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arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend

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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@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-2-17e05e493471@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Mark Brown 2024-02-13 23:06:33 +00:00 committed by Will Deacon
parent 9533864816
commit d7b77a0d56
1 changed files with 2 additions and 0 deletions
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arch/arm64/kernel/fpsimd.c
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@ -1320,6 +1320,8 @@ 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);