PCI: aardvark: Deduplicate code in advk_pcie_rd_conf()

Avoid code repetition in advk_pcie_rd_conf() by handling errors with
goto jump, as is customary in kernel.

Link: https://lore.kernel.org/r/20211005180952.6812-9-kabel@kernel.org
Fixes: 43f5c77b ("PCI: aardvark: Fix reporting CRS value")
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/pci-aardvark.c

@@ -920,18 +920,8 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 		    (le16_to_cpu(pcie->bridge.pcie_conf.rootctl) &
 		     PCI_EXP_RTCTL_CRSSVE);
 
-	if (advk_pcie_pio_is_running(pcie)) {
-		/*
-		 * If it is possible return Completion Retry Status so caller
-		 * tries to issue the request again instead of failing.
-		 */
-		if (allow_crs) {
-			*val = CFG_RD_CRS_VAL;
-			return PCIBIOS_SUCCESSFUL;
-		}
-		*val = 0xffffffff;
-		return PCIBIOS_SET_FAILED;
-	}
+	if (advk_pcie_pio_is_running(pcie))
+		goto try_crs;
 
 	/* Program the control register */
 	reg = advk_readl(pcie, PIO_CTRL);
@@ -955,25 +945,13 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 	advk_writel(pcie, 1, PIO_START);
 
 	ret = advk_pcie_wait_pio(pcie);
-	if (ret < 0) {
-		/*
-		 * If it is possible return Completion Retry Status so caller
-		 * tries to issue the request again instead of failing.
-		 */
-		if (allow_crs) {
-			*val = CFG_RD_CRS_VAL;
-			return PCIBIOS_SUCCESSFUL;
-		}
-		*val = 0xffffffff;
-		return PCIBIOS_SET_FAILED;
-	}
+	if (ret < 0)
+		goto try_crs;
 
 	/* Check PIO status and get the read result */
 	ret = advk_pcie_check_pio_status(pcie, allow_crs, val);
-	if (ret < 0) {
-		*val = 0xffffffff;
-		return PCIBIOS_SET_FAILED;
-	}
+	if (ret < 0)
+		goto fail;
 
 	if (size == 1)
 		*val = (*val >> (8 * (where & 3))) & 0xff;
@@ -981,6 +959,20 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
 		*val = (*val >> (8 * (where & 3))) & 0xffff;
 
 	return PCIBIOS_SUCCESSFUL;
+
+try_crs:
+	/*
+	 * If it is possible, return Completion Retry Status so that caller
+	 * tries to issue the request again instead of failing.
+	 */
+	if (allow_crs) {
+		*val = CFG_RD_CRS_VAL;
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+fail:
+	*val = 0xffffffff;
+	return PCIBIOS_SET_FAILED;
 }
 
 static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,