Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
From:   James Morse <james.morse@arm.com>
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 <salil.mehta@huawei.com>,
        Russell King <linux@armlinux.org.uk>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        jianyong.wu@arm.com, justin.he@arm.com
Subject: [RFC PATCH v2 17/35] ACPI: processor: Register all CPUs from acpi_processor_get_info()
Date:   Wed, 13 Sep 2023 16:38:05 +0000
Message-Id: <20230913163823.7880-18-james.morse@arm.com>
In-Reply-To: <20230913163823.7880-1-james.morse@arm.com>
References: <20230913163823.7880-1-james.morse@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

To allow ACPI to skip the call to arch_register_cpu() when the _STA
value indicates the CPU can't be brought online right now, move the
arch_register_cpu() call into acpi_processor_get_info().

Systems can still be booted with 'acpi=off', or not include an
ACPI description at all. For these, the CPUs continue to be
registered by cpu_dev_register_generic().

This moves the CPU register logic back to a subsys_initcall(),
while the memory nodes will have been registered earlier.

Signed-off-by: James Morse <james.morse@arm.com>
---
 drivers/acpi/acpi_processor.c | 13 +++++++++++++
 drivers/base/cpu.c            |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index a01e315aa16a..867782bc50b0 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -313,6 +313,19 @@ static int acpi_processor_get_info(struct acpi_device *device)
 			cpufreq_add_device("acpi-cpufreq");
 	}
 
+	/*
+	 * Register CPUs that are present.
+	 * Use get_cpu_device() to skip duplicate CPU descriptions from
+	 * firmware.
+	 */
+	if (!invalid_logical_cpuid(pr->id) && cpu_present(pr->id) &&
+	    !get_cpu_device(pr->id)) {
+		int ret = arch_register_cpu(pr->id);
+
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 *  Extra Processor objects may be enumerated on MP systems with
 	 *  less than the max # of CPUs. They should be ignored _iff
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index d31c936f0955..677f963e02ce 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -537,7 +537,7 @@ static void __init cpu_dev_register_generic(void)
 {
 	int i, ret;
 
-	if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES))
+	if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES) || !acpi_disabled)
 		return;
 
 	for_each_present_cpu(i) {
-- 
2.39.2