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: 9808287 X-Patchwork-Delegate: rjw@sisk.pl 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 CFE826038C for ; Sun, 25 Jun 2017 17:31:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B137026247 for ; Sun, 25 Jun 2017 17:31:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A20832858B; Sun, 25 Jun 2017 17:31:50 +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=-1.9 required=2.0 tests=BAYES_00 autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3942726247 for ; Sun, 25 Jun 2017 17:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751330AbdFYRbY (ORCPT ); Sun, 25 Jun 2017 13:31:24 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:37360 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbdFYRbX (ORCPT ); Sun, 25 Jun 2017 13:31:23 -0400 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" cc: Brian Norris , Heiko Stuebner , Linus Walleij , linux-rockchip@lists.infradead.org, Julia Cartwright , LKML , linux-gpio@vger.kernel.org, John Keeping , linux-pm@vger.kernel.org, Doug Anderson , Peter Zijlstra , Tony Lindgren , "Rafael J. Wysocki" 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 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.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);