From nobody Wed Dec 17 14:01:45 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34D8BC77B75 for ; Wed, 19 Apr 2023 22:58:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233777AbjDSW6B (ORCPT ); Wed, 19 Apr 2023 18:58:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233532AbjDSW5h (ORCPT ); Wed, 19 Apr 2023 18:57:37 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 002148689 for ; Wed, 19 Apr 2023 15:57:22 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id d2e1a72fcca58-63b8b19901fso482898b3a.3 for ; Wed, 19 Apr 2023 15:57:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1681945042; x=1684537042; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=HWZTrwd5TxmiYLg/mD/63PXcodsl+Y0F8uDPTGYpPFY=; b=ENMXPNPKpUB8x1TeX9CInNTf6Pzm3ER8KeB8ofn5pxz8+lYuSyslgYS+81+WV7V/1A LEf1UqVF5i1wcOYXFEEwNvpTG7LVOyK7V5Mhz7v0lcNNeXQSBJN/9y2kPBa/eges+Jb3 b6xm1J9kPVn558DdKvWhugxeLv8noIfLhyE0A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681945042; x=1684537042; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=HWZTrwd5TxmiYLg/mD/63PXcodsl+Y0F8uDPTGYpPFY=; b=FvMZAIicvty5bpZJe+ih745/7PxOVk8Y/I0a7HUf2hxGoydAb36HAzrsT2NFSJ+jvF wfpzZowD+sPiMQlT1rnN6Su1XCV9UPYfGVOuJKmPukhiLpPU8+TIThN3H30Ag2WSz/+r jaFNVxPHlU4hV3Zcs2vQBYnAuOKFt+0yzD2oV0sNr2Lqnp4Q0OU0tCQcm/hhfl2N7HcZ t3UJj7r6/hUl+wSudyLW4EDI3oM3ciZPOB6Mz50KNmZ8XjLKv+Yh4kRT3HnDo/riooho smz8CCRoYHEFPXycISBN7lIBmpoMwkTNPsr/JW4K/nyJwwJjKcaxRzDE+4JCXng8/Yup WM/A== X-Gm-Message-State: AAQBX9eerhJnrCTIEjRyDUir0CZJQX38adsN7IEqfmbp6VU03n7YTMv2 m/LR0SLrgzb4gFbl1eJtOcVlaw== X-Google-Smtp-Source: AKy350bzal91TPSNwTZw0WiWqcU5p5zvcdk0BkVsNFuBNbks1jS5AwavXMPCBAcH6HwZUkYAxgIWew== X-Received: by 2002:a05:6a20:8b2f:b0:cc:5f27:d003 with SMTP id l47-20020a056a208b2f00b000cc5f27d003mr42212pzh.56.1681945041867; Wed, 19 Apr 2023 15:57:21 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:8b1:fa03:670e:b784]) by smtp.gmail.com with ESMTPSA id h15-20020a17090aea8f00b00246ea338c96sm1847101pjz.53.2023.04.19.15.57.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Apr 2023 15:57:21 -0700 (PDT) From: Douglas Anderson To: Catalin Marinas , Will Deacon , Sumit Garg , Daniel Thompson , Marc Zyngier , Mark Rutland Cc: ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net, Chen-Yu Tsai , Masayoshi Mizuma , Peter Zijlstra , Ard Biesheuvel , "Rafael J . Wysocki" , linux-arm-kernel@lists.infradead.org, Stephen Boyd , Lecopzer Chen , Thomas Gleixner , linux-perf-users@vger.kernel.org, Douglas Anderson , Alexandru Elisei , Masayoshi Mizuma , linux-kernel@vger.kernel.org Subject: [PATCH v8 09/10] arm64: kgdb: Roundup cpus using IPI as NMI Date: Wed, 19 Apr 2023 15:56:03 -0700 Message-ID: <20230419155341.v8.9.I2ef26d1b3bfbed2d10a281942b0da7d9854de05e@changeid> X-Mailer: git-send-email 2.40.0.634.g4ca3ef3211-goog In-Reply-To: <20230419225604.21204-1-dianders@chromium.org> References: <20230419225604.21204-1-dianders@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Sumit Garg arm64 platforms with GICv3 or later supports pseudo NMIs which can be leveraged to roundup CPUs which are stuck in hard lockup state with interrupts disabled that wouldn't be possible with a normal IPI. So instead switch to roundup CPUs using IPI turned as NMI. And in case a particular arm64 platform doesn't supports pseudo NMIs, it will switch back to default kgdb CPUs roundup mechanism. Signed-off-by: Sumit Garg Tested-by: Chen-Yu Tsai Signed-off-by: Douglas Anderson --- (no changes since v1) arch/arm64/kernel/ipi_nmi.c | 5 +++++ arch/arm64/kernel/kgdb.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/arm64/kernel/ipi_nmi.c b/arch/arm64/kernel/ipi_nmi.c index c592e92b8cbf..2adaaf1519e5 100644 --- a/arch/arm64/kernel/ipi_nmi.c +++ b/arch/arm64/kernel/ipi_nmi.c @@ -8,6 +8,7 @@ =20 #include #include +#include #include #include =20 @@ -45,10 +46,14 @@ bool arch_trigger_cpumask_backtrace(const cpumask_t *ma= sk, bool exclude_self) static irqreturn_t ipi_nmi_handler(int irq, void *data) { irqreturn_t ret =3D IRQ_NONE; + unsigned int cpu =3D smp_processor_id(); =20 if (nmi_cpu_backtrace(get_irq_regs())) ret =3D IRQ_HANDLED; =20 + if (!kgdb_nmicallback(cpu, get_irq_regs())) + ret =3D IRQ_HANDLED; + return ret; } =20 diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index cda9c1e9864f..2c85bc1df013 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -17,6 +17,7 @@ =20 #include #include +#include #include #include =20 @@ -354,3 +355,20 @@ int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) return aarch64_insn_write((void *)bpt->bpt_addr, *(u32 *)bpt->saved_instr); } + +void kgdb_roundup_cpus(void) +{ + struct cpumask mask; + + if (!arm64_supports_nmi()) { + kgdb_smp_call_nmi_hook(); + return; + } + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(raw_smp_processor_id(), &mask); + if (cpumask_empty(&mask)) + return; + + arm64_send_nmi(&mask); +} --=20 2.40.0.634.g4ca3ef3211-goog