p2sb: Move P2SB hide and unhide code to p2sb_scan_and_cache()

To prepare for the following fix, move the code to hide and unhide the
P2SB device from p2sb_cache_resources() to p2sb_scan_and_cache().

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241128002836.373745-4-shinichiro.kawasaki@wdc.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: kawasaki

drivers/platform/x86/p2sb.c

@@ -98,13 +98,25 @@ static void p2sb_scan_and_cache_devfn(struct pci_bus *bus, unsigned int devfn)
 
 static int p2sb_scan_and_cache(struct pci_bus *bus, unsigned int devfn)
 {
+	/*
+	 * The BIOS prevents the P2SB device from being enumerated by the PCI
+	 * subsystem, so we need to unhide and hide it back to lookup the BAR.
+	 * Unhide the P2SB device here, if needed.
+	 */
+	if (p2sb_hidden_by_bios)
+		pci_bus_write_config_dword(bus, devfn, P2SBC, 0);
+
 	/* Scan the P2SB device and cache its BAR0 */
 	p2sb_scan_and_cache_devfn(bus, devfn);
 
 	/* On Goldmont p2sb_bar() also gets called for the SPI controller */
 	if (devfn == P2SB_DEVFN_GOLDMONT)
 		p2sb_scan_and_cache_devfn(bus, SPI_DEVFN_GOLDMONT);
 
+	/* Hide the P2SB device, if it was hidden */
+	if (p2sb_hidden_by_bios)
+		pci_bus_write_config_dword(bus, devfn, P2SBC, P2SBC_HIDE);
+
 	if (!p2sb_valid_resource(&p2sb_resources[PCI_FUNC(devfn)].res))
 		return -ENOENT;
 
@@ -153,22 +165,11 @@ static int p2sb_cache_resources(void)
 	 */
 	pci_lock_rescan_remove();
 
-	/*
-	 * The BIOS prevents the P2SB device from being enumerated by the PCI
-	 * subsystem, so we need to unhide and hide it back to lookup the BAR.
-	 * Unhide the P2SB device here, if needed.
-	 */
 	pci_bus_read_config_dword(bus, devfn_p2sb, P2SBC, &value);
 	p2sb_hidden_by_bios = value & P2SBC_HIDE;
-	if (p2sb_hidden_by_bios)
-		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, 0);
 
 	ret = p2sb_scan_and_cache(bus, devfn_p2sb);
 
-	/* Hide the P2SB device, if it was hidden */
-	if (p2sb_hidden_by_bios)
-		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, P2SBC_HIDE);
-
 	pci_unlock_rescan_remove();
 
 	return ret;