x86, ioapic: Panic on irq-pin binding only if needed

Though the most time we are to panic on irq-pin allocation
fails, for PCI interrupts it's not the case and we could
continue operate even if irq-pin allocation failed.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090805200931.GB5319@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 2a145d3..2999f3d 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -490,7 +490,8 @@ static void ioapic_mask_entry(int apic, int pin)
  * shared ISA-space IRQs, so we have to support them. We are super
  * fast in the common case, and fast for shared ISA-space IRQs.
  */
-static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+static int
+add_pin_to_irq_node_nopanic(struct irq_cfg *cfg, int node, int apic, int pin)
 {
        struct irq_pin_list **last, *entry;
 
@@ -498,19 +499,27 @@ static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin
        last = &cfg->irq_2_pin;
        for_each_irq_pin(entry, cfg->irq_2_pin) {
                if (entry->apic == apic && entry->pin == pin)
-                       return;
+                       return 0;
                last = &entry->next;
        }
 
        entry = get_one_free_irq_2_pin(node);
        if (!entry) {
-               printk(KERN_ERR "can not alloc irq_pin_list\n");
-               BUG_ON(1);
+               printk(KERN_ERR "can not alloc irq_pin_list (%d,%d,%d)\n",
+                               node, apic, pin);
+               return -ENOMEM;
        }
        entry->apic = apic;
        entry->pin = pin;
 
        *last = entry;
+       return 0;
+}
+
+static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+{
+       if (add_pin_to_irq_node_nopanic(cfg, node, apic, pin))
+               panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
 }
 
 /*
@@ -3843,7 +3852,11 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
         */
        if (irq >= NR_IRQS_LEGACY) {
                cfg = desc->chip_data;
-               add_pin_to_irq_node(cfg, node, ioapic, pin);
+               if (add_pin_to_irq_node_nopanic(cfg, node, ioapic, pin)) {
+                       printk(KERN_INFO "can not add pin %d for irq %d\n",
+                               pin, irq);
+                       return 0;
+               }
        }
 
        setup_IO_APIC_irq(ioapic, pin, irq, desc, trigger, polarity);