[PATCH] genirq: i386 irq: Dynamic irq support

The current implementation of create_irq() is a hack but it is the current
hack that msi.c uses, and unfortunately the ``generic'' apic msi ops depend on
this hack.  Thus we are stuck this hack of assuming irq == vector until the
depencencies in the generic msi code are removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index b3b0189..fca689c 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -2483,6 +2483,54 @@ static int __init ioapic_init_sysfs(void)
 
 device_initcall(ioapic_init_sysfs);
 
+#ifdef CONFIG_PCI_MSI
+/*
+ * Dynamic irq allocate and deallocation for MSI
+ */
+int create_irq(void)
+{
+       /* Hack of the day: irq == vector.
+        *
+        * Ultimately this will be be more general,
+        * and not depend on the irq to vector identity mapping.
+        * But this version is needed until msi.c can cope with
+        * the more general form.
+        */
+       int irq, vector;
+       unsigned long flags;
+       vector = assign_irq_vector(AUTO_ASSIGN);
+       irq = vector;
+
+       if (vector >= 0) {
+               struct irq_desc *desc;
+
+               spin_lock_irqsave(&vector_lock, flags);
+               vector_irq[vector] = irq;
+               irq_vector[irq] = vector;
+               spin_unlock_irqrestore(&vector_lock, flags);
+
+               set_intr_gate(vector, interrupt[irq]);
+
+               dynamic_irq_init(irq);
+       }
+       return irq;
+}
+
+void destroy_irq(unsigned int irq)
+{
+       unsigned long flags;
+       unsigned int vector;
+
+       dynamic_irq_cleanup(irq);
+
+       spin_lock_irqsave(&vector_lock, flags);
+       vector = irq_vector[irq];
+       vector_irq[vector] = -1;
+       irq_vector[irq] = 0;
+       spin_unlock_irqrestore(&vector_lock, flags);
+}
+#endif /* CONFIG_PCI_MSI */
+
 /* --------------------------------------------------------------------------
                           ACPI-based IOAPIC Configuration
    -------------------------------------------------------------------------- */