powerpc/mm: Enable radix GTSE only if supported.
Make GTSE an MMU feature and enable it by default for radix.
However for guest, conditionally enable it if hypervisor supports
it via OV5 vector. Let prom_init ask for radix GTSE only if the
support exists.
Having GTSE as an MMU feature will make it easy to enable radix
without GTSE. Currently radix assumes GTSE is enabled by default.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703053608.12884-2-bharata@linux.ibm.com
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 90c604d..cbc605c 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -1336,12 +1336,15 @@ static void __init prom_check_platform_support(void)
}
}
- if (supported.radix_mmu && supported.radix_gtse &&
- IS_ENABLED(CONFIG_PPC_RADIX_MMU)) {
- /* Radix preferred - but we require GTSE for now */
- prom_debug("Asking for radix with GTSE\n");
+ if (supported.radix_mmu && IS_ENABLED(CONFIG_PPC_RADIX_MMU)) {
+ /* Radix preferred - Check if GTSE is also supported */
+ prom_debug("Asking for radix\n");
ibm_architecture_vec.vec5.mmu = OV5_FEAT(OV5_MMU_RADIX);
- ibm_architecture_vec.vec5.radix_ext = OV5_FEAT(OV5_RADIX_GTSE);
+ if (supported.radix_gtse)
+ ibm_architecture_vec.vec5.radix_ext =
+ OV5_FEAT(OV5_RADIX_GTSE);
+ else
+ prom_debug("Radix GTSE isn't supported\n");
} else if (supported.hash_mmu) {
/* Default to hash mmu (if we can) */
prom_debug("Asking for hash\n");