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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C1829C433F5 for ; Mon, 11 Apr 2022 23:39:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EPNkajefZ46QJ7Q+C9ykPQihnAuk5H+sKwKlq1TxyyY=; b=F2C/FjNxgRsYhi EqJnOjXwdX0N7VQbDIgHhoXrLd/iUjghoGdXI0I+qDxHL2let716jRcebSYAdSbqMQlRpdS8tVQz3 55Sa35CpuRhhVoXS/ahQPNjXaAhtyMix8KuEFeK054V7CVn5Fa8Tq/LqfnbIaCw8arACtPpLHolwF LTW9LKlCMdYkD0sqtNOmUTruZO0lyU4jCHKKgjTMLeZ2+OYZoC+9n20xbjZalxPGj/Rz54wGLakMX 9D3DaCw0qRrMs9IYMDWtDhzC4V5GAFMwHxXiQBL0mx/AQnBvL3c9elS2RUgtP8tlg4EKL2LWhokLK TXfMRk3RpEIm6CFldMEg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ne3ce-00ApD4-Lp; Mon, 11 Apr 2022 23:39:04 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ne3ca-00ApBh-MN for linux-riscv@lists.infradead.org; Mon, 11 Apr 2022 23:39:02 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: dmitry.osipenko) with ESMTPSA id ADD321F42D86 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1649720339; bh=kCYEDdovCVMqMqsKDmHApZZjAvEttkamvjOxDRb8Y/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nx08HokVCqLuQkUWX3rv2fv4uikfMucJnDiwNH7NGzpcW8362/JzsFA+T8pnB9rNP Nh2tUIEYoUm4h2VGRFzMQLXuy7mgTy+c0khut3jaDscDSqMMvUMEsukDJLG8tD4MDL vj4ggPnYxoa3v867GyElYDQzvBgZSBXa3mIdsCHhXm+tguMql+U+E5xj8wPXMcK7A6 0uh9uoi/rCbMu8A/I2IZxr0lSB4su90p49BTCC/554FnGngEacX7JTRv7MVDZF7lqU cVn2/2/romM/vCOmLU+jii/LndRccn1z1q7pRnyFpKcq7XTRFlJuAGp/K99F3f919c C0mZWcTbiCkjQ== From: Dmitry Osipenko To: Thierry Reding , Jonathan Hunter , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Geert Uytterhoeven , Greg Ungerer , Joshua Thompson , Thomas Bogendoerfer , Sebastian Reichel , Linus Walleij , Philipp Zabel , Greentime Hu , Vincent Chen , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Yoshinori Sato , Rich Felker , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , "Rafael J. Wysocki" , Len Brown , Santosh Shilimkar , Krzysztof Kozlowski , Liam Girdwood , Mark Brown , Pavel Machek , Lee Jones , Andrew Morton , Guenter Roeck , Daniel Lezcano , Andy Shevchenko , Ulf Hansson , =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= Cc: linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org Subject: [PATCH v7 01/20] notifier: Add blocking_notifier_call_chain_is_empty() Date: Tue, 12 Apr 2022 02:38:13 +0300 Message-Id: <20220411233832.391817-2-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220411233832.391817-1-dmitry.osipenko@collabora.com> References: <20220411233832.391817-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220411_163900_895586_08925632 X-CRM114-Status: GOOD ( 11.78 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add blocking_notifier_call_chain_is_empty() that returns true if call chain is empty. Signed-off-by: Dmitry Osipenko --- include/linux/notifier.h | 2 ++ kernel/notifier.c | 13 +++++++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 87069b8459af..d4717bc0ab85 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -173,6 +173,8 @@ extern int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh extern int raw_notifier_call_chain_robust(struct raw_notifier_head *nh, unsigned long val_up, unsigned long val_down, void *v); +extern bool blocking_notifier_call_chain_is_empty(struct blocking_notifier_head *nh); + #define NOTIFY_DONE 0x0000 /* Don't care */ #define NOTIFY_OK 0x0001 /* Suits me */ #define NOTIFY_STOP_MASK 0x8000 /* Don't call further */ diff --git a/kernel/notifier.c b/kernel/notifier.c index ba005ebf4730..4ed6bda8f127 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -323,6 +323,19 @@ int blocking_notifier_call_chain(struct blocking_notifier_head *nh, } EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); +/** + * blocking_notifier_call_chain_is_empty - Check whether notifier chain is empty + * @nh: Pointer to head of the blocking notifier chain + * + * Checks whether notifier chain is empty. + * + * Returns true is notifier chain is empty, false otherwise. + */ +bool blocking_notifier_call_chain_is_empty(struct blocking_notifier_head *nh) +{ + return !rcu_access_pointer(nh->head); +} + /* * Raw notifier chain routines. There is no protection; * the caller must provide it. Use at your own risk! -- 2.35.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv