Hello,

In 2.6.16-rc6-mm1, I've seen tons of compiler warnings on ia64:

include2/asm/msi.h: In function `ia64_msi_init':
include2/asm/msi.h:23: warning: implicit declaration of function `msi_register'
In file included from include2/asm/machvec.h:408,
                 from include2/asm/io.h:70,
                 from include2/asm/smp.h:20,
                 from /build/rc6/source/include/linux/smp.h:22,

The problem is that msi_register() is used in ia64_msi_init()
without declaration.
Since ia64_msi_init() is a part of machine vector, most of files
hit this warning and may hide other important messages.

Other than ia64, i386 and x86_64 have similar msi.h.
But they are not affected since include/asm/msi.h isn't
included without drivers/pci/pci.h where msi_register() is
declared.

The attached patch fixes this specific problem.
Proper fix might be moving the declaration in common header
but including something from machvec.h causes a lot of other
problems, so it would be nice if someone have better idea on this.

Thanks,
-- 
Jun'ichi Nomura, NEC Solutions (America), Inc.