msi: Make MSI useable more architectures

The arch hooks arch_setup_msi_irq and arch_teardown_msi_irq are now
responsible for allocating and freeing the linux irq in addition to
setting up the the linux irq to work with the interrupt.

arch_setup_msi_irq now takes a pci_device and a msi_desc and returns
an irq.

With this change in place this code should be useable by all platforms
except those that won't let the OS touch the hardware like ppc RTAS.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 12 insertions, 5 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index d7bad90a5ad8..6be6730acb5c 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -1956,24 +1956,31 @@ static struct irq_chip msi_chip = {
 	.retrigger	= ioapic_retrigger_irq,
 };
 
-int arch_setup_msi_irq(unsigned int irq, struct pci_dev *dev)
+int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
 	struct msi_msg msg;
-	int ret;
+	int irq, ret;
+	irq = create_irq();
+	if (irq < 0)
+		return irq;
+
+	set_irq_msi(irq, desc);
 	ret = msi_compose_msg(dev, irq, &msg);
-	if (ret < 0)
+	if (ret < 0) {
+		destroy_irq(irq);
 		return ret;
+	}
 
 	write_msi_msg(irq, &msg);
 
 	set_irq_chip_and_handler_name(irq, &msi_chip, handle_edge_irq, "edge");
 
-	return 0;
+	return irq;
 }
 
 void arch_teardown_msi_irq(unsigned int irq)
 {
-	return;
+	destroy_irq(irq);
 }
 
 #endif /* CONFIG_PCI_MSI */