x86: Distangle ioapic and i8259
The proposed Moorestown support patches use an extra feature flag
mechanism to make the ioapic work w/o an i8259. There is a much
simpler solution.
Most i8259 specific functions are already called dependend on the irq
number less than NR_IRQS_LEGACY. Replacing that constant by a
read_mostly variable which can be set to 0 by the platform setup code
allows us to achieve the same without any special feature flags.
That trivial change allows us to proceed with MRST w/o doing a full
blown overhaul of the ioapic code which would delay MRST unduly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 5f46871..6c96129 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -91,6 +91,11 @@
/* # of MP IRQ source entries */
int mp_irq_entries;
+/* Number of legacy interrupts */
+static int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY;
+/* GSI interrupts */
+static int nr_irqs_gsi = NR_IRQS_LEGACY;
+
#if defined (CONFIG_MCA) || defined (CONFIG_EISA)
int mp_bus_id_to_type[MAX_MP_BUSSES];
#endif
@@ -172,6 +177,12 @@
[15] = { .vector = IRQ15_VECTOR, },
};
+void __init io_apic_disable_legacy(void)
+{
+ nr_legacy_irqs = 0;
+ nr_irqs_gsi = 0;
+}
+
int __init arch_early_irq_init(void)
{
struct irq_cfg *cfg;
@@ -189,7 +200,7 @@
desc->chip_data = &cfg[i];
zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node);
zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node);
- if (i < NR_IRQS_LEGACY)
+ if (i < nr_legacy_irqs)
cpumask_setall(cfg[i].domain);
}
@@ -883,7 +894,7 @@
*/
static int EISA_ELCR(unsigned int irq)
{
- if (irq < NR_IRQS_LEGACY) {
+ if (irq < nr_legacy_irqs) {
unsigned int port = 0x4d0 + (irq >> 3);
return (inb(port) >> (irq & 7)) & 1;
}
@@ -1480,7 +1491,7 @@
}
ioapic_register_intr(irq, desc, trigger);
- if (irq < NR_IRQS_LEGACY)
+ if (irq < nr_legacy_irqs)
disable_8259A_irq(irq);
ioapic_write_entry(apic_id, pin, entry);
@@ -1851,7 +1862,7 @@
unsigned int v;
unsigned long flags;
- if (apic_verbosity == APIC_QUIET)
+ if (apic_verbosity == APIC_QUIET || !nr_legacy_irqs)
return;
printk(KERN_DEBUG "\nprinting PIC contents\n");
@@ -1914,6 +1925,10 @@
spin_unlock_irqrestore(&ioapic_lock, flags);
nr_ioapic_registers[apic] = reg_01.bits.entries+1;
}
+
+ if (!nr_legacy_irqs)
+ return;
+
for(apic = 0; apic < nr_ioapics; apic++) {
int pin;
/* See if any of the pins is in ExtINT mode */
@@ -1968,6 +1983,9 @@
*/
clear_IO_APIC();
+ if (!nr_legacy_irqs)
+ return;
+
/*
* If the i8259 is routed through an IOAPIC
* Put that IOAPIC in virtual wire mode
@@ -2198,7 +2216,7 @@
struct irq_cfg *cfg;
spin_lock_irqsave(&ioapic_lock, flags);
- if (irq < NR_IRQS_LEGACY) {
+ if (irq < nr_legacy_irqs) {
disable_8259A_irq(irq);
if (i8259A_irq_pending(irq))
was_pending = 1;
@@ -2709,7 +2727,7 @@
* so default to an old-fashioned 8259
* interrupt if we can..
*/
- if (irq < NR_IRQS_LEGACY)
+ if (irq < nr_legacy_irqs)
make_8259A_irq(irq);
else
/* Strange. Oh, well.. */
@@ -3045,7 +3063,7 @@
* the I/O APIC in all cases now. No actual device should request
* it anyway. --macro
*/
-#define PIC_IRQS (1 << PIC_CASCADE_IR)
+#define PIC_IRQS (1UL << PIC_CASCADE_IR)
void __init setup_IO_APIC(void)
{
@@ -3053,8 +3071,7 @@
/*
* calling enable_IO_APIC() is moved to setup_local_APIC for BP
*/
-
- io_apic_irqs = ~PIC_IRQS;
+ io_apic_irqs = nr_legacy_irqs ? ~PIC_IRQS : ~0UL;
apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
/*
@@ -3065,7 +3082,8 @@
sync_Arb_IDs();
setup_IO_APIC_irqs();
init_IO_APIC_traps();
- check_timer();
+ if (nr_legacy_irqs)
+ check_timer();
}
/*
@@ -3166,7 +3184,6 @@
device_initcall(ioapic_init_sysfs);
-static int nr_irqs_gsi = NR_IRQS_LEGACY;
/*
* Dynamic irq allocate and deallocation
*/
@@ -3907,7 +3924,7 @@
/*
* IRQs < 16 are already in the irq_2_pin[] map
*/
- if (irq >= NR_IRQS_LEGACY) {
+ if (irq >= nr_legacy_irqs) {
cfg = desc->chip_data;
add_pin_to_irq_node(cfg, node, ioapic, pin);
}