ata: pata_sil680: fix result type of sil680_sel{dev|reg}()

sil680_sel{dev|reg}() return a PCI config space address but needlessly
use the *unsigned long* type for that, whereas the PCI config space
accessors take *int* for the address parameter. Switch these functions
to returning *int*, updating the local variables at their call sites.
Get rid of the 'base' local variables in these functions, while at it...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Signed-off-by: Sergey Shtylyov <[e-mail]>
Signed-off-by: Damien Le Moal <[e-mail]>

drivers/ata/pata_sil680.c

···
  *	criticial.
  */
 
-static unsigned long sil680_selreg(struct ata_port *ap, int r)
+static int sil680_selreg(struct ata_port *ap, int r)
 {
-	unsigned long base = 0xA0 + r;
-	base += (ap->port_no << 4);
-	return base;
+	return 0xA0 + (ap->port_no << 4) + r;
 }
 
 /**
···
  *	the unit shift.
  */
 
-static unsigned long sil680_seldev(struct ata_port *ap, struct ata_device *adev, int r)
+static int sil680_seldev(struct ata_port *ap, struct ata_device *adev, int r)
 {
-	unsigned long base = 0xA0 + r;
-	base += (ap->port_no << 4);
-	base |= adev->devno ? 2 : 0;
-	return base;
+	return 0xA0 + (ap->port_no << 4) + r + (adev->devno << 1);
 }
 
 
···
 static int sil680_cable_detect(struct ata_port *ap)
 {
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned long addr = sil680_selreg(ap, 0);
+	int addr = sil680_selreg(ap, 0);
 	u8 ata66;
+
 	pci_read_config_byte(pdev, addr, &ata66);
 	if (ata66 & 1)
 		return ATA_CBL_PATA80;
···
 		0x328A, 0x2283, 0x1281, 0x10C3, 0x10C1
 	};
 
-	unsigned long tfaddr = sil680_selreg(ap, 0x02);
-	unsigned long addr = sil680_seldev(ap, adev, 0x04);
-	unsigned long addr_mask = 0x80 + 4 * ap->port_no;
+	int tfaddr = sil680_selreg(ap, 0x02);
+	int addr = sil680_seldev(ap, adev, 0x04);
+	int addr_mask = 0x80 + 4 * ap->port_no;
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 	int pio = adev->pio_mode - XFER_PIO_0;
 	int lowest_pio = pio;
···
 	static const u16 dma_table[3] = { 0x2208, 0x10C2, 0x10C1 };
 
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned long ma = sil680_seldev(ap, adev, 0x08);
-	unsigned long ua = sil680_seldev(ap, adev, 0x0C);
-	unsigned long addr_mask = 0x80 + 4 * ap->port_no;
+	int ma = sil680_seldev(ap, adev, 0x08);
+	int ua = sil680_seldev(ap, adev, 0x0C);
+	int addr_mask = 0x80 + 4 * ap->port_no;
 	int port_shift = adev->devno * 4;
 	u8 scsc, mode;
 	u16 multi, ultra;
···
 static bool sil680_sff_irq_check(struct ata_port *ap)
 {
 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
-	unsigned long addr	= sil680_selreg(ap, 1);
+	int addr		= sil680_selreg(ap, 1);
 	u8 val;
 
 	pci_read_config_byte(pdev, addr, &val);