powerpc: Fix interrupt-tree parsing

The interrupt-tree parsing code wasn't offsetting interrupt numbers
by 16 on 32-bit platforms with an i8259 interrupt controller, and
it was confused about the encoding of interrupt sense and level
(which is different for i8259 and openpic interrupt controllers,
just to make things interesting).
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/prom.c

@@ -296,13 +296,28 @@ static int __devinit map_interrupt(unsigned int **irq, struct device_node **ictr
 	return nintrc;
 }
 
+static unsigned char map_isa_senses[4] = {
+	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
+	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
+	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
+	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE
+};
+
+static unsigned char map_mpic_senses[4] = {
+	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE,
+	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
+	/* 2 seems to be used for the 8259 cascade... */
+	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
+	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
+};
+
 static int __devinit finish_node_interrupts(struct device_node *np,
 					    unsigned long *mem_start,
 					    int measure_only)
 {
 	unsigned int *ints;
 	int intlen, intrcells, intrcount;
-	int i, j, n;
+	int i, j, n, sense;
 	unsigned int *irq, virq;
 	struct device_node *ic;
 
@@ -332,7 +347,8 @@ static int __devinit finish_node_interrupts(struct device_node *np,
 
 		for (i = 0; i < np->n_intrs; ++i) {
 			np->intrs[i].line = *ints++;
-			np->intrs[i].sense = 1;
+			np->intrs[i].sense = IRQ_SENSE_LEVEL
+				| IRQ_POLARITY_NEGATIVE;
 		}
 		return 0;
 	}
@@ -359,19 +375,20 @@ static int __devinit finish_node_interrupts(struct device_node *np,
 		/* don't map IRQ numbers under a cascaded 8259 controller */
 		if (ic && device_is_compatible(ic, "chrp,iic")) {
 			np->intrs[intrcount].line = irq[0];
+			sense = (n > 1)? (irq[1] & 3): 3;
+			np->intrs[intrcount].sense = map_isa_senses[sense];
 		} else {
-#ifdef CONFIG_PPC64
 			virq = virt_irq_create_mapping(irq[0]);
+#ifdef CONFIG_PPC64
 			if (virq == NO_IRQ) {
 				printk(KERN_CRIT "Could not allocate interrupt"
 				       " number for %s\n", np->full_name);
 				continue;
 			}
-			virq = irq_offset_up(virq);
-#else
-			virq = irq[0];
 #endif
-			np->intrs[intrcount].line = virq;
+			np->intrs[intrcount].line = irq_offset_up(virq);
+			sense = (n > 1)? (irq[1] & 3): 1;
+			np->intrs[intrcount].sense = map_mpic_senses[sense];
 		}
 
 #ifdef CONFIG_PPC64
@@ -386,9 +403,6 @@ static int __devinit finish_node_interrupts(struct device_node *np,
 				break;
 		}
 #endif
-		np->intrs[intrcount].sense = 1;
-		if (n > 1)
-			np->intrs[intrcount].sense = irq[1];
 		if (n > 2) {
 			printk("hmmm, got %d intr cells for %s:", n,
 			       np->full_name);
@@ -1401,15 +1415,13 @@ void __init prom_get_irq_senses(unsigned char *senses, int off, int max)
 	int i, j;
 
 	/* default to level-triggered */
-	memset(senses, 1, max - off);
+	memset(senses, IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE, max - off);
 
 	for (np = allnodes; np != 0; np = np->allnext) {
 		for (j = 0; j < np->n_intrs; j++) {
 			i = np->intrs[j].line;
 			if (i >= off && i < max)
-				senses[i-off] = np->intrs[j].sense ?
-					IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE :
-					IRQ_SENSE_EDGE | IRQ_POLARITY_POSITIVE;
+				senses[i-off] = np->intrs[j].sense;
 		}
 	}
 }

include/asm-powerpc/irq.h

@@ -432,6 +432,8 @@ extern unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
 extern unsigned long ppc_lost_interrupts[NR_MASK_WORDS];
 extern atomic_t ppc_n_lost_interrupts;
 
+#define virt_irq_create_mapping(x)	(x)
+
 #endif
 
 /*