[PATCH] More SiS interrupt routing

It turns out that the SiS irq routing logic doesn't go by chipset
after all - it's just that some pirq entries are "legacy" numbers,
while others are raw offsets into PCI config space (and the legacy
numbers are more commonly used with the older chipsets, which
explains the correlations).

This simplifies the router code substantially.

arch/i386/pci/irq.c

@@ -327,152 +327,30 @@ static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
 #define PIRQ_SIS_IRQ_DISABLE	0x80
 #define PIRQ_SIS_USB_ENABLE	0x40
 
-/* return value:
- * -1 on error
- * 0 for PCI INTA-INTD
- * 0 or enable bit mask to check or set for onchip functions
- */
-static inline int pirq_sis5595_onchip(int pirq, int *reg)
-{
-	int ret = -1;
-
-	*reg = pirq;
-	switch(pirq) {
-	case 0x01:
-	case 0x02:
-	case 0x03:
-	case 0x04:
-		*reg += 0x40;
-	case 0x41:
-	case 0x42:
-	case 0x43:
-	case 0x44:
-		ret = 0;
-		break;
-
-	case 0x62:
-		ret = PIRQ_SIS_USB_ENABLE;	/* documented for 5595 */
-		break;
-
-	case 0x61:
-	case 0x6a:
-	case 0x7e:
-		printk(KERN_INFO "SiS pirq: IDE/ACPI/DAQ mapping not implemented: (%u)\n",
-		       (unsigned) pirq);
-		/* fall thru */
-	default:
-		printk(KERN_INFO "SiS router unknown request: (%u)\n",
-		       (unsigned) pirq);
-		break;
-	}
-	return ret;
-}		
-
-/* return value:
- * -1 on error
- * 0 for PCI INTA-INTD
- * 0 or enable bit mask to check or set for onchip functions
- */
-static inline int pirq_sis96x_onchip(int pirq, int *reg)
-{
-	int ret = -1;
-
-	*reg = pirq;
-	switch(pirq) {
-	case 0x01:
-	case 0x02:
-	case 0x03:
-	case 0x04:
-		*reg += 0x40;
-	case 0x41:
-	case 0x42:
-	case 0x43:
-	case 0x44:
-	case 0x60:
-	case 0x61:
-	case 0x62:
-	case 0x63:
-		ret = 0;
-		break;
-
-	default:
-		printk(KERN_INFO "SiS router unknown request: (%u)\n",
-		       (unsigned) pirq);
-		break;
-	}
-	return ret;
-}		
-
-
-static int pirq_sis5595_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
+static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
 	u8 x;
-	int reg, check;
-
-	check = pirq_sis5595_onchip(pirq, &reg);
-	if (check < 0)
-		return 0;
+	int reg;
 
+	reg = pirq;
+	if (reg >= 0x01 && reg <= 0x04)
+		reg += 0x40;
 	pci_read_config_byte(router, reg, &x);
-	if (check != 0  &&  !(x & check))
-		return 0;
-
 	return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
 }
 
-static int pirq_sis96x_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
+static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
 {
 	u8 x;
-	int reg, check;
-
-	check = pirq_sis96x_onchip(pirq, &reg);
-	if (check < 0)
-		return 0;
+	int reg;
 
+	reg = pirq;
+	if (reg >= 0x01 && reg <= 0x04)
+		reg += 0x40;
 	pci_read_config_byte(router, reg, &x);
-	if (check != 0  &&  !(x & check))
-		return 0;
-
-	return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
-}
-
-static int pirq_sis5595_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
-{
-	u8 x;
-	int reg, set;
-
-	set = pirq_sis5595_onchip(pirq, &reg);
-	if (set < 0)
-		return 0;
-
-	x = (irq & PIRQ_SIS_IRQ_MASK);
-	if (x == 0)
-		x = PIRQ_SIS_IRQ_DISABLE;
-	else
-		x |= set;
-
-	pci_write_config_byte(router, reg, x);
-
-	return 1;
-}
-
-static int pirq_sis96x_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
-{
-	u8 x;
-	int reg, set;
-
-	set = pirq_sis96x_onchip(pirq, &reg);
-	if (set < 0)
-		return 0;
-
-	x = (irq & PIRQ_SIS_IRQ_MASK);
-	if (x == 0)
-		x = PIRQ_SIS_IRQ_DISABLE;
-	else
-		x |= set;
-
+	x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
+	x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
 	pci_write_config_byte(router, reg, x);
-
 	return 1;
 }
 
@@ -657,26 +535,11 @@ static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router,
 	if (device != PCI_DEVICE_ID_SI_503)
 		return 0;
 		
-	/*
-	 * In case of SiS south bridge, we need to detect the two
-	 * kinds of routing tables we have seen so far (5595 and 96x). 
-	 *
-	 * The 96x tends to still come with routing tables that claim
-	 * to be 503's.. Silly thing. Check the actual router chip.
-	 */
-	if ((router->device & 0xfff0) == 0x0960) {
-		r->name = "SIS96x";
-		r->get = pirq_sis96x_get;
-		r->set = pirq_sis96x_set;
-		DBG("PCI: Detecting SiS router at %02x:%02x : SiS096x detected\n",
-		    rt->rtr_bus, rt->rtr_devfn);
-	} else {
-		r->name = "SIS5595";
-		r->get = pirq_sis5595_get;
-		r->set = pirq_sis5595_set;
-		DBG("PCI: Detecting SiS router at %02x:%02x : SiS5595 detected\n",
+	r->name = "SIS";
+	r->get = pirq_sis_get;
+	r->set = pirq_sis_set;
+	DBG("PCI: Detecting SiS router at %02x:%02x\n",
 	    rt->rtr_bus, rt->rtr_devfn);
-	}
 	return 1;
 }