From patchwork Mon Dec 3 18:05:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10710305 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14D2D1057 for ; Mon, 3 Dec 2018 18:09:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06EC72A823 for ; Mon, 3 Dec 2018 18:09:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EE1AA2A852; Mon, 3 Dec 2018 18:09:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 97D842A823 for ; Mon, 3 Dec 2018 18:09:27 +0000 (UTC) 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:References:In-Reply-To: Message-Id:Date: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=QMZBwtM/89Ylsg+8qDsAq9GkGLoCNdvolgWdWJre5pI=; b=ai5TL3MCK7SGyy VUZlvKbyILKNaCVDe/SNW6Or4f5ix680A9D7kqxP6xBmlxrpyoN7jWmRyLXoheKkDYAWfgZAH8C5+ 5UFSYxBq1sPqupWQDPSeULp3HTBcVm5Jib7ll6UfJ05Ynn41j4GADqUJV+cy3DhO9ez/39DrbKTWM ZqrnqWd7nIq5fJl52wN1x9BrKxsjQPSoRURyjKZoyOQxoiduojJKy0mXBBP0lVwSz9cqGorYf9mDt 3DgYvG6O1WE/w46hIg09YNILZ69mZNYuKCI9IXr/IuN1oGS1bDF7/C+YieV1pODcROn9RbsF8OD2J uQowJB7Ddjlyu5zxuQ9Q==; 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 1gTsek-0007cX-Mn; Mon, 03 Dec 2018 18:09:18 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gTsco-0005El-Gj for linux-arm-kernel@lists.infradead.org; Mon, 03 Dec 2018 18:07:47 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 93DF21715; Mon, 3 Dec 2018 10:07:07 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C3C443F59C; Mon, 3 Dec 2018 10:07:04 -0800 (PST) From: James Morse To: linux-acpi@vger.kernel.org Subject: [PATCH v7 09/25] ACPI / APEI: Generalise the estatus queue's notify code Date: Mon, 3 Dec 2018 18:05:57 +0000 Message-Id: <20181203180613.228133-10-james.morse@arm.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181203180613.228133-1-james.morse@arm.com> References: <20181203180613.228133-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181203_100719_532066_2E2952C3 X-CRM114-Status: GOOD ( 14.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rafael Wysocki , Tony Luck , Fan Wu , Xie XiuQi , Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , Dongjiu Geng , linux-mm@kvack.org, Borislav Petkov , James Morse , Naoya Horiguchi , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Len Brown Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Refactor the estatus queue's pool notification routine from NOTIFY_NMI's handlers. This will allow another notification method to use the estatus queue without duplicating this code. This patch adds rcu_read_lock()/rcu_read_unlock() around the list list_for_each_entry_rcu() walker. These aren't strictly necessary as the whole nmi_enter/nmi_exit() window is a spooky RCU read-side critical section. _in_nmi_notify_one() is separate from the rcu-list walker for a later caller that doesn't need to walk a list. Signed-off-by: James Morse Reviewed-by: Punit Agrawal Tested-by: Tyler Baicar --- Changes since v6: * Removed pool grow/remove code as this is no longer necessary. Changes since v3: * Removed duplicate or redundant paragraphs in commit message. * Fixed the style of a zero check. Changes since v1: * Tidied up _in_nmi_notify_one(). --- drivers/acpi/apei/ghes.c | 63 ++++++++++++++++++++++++++-------------- 1 file changed, 41 insertions(+), 22 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index d06456e60318..366dbdd41ef3 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -907,37 +907,56 @@ static void __process_error(struct ghes *ghes) #endif } -static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) +static int _in_nmi_notify_one(struct ghes *ghes) { u64 buf_paddr; - struct ghes *ghes; - int sev, ret = NMI_DONE; + int sev; - if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) - return ret; + if (ghes_read_estatus(ghes, &buf_paddr)) { + ghes_clear_estatus(ghes, buf_paddr); + return -ENOENT; + } - list_for_each_entry_rcu(ghes, &ghes_nmi, list) { - if (ghes_read_estatus(ghes, &buf_paddr)) { - ghes_clear_estatus(ghes, buf_paddr); - continue; - } else { - ret = NMI_HANDLED; - } + sev = ghes_severity(ghes->estatus->error_severity); + if (sev >= GHES_SEV_PANIC) { + ghes_print_queued_estatus(); + __ghes_panic(ghes); + } - sev = ghes_severity(ghes->estatus->error_severity); - if (sev >= GHES_SEV_PANIC) { - ghes_print_queued_estatus(); - __ghes_panic(ghes); - } + __process_error(ghes); + ghes_clear_estatus(ghes, buf_paddr); - __process_error(ghes); - ghes_clear_estatus(ghes, buf_paddr); + return 0; +} + +static int ghes_estatus_queue_notified(struct list_head *rcu_list) +{ + int ret = -ENOENT; + struct ghes *ghes; + + rcu_read_lock(); + list_for_each_entry_rcu(ghes, rcu_list, list) { + if (!_in_nmi_notify_one(ghes)) + ret = 0; } + rcu_read_unlock(); -#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - if (ret == NMI_HANDLED) + if (IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && !ret) irq_work_queue(&ghes_proc_irq_work); -#endif + + return ret; +} + +static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) +{ + int ret = NMI_DONE; + + if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) + return ret; + + if (!ghes_estatus_queue_notified(&ghes_nmi)) + ret = NMI_HANDLED; + atomic_dec(&ghes_in_nmi); return ret; }