openwrt/target/linux/bcm4908/patches-5.15/301-arm64-don-t-issue-HVC-on-boot.patch

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From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Thu, 12 Aug 2021 11:52:42 +0200
Subject: [PATCH] arm64: don't issue HVC on boot
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Broadcom's CFE loader seems to miss setting SCR_EL3.HCE which results in
generating an UNDEF and kernel panic on the first HVC.
HVC gets issued by kernels 5.12+ while booting, by kexec and KVM. Until
someone finds a workaround we have to avoid all above.
Workarounds: 0c93df9622d4 ("arm64: Initialise as nVHE before switching to VHE")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
arch/arm64/kernel/hyp-stub.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -238,7 +238,7 @@ SYM_FUNC_START(switch_to_vhe)
// Turn the world upside down
mov x0, #HVC_VHE_RESTART
- hvc #0
+// hvc #0
1:
ret
SYM_FUNC_END(switch_to_vhe)