From 79491ddfb42951f68eb727be60a1a6bd7803fbce Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 13 Feb 2024 23:06:33 +0000 Subject: [PATCH] arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend [ 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 Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-2-17e05e493471@kernel.org Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- 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 ce0bc01b4208..5cdfcc9e3e54 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1415,6 +1415,8 @@ 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);