[boot-wrapper v3 3/4] aarch64: Implement PSCI for Armv8-R

[Luca Fancellu <luca.fancellu@arm.com>]

Armv8-R doesn't have EL3, so the PSCI vector needs to be
installed in VBAR_EL2 and the conduit needs to be 'hcv'
instead of 'smc'.

Implement the modifications needed when --with-bw-arch is
'aarch64-r'.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
Changes from v2:
 - Major rework, reason in the cover letter.
---
 Makefile.am         |  2 +-
 arch/aarch64/init.c | 14 +++++++++++---
 configure.ac        |  3 +++
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index bf97b989d5d7..62e2988c0dd3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -57,7 +57,7 @@ ARCH_OBJ	+= psci.o
 COMMON_OBJ	+= psci.o
 PSCI_NODE	:= psci {				\
 			compatible = \"arm,psci\";	\
-			method = \"smc\";		\
+			method = \"$(PSCI_METHOD)\";	\
 			cpu_on = <$(PSCI_CPU_ON)>;	\
 			cpu_off = <$(PSCI_CPU_OFF)>;	\
 		   };
diff --git a/arch/aarch64/init.c b/arch/aarch64/init.c
index b0abde11ebd6..d8cf390dce20 100644
--- a/arch/aarch64/init.c
+++ b/arch/aarch64/init.c
@@ -211,12 +211,20 @@ extern char psci_vectors[];
 
 static void cpu_init_psci_arch(unsigned int cpu)
 {
-	if (mrs(CurrentEL) != CURRENTEL_EL3) {
+		switch (mrs(CurrentEL)) {
+#if !defined(BOOTWRAPPER_64R)
+	case CURRENTEL_EL3:
+		msr(VBAR_EL3, (unsigned long)psci_vectors);
+		break;
+#else
+	case CURRENTEL_EL2:
+		msr(VBAR_EL2, (unsigned long)psci_vectors);
+		break;
+#endif
+	default:
 		print_cpu_warn(cpu, "PSCI could not be initialized (not booted at EL3).\r\n");
 		return;
 	}
-
-	msr(VBAR_EL3, (unsigned long)psci_vectors);
 	isb();
 }
 #else
diff --git a/configure.ac b/configure.ac
index 88dbf9ba4f08..381f82612434 100644
--- a/configure.ac
+++ b/configure.ac
@@ -107,6 +107,9 @@ AC_ARG_ENABLE([psci],
 	[USE_PSCI=$enableval], [USE_PSCI="yes"])
 AM_CONDITIONAL([PSCI], [test "x$USE_PSCI" = "xyes"])
 AS_IF([test "x$USE_PSCI" = "xyes"], [], [USE_PSCI=no])
+AS_IF([test "x$USE_ARCH" = "xaarch64-r"],
+	AC_SUBST([PSCI_METHOD], [hvc]), AC_SUBST([PSCI_METHOD], [smc])
+)
 
 AS_IF([test "x$USE_PSCI" != "xyes" -a "x$KERNEL_ES" = "x32"],
 	[AC_MSG_ERROR([With an AArch32 kernel, boot method must be PSCI.])]
-- 
2.34.1