From patchwork Tue Nov 7 10:29:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 13448435 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 71DACC4167B for ; Tue, 7 Nov 2023 10:30:15 +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:Date:Message-Id:MIME-Version:Subject:Cc :To:From:References:In-Reply-To:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PtR5TjmA1ZM1+6urK5q6ZDWYWV/1Mu/xZQE7OESum6w=; b=X2i+pOS4jS82A5 G8b4UE6HnEAZQrZw2kVodkOK4btMwYvDRL/1zpZdO2i89znj5zx84NdHh80XiaQT8Jp6dL4P93oCS IpvtYzSIipkB6Dh7HyAAaIxUoXcbi0kukZ1aVWJTIJTlceI3BlnFvY2cqY5RV4n9AB0ZG2YWiBrc2 9DP7XATPeV2WPcsAbeVKloGgWh37m0wRMlrab98tLDq3kUKrue3SOcZynLCwvp33Z0SrlRAmQJedV jxYiraXF3tV8Xy5Gq5i3WP+gS8rCRldtF3DkptRL+qgSVLf6EKlSAHzUlVgARSO7mYqFmC8LVgGRj f2hcC3n6QmxhSS2INrBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r0JLM-00135M-2o; Tue, 07 Nov 2023 10:30:00 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r0JLJ-00130i-1q; Tue, 07 Nov 2023 10:29:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=+gACgpTQj8OpvruPj/p3shExXAIg9qVB65uOYbGxgdU=; b=KqJga0cJkf0ea2I44dro/hehY+ hdGHrWJf9SO9FdCGw+AG9MFvt/hy1EM8laesvxJR3tlIJm04unhSe1TyMvk5EOkVpAVmnQEzEGvk2 erEqCrnXjQNiZHzYYZxVVhyVh7jBOTkO5gRjjijQwz8tW3XZQPsB1UeV4/h/eZcKG86V0Hz8ev82u xdr3rDxe/M5yjtU8f98kyXf+5wrQ8fSNhMKHgI8hgzksRtWxYcmdC1WQdfIj4RfgFB3Dh5PyS4lKJ OOd1sULTW/XN1dkdCIkVRG8j5hzT0k/nvc0vkOLSQ3xApjwWJrgOiQMzmMmP6FLoc0jLsOWEoyIsS XcI5Shxw==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:54700 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1r0JKo-0000Dk-39; Tue, 07 Nov 2023 10:29:27 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1r0JKq-00CTwZ-Mh; Tue, 07 Nov 2023 10:29:28 +0000 In-Reply-To: References: From: Russell King (Oracle) To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev, x86@kernel.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org Cc: Salil Mehta , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com, James Morse , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH RFC 02/22] x86: intel_epb: Don't rely on link order MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Tue, 07 Nov 2023 10:29:28 +0000 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231107_022957_605175_2D756002 X-CRM114-Status: GOOD ( 11.54 ) 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: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: James Morse intel_epb_init() is called as a subsys_initcall() to register cpuhp callbacks. The callbacks make use of get_cpu_device() which will return NULL unless register_cpu() has been called. register_cpu() is called from topology_init(), which is also a subsys_initcall(). This is fragile. Moving the register_cpu() to a different subsys_initcall() leads to a NULL dereference during boot. Make intel_epb_init() a late_initcall(), user-space can't provide a policy before this point anyway. Signed-off-by: James Morse Signed-off-by: Russell King (Oracle) Reviewed-by: Gavin Shan Reviewed-by: Jonathan Cameron --- subsys_initcall_sync() would be an option, but moving the register_cpu() calls into ACPI also means adding a safety net for CPUs that are online but not described properly by firmware. This lives in subsys_initcall_sync(). --- arch/x86/kernel/cpu/intel_epb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel_epb.c b/arch/x86/kernel/cpu/intel_epb.c index e4c3ba91321c..f18d35fe27a9 100644 --- a/arch/x86/kernel/cpu/intel_epb.c +++ b/arch/x86/kernel/cpu/intel_epb.c @@ -237,4 +237,4 @@ static __init int intel_epb_init(void) cpuhp_remove_state(CPUHP_AP_X86_INTEL_EPB_ONLINE); return ret; } -subsys_initcall(intel_epb_init); +late_initcall(intel_epb_init);