6.7-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Brown <broonie@xxxxxxxxxx>
[ Upstream commit d7b77a0d565b048cb0808fa8a4fb031352b22a01 ]
The fields in SMCR_EL1 reset to an architecturally UNKNOWN value. Since we
do not otherwise manage the traps configured in this register at runtime we
need to reconfigure them after a suspend in case nothing else was kind
enough to preserve them for us. Do so for SMCR_EL1.EZT0.
Fixes: d4913eee152d ("arm64/sme: Add basic enumeration for SME2")
Reported-by: Jackson Cooper-Driver <Jackson.Cooper-Driver@xxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-2-17e05e493471@xxxxxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/arm64/kernel/fpsimd.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index db1eba8d5f66d..0898ac9979045 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1348,6 +1348,8 @@ void sme_suspend_exit(void)
if (system_supports_fa64())
smcr |= SMCR_ELx_FA64;
+ if (system_supports_sme2())
+ smcr |= SMCR_ELx_EZT0;
write_sysreg_s(smcr, SYS_SMCR_EL1);
write_sysreg_s(0, SYS_SMPRI_EL1);
--
2.43.0
