irq_domain: Add support for base irq and hwirq in legacy mappings
Add support for a legacy mapping where irq = (hwirq - first_hwirq + first_irq)
so that a controller driver can allocate a fixed range of irq_descs and use
a simple calculation to translate back and forth between linux and hw irq
numbers. This is needed to use an irq_domain with many of the ARM interrupt
controller drivers that manage their own irq_desc allocations. Ultimately
the goal is to migrate those drivers to use the linear revmap, but doing it
this way allows each driver to be converted separately which makes the
migration path easier.
This patch generalizes the IRQ_DOMAIN_MAP_LEGACY method to use
(first_irq-first_hwirq) as the offset between hwirq and linux irq number,
and adds checks to make sure that the hwirq number does not exceed range
assigned to the controller.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 728cc30..fe0b09d 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -36,9 +36,6 @@
/* Total number of virq in the platform */
#define NR_IRQS CONFIG_NR_IRQS
-/* Number of irqs reserved for the legacy controller */
-#define NUM_ISA_INTERRUPTS 16
-
/* Same thing, used by the generic IRQ code */
#define NR_IRQS_LEGACY NUM_ISA_INTERRUPTS
diff --git a/arch/powerpc/sysdev/i8259.c b/arch/powerpc/sysdev/i8259.c
index 573a73b..997df6a 100644
--- a/arch/powerpc/sysdev/i8259.c
+++ b/arch/powerpc/sysdev/i8259.c
@@ -263,7 +263,7 @@
raw_spin_unlock_irqrestore(&i8259_lock, flags);
/* create a legacy host */
- i8259_host = irq_domain_add_legacy(node, &i8259_host_ops, NULL);
+ i8259_host = irq_domain_add_legacy_isa(node, &i8259_host_ops, NULL);
if (i8259_host == NULL) {
printk(KERN_ERR "i8259: failed to allocate irq host !\n");
return;
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index 1be26f4..188012c 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -419,7 +419,7 @@
{
DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
- pci_irq_host = irq_domain_add_legacy(node, &pci_irq_domain_ops, NULL);
+ pci_irq_host = irq_domain_add_legacy_isa(node, &pci_irq_domain_ops, NULL);
if (pci_irq_host == NULL) {
printk(KERN_ERR "pci_irq_host: failed to allocate irq domain!\n");
return;