From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAE4AC4363A for ; Thu, 29 Oct 2020 14:59:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F11120756 for ; Thu, 29 Oct 2020 14:59:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="VaV6/Go+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728016AbgJ2O7F (ORCPT ); Thu, 29 Oct 2020 10:59:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728006AbgJ2O7E (ORCPT ); Thu, 29 Oct 2020 10:59:04 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AE54C0613CF for ; Thu, 29 Oct 2020 07:59:04 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id 1so1423100ple.2 for ; Thu, 29 Oct 2020 07:59:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=vRwqyoyBEeMity0cyda+uu/rJEIK2HXvyD5N7tr1KQA=; b=VaV6/Go+khoksNqGfCUHDeBSHVzAJEA+svM5XJTrMpaiwQW5OlTmX/9P+0AhI2Wgrc eaYH6kMXDCKlBsBdwgq0a2AvqpQJFku5TSiBp8O9O1W6GvFJvEqB0WWZiW7gaMNQT2PN JjueUsyk1j1ZDQ4eRWBrzvLUpzbK6D7wXp99Ea6n2DFJoqRpGOqqVsM7B4ahs+rEim/x 7GCHwMuXp3+jVVF5LWSemEJME2d/XEGagujBza5F+oXi2yDsg2/yn7tJa2lMuruEsQyG zzn4vNRJTm1+P8cplXnjZhqwceqWIQYRcmtckz5f8cQH8CuKEpDZGwf2pC+80kwUCRzu /OlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=vRwqyoyBEeMity0cyda+uu/rJEIK2HXvyD5N7tr1KQA=; b=A+ECdSx4yRFBrz7SiVshaU2+RjjwBeZW+vB1QuMh+Jb9WzpiHABomg4B41JQJ5fA1C sfFJWeb5h/6lhhGPkDd3+5EipckoJnB78mcCE7n3EeC7yf+lwhW3xMA0Z6PSTlsCWloL 18xXY3GKn3dxbL5oSJ3foVvp1/5YWLC51nWRmds0WZj7QKSXYQq5WVqng2HqXoU2TFkr fyKiVCiZhUpkDfeyB118Oxpzxpd4O7Iz7LSoYPfwFGGbSVf6MSJMDrC6YbKvSur45I1B r4fjs+A6lNOLDa59dRHZ5ktL0SqL4/GCGzSIaICoBsAqAAiR5BYY56gBFNGVDTSJBT5K JgrA== X-Gm-Message-State: AOAM5327eyyXoCOUOatxdBxtUnxvp9UZLSeHTmDtRMi0+10rG36hevtV TV8L+1pp17VQzZIa/33jNx13OA== X-Google-Smtp-Source: ABdhPJyZHAWcF9UXIuaciASbmUM2nhi5xQ3CWgJ6UeAed6E2uiOLILawF0T8+k3uKF2R+aWSxlR5CA== X-Received: by 2002:a17:902:7c86:b029:d5:f680:f756 with SMTP id y6-20020a1709027c86b02900d5f680f756mr4717679pll.39.1603983543591; Thu, 29 Oct 2020 07:59:03 -0700 (PDT) Received: from localhost.localdomain ([117.252.71.231]) by smtp.gmail.com with ESMTPSA id j11sm3085082pfc.64.2020.10.29.07.58.54 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Oct 2020 07:59:02 -0700 (PDT) From: Sumit Garg To: maz@kernel.org, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, tglx@linutronix.de, jason@lakedaemon.net, linux@armlinux.org.uk, tsbogend@alpha.franken.de, mpe@ellerman.id.au, davem@davemloft.net, mingo@redhat.com, bp@alien8.de, x86@kernel.org, mark.rutland@arm.com, julien.thierry.kdev@gmail.com, dianders@chromium.org, daniel.thompson@linaro.org, jason.wessel@windriver.com, msys.mizuma@gmail.com, ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net, linux-kernel@vger.kernel.org, Sumit Garg Subject: [PATCH v6 6/7] kgdb: roundup: Allow runtime arch specific override Date: Thu, 29 Oct 2020 20:26:26 +0530 Message-Id: <1603983387-8738-7-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1603983387-8738-1-git-send-email-sumit.garg@linaro.org> References: <1603983387-8738-1-git-send-email-sumit.garg@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a new API kgdb_arch_roundup_cpus() for a particular archichecture to override default kgdb roundup and if it detects at runtime to not support NMI roundup then it can fallback to default implementation using async SMP cross-calls. Currently such an architecture example is arm64 supporting pseudo NMIs feature which is only available on platforms which have support for GICv3 or later version. Signed-off-by: Sumit Garg --- arch/powerpc/kernel/kgdb.c | 3 ++- arch/sparc/kernel/smp_64.c | 3 ++- arch/x86/kernel/kgdb.c | 6 ++++-- include/linux/kgdb.h | 5 +++-- kernel/debug/debug_core.c | 10 +++++++++- 5 files changed, 20 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index 4090802..126575d 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -125,9 +125,10 @@ static int kgdb_debugger_ipi(struct pt_regs *regs) } #ifdef CONFIG_SMP -void kgdb_roundup_cpus(void) +bool kgdb_arch_roundup_cpus(void) { smp_send_debugger_break(); + return true; } #endif diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index e38d8bf..c459c83 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -1014,9 +1014,10 @@ void flush_dcache_page_all(struct mm_struct *mm, struct page *page) } #ifdef CONFIG_KGDB -void kgdb_roundup_cpus(void) +bool kgdb_arch_roundup_cpus(void) { smp_cross_call(&xcall_kgdb_capture, 0, 0, 0); + return true; } #endif diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index ff7878d..1b756d9 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -404,7 +404,8 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs) #ifdef CONFIG_SMP /** - * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * kgdb_arch_roundup_cpus - Get other CPUs into a holding pattern + * in an architectural specific manner * * On SMP systems, we need to get the attention of the other CPUs * and get them be in a known state. This should do what is needed @@ -414,9 +415,10 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs) * * On non-SMP systems, this is not called. */ -void kgdb_roundup_cpus(void) +bool kgdb_arch_roundup_cpus(void) { apic_send_IPI_allbutself(NMI_VECTOR); + return true; } #endif diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 0d6cf64..f9db5b8 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -200,7 +200,8 @@ kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer, extern void kgdb_call_nmi_hook(void *ignored); /** - * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * kgdb_arch_roundup_cpus - Get other CPUs into a holding pattern + * in an architectural specific manner * * On SMP systems, we need to get the attention of the other CPUs * and get them into a known state. This should do what is needed @@ -210,7 +211,7 @@ extern void kgdb_call_nmi_hook(void *ignored); * * On non-SMP systems, this is not called. */ -extern void kgdb_roundup_cpus(void); +extern bool kgdb_arch_roundup_cpus(void); /** * kgdb_arch_set_pc - Generic call back to the program counter diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1e75a89..27e401c 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -241,13 +241,21 @@ void __weak kgdb_call_nmi_hook(void *ignored) } NOKPROBE_SYMBOL(kgdb_call_nmi_hook); -void __weak kgdb_roundup_cpus(void) +bool __weak kgdb_arch_roundup_cpus(void) +{ + return false; +} + +static void kgdb_roundup_cpus(void) { call_single_data_t *csd; int this_cpu = raw_smp_processor_id(); int cpu; int ret; + if (kgdb_arch_roundup_cpus()) + return; + for_each_online_cpu(cpu) { /* No need to roundup ourselves */ if (cpu == this_cpu) -- 2.7.4