From 12633e803a2a556f6469e0933d08233d0844a2d9 Mon Sep 17 00:00:00 2001
From: Nathan Fontenot <nfont@austin.ibm.com>
Date: Wed, 25 Nov 2009 17:23:25 +0000
Subject: sysfs/cpu: Add probe/release files
Version 3 of this patch is updated with documentation added to
Documentation/ABI. There are no changes to any of the C code from v2
of the patch.
In order to support kernel DLPAR of CPU resources we need to provide an
interface to add (probe) and remove (release) the resource from the system.
This patch Creates new generic probe and release sysfs files to facilitate
cpu probe/release. The probe/release interface provides for allowing each
arch to supply their own routines for implementing the backend of adding
and removing cpus to/from the system.
This also creates the powerpc specific stubs to handle the arch callouts
from writes to the sysfs files.
The creation and use of these files is regulated by the
CONFIG_ARCH_CPU_PROBE_RELEASE option so that only architectures that need the
capability will have the files created.
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
drivers/base/cpu.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
(limited to 'drivers/base')
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index e62a4ccea54..7c03af7b84a 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -72,6 +72,38 @@ void unregister_cpu(struct cpu *cpu)
per_cpu(cpu_sys_devices, logical_cpu) = NULL;
return;
}
+
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+static ssize_t cpu_probe_store(struct class *class, const char *buf,
+ size_t count)
+{
+ return arch_cpu_probe(buf, count);
+}
+
+static ssize_t cpu_release_store(struct class *class, const char *buf,
+ size_t count)
+{
+ return arch_cpu_release(buf, count);
+}
+
+static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
+static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
+
+int __init cpu_probe_release_init(void)
+{
+ int rc;
+
+ rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+ &class_attr_probe.attr);
+ if (!rc)
+ rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+ &class_attr_release.attr);
+
+ return rc;
+}
+device_initcall(cpu_probe_release_init);
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
#else /* ... !CONFIG_HOTPLUG_CPU */
static inline void register_cpu_control(struct cpu *cpu)
{
--
cgit