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From f5a31b4f4ea8daaa0d337d5a2322ddb1912083fc Mon Sep 17 00:00:00 2001
From: Qi Feng <qi.feng@arm.com>
Date: Wed, 26 May 2021 17:52:01 +0800
Subject: [PATCH] Allow --enable-psci to choose between smc and hvc
According to Armv8-R AArch64 manual [1], Armv8-R AArch64 does not
support smc:
- Pseudocode for AArch64.CheckForSMCUndefOrTrap has this snippet:
if !HaveEL(EL3) || PSTATE.EL == EL0 then
UNDEFINED;
And Armv8-R AArch64 does not have EL3.
- In the document of HCR_EL2 TSC bit:
If EL3 is not implemented and HCR_EL2.NV is 0, it is IMPLEMENTATION
DEFINED whether this bit is:
- RES0.
- Implemented with the functionality as described in HCR_EL2.TSC.
So hvc is needed in this situation. And due to the lack of libfdt, the
psci method cannot be modified at runtime.
To use smc, use --enable-psci or --enable-psci=smc.
To use hvc, use --enable-psci=hvc.
[1]: https://developer.arm.com/documentation/ddi0600/latest/
Issue-Id: SCM-2654
Upstream-Status: Pending
Signed-off-by: Qi Feng <qi.feng@arm.com>
Change-Id: Ib8afabdad2d98bc37371d165bbb6f1f9b88bfc87
Upstream-Status: Pending
Signed-off-by: Huifeng Zhang <Huifeng.Zhang@arm.com>
---
Makefile.am | 10 +++++-----
configure.ac | 14 +++++++++-----
2 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index f941b07..88a27de 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -50,11 +50,11 @@ endif
if PSCI
ARCH_OBJ += psci.o
COMMON_OBJ += psci.o
-PSCI_NODE := psci { \
- compatible = \"arm,psci\"; \
- method = \"smc\"; \
- cpu_on = <$(PSCI_CPU_ON)>; \
- cpu_off = <$(PSCI_CPU_OFF)>; \
+PSCI_NODE := psci { \
+ compatible = \"arm,psci\"; \
+ method = \"$(PSCI_METHOD)\"; \
+ cpu_on = <$(PSCI_CPU_ON)>; \
+ cpu_off = <$(PSCI_CPU_OFF)>; \
};
CPU_NODES := $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/addpsci.pl $(KERNEL_DTB))
else
diff --git a/configure.ac b/configure.ac
index 9e3b722..53e51be 100644
--- a/configure.ac
+++ b/configure.ac
@@ -83,13 +83,17 @@ AS_IF([test "x$X_IMAGE" != "x"],
# Allow a user to pass --enable-psci
AC_ARG_ENABLE([psci],
AS_HELP_STRING([--disable-psci], [disable the psci boot method]),
- [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_PSCI" != "xyes" -a "x$KERNEL_ES" = "x32"],
+ [case "${enableval}" in
+ yes|smc) USE_PSCI=smc ;;
+ hvc) USE_PSCI=hvc ;;
+ *) AC_MSG_ERROR([Bad value "${enableval}" for --enable-psci. Use "smc" or "hvc"]) ;;
+ esac], [USE_PSCI="yes"])
+AM_CONDITIONAL([PSCI], [test "x$USE_PSCI" = "xyes" -o "x$USE_PSCI" = "xsmc" -o "x$USE_PSCI" = "xhvc"])
+
+AS_IF([test "x$USE_PSCI" = "xno" -a "x$KERNEL_ES" = "x32"],
[AC_MSG_ERROR([With an AArch32 kernel, boot method must be PSCI.])]
)
+AC_SUBST([PSCI_METHOD], [$USE_PSCI])
# Allow a user to pass --with-initrd
AC_ARG_WITH([initrd],
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