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>

1 files changed, 18 insertions, 5 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 2a145d3a837..2999f3dd588 100644
--- 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);