[POWERPC] Add new interrupt mapping core and change platforms to use it

This adds the new irq remapper core and removes the old one.  Because
there are some fundamental conflicts with the old code, like the value
of NO_IRQ which I'm now setting to 0 (as per discussions with Linus),
etc..., this commit also changes the relevant platform and driver code
over to use the new remapper (so as not to cause difficulties later
in bisecting).

This patch removes the old pre-parsing of the open firmware interrupt
tree along with all the bogus assumptions it made to try to renumber
interrupts according to the platform. This is all to be handled by the
new code now.

For the pSeries XICS interrupt controller, a single remapper host is
created for the whole machine regardless of how many interrupt
presentation and source controllers are found, and it's set to match
any device node that isn't a 8259.  That works fine on pSeries and
avoids having to deal with some of the complexities of split source
controllers vs. presentation controllers in the pSeries device trees.

The powerpc i8259 PIC driver now always requests the legacy interrupt
range. It also has the feature of being able to match any device node
(including NULL) if passed no device node as an input. That will help
porting over platforms with broken device-trees like Pegasos who don't
have a proper interrupt tree.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 66 insertions, 44 deletions

diff --git a/arch/powerpc/platforms/chrp/setup.c b/arch/powerpc/platforms/chrp/setup.c
index a5dffc8d93a..bb10171132f 100644
--- a/arch/powerpc/platforms/chrp/setup.c
+++ b/arch/powerpc/platforms/chrp/setup.c
@@ -59,7 +59,7 @@ void rtas_indicator_progress(char *, unsigned short);
 int _chrp_type;
 EXPORT_SYMBOL(_chrp_type);
 
-struct mpic *chrp_mpic;
+static struct mpic *chrp_mpic;
 
 /* Used for doing CHRP event-scans */
 DEFINE_PER_CPU(struct timer_list, heartbeat_timer);
@@ -315,19 +315,13 @@ chrp_event_scan(unsigned long unused)
 		  jiffies + event_scan_interval);
 }
 
-void chrp_8259_cascade(unsigned int irq, struct irq_desc *desc,
-			struct pt_regs *regs)
+static void chrp_8259_cascade(unsigned int irq, struct irq_desc *desc,
+			      struct pt_regs *regs)
 {
-	unsigned int max = 100;
-
-	while(max--) {
-		int irq = i8259_irq(regs);
-		if (max == 99)
-			desc->chip->eoi(irq);
-		if (irq < 0)
-			break;
-		generic_handle_irq(irq, regs);
-	};
+	unsigned int cascade_irq = i8259_irq(regs);
+	if (cascade_irq != NO_IRQ)
+		generic_handle_irq(cascade_irq, regs);
+	desc->chip->eoi(irq);
 }
 
 /*
@@ -336,18 +330,17 @@ void chrp_8259_cascade(unsigned int irq, struct irq_desc *desc,
 static void __init chrp_find_openpic(void)
 {
 	struct device_node *np, *root;
-	int len, i, j, irq_count;
+	int len, i, j;
 	int isu_size, idu_size;
 	unsigned int *iranges, *opprop = NULL;
 	int oplen = 0;
 	unsigned long opaddr;
 	int na = 1;
-	unsigned char init_senses[NR_IRQS - NUM_8259_INTERRUPTS];
 
-	np = find_type_devices("open-pic");
+	np = of_find_node_by_type(NULL, "open-pic");
 	if (np == NULL)
 		return;
-	root = find_path_device("/");
+	root = of_find_node_by_path("/");
 	if (root) {
 		opprop = (unsigned int *) get_property
 			(root, "platform-open-pic", &oplen);
@@ -358,19 +351,15 @@ static void __init chrp_find_openpic(void)
 		oplen /= na * sizeof(unsigned int);
 	} else {
 		struct resource r;
-		if (of_address_to_resource(np, 0, &r))
-			return;
+		if (of_address_to_resource(np, 0, &r)) {
+			goto bail;
+		}
 		opaddr = r.start;
 		oplen = 0;
 	}
 
 	printk(KERN_INFO "OpenPIC at %lx\n", opaddr);
 
-	irq_count = NR_IRQS - NUM_ISA_INTERRUPTS - 4; /* leave room for IPIs */
-	prom_get_irq_senses(init_senses, NUM_ISA_INTERRUPTS, NR_IRQS - 4);
-	/* i8259 cascade is always positive level */
-	init_senses[0] = IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE;
-
 	iranges = (unsigned int *) get_property(np, "interrupt-ranges", &len);
 	if (iranges == NULL)
 		len = 0;	/* non-distributed mpic */
@@ -397,15 +386,12 @@ static void __init chrp_find_openpic(void)
 	if (len > 1)
 		isu_size = iranges[3];
 
-	chrp_mpic = mpic_alloc(opaddr, MPIC_PRIMARY,
-			       isu_size, NUM_ISA_INTERRUPTS, irq_count,
-			       NR_IRQS - 4, init_senses, irq_count,
-			       " MPIC    ");
+	chrp_mpic = mpic_alloc(np, opaddr, MPIC_PRIMARY,
+			       isu_size, 0, " MPIC    ");
 	if (chrp_mpic == NULL) {
 		printk(KERN_ERR "Failed to allocate MPIC structure\n");
-		return;
+		goto bail;
 	}
-
 	j = na - 1;
 	for (i = 1; i < len; ++i) {
 		iranges += 2;
@@ -417,7 +403,10 @@ static void __init chrp_find_openpic(void)
 	}
 
 	mpic_init(chrp_mpic);
-	set_irq_chained_handler(NUM_ISA_INTERRUPTS, chrp_8259_cascade);
+	ppc_md.get_irq = mpic_get_irq;
+ bail:
+	of_node_put(root);
+	of_node_put(np);
 }
 
 #if defined(CONFIG_VT) && defined(CONFIG_INPUT_ADBHID) && defined(XMON)
@@ -428,14 +417,34 @@ static struct irqaction xmon_irqaction = {
 };
 #endif
 
-void __init chrp_init_IRQ(void)
+static void __init chrp_find_8259(void)
 {
-	struct device_node *np;
+	struct device_node *np, *pic = NULL;
 	unsigned long chrp_int_ack = 0;
-#if defined(CONFIG_VT) && defined(CONFIG_INPUT_ADBHID) && defined(XMON)
-	struct device_node *kbd;
-#endif
+	unsigned int cascade_irq;
 
+	/* Look for cascade */
+	for_each_node_by_type(np, "interrupt-controller")
+		if (device_is_compatible(np, "chrp,iic")) {
+			pic = np;
+			break;
+		}
+	/* Ok, 8259 wasn't found. We need to handle the case where
+	 * we have a pegasos that claims to be chrp but doesn't have
+	 * a proper interrupt tree
+	 */
+	if (pic == NULL && chrp_mpic != NULL) {
+		printk(KERN_ERR "i8259: Not found in device-tree"
+		       " assuming no legacy interrupts\n");
+		return;
+	}
+
+	/* Look for intack. In a perfect world, we would look for it on
+	 * the ISA bus that holds the 8259 but heh... Works that way. If
+	 * we ever see a problem, we can try to re-use the pSeries code here.
+	 * Also, Pegasos-type platforms don't have a proper node to start
+	 * from anyway
+	 */
 	for (np = find_devices("pci"); np != NULL; np = np->next) {
 		unsigned int *addrp = (unsigned int *)
 			get_property(np, "8259-interrupt-acknowledge", NULL);
@@ -446,11 +455,29 @@ void __init chrp_init_IRQ(void)
 		break;
 	}
 	if (np == NULL)
-		printk(KERN_ERR "Cannot find PCI interrupt acknowledge address\n");
+		printk(KERN_WARNING "Cannot find PCI interrupt acknowledge"
+		       " address, polling\n");
+
+	i8259_init(pic, chrp_int_ack);
+	if (ppc_md.get_irq == NULL)
+		ppc_md.get_irq = i8259_irq;
+	if (chrp_mpic != NULL) {
+		cascade_irq = irq_of_parse_and_map(pic, 0);
+		if (cascade_irq == NO_IRQ)
+			printk(KERN_ERR "i8259: failed to map cascade irq\n");
+		else
+			set_irq_chained_handler(cascade_irq,
+						chrp_8259_cascade);
+	}
+}
 
+void __init chrp_init_IRQ(void)
+{
+#if defined(CONFIG_VT) && defined(CONFIG_INPUT_ADBHID) && defined(XMON)
+	struct device_node *kbd;
+#endif
 	chrp_find_openpic();
-
-	i8259_init(chrp_int_ack, 0);
+	chrp_find_8259();
 
 	if (_chrp_type == _CHRP_Pegasos)
 		ppc_md.get_irq        = i8259_irq;
@@ -535,10 +562,6 @@ static int __init chrp_probe(void)
 	DMA_MODE_READ = 0x44;
 	DMA_MODE_WRITE = 0x48;
 	isa_io_base = CHRP_ISA_IO_BASE;		/* default value */
-	ppc_do_canonicalize_irqs = 1;
-
-	/* Assume we have an 8259... */
-	__irq_offset_value = NUM_ISA_INTERRUPTS;
 
 	return 1;
 }
@@ -550,7 +573,6 @@ define_machine(chrp) {
 	.init			= chrp_init2,
 	.show_cpuinfo		= chrp_show_cpuinfo,
 	.init_IRQ		= chrp_init_IRQ,
-	.get_irq		= mpic_get_irq,
 	.pcibios_fixup		= chrp_pcibios_fixup,
 	.restart		= rtas_restart,
 	.power_off		= rtas_power_off,