[POWERPC] PowerPC MSI infrastructure

This provides the architecture specific hooks to support MSI on
powerpc.  We implement the newly added arch_setup_msi_irqs() and
arch_teardown_msi_irqs(), and then delegate to ppc_md routines.

Platforms that don't implement MSI will leave the ppc_md calls blank,
arch_msi_check_device() will detect this and return ENOSYS. Drivers
should detect this error and continue to use LSI.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index daa08b1..6cf1a83 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -120,6 +120,14 @@
 	/* To setup PHBs when using automatic OF platform driver for PCI */
 	int		(*pci_setup_phb)(struct pci_controller *host);
 
+#ifdef CONFIG_PCI_MSI
+	int		(*msi_check_device)(struct pci_dev* dev,
+					    int nvec, int type);
+	int		(*setup_msi_irqs)(struct pci_dev *dev,
+					  int nvec, int type);
+	void		(*teardown_msi_irqs)(struct pci_dev *dev);
+#endif
+
 	void		(*restart)(char *cmd);
 	void		(*power_off)(void);
 	void		(*halt)(void);