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[73.224.175.84]) by smtp.gmail.com with ESMTPSA id 00721157ae682-72f791a3fbfsm14663937b3.48.2025.09.12.17.09.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Sep 2025 17:09:08 -0700 (PDT) From: "Yury Norov (NVIDIA)" To: Catalin Marinas , Will Deacon , Mark Rutland , Mark Brown , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: "Yury Norov (NVIDIA)" Subject: [PATCH] arm64/fpsimd: simplify sme_setup() Date: Fri, 12 Sep 2025 20:09:05 -0400 Message-ID: <20250913000906.67086-1-yury.norov@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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) --- 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 c37f02d7194e..e3f8f51748bc 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; =20 + min_bit =3D 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 >=3D SVE_VQ_MAX); =20 - min_bit =3D find_last_bit(info->vq_map, SVE_VQ_MAX); info->min_vl =3D sve_vl_from_vq(__bit_to_vq(min_bit)); =20 max_bit =3D find_first_bit(info->vq_map, SVE_VQ_MAX); --=20 2.43.0