PPC32: Modify openpic_get_irq() to call i8259_irq() for cascaded IRQs. This

requires that i8259_init() be called with the real address where PCI
interrupt-acknowledge transactions will be generated.

arch/ppc/kernel/i8259.c

@@ -171,6 +171,10 @@ static struct resource pic_edgectrl_iores = {
 	"8259 edge control", 0x4d0, 0x4d1, IORESOURCE_BUSY
 };
 
+/* i8259_init()
+ * intack_addr - PCI interrupt acknowledge (real) address which will return
+ *               the active irq from the 8259
+ */
 void __init i8259_init(long intack_addr)
 {
 	unsigned long flags;
@@ -205,6 +209,9 @@ void __init i8259_init(long intack_addr)
 	request_resource(&ioport_resource, &pic2_iores);
 	request_resource(&ioport_resource, &pic_edgectrl_iores);
 
-	if (intack_addr)
-		pci_intack = ioremap(intack_addr, 1);
+	/* XXX remove me after board maintainers fix their i8259_init calls */
+	if (intack_addr == 0)
+		panic("You must supply a PCI interrupt acknowledge address to i8259_init()\n");
+
+	pci_intack = ioremap(intack_addr, 1);
 }

arch/ppc/kernel/open_pic.c

@@ -46,7 +46,6 @@ extern int use_of_interrupt_tree;
 static u_int NumProcessors;
 static u_int NumSources;
 static int open_pic_irq_offset;
-static volatile unsigned char *chrp_int_ack_special;
 static volatile OpenPIC_Source *ISR[NR_IRQS];
 
 /* Global Operations */
@@ -303,8 +302,7 @@ void openpic_set_sources(int first_irq, int num_irqs, void *first_ISR)
 		ISR[i] = src;
 }
 
-void __init openpic_init(int main_pic, int offset, unsigned char *chrp_ack,
-			 int programmer_switch_irq)
+void __init openpic_init(int main_pic, int offset, int programmer_switch_irq)
 {
 	u_int t, i;
 	u_int timerfreq;
@@ -357,7 +355,6 @@ void __init openpic_init(int main_pic, int offset, unsigned char *chrp_ack,
 		return;
 
 	open_pic_irq_offset = offset;
-	chrp_int_ack_special = chrp_ack;
 
 	/* Initialize timer interrupts */
 	if ( ppc_md.progress ) ppc_md.progress("openpic timer",0x3ba);
@@ -814,19 +811,13 @@ openpic_get_irq(struct pt_regs *regs)
 	/* Management of the cascade should be moved out of here */
 
 	/* Yep - because openpic !=> i8259, for one thing. -VAL */
-        if (open_pic_irq_offset && irq == open_pic_irq_offset)
-        {
-                /*
-                 * This magic address generates a PCI IACK cycle.
-                 */
-		if ( chrp_int_ack_special )
-			irq = *chrp_int_ack_special;
+	if (open_pic_irq_offset && irq == open_pic_irq_offset)
+	{
 #ifndef CONFIG_GEMINI
-		else
-			irq = i8259_poll();
+		irq = i8259_irq(regs); /* get IRQ from cascade */
 #endif
 		openpic_eoi();
-        }
+	}
 	if (irq == OPENPIC_VEC_SPURIOUS + open_pic_irq_offset)
 		irq = -1;
 	return irq;

arch/ppc/platforms/chrp_setup.c

@@ -386,7 +386,7 @@ void __init chrp_init_IRQ(void)
 {
 	struct device_node *np;
 	int i;
-	unsigned char* chrp_int_ack_special = 0;
+	unsigned long chrp_int_ack;
 	unsigned char init_senses[NR_IRQS - NUM_8259_INTERRUPTS];
 	int nmi_irq = -1;
 #if defined(CONFIG_VT) && defined(CONFIG_ADB_KEYBOARD) && defined(XMON)	
@@ -396,14 +396,14 @@ void __init chrp_init_IRQ(void)
 	for (np = find_devices("pci"); np != NULL; np = np->next) {
 		unsigned int *addrp = (unsigned int *)
 			get_property(np, "8259-interrupt-acknowledge", NULL);
+
 		if (addrp == NULL)
 			continue;
-		chrp_int_ack_special = (unsigned char *)
-			ioremap(addrp[prom_n_addr_cells(np)-1], 1);
+		chrp_int_ack = addrp[prom_n_addr_cells(np)-1];
 		break;
 	}
 	if (np == NULL)
-		printk("Cannot find pci to get ack address\n");
+		printk(KERN_ERR "Cannot find PCI interrupt acknowledge address\n");
 
 	chrp_find_openpic();
 
@@ -411,11 +411,11 @@ void __init chrp_init_IRQ(void)
 	OpenPIC_InitSenses = init_senses;
 	OpenPIC_NumInitSenses = NR_IRQS - NUM_8259_INTERRUPTS;
 
-	openpic_init(1, NUM_8259_INTERRUPTS, chrp_int_ack_special, nmi_irq);
+	openpic_init(1, NUM_8259_INTERRUPTS, nmi_irq);
 
 	for (i = 0; i < NUM_8259_INTERRUPTS; i++)
 		irq_desc[i].handler = &i8259_pic;
-	i8259_init(0);
+	i8259_init(chrp_int_ack);
 
 #if defined(CONFIG_VT) && defined(CONFIG_ADB_KEYBOARD) && defined(XMON)
 	/* see if there is a keyboard in the device tree

arch/ppc/platforms/lopec_setup.c

@@ -217,13 +217,17 @@ lopec_init_IRQ(void)
 	/* Skip reserved space and map Message Unit Interrupt (I2O) */
 	openpic_set_sources(19, 1, OpenPIC_Addr + 0x110C0);
 
-	openpic_init(1, NUM_8259_INTERRUPTS, NULL, -1);
+	openpic_init(1, NUM_8259_INTERRUPTS, -1);
 
 	/* Map i8259 interrupts */
 	for(i = 0; i < NUM_8259_INTERRUPTS; i++)
 		irq_desc[i].handler = &i8259_pic;
 
-	i8259_init(0);
+	/*
+	 * The EPIC allows for a read in the range of 0xFEF00000 ->
+	 * 0xFEFFFFFF to generate a PCI interrupt-acknowledge transaction.
+	 */
+	i8259_init(0xfef00000);
 }
 
 void __init

arch/ppc/platforms/pmac_pic.c

@@ -373,7 +373,7 @@ pmac_pic_init(void)
 			ppc_md.get_irq = openpic_get_irq;
 			OpenPIC_Addr = ioremap(irqctrler->addrs[0].address,
 					       irqctrler->addrs[0].size);
-			openpic_init(1, 0, 0, nmi_irq);
+			openpic_init(1, 0, nmi_irq);
 #ifdef CONFIG_XMON
 			if (nmi_irq >= 0)
 				request_irq(nmi_irq, xmon_irq, 0,

arch/ppc/platforms/prep_setup.c

@@ -691,7 +691,7 @@ prep_init_IRQ(void)
 	int i;
 
 	if (OpenPIC_Addr != NULL)
-		openpic_init(1, NUM_8259_INTERRUPTS, 0, -1);
+		openpic_init(1, NUM_8259_INTERRUPTS, -1);
 	for ( i = 0 ; i < NUM_8259_INTERRUPTS ; i++ )
 		irq_desc[i].handler = &i8259_pic;
 	i8259_init(0xbffffff0); /* PCI interrupt ack address for MPC105 and 106 */

include/asm-ppc/open_pic.h

@@ -55,7 +55,7 @@ extern void* OpenPIC_Addr;
 
 /* Exported functions */
 extern void openpic_set_sources(int first_irq, int num_irqs, void *isr);
-extern void openpic_init(int, int, unsigned char *, int);
+extern void openpic_init(int, int, int);
 extern u_int openpic_irq(void);
 extern void openpic_eoi(void);
 extern void openpic_request_IPIs(void);