[PATCH v2 1/2] powerpc/mm: Fix build break when PPC_NATIVE=n

[Michael Ellerman]

The recent commit to rework the hash MMU setup broke the build when
CONFIG_PPC_NATIVE=n. Fix it by adding an IS_ENABLED() check before
calling hpte_init_native().

Removing the else clause opens the possibility that we don't set any
ops, which would probably lead to a strange crash later. So add a check
that we correctly initialised at least one member of the struct.

Fixes: 166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code")
Reported-by: Stephen Rothwell <sfr at canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/mm/hash_utils_64.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 341632471b9d..381b5894cc99 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -931,9 +931,12 @@ void __init hash__early_init_mmu(void)
 		ps3_early_mm_init();
 	else if (firmware_has_feature(FW_FEATURE_LPAR))
 		hpte_init_lpar();
-	else
+	else if IS_ENABLED(CONFIG_PPC_NATIVE)
 		hpte_init_native();
 
+	if (!mmu_hash_ops.hpte_insert)
+		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
+
 	/* Initialize the MMU Hash table and create the linear mapping
 	 * of memory. Has to be done before SLB initialization as this is
 	 * currently where the page size encoding is obtained.
-- 
2.7.4