6.6-stable review patch. If anyone has any objections, please let me know.
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From: Mark Brown broonie@kernel.org
[ 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@arm.com Signed-off-by: Mark Brown broonie@kernel.org Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-2-17e05e493471@kernel... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 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);