PCI: Bring the PCIe speed to MBps logic to new pcie_dev_speed_mbps()

Bring the switch case in pcie_link_speed_mbps() to new function to
the header file so that it can be used in other places like
in controller driver.

Link: https://lore.kernel.org/linux-pci/20240619-opp_support-v15-3-aa769a2173a3@quicinc.com
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: Krishna chaitanya chundru

drivers/pci/pci.c

@@ -6020,24 +6020,7 @@ int pcie_link_speed_mbps(struct pci_dev *pdev)
 	if (err)
 		return err;
 
-	switch (to_pcie_link_speed(lnksta)) {
-	case PCIE_SPEED_2_5GT:
-		return 2500;
-	case PCIE_SPEED_5_0GT:
-		return 5000;
-	case PCIE_SPEED_8_0GT:
-		return 8000;
-	case PCIE_SPEED_16_0GT:
-		return 16000;
-	case PCIE_SPEED_32_0GT:
-		return 32000;
-	case PCIE_SPEED_64_0GT:
-		return 64000;
-	default:
-		break;
-	}
-
-	return -EINVAL;
+	return pcie_dev_speed_mbps(to_pcie_link_speed(lnksta));
 }
 EXPORT_SYMBOL(pcie_link_speed_mbps);
 

drivers/pci/pci.h

@@ -290,6 +290,28 @@ void pci_bus_put(struct pci_bus *bus);
 	 (speed) == PCIE_SPEED_2_5GT  ?  2500*8/10 : \
 	 0)
 
+static inline int pcie_dev_speed_mbps(enum pci_bus_speed speed)
+{
+	switch (speed) {
+	case PCIE_SPEED_2_5GT:
+		return 2500;
+	case PCIE_SPEED_5_0GT:
+		return 5000;
+	case PCIE_SPEED_8_0GT:
+		return 8000;
+	case PCIE_SPEED_16_0GT:
+		return 16000;
+	case PCIE_SPEED_32_0GT:
+		return 32000;
+	case PCIE_SPEED_64_0GT:
+		return 64000;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
 const char *pci_speed_string(enum pci_bus_speed speed);
 enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev);
 enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev);