From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6AA1C33DA; Wed, 13 Sep 2023 16:39:07 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 43985C15; Wed, 13 Sep 2023 09:39:44 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4845B3F5A1; Wed, 13 Sep 2023 09:39:05 -0700 (PDT) From: James Morse 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 Cc: x86@kernel.org, Salil Mehta , Russell King , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com Subject: [RFC PATCH v2 07/35] x86: intel_epb: Don't rely on link order Date: Wed, 13 Sep 2023 16:37:55 +0000 Message-Id: <20230913163823.7880-8-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230913163823.7880-1-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: loongarch@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 derefernce 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 --- 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); -- 2.39.2