We want to initialise register_process_table() before ppc_md is setup,
so that it can be called as part of MMU init (at least on Radix ATM).
That no longer works because probe_machine() requires that ppc_md be
empty before it's called, and we now do probe_machine() much later.
So make register_process_table a global for now. It will probably move
into a mmu_radix_ops struct at some point in the future.
This was broken by me when applying commit 
7025776ed1eb "powerpc/mm:
Move hash table ops to a separate structure" due to conflicts with other
patches.
Fixes: 7025776ed1eb ("powerpc/mm: Move hash table ops to a separate structure")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
        return hash__setup_initial_memory_limit(first_memblock_base,
                                           first_memblock_size);
 }
+
+extern int (*register_process_table)(unsigned long base, unsigned long page_size,
+                                    unsigned long tbl_size);
+
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_BOOK3S_64_MMU_H_ */
 
 #ifdef CONFIG_ARCH_RANDOM
        int (*get_random_seed)(unsigned long *v);
 #endif
-       int (*register_process_table)(unsigned long base, unsigned long page_size,
-                                     unsigned long tbl_size);
 };
 
 extern void e500_idle(void);
 
        mmu_hash_ops.hugepage_invalidate   = native_hugepage_invalidate;
 
        if (cpu_has_feature(CPU_FTR_ARCH_300))
-               ppc_md.register_process_table = native_register_proc_table;
+               register_process_table = native_register_proc_table;
 }
 
 #include "mmu_decl.h"
 #include <trace/events/thp.h>
 
+int (*register_process_table)(unsigned long base, unsigned long page_size,
+                             unsigned long tbl_size);
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /*
  * This is called when relaxing access to a hugepage. It's also called in the page
 
         * of process table here. But our linear mapping also enable us to use
         * physical address here.
         */
-       ppc_md.register_process_table(__pa(process_tb), 0, PRTB_SIZE_SHIFT - 12);
+       register_process_table(__pa(process_tb), 0, PRTB_SIZE_SHIFT - 12);
        pr_info("Process table %p and radix root for kernel: %p\n", process_tb, init_mm.pgd);
 }
 
 
 void __init radix_init_native(void)
 {
-       ppc_md.register_process_table = native_register_process_table;
+       register_process_table = native_register_process_table;
 }
 
 static int __init get_idx_from_shift(unsigned int shift)