This is a note to let you know that I've just added the patch titled
arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-sme-restore-smcr_el1.ezt0-on-exit-from-suspend.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c28c38b5320b206876828cde7f6fb6406b19cec7
Author: Mark Brown <broonie@xxxxxxxxxx>
Date: Tue Feb 13 23:06:33 2024 +0000
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 <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>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index ce0bc01b4208d..5cdfcc9e3e54b 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);
