From patchwork Sun Jun 25 17:31:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 9808291 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 197136038C for ; Sun, 25 Jun 2017 17:32:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04ADE28113 for ; Sun, 25 Jun 2017 17:32:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC70828662; Sun, 25 Jun 2017 17:32:48 +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=-1.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, T_DKIM_INVALID autolearn=no version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9099228113 for ; Sun, 25 Jun 2017 17:31:58 +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:Message-ID: In-Reply-To:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=abJ1CuQkuJAtbkJ1ZSezCMKcOnUtzkvTj3sNAhEwcY8=; b=jE+An36lxM7sYg xEGuKhB6SDSA5tnlbopJdyzWgvvmxetwBvrPj/izCZrq/5AmdqIEy8JVmOD4uRIEFKGk7PCzee1k+ H/AITJClBEcKAiDnA4PrYBstmF/uP9W+gMrMm148oZ2vkCdhRlAUSsTTtCFDdOTiasDmWBuG4bX8C 8+OkcV2po9m1SNDdZ9eIxXOyfJLT1d5HZlLGeL6Qk+zTXWdqzJ7gsJf5PDdjR6/QV/Jhv45hpUs80 m4f0LXpK5OTwEN16nlJ1JAvjXe13bj23yaTfQRFbomZvU/0Lu5FfvkdBP/cLCpTgw9PSZ0Gq6lDFB x93odLFFfJj43/vs/Njg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dPBNy-0005rI-HH; Sun, 25 Jun 2017 17:31:46 +0000 Received: from galois.linutronix.de ([2a01:7a0:2:106d:700::1]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dPBNu-0005oo-Ea for linux-rockchip@lists.infradead.org; Sun, 25 Jun 2017 17:31:44 +0000 Received: from localhost ([127.0.0.1]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1dPBMW-0003dM-R0; Sun, 25 Jun 2017 19:30:17 +0200 Date: Sun, 25 Jun 2017 19:31:13 +0200 (CEST) From: Thomas Gleixner To: "Paul E. McKenney" Subject: [PATCH v2] PM / wakeirq: Convert to SRCU In-Reply-To: <20170625144559.GA3721@linux.vnet.ibm.com> Message-ID: References: <20170624135320.GS3721@linux.vnet.ibm.com> <20170625144559.GA3721@linux.vnet.ibm.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170625_103142_674199_A9C3155D X-CRM114-Status: GOOD ( 13.80 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Heiko Stuebner , Julia Cartwright , Peter Zijlstra , Linus Walleij , Brian Norris , "Rafael J. Wysocki" , LKML , Doug Anderson , linux-rockchip@lists.infradead.org, Tony Lindgren , John Keeping , linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+patchwork-linux-rockchip=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The wakeirq infrastructure uses RCU to protect the list of wakeirqs. That breaks the irq bus locking infrastructure, which is allows sleeping functions to be called so interrupt controllers behind slow busses, e.g. i2c, can be handled. The wakeirq functions hold rcu_read_lock and call into irq functions, which in case of interrupts using the irq bus locking will trigger a might_sleep() splat. Convert the wakeirq infrastructure to Sleepable RCU and unbreak it. Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling") Reported-by: Brian Norris Suggested-by: Paul E. McKenney Signed-off-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Brian Norris --- drivers/base/power/wakeup.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -60,6 +60,8 @@ static LIST_HEAD(wakeup_sources); static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); +DEFINE_STATIC_SRCU(wakeup_srcu); + static struct wakeup_source deleted_ws = { .name = "deleted", .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock), @@ -198,7 +200,7 @@ void wakeup_source_remove(struct wakeup_ spin_lock_irqsave(&events_lock, flags); list_del_rcu(&ws->entry); spin_unlock_irqrestore(&events_lock, flags); - synchronize_rcu(); + synchronize_srcu(&wakeup_srcu); } EXPORT_SYMBOL_GPL(wakeup_source_remove); @@ -332,12 +334,12 @@ void device_wakeup_detach_irq(struct dev void device_wakeup_arm_wake_irqs(void) { struct wakeup_source *ws; + int srcuidx; - rcu_read_lock(); + srcuidx = srcu_read_lock(&wakeup_srcu); list_for_each_entry_rcu(ws, &wakeup_sources, entry) dev_pm_arm_wake_irq(ws->wakeirq); - - rcu_read_unlock(); + srcu_read_unlock(&wakeup_srcu, srcuidx); } /** @@ -348,12 +350,12 @@ void device_wakeup_arm_wake_irqs(void) void device_wakeup_disarm_wake_irqs(void) { struct wakeup_source *ws; + int srcuidx; - rcu_read_lock(); + srcuidx = srcu_read_lock(&wakeup_srcu); list_for_each_entry_rcu(ws, &wakeup_sources, entry) dev_pm_disarm_wake_irq(ws->wakeirq); - - rcu_read_unlock(); + srcu_read_unlock(&wakeup_srcu, srcuidx); } /** @@ -804,10 +806,10 @@ EXPORT_SYMBOL_GPL(pm_wakeup_dev_event); void pm_print_active_wakeup_sources(void) { struct wakeup_source *ws; - int active = 0; + int srcuidx, active = 0; struct wakeup_source *last_activity_ws = NULL; - rcu_read_lock(); + srcuidx = srcu_read_lock(&wakeup_srcu); list_for_each_entry_rcu(ws, &wakeup_sources, entry) { if (ws->active) { pr_debug("active wakeup source: %s\n", ws->name); @@ -823,7 +825,7 @@ void pm_print_active_wakeup_sources(void if (!active && last_activity_ws) pr_debug("last active wakeup source: %s\n", last_activity_ws->name); - rcu_read_unlock(); + srcu_read_unlock(&wakeup_srcu, srcuidx); } EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); @@ -950,8 +952,9 @@ void pm_wakep_autosleep_enabled(bool set { struct wakeup_source *ws; ktime_t now = ktime_get(); + int srcuidx; - rcu_read_lock(); + srcuidx = srcu_read_lock(&wakeup_srcu); list_for_each_entry_rcu(ws, &wakeup_sources, entry) { spin_lock_irq(&ws->lock); if (ws->autosleep_enabled != set) { @@ -965,7 +968,7 @@ void pm_wakep_autosleep_enabled(bool set } spin_unlock_irq(&ws->lock); } - rcu_read_unlock(); + srcu_read_unlock(&wakeup_srcu, srcuidx); } #endif /* CONFIG_PM_AUTOSLEEP */ @@ -1026,15 +1029,16 @@ static int print_wakeup_source_stats(str static int wakeup_sources_stats_show(struct seq_file *m, void *unused) { struct wakeup_source *ws; + int srcuidx; seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" "expire_count\tactive_since\ttotal_time\tmax_time\t" "last_change\tprevent_suspend_time\n"); - rcu_read_lock(); + srcuidx = srcu_read_lock(&wakeup_srcu); list_for_each_entry_rcu(ws, &wakeup_sources, entry) print_wakeup_source_stats(m, ws); - rcu_read_unlock(); + srcu_read_unlock(&wakeup_srcu, srcuidx); print_wakeup_source_stats(m, &deleted_ws);