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authorThomas Gleixner <tglx@linutronix.de>2009-08-29 18:09:57 +0200
committerThomas Gleixner <tglx@linutronix.de>2009-08-31 19:23:09 +0200
commitbc07844a33734c4b2f32ef26d942d2f3ef9302ea (patch)
treeae8cbb6dc9a17baca82a829e77c5b7fc5781b2a5 /arch
parent3f4110a48a749a1aa1c54fb807afb3f32f49711c (diff)
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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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/io_apic.h2
-rw-r--r--arch/x86/kernel/apic/io_apic.c41
2 files changed, 31 insertions, 12 deletions
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 2b8aeb89933a..e1f89a1a07ef 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -143,6 +143,8 @@ extern int noioapicreroute;
/* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
extern int timer_through_8259;
+extern void io_apic_disable_legacy(void);
+
/*
* If we use the IO-APIC for IRQ routing, disable automatic
* assignment of PCI IRQ's.
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 5f4687187ceb..6c961290a5f8 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -91,6 +91,11 @@ struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
/* # 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 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = {
[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 @@ int __init arch_early_irq_init(void)
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 __init find_isa_irq_apic(int irq, int type)
*/
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 @@ static void setup_IO_APIC_irq(int apic_id, int pin, unsigned int irq, struct irq
}
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 @@ __apicdebuginit(void) print_PIC(void)
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 @@ void __init enable_IO_APIC(void)
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 @@ void disable_IO_APIC(void)
*/
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 @@ static unsigned int startup_ioapic_irq(unsigned int irq)
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 @@ static inline void init_IO_APIC_traps(void)
* 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 @@ out:
* 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 @@ void __init setup_IO_APIC(void)
/*
* 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 @@ void __init setup_IO_APIC(void)
sync_Arb_IDs();
setup_IO_APIC_irqs();
init_IO_APIC_traps();
- check_timer();
+ if (nr_legacy_irqs)
+ check_timer();
}
/*
@@ -3166,7 +3184,6 @@ static int __init ioapic_init_sysfs(void)
device_initcall(ioapic_init_sysfs);
-static int nr_irqs_gsi = NR_IRQS_LEGACY;
/*
* Dynamic irq allocate and deallocation
*/
@@ -3907,7 +3924,7 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
/*
* 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);
}