From patchwork Wed Dec 13 12:50:33 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: 754229 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="ryyhQHuR" Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45293170A; Wed, 13 Dec 2023 04:50:36 -0800 (PST) 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=CzUDlXDbVRENX5I3t4jDtWhqIqX9ckshZ8M9DQwNtkI=; b=ryyhQHuRHb7agprV7SzAPCOWs7 +KSXGolWfQxBz68idh9LhxWZ4JzZ71clasxJMQDmclWim/lWLX+Gb1xqGHQ9n3UU4aTI4I9d13qgo hj4BIus5sr1uZgPAKqSg5BR+qboNz0g2L0iDXYBeGJ7lvBRoed+H+5R2YFjK8ueU93g8YItCdFaeb fxbImF1Xl0TwiBldiAdAMRv9Tgek/TNe6QoJrV9pJFFkVccAuQ3oipJY0EaPDNElQ4hd2UdXqoxdp PQJmrKVqAhtuUZLhBMQbgjSydQTFhRQyXfg22Jx79LASfFaMpnGo14mdNGw9zQWMI8ZnrjSj92Dyh 1BXBKHfg==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:50070 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 1rDOh5-0008Gu-1L; Wed, 13 Dec 2023 12:50:31 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rDOh7-00Dvl7-LR; Wed, 13 Dec 2023 12:50:33 +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, acpica-devel@lists.linuxfoundation.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 Subject: [PATCH RFC v3 16/21] arm64: psci: Ignore DENIED CPUs Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Message-Id: Sender: Russell King Date: Wed, 13 Dec 2023 12:50:33 +0000 From: Jean-Philippe Brucker When a CPU is marked as disabled, but online capable in the MADT, PSCI applies some firmware policy to control when it can be brought online. PSCI returns DENIED to a CPU_ON request if this is not currently permitted. The OS can learn the current policy from the _STA enabled bit. Handle the PSCI DENIED return code gracefully instead of printing an error. See https://developer.arm.com/documentation/den0022/f/?lang=en page 58. Signed-off-by: Jean-Philippe Brucker [ morse: Rewrote commit message ] Signed-off-by: James Morse Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Signed-off-by: Russell King (Oracle) Reviewed-by: Jonathan Cameron --- Changes since RFC v2 * Add specification reference * Use EPERM rather than EPROBE_DEFER Changes since RFC v3: * Use EPERM everywhere * Drop unnecessary changes to drivers/firmware/psci/psci.c --- arch/arm64/kernel/psci.c | 2 +- arch/arm64/kernel/smp.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 29a8e444db83..fabd732d0a2d 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -40,7 +40,7 @@ static int cpu_psci_cpu_boot(unsigned int cpu) { phys_addr_t pa_secondary_entry = __pa_symbol(secondary_entry); int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry); - if (err) + if (err && err != -EPERM) pr_err("failed to boot CPU%d (%d)\n", cpu, err); return err; diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index defbab84e9e5..6bc9094feb19 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -132,7 +132,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) /* Now bring the CPU into our world */ ret = boot_secondary(cpu, idle); if (ret) { - pr_err("CPU%u: failed to boot: %d\n", cpu, ret); + if (ret != -EPERM) + pr_err("CPU%u: failed to boot: %d\n", cpu, ret); return ret; }