PCI: dwc: ep: Remove deinit() callback from struct dw_pcie_ep_ops

deinit() callback was solely introduced for the pcie-rcar-gen4 driver where
it is used to do platform specific resource deallocation. And this callback
is called right at the end of the dw_pcie_ep_exit() API. So it doesn't
matter whether it is called within or outside of dw_pcie_ep_exit() API.

So let's remove this callback and directly call rcar_gen4_pcie_ep_deinit()
in pcie-rcar-gen4 driver to do resource deallocation after the completion
of dw_pcie_ep_exit() API in rcar_gen4_remove_dw_pcie_ep().

This simplifies the DWC layer.

Link: https://lore.kernel.org/linux-pci/20240327-pci-dbi-rework-v12-3-082625472414@linaro.org
Signed-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>

Author: Mani-Sadhasivam

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

@@ -637,9 +637,6 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 			      epc->mem->window.page_size);
 
 	pci_epc_mem_exit(epc);
-
-	if (ep->ops->deinit)
-		ep->ops->deinit(ep);
 }
 EXPORT_SYMBOL_GPL(dw_pcie_ep_exit);
 
@@ -844,7 +841,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 			       ep->page_size);
 	if (ret < 0) {
 		dev_err(dev, "Failed to initialize address space\n");
-		goto err_ep_deinit;
+		return ret;
 	}
 
 	ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
@@ -881,10 +878,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 err_exit_epc_mem:
 	pci_epc_mem_exit(epc);
 
-err_ep_deinit:
-	if (ep->ops->deinit)
-		ep->ops->deinit(ep);
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dw_pcie_ep_init);

drivers/pci/controller/dwc/pcie-designware.h

@@ -333,7 +333,6 @@ struct dw_pcie_rp {
 struct dw_pcie_ep_ops {
 	void	(*pre_init)(struct dw_pcie_ep *ep);
 	void	(*init)(struct dw_pcie_ep *ep);
-	void	(*deinit)(struct dw_pcie_ep *ep);
 	int	(*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
 			     unsigned int type, u16 interrupt_num);
 	const struct pci_epc_features* (*get_features)(struct dw_pcie_ep *ep);

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

@@ -352,11 +352,8 @@ static void rcar_gen4_pcie_ep_init(struct dw_pcie_ep *ep)
 		dw_pcie_ep_reset_bar(pci, bar);
 }
 
-static void rcar_gen4_pcie_ep_deinit(struct dw_pcie_ep *ep)
+static void rcar_gen4_pcie_ep_deinit(struct rcar_gen4_pcie *rcar)
 {
-	struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
-	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
-
 	writel(0, rcar->base + PCIEDMAINTSTSEN);
 	rcar_gen4_pcie_common_deinit(rcar);
 }
@@ -410,7 +407,6 @@ static unsigned int rcar_gen4_pcie_ep_get_dbi2_offset(struct dw_pcie_ep *ep,
 static const struct dw_pcie_ep_ops pcie_ep_ops = {
 	.pre_init = rcar_gen4_pcie_ep_pre_init,
 	.init = rcar_gen4_pcie_ep_init,
-	.deinit = rcar_gen4_pcie_ep_deinit,
 	.raise_irq = rcar_gen4_pcie_ep_raise_irq,
 	.get_features = rcar_gen4_pcie_ep_get_features,
 	.get_dbi_offset = rcar_gen4_pcie_ep_get_dbi_offset,
@@ -420,18 +416,24 @@ 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;
+	int ret;
 
 	if (!IS_ENABLED(CONFIG_PCIE_RCAR_GEN4_EP))
 		return -ENODEV;
 
 	ep->ops = &pcie_ep_ops;
 
-	return dw_pcie_ep_init(ep);
+	ret = dw_pcie_ep_init(ep);
+	if (ret)
+		rcar_gen4_pcie_ep_deinit(rcar);
+
+	return ret;
 }
 
 static void rcar_gen4_remove_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 {
 	dw_pcie_ep_exit(&rcar->dw.ep);
+	rcar_gen4_pcie_ep_deinit(rcar);
 }
 
 /* Common */