From nobody Fri Dec 19 08:06:31 2025 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 8A38C215764 for ; Wed, 26 Feb 2025 03:01:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740538909; cv=none; b=IGMIjOxS8FyBEF5ZK86INB64gBPXrmWqAptxNBPwlFGrvlGfH8W41qHPiENW4LVpQMGGgB1mg1W4lIqCMeDal7ezcC13aWQ2bedL6e4E8mXYfHO2eu1kQgNSz4eRhf9MuIBKfn7419mV80sK3T/Uo03BWIp/oiw3MDrFlj26k8c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740538909; c=relaxed/simple; bh=JUwyQmPKvTyN71rE3To1nzsYszhH81j9dtrjka017cg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IrWqAM/0Onw3EuHo1M0RZvbUoBPIqPHyWhLsI2/Eg3mKh9VS2lm09P0u5gx2yJOlqI2q1nfdQaxR24xQ3sBAprcYdalxV1KBPnFJHmnhjJeQ8mR11Qos+LbOEy5g99X/yz6me0EHuv9WOeqsA07Y6KtZ5TqscT54oAvlqbCV0u4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=shelob.surriel.com; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shelob.surriel.com Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tn7fw-000000001Y5-0hvS; Tue, 25 Feb 2025 22:01:32 -0500 From: Rik van Riel To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jackmanb@google.com, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com, Manali.Shukla@amd.com, mingo@kernel.org, Rik van Riel Subject: [PATCH v14 04/13] x86/mm: use INVLPGB for kernel TLB flushes Date: Tue, 25 Feb 2025 22:00:39 -0500 Message-ID: <20250226030129.530345-5-riel@surriel.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250226030129.530345-1-riel@surriel.com> References: <20250226030129.530345-1-riel@surriel.com> 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 Sender: riel@surriel.com Content-Type: text/plain; charset="utf-8" Use broadcast TLB invalidation for kernel addresses when available. Remove the need to send IPIs for kernel TLB flushes. Signed-off-by: Rik van Riel Tested-by: Manali Shukla Tested-by: Brendan Jackman Tested-by: Michael Kelley Acked-by: Dave Hansen --- arch/x86/mm/tlb.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index dbcb5c968ff9..f44a03bca41c 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1077,6 +1077,18 @@ void flush_tlb_all(void) on_each_cpu(do_flush_tlb_all, NULL, 1); } =20 +static void invlpgb_kernel_range_flush(struct flush_tlb_info *info) +{ + unsigned long addr, nr; + + for (addr =3D info->start; addr < info->end; addr +=3D nr << PAGE_SHIFT) { + nr =3D (info->end - addr) >> PAGE_SHIFT; + nr =3D clamp_val(nr, 1, invlpgb_count_max); + invlpgb_flush_addr_nosync(addr, nr); + } + __tlbsync(); +} + static void do_kernel_range_flush(void *info) { struct flush_tlb_info *f =3D info; @@ -1087,6 +1099,22 @@ static void do_kernel_range_flush(void *info) flush_tlb_one_kernel(addr); } =20 +static void kernel_tlb_flush_all(struct flush_tlb_info *info) +{ + if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) + invlpgb_flush_all(); + else + on_each_cpu(do_flush_tlb_all, NULL, 1); +} + +static void kernel_tlb_flush_range(struct flush_tlb_info *info) +{ + if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) + invlpgb_kernel_range_flush(info); + else + on_each_cpu(do_kernel_range_flush, info, 1); +} + void flush_tlb_kernel_range(unsigned long start, unsigned long end) { struct flush_tlb_info *info; @@ -1097,9 +1125,9 @@ void flush_tlb_kernel_range(unsigned long start, unsi= gned long end) TLB_GENERATION_INVALID); =20 if (info->end =3D=3D TLB_FLUSH_ALL) - on_each_cpu(do_flush_tlb_all, NULL, 1); + kernel_tlb_flush_all(info); else - on_each_cpu(do_kernel_range_flush, info, 1); + kernel_tlb_flush_range(info); =20 put_flush_tlb_info(); } --=20 2.47.1