PCI/MSI: Use #ifdefs instead of weak functions

Weak functions aren't all they're cracked up to be. They lead to
incorrect binaries with some toolchains, they require us to have empty
functions we otherwise wouldn't, and the unused code is not elided
(as of gcc 4.3.2 anyway).

So replace the weak MSI arch hooks with the #define foo foo idiom. We no
longer need empty versions of arch_setup/teardown_msi_irq().

This is less source (by 1 line!), and results in smaller binaries too:

   text	   data	    bss	    dec	    hex	filename
9354300	1693916	 678424	11726640 b2ef30	build/powerpc/vmlinux-before
9354052	1693852	 678424	11726328 b2edf8	build/powerpc/vmlinux-after

Also smaller on x86_64 and arm (iop13xx).

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 3548159a1beb..ba17d5d90a49 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -114,6 +114,10 @@ extern int pci_domain_nr(struct pci_bus *bus);
 /* Decide whether to display the domain number in /proc */
 extern int pci_proc_domain(struct pci_bus *bus);
 
+/* MSI arch hooks */
+#define arch_setup_msi_irqs arch_setup_msi_irqs
+#define arch_teardown_msi_irqs arch_teardown_msi_irqs
+#define arch_msi_check_device arch_msi_check_device
 
 struct vm_area_struct;
 /* Map a range of PCI memory or I/O space for a device into user space */