powerpc/mm: Move register_process_table() out of ppc_md

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>

arch/powerpc/include/asm/book3s/64/mmu.h

@@ -134,5 +134,9 @@ static inline void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	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_ */

arch/powerpc/include/asm/machdep.h

@@ -219,8 +219,6 @@ struct machdep_calls {
 #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);

arch/powerpc/mm/hash_native_64.c

@@ -747,5 +747,5 @@ void __init hpte_init_native(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;
 }

arch/powerpc/mm/pgtable-book3s64.c

@@ -14,6 +14,9 @@
 #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

arch/powerpc/mm/pgtable-radix.c

@@ -171,7 +171,7 @@ redo:
 	 * 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);
 }
 
@@ -198,7 +198,7 @@ static void __init radix_init_partition_table(void)
 
 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)