[PATCH 12/25] x86_64 irq: Dynamic irq support

From: Eric W. Biederman
Date: Tue Jun 20 2006 - 18:29:44 EST


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 this hack of assuming irq == vector until the depencencies
in the generic irq code are removed.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
arch/x86_64/kernel/io_apic.c | 48 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 48 insertions(+), 0 deletions(-)

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index f50be45..ae64a63 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -2013,6 +2013,54 @@ 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
+
/* --------------------------------------------------------------------------
ACPI-based IOAPIC Configuration
-------------------------------------------------------------------------- */
--
1.4.0.gc07e

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