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| author | Mark Brown <broonie@kernel.org> | 2023-06-09 23:43:41 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-06-16 18:43:09 +0100 |
| commit | af3215fd02308c9aa982a028284d6414eeb60c04 (patch) | |
| tree | 4878fbde35330bdedf31015541c794a62ace95e3 /arch/arm64 | |
| parent | ab9b4008092c86dc12497af155a0901cc1156999 (diff) | |
| download | lwn-af3215fd02308c9aa982a028284d6414eeb60c04.tar.gz lwn-af3215fd02308c9aa982a028284d6414eeb60c04.zip | |
arm64/fpsimd: Exit streaming mode when flushing tasks
Ensure there is no path where we might attempt to save SME state after we
flush a task by updating the SVCR register state as well as updating our
in memory state. I haven't seen a specific case where this is happening or
seen a path where it might happen but for the cost of a single low overhead
instruction it seems sensible to close the potential gap.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230607-arm64-flush-svcr-v2-1-827306001841@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 2fbafa5cc7ac..7a1aeb95d7c3 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1649,6 +1649,7 @@ void fpsimd_flush_thread(void) fpsimd_flush_thread_vl(ARM64_VEC_SME); current->thread.svcr = 0; + sme_smstop(); } current->thread.fp_type = FP_STATE_FPSIMD; |