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From:   Mark Brown <broonie@kernel.org>
Date:   Tue, 27 Dec 2022 13:06:35 +0000
Subject: [PATCH 1/4] kselftest/arm64: Fix syscall-abi for systems without 128 bit SME
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Message-Id: <20221223-arm64-syscall-abi-sme-only-v1-1-4fabfbd62087@kernel.org>
References: <20221223-arm64-syscall-abi-sme-only-v1-0-4fabfbd62087@kernel.org>
In-Reply-To: <20221223-arm64-syscall-abi-sme-only-v1-0-4fabfbd62087@kernel.org>
To:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org>
Cc:     Shuah Khan <skhan@linuxfoundation.org>,
        linux-arm-kernel@lists.infradead.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        Mark Brown <broonie@kernel.org>
Precedence: bulk

SME does not mandate any specific VL so we may not have 128 bit SME but
the algorithm used for enumerating VLs assumes that we will. Add the
required check to ensure that the algorithm terminates.

Fixes: 43e3f85523e4 ("kselftest/arm64: Add SME support to syscall ABI test")
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/abi/syscall-abi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/arm64/abi/syscall-abi.c b/tools/testing/selftests/arm64/abi/syscall-abi.c
index dd7ebe536d05..ffe719b50c21 100644
--- a/tools/testing/selftests/arm64/abi/syscall-abi.c
+++ b/tools/testing/selftests/arm64/abi/syscall-abi.c
@@ -390,6 +390,10 @@ static void test_one_syscall(struct syscall_cfg *cfg)
 
 			sme_vl &= PR_SME_VL_LEN_MASK;
 
+			/* Found lowest VL */
+			if (sve_vq_from_vl(sme_vl) > sme_vq)
+				break;
+
 			if (sme_vq != sve_vq_from_vl(sme_vl))
 				sme_vq = sve_vq_from_vl(sme_vl);
 
@@ -461,6 +465,10 @@ int sme_count_vls(void)
 
 		vl &= PR_SME_VL_LEN_MASK;
 
+		/* Found lowest VL */
+		if (sve_vq_from_vl(vl) > vq)
+			break;
+
 		if (vq != sve_vq_from_vl(vl))
 			vq = sve_vq_from_vl(vl);
 

-- 
2.30.2