From 19dd484cd19c308e2ea763f8d31e43a7f1ab6141 Mon Sep 17 00:00:00 2001 From: "Yury Norov (NVIDIA)" Date: Fri, 12 Sep 2025 20:09:05 -0400 Subject: [PATCH] arm64/fpsimd: simplify sme_setup() The function checks info->vq_map for emptiness right before calling find_last_bit(). We can use the find_last_bit() output and save on bitmap_empty() call, which is O(N). Signed-off-by: Yury Norov (NVIDIA) Signed-off-by: Will Deacon --- arch/arm64/kernel/fpsimd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index c37f02d7194e0..e3f8f51748bc9 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1265,6 +1265,8 @@ void __init sme_setup(void) if (!system_supports_sme()) return; + min_bit = find_last_bit(info->vq_map, SVE_VQ_MAX); + /* * SME doesn't require any particular vector length be * supported but it does require at least one. We should have @@ -1272,9 +1274,8 @@ void __init sme_setup(void) * let's double check here. The bitmap is SVE_VQ_MAP sized for * sharing with SVE. */ - WARN_ON(bitmap_empty(info->vq_map, SVE_VQ_MAX)); + WARN_ON(min_bit >= SVE_VQ_MAX); - min_bit = find_last_bit(info->vq_map, SVE_VQ_MAX); info->min_vl = sve_vl_from_vq(__bit_to_vq(min_bit)); max_bit = find_first_bit(info->vq_map, SVE_VQ_MAX); -- 2.47.3