powerpc/mm: Fix build break when PPC_NATIVE=n

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@canb.auug.org.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 4 insertions, 1 deletions

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.