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authorMark Brown <broonie@kernel.org>2024-02-14 00:06:33 +0100
committerWill Deacon <will@kernel.org>2024-02-20 13:19:16 +0100
commitd7b77a0d565b048cb0808fa8a4fb031352b22a01 (patch)
tree44c86cfbf3f63edd77af516c1af8a3840b59a042
parentarm64/sme: Restore SME registers on exit from suspend (diff)
downloadlinux-d7b77a0d565b048cb0808fa8a4fb031352b22a01.tar.xz
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arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend
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>
-rw-r--r--arch/arm64/kernel/fpsimd.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index d52592088afa..f27acca550d5 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -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);