 
@@ -867,29 +866,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		goto err_exit_epc_mem;
 	}
 
-	if (ep->ops->get_features) {
-		epc_features = ep->ops->get_features(ep);
-		if (epc_features->core_init_notifier)
-			return 0;
-	}
-
-	/*
-	 * NOTE:- Avoid accessing the hardware (Ex:- DBI space) before this
-	 * step as platforms that implement 'core_init_notifier' feature may
-	 * not have the hardware ready (i.e. core initialized) for access
-	 * (Ex: tegra194). Any hardware access on such platforms result
-	 * in system hang.
-	 */
-	ret = dw_pcie_ep_init_registers(ep);
-	if (ret)
-		goto err_free_epc_mem;
-
 	return 0;
 
-err_free_epc_mem:
-	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
-			      epc->mem->window.page_size);
-
 err_exit_epc_mem:
 	pci_epc_mem_exit(epc);
 

drivers/pci/controller/dwc/pcie-designware-plat.c

@@ -145,6 +145,15 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
 
 		pci->ep.ops = &pcie_ep_ops;
 		ret = dw_pcie_ep_init(&pci->ep);
+		if (ret)
+			return ret;
+
+		ret = dw_pcie_ep_init_registers(&pci->ep);
+		if (ret) {
+			dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+			dw_pcie_ep_deinit(&pci->ep);
+		}
+
 		break;
 	default:
 		dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);

drivers/pci/controller/dwc/pcie-keembay.c

@@ -396,6 +396,7 @@ static int keembay_pcie_probe(struct platform_device *pdev)
 	struct keembay_pcie *pcie;
 	struct dw_pcie *pci;
 	enum dw_pcie_device_mode mode;
+	int ret;
 
 	data = device_get_match_data(dev);
 	if (!data)
@@ -430,11 +431,24 @@ static int keembay_pcie_probe(struct platform_device *pdev)
 			return -ENODEV;
 
 		pci->ep.ops = &keembay_pcie_ep_ops;
-		return dw_pcie_ep_init(&pci->ep);
+		ret = dw_pcie_ep_init(&pci->ep);
+		if (ret)
+			return ret;
+
+		ret = dw_pcie_ep_init_registers(&pci->ep);
+		if (ret) {
+			dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+			dw_pcie_ep_deinit(&pci->ep);
+			return ret;
+		}
+
+		break;
 	default:
 		dev_err(dev, "Invalid device type %d\n", pcie->mode);
 		return -ENODEV;
 	}
+
+	return 0;
 }
 
 static const struct keembay_pcie_of_data keembay_pcie_rc_of_data = {

drivers/pci/controller/dwc/pcie-rcar-gen4.c

@@ -416,6 +416,7 @@ static const struct dw_pcie_ep_ops pcie_ep_ops = {
 static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 {
 	struct dw_pcie_ep *ep = &rcar->dw.ep;
+	struct device *dev = rcar->dw.dev;
 	int ret;
 
 	if (!IS_ENABLED(CONFIG_PCIE_RCAR_GEN4_EP))
@@ -424,8 +425,17 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 	ep->ops = &pcie_ep_ops;
 
 	ret = dw_pcie_ep_init(ep);
-	if (ret)
+	if (ret) {
 		rcar_gen4_pcie_ep_deinit(rcar);
+		return ret;
+	}
+
+	ret = dw_pcie_ep_init_registers(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(ep);
+		rcar_gen4_pcie_ep_deinit(rcar);
+	}
 
 	return ret;
 }

drivers/pci/controller/dwc/pcie-uniphier-ep.c

@@ -399,7 +399,18 @@ static int uniphier_pcie_ep_probe(struct platform_device *pdev)
 		return ret;
 
 	priv->pci.ep.ops = &uniphier_pcie_ep_ops;
-	return dw_pcie_ep_init(&priv->pci.ep);
+	ret = dw_pcie_ep_init(&priv->pci.ep);
+	if (ret)
+		return ret;
+
+	ret = dw_pcie_ep_init_registers(&priv->pci.ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(&priv->pci.ep);
+		return ret;
+	}
+
+	return 0;
 }
 
 static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {