[PATCH 4.16 059/196] powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit

From: Greg Kroah-Hartman
Date: Sun Apr 22 2018 - 09:57:04 EST

4.16-stable review patch. If anyone has any objections, please let me know.


From: Nicholas Piggin <npiggin@xxxxxxxxx>

commit c130153e453cba0f37ad10fa18a1aa9c9a598a59 upstream.

The pkey code added a CPU_FTR_PKEY bit, but did not add it to the
dt_cpu_ftrs feature set. Although capability is supported by all
processors in the base dt_cpu_ftrs set for 64s, it's a significant
and sufficiently well defined feature to make it optional. So add
it as a quirk for now, which can be versioned out then controlled
by the firmware (once dt_cpu_ftrs gains versioning support).

Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Cc: stable@xxxxxxxxxxxxxxx # v4.16+
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/powerpc/kernel/dt_cpu_ftrs.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -658,6 +658,13 @@ static void __init cpufeatures_setup_sta
cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
+ /*
+ * PKEY was not in the initial base or feature node
+ * specification, but it should become optional in the next
+ * cpu feature version sequence.
+ */
+ cur_cpu_spec->cpu_features |= CPU_FTR_PKEY;

static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)