From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97E72396579; Thu, 9 Jul 2026 00:52:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783558376; cv=none; b=WxOO+EdHgpx6gYDcbTBsUGD+/vYiRNiF6Tj5pYutiitvv5FbjvHoN9dQjrkjOo+xHrMfD1kVgYBnqomX1bFdZkURs+1Fu7p/5i8/zjytSURU8OKFHk9uen9F6SSrhQCT4HFvSRtPPdYaKQZ5B1YuoBN+0IftpMn9NXTcdAmN8Tc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783558376; c=relaxed/simple; bh=neew/zQKQc9VPVi7macEuVISGaMZgaNeHcW5WvUvtiM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=gKvThChSCOuWEgNp71tzlGGZTv0GA6cvulEnJsmVUZQd/9kf6vhq55ZPyMHJiJZlGQeT95+e+pynQDww6mqOFBefoj2QGcGGBNxrMTtpNilRk60J5dk5oUOX1a8kmx1LhhOgzWOjf873U+rzljHorKS1YVd1E6ayc2b7uRflaDw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JUMu2w8v; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JUMu2w8v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4780E1F000E9; Thu, 9 Jul 2026 00:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783558375; bh=X4HlyMbyPhKCnIL3AvhZ79kxUeT3XQMJg0KjZKyp1dU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=JUMu2w8vQvMzmt9ADpIztO/PmzTnYneDyT5/F4o3erz9msnqX3P9z8fXTBB9hefcO TimcoUmZWagvDEJ06ggP1wAQ4rWD+dgTPXEScAXrKiCco1TzKYI2IgCZ2f+vVn6fZO hbf1Tq5GozmKATaallMSTfrvqR4qFJ0QaCAK58ExTcQ2JDNulgpHZWy9+dlVgE5l4C gU9CbfOh50UD0HXSxQ1MrmGxUYys+IKzRKRggaPOcWdBKQfGSSF45BIjzctNUUbE88 dkjnNGci72JcbcosJACqzDqma7Sx7SZJEF4Cw8KFd1HWN/UlYee5iiT3U/V5qR60Gu mLx7XHCrmy9lw== From: Mark Brown Date: Thu, 09 Jul 2026 01:51:41 +0100 Subject: [PATCH v11 04/29] arm64/sve: Factor virtualizable VL discovery out of SVE specific code Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260709-kvm-arm64-sme-v11-4-32799f66db9d@kernel.org> References: <20260709-kvm-arm64-sme-v11-0-32799f66db9d@kernel.org> In-Reply-To: <20260709-kvm-arm64-sme-v11-0-32799f66db9d@kernel.org> To: Marc Zyngier , Joey Gouly , Catalin Marinas , Suzuki K Poulose , Will Deacon , Paolo Bonzini , Jonathan Corbet , Shuah Khan , Oliver Upton Cc: Dave Martin , Fuad Tabba , Mark Rutland , Ben Horgan , Jean-Philippe Brucker , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Peter Maydell , Eric Auger , Mark Brown X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2673; i=broonie@kernel.org; h=from:subject:message-id; bh=neew/zQKQc9VPVi7macEuVISGaMZgaNeHcW5WvUvtiM=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBqTvC98EPz3V9/AxA2ctVBmogPMysf+ANGUElc6 7/1yiSJoPeJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCak7wvQAKCRAk1otyXVSH 0GhLCACDfFY28B+Wo/awGJVxfMtSbkkTmZNrOlZrdlIvJ6eQMO87Ms6n3g0qMcvOC7vXYMzZS39 cgBX2ZmVnnOdwLoEcdBaBBFkpjQ4DLlt5WmeNT8JgE+Dh1DcrO+dlq8otC3ymw4u4n7fwflzon7 YsmNKzD478AXFIEisgACc5zZXsG6OjXy3OWxvQXIbb25AhX6jYAiaTV+rCDTu9GO8JNNguwOA2Q xGnJjf7p/Z0JW6eTKYzVGpiEjXfnE6KEvggu7yB+dsVpo6zx+9PVT6tNT7uYqIrloX5YSzkgS0s 0KOioxQA4AaDKZKn26K+bK7yhXYky8q5SzPDHC/S4n+azFL6 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB In preparation for reuising it for SME pull the code for discovering the maximum virtualizable vector length out of sve_setup() into a separate function. Signed-off-by: Mark Brown --- arch/arm64/kernel/fpsimd.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index dc1ad10e39a2..5c156e2a47ea 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1114,6 +1114,29 @@ int vec_verify_vq_map(enum vec_type type) return 0; } +static int vec_virtualisable_vl(struct vl_info *info) +{ + DECLARE_BITMAP(partial_only_map, SVE_VQ_MAX); + unsigned long b_min_partial, b_max_virt; + + bitmap_andnot(partial_only_map, info->vq_partial_map, info->vq_map, + SVE_VQ_MAX); + b_min_partial = find_last_bit(partial_only_map, SVE_VQ_MAX); + + /* All implemented VLs are virtualisable */ + if (b_min_partial >= SVE_VQ_MAX) + return info->max_vl; + + b_max_virt = find_next_bit(info->vq_map, SVE_VQ_MAX, b_min_partial); + + /* No implemented VLs are virtualisable */ + if (b_max_virt >= SVE_VQ_MAX) + return 0; + + /* At least one virtualisable VL exists */ + return sve_vl_from_vq(__bit_to_vq(b_max_virt)); +} + void cpu_enable_sve(const struct arm64_cpu_capabilities *__always_unused p) { write_sysreg(read_sysreg(CPACR_EL1) | CPACR_EL1_ZEN_EL1EN, CPACR_EL1); @@ -1125,8 +1148,6 @@ void cpu_enable_sve(const struct arm64_cpu_capabilities *__always_unused p) void __init sve_setup(void) { struct vl_info *info = &vl_info[ARM64_VEC_SVE]; - DECLARE_BITMAP(tmp_map, SVE_VQ_MAX); - unsigned long b; int max_bit; if (!system_supports_sve()) @@ -1149,21 +1170,7 @@ void __init sve_setup(void) */ set_sve_default_vl(find_supported_vector_length(ARM64_VEC_SVE, 64)); - bitmap_andnot(tmp_map, info->vq_partial_map, info->vq_map, - SVE_VQ_MAX); - - b = find_last_bit(tmp_map, SVE_VQ_MAX); - if (b >= SVE_VQ_MAX) - /* No non-virtualisable VLs found */ - info->max_virtualisable_vl = SVE_VQ_MAX; - else if (WARN_ON(b == SVE_VQ_MAX - 1)) - /* No virtualisable VLs? This is architecturally forbidden. */ - info->max_virtualisable_vl = SVE_VQ_MIN; - else /* b + 1 < SVE_VQ_MAX */ - info->max_virtualisable_vl = sve_vl_from_vq(__bit_to_vq(b + 1)); - - if (info->max_virtualisable_vl > info->max_vl) - info->max_virtualisable_vl = info->max_vl; + info->max_virtualisable_vl = vec_virtualisable_vl(info); pr_info("%s: maximum available vector length %u bytes per vector\n", info->name, info->max_vl); -- 2.47.3