Apparently it is possible for firmware to indicate that SMCCC_VERSION is

implemented but have that call return NOT_SUPPORTED.  Makes no sense,
but the SMCCC standard documents this and tells us to treat this as v1.0.
Change the code accordingly.  Turn a few checks that should always be true
into KASSERTs to keep the control flow simple.

ok patrick@

diff --git a/sys/dev/fdt/psci.c b/sys/dev/fdt/psci.c
index f0e37c5..26c328f 100644 (file)
--- a/sys/dev/fdt/psci.c
+++ b/sys/dev/fdt/psci.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: psci.c,v 1.8 2018/05/23 09:12:34 kettenis Exp $       */
+/*     $OpenBSD: psci.c,v 1.9 2021/10/10 16:20:37 kettenis Exp $       */
 
 /*
  * Copyright (c) 2016 Jonathan Gray <jsg@openbsd.org>
@@ -208,11 +208,15 @@ int32_t
 smccc_version(void)
 {
        struct psci_softc *sc = psci_sc;
+       int32_t version;
 
-       if (sc && sc->sc_callfn)
-               return (*sc->sc_callfn)(SMCCC_VERSION, 0, 0, 0);
+       KASSERT(sc && sc->sc_callfn);
+       version = (*sc->sc_callfn)(SMCCC_VERSION, 0, 0, 0);
+       if (version != PSCI_NOT_SUPPORTED)
+               return version;
 
-       return PSCI_NOT_SUPPORTED;
+       /* Treat NOT_SUPPORTED as 1.0 */
+       return 0x10000;
 }
 
 int32_t
@@ -220,10 +224,8 @@ smccc_arch_features(uint32_t arch_func_id)
 {
        struct psci_softc *sc = psci_sc;
 
-       if (sc && sc->sc_callfn)
-               return (*sc->sc_callfn)(SMCCC_ARCH_FEATURES, arch_func_id, 0, 0);
-
-       return PSCI_NOT_SUPPORTED;
+       KASSERT(sc && sc->sc_callfn);
+       return (*sc->sc_callfn)(SMCCC_ARCH_FEATURES, arch_func_id, 0, 0);
 }
 
 uint32_t