linux-kernel - [PATCH 13/25] drivers base/topology: Convert to hotplug state machine

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  3 Nov 2016 15:50:09 +0100
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     rt@...utronix.de,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 13/25] drivers base/topology: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

The removal of the files happens now in the prepare down stage as there is
no reason to keep them around until the cpu has actually died.

Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 drivers/base/topology.c    | 42 +++++-------------------------------------
 include/linux/cpuhotplug.h |  1 +
 2 files changed, 6 insertions(+), 37 deletions(-)

diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index df3c97cb4c99..d6ec1c546f5b 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -118,51 +118,19 @@ static int topology_add_dev(unsigned int cpu)
 	return sysfs_create_group(&dev->kobj, &topology_attr_group);
 }
 
-static void topology_remove_dev(unsigned int cpu)
+static int topology_remove_dev(unsigned int cpu)
 {
 	struct device *dev = get_cpu_device(cpu);
 
 	sysfs_remove_group(&dev->kobj, &topology_attr_group);
-}
-
-static int topology_cpu_callback(struct notifier_block *nfb,
-				 unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-	int rc = 0;
-
-	switch (action) {
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
-		rc = topology_add_dev(cpu);
-		break;
-	case CPU_UP_CANCELED:
-	case CPU_UP_CANCELED_FROZEN:
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		topology_remove_dev(cpu);
-		break;
-	}
-	return notifier_from_errno(rc);
+	return 0;
 }
 
 static int topology_sysfs_init(void)
 {
-	int cpu;
-	int rc = 0;
-
-	cpu_notifier_register_begin();
-
-	for_each_online_cpu(cpu) {
-		rc = topology_add_dev(cpu);
-		if (rc)
-			goto out;
-	}
-	__hotcpu_notifier(topology_cpu_callback, 0);
-
-out:
-	cpu_notifier_register_done();
-	return rc;
+	return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
+				 "base/topology:prepare", topology_add_dev,
+				 topology_remove_dev);
 }
 
 device_initcall(topology_sysfs_init);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 86b940f19df8..3410d83cc2e2 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -57,6 +57,7 @@ enum cpuhp_state {
 	CPUHP_SH_SH3X_PREPARE,
 	CPUHP_BLK_MQ_PREPARE,
 	CPUHP_NET_FLOW_PREPARE,
+	CPUHP_TOPOLOGY_PREPARE,
 	CPUHP_TIMERS_DEAD,
 	CPUHP_NOTF_ERR_INJ_PREPARE,
 	CPUHP_MIPS_SOC_PREPARE,
-- 
2.10.2