From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Anders Roxell <anders.roxell@linaro.org>,
Naresh Kamboju <naresh.kamboju@linaro.org>,
Mark Brown <broonie@kernel.org>
Subject: [PATCH] arm64/fpsimd: Exit streaming mode when flushing tasks
Date: Wed, 07 Jun 2023 21:30:51 +0100 [thread overview]
Message-ID: <20230607-arm64-flush-svcr-v1-1-7821a6199e0a@kernel.org> (raw)
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>
---
arch/arm64/kernel/fpsimd.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 2fbafa5cc7ac..1627e0efe39a 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_sm();
}
current->thread.fp_type = FP_STATE_FPSIMD;
---
base-commit: 44c026a73be8038f03dbdeef028b642880cf1511
change-id: 20230607-arm64-flush-svcr-47cc76a8cbbc
Best regards,
--
Mark Brown <broonie@kernel.org>
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next reply other threads:[~2023-06-07 20:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-07 20:30 Mark Brown [this message]
2023-06-08 15:28 ` [PATCH] arm64/fpsimd: Exit streaming mode when flushing tasks Anders Roxell
2023-06-08 15:51 ` Mark Rutland
2023-06-08 16:04 ` Mark Brown
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