From: Mark Brown <broonie@kernel.org> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org> Cc: Marc Zyngier <maz@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Zhang Lei <zhang.lei@jp.fujitsu.com>, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown <broonie@kernel.org> Subject: [PATCH v2 0/3] arm64/sve: Document our actual SVE syscall ABI Date: Mon, 15 Aug 2022 14:26:19 +0100 [thread overview] Message-ID: <20220815132622.220118-1-broonie@kernel.org> (raw) Currently our SVE syscall ABI documentation does not reflect the actual implemented ABI, it says that register state not shared with FPSIMD becomes undefined on syscall when in reality we always clear it. Since changing this would cause a change in the observed kernel behaviour there is a substantial desire to avoid taking advantage of the documented ABI so instead let's document what we actually do so it's clear that it is in reality an ABI. There has been some pushback on tightening the documentation in the past but it is hard to see who that helps, it makes the implementation decisions less clear and makes it harder for people to discover and make use of the actual ABI. The main practical concern is that qemu's user mode does not currently flush the registers. v2: - Rebase onto v6.0-rc1. Mark Brown (3): kselftest/arm64: Correct buffer allocation for SVE Z registers arm64/sve: Document our actual ABI for clearing registers on syscall kselftest/arm64: Enforce actual ABI for SVE syscalls Documentation/arm64/sve.rst | 2 +- .../testing/selftests/arm64/abi/syscall-abi.c | 61 ++++++++++++------- 2 files changed, 41 insertions(+), 22 deletions(-) base-commit: 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org> Cc: Marc Zyngier <maz@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Zhang Lei <zhang.lei@jp.fujitsu.com>, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown <broonie@kernel.org> Subject: [PATCH v2 0/3] arm64/sve: Document our actual SVE syscall ABI Date: Mon, 15 Aug 2022 14:26:19 +0100 [thread overview] Message-ID: <20220815132622.220118-1-broonie@kernel.org> (raw) Currently our SVE syscall ABI documentation does not reflect the actual implemented ABI, it says that register state not shared with FPSIMD becomes undefined on syscall when in reality we always clear it. Since changing this would cause a change in the observed kernel behaviour there is a substantial desire to avoid taking advantage of the documented ABI so instead let's document what we actually do so it's clear that it is in reality an ABI. There has been some pushback on tightening the documentation in the past but it is hard to see who that helps, it makes the implementation decisions less clear and makes it harder for people to discover and make use of the actual ABI. The main practical concern is that qemu's user mode does not currently flush the registers. v2: - Rebase onto v6.0-rc1. Mark Brown (3): kselftest/arm64: Correct buffer allocation for SVE Z registers arm64/sve: Document our actual ABI for clearing registers on syscall kselftest/arm64: Enforce actual ABI for SVE syscalls Documentation/arm64/sve.rst | 2 +- .../testing/selftests/arm64/abi/syscall-abi.c | 61 ++++++++++++------- 2 files changed, 41 insertions(+), 22 deletions(-) base-commit: 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2022-08-15 13:27 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-08-15 13:26 Mark Brown [this message] 2022-08-15 13:26 ` [PATCH v2 0/3] arm64/sve: Document our actual SVE syscall ABI Mark Brown 2022-08-15 13:26 ` [PATCH v2 1/3] kselftest/arm64: Correct buffer allocation for SVE Z registers Mark Brown 2022-08-15 13:26 ` Mark Brown 2022-08-15 13:26 ` [PATCH v2 2/3] arm64/sve: Document our actual ABI for clearing registers on syscall Mark Brown 2022-08-15 13:26 ` Mark Brown 2022-08-15 13:26 ` [PATCH v2 3/3] kselftest/arm64: Enforce actual ABI for SVE syscalls Mark Brown 2022-08-15 13:26 ` Mark Brown
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