This allows platforms which don't have anything to do at setup_arch time
(like a bunch of the 4xx platforms) to eliminate an empty setup_arch hook.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
        conswitchp = &dummy_con;
 #endif
 
-       ppc_md.setup_arch();
+       if (ppc_md.setup_arch)
+               ppc_md.setup_arch();
        if ( ppc_md.progress ) ppc_md.progress("arch: exit", 0x3eab);
 
        paging_init();
 
        conswitchp = &dummy_con;
 #endif
 
-       ppc_md.setup_arch();
+       if (ppc_md.setup_arch)
+               ppc_md.setup_arch();
 
        paging_init();
        ppc64_boot_msg(0x15, "Setup Done");
 
 #endif /* CONFIG_PPC64 */
 
        int             (*probe)(void);
-       void            (*setup_arch)(void);
+       void            (*setup_arch)(void); /* Optional, may be NULL */
        void            (*init_early)(void);
        /* Optional, may be NULL. */
        void            (*show_cpuinfo)(struct seq_file *m);