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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 33063C5CFFE for ; Tue, 11 Dec 2018 10:20:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0336520811 for ; Tue, 11 Dec 2018 10:20:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="M2MaOeqz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0336520811 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:In-Reply-To: Date:References:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=m/dC+UmxgHnubBvqPKP3CkhNivekzqxtR0FyWx4ctDQ=; b=M2MaOeqzxSzCOK sEiBALSDn41MnSYPaLqLKj8RxGAkvBVztWNKQFz5FcbLdA6GSwZv8qCD8NCsvRsRXSVGZ23goibdR qxQClDjNSIwQRlMZ5OIBcmN82SkUhSyjkMVaQc4l40jpWPhKR7/+jzckabkooHarX1E67jOF2UFFU UT1pm6C6DZx7F7BUoCH7RqnYkTd58WVcmhsqwGjRzSXdHZq46aZ02vWyvd/x9tOjvLyN++oRxTbX7 3vp53Vsmxpyi7j5jyU36Jzywdwy5N7i2Soa7Rt954WWtoRwGjJPSSS9ZGHydaCMr7fGgsrYnfvmDV fAF905wUhM/5oGr6j0/Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWf9r-0003fG-9h; Tue, 11 Dec 2018 10:20:55 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWf9o-0003YJ-Fh for linux-riscv@lists.infradead.org; Tue, 11 Dec 2018 10:20:54 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 05C82AE06; Tue, 11 Dec 2018 10:20:41 +0000 (UTC) From: Andreas Schwab To: Atish Patra Subject: [PATCH v2] riscv: don't stop itself in smp_send_stop References: <72991c58-91f5-abb1-54f9-35ae4533a26e@wdc.com> X-Yow: I'm RELIGIOUS!! I love a man with a HAIRPIECE!! Equip me with MISSILES!! Date: Tue, 11 Dec 2018 11:20:40 +0100 In-Reply-To: (Andreas Schwab's message of "Mon, 10 Dec 2018 11:58:12 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.90 (gnu/linux) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181211_022052_666161_A3675D7C X-CRM114-Status: GOOD ( 13.24 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-riscv@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org Add IPI_CPU_STOP message and use it in smp_send_stop to stop other cpus, but not itself. Mark cpu offline on reception of IPI_CPU_STOP. Signed-off-by: Andreas Schwab --- arch/riscv/kernel/smp.c | 43 ++++++++++++++++++++++++++++++++++------- 1 file changed, 36 insertions(+), 7 deletions(-) diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 57b1383e5e..b813264416 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -31,6 +32,7 @@ enum ipi_message_type { IPI_RESCHEDULE, IPI_CALL_FUNC, + IPI_CPU_STOP, IPI_MAX }; @@ -66,6 +68,13 @@ int setup_profiling_timer(unsigned int multiplier) return -EINVAL; } +static void ipi_stop(void) +{ + set_cpu_online (smp_processor_id(), false); + while (1) + wait_for_interrupt(); +} + void riscv_software_interrupt(void) { unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits; @@ -94,6 +103,11 @@ void riscv_software_interrupt(void) generic_smp_call_function_interrupt(); } + if (ops & (1 << IPI_CPU_STOP)) { + stats[IPI_CPU_STOP]++; + ipi_stop(); + } + BUG_ON((ops >> IPI_MAX) != 0); /* Order data access and bit testing. */ @@ -121,6 +135,7 @@ send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) static const char * const ipi_names[] = { [IPI_RESCHEDULE] = "Rescheduling interrupts", [IPI_CALL_FUNC] = "Function call interrupts", + [IPI_CPU_STOP] = "CPU stop interrupts", }; void show_ipi_stats(struct seq_file *p, int prec) @@ -146,15 +161,29 @@ void arch_send_call_function_single_ipi(int cpu) send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC); } -static void ipi_stop(void *unused) -{ - while (1) - wait_for_interrupt(); -} - void smp_send_stop(void) { - on_each_cpu(ipi_stop, NULL, 1); + unsigned long timeout; + + if (num_online_cpus() > 1) { + cpumask_t mask; + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + + if (system_state <= SYSTEM_RUNNING) + pr_crit("SMP: stopping secondary CPUs\n"); + send_ipi_message(&mask, IPI_CPU_STOP); + } + + /* Wait up to one second for other CPUs to stop */ + timeout = USEC_PER_SEC; + while (num_online_cpus() > 1 && timeout--) + udelay(1); + + if (num_online_cpus() > 1) + pr_warning("SMP: failed to stop secondary CPUs %*pbl\n", + cpumask_pr_args(cpu_online_mask)); } void smp_send_reschedule(int cpu) -- 2.20.0 -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv