Andrey Panin wrote:
On 254, 09 11, 2009 at 04:15:33PM -0500, Nathan Fontenot wrote:
This adds the capability to DLPAR add and remove CPUs from the kernel. The
creates two new files /sys/devices/system/cpu/probe and
/sys/devices/system/cpu/release to handle the DLPAR addition and
removal of
CPUs respectively.
CPU DLPAR add is accomplished by writing the drc-index of the CPU to the
probe file, and removal is done by writing the device-tree path of the cpu
to the release file.
Signed-off-by: Nathan Fontenot <nf...@austin.ibm.com>
+static ssize_t cpu_probe_store(struct class *class, const char *buf,
+ size_t count)
+{
+ struct device_node *dn;
+ u32 drc_index;
+ char *cpu_name;
+ int rc;
+
+ drc_index = simple_strtoull(buf, NULL, 0);
+ if (!drc_index)
+ return -EINVAL;
+
+ rc = acquire_drc(drc_index);
+ if (rc)
+ return rc;
+
+ dn = configure_connector(drc_index);
+ if (!dn) {
+ release_drc(drc_index);
+ return rc;
+ }
+
+ /* fixup dn name */
+ cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
+ GFP_KERNEL);
Unchecked memory allocation with immediate crash in case of failure.
Yep, thats a bad thing. I'll fix this in an updated patch. thanks.
-Nathan
+ sprintf(cpu_name, "/cpus/%s", dn->full_name);
+ kfree(dn->full_name);
+ dn->full_name = cpu_name;
+
+ rc = add_device_tree_nodes(dn);
+ if (rc)
+ release_drc(drc_index);
+
+ return rc ? rc : count;
+}
+
+static ssize_t cpu_release_store(struct class *class, const char *buf,
+ size_t count)
+{
+ struct device_node *dn;
+ u32 *drc_index;
+ int rc;
+
+ dn = of_find_node_by_path(buf);
+ if (!dn)
+ return -EINVAL;
+
+ drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);
+ if (!drc_index) {
+ of_node_put(dn);
+ return -EINVAL;
+ }
+
+ rc = release_drc(*drc_index);
+ if (rc) {
+ of_node_put(dn);
+ return rc;
+ }
+
+ rc = remove_device_tree_nodes(dn);
+ if (rc)
+ acquire_drc(*drc_index);
+
+ of_node_put(dn);
+ return rc? rc : count;
+}
+
static struct class_attribute class_attr_mem_release =
__ATTR(release, S_IWUSR, NULL, memory_release_store);
+static struct class_attribute class_attr_cpu_probe =
+ __ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
+static struct class_attribute class_attr_cpu_release =
+ __ATTR(release, S_IWUSR, NULL, cpu_release_store);
static int pseries_dlpar_init(void)
{
@@ -576,6 +648,18 @@
printk(KERN_INFO "DLPAR: Could not create sysfs memory "
"release file\n");
+ rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+ &class_attr_cpu_probe.attr);
+ if (rc)
+ printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+ "probe file\n");
+
+ rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+ &class_attr_cpu_release.attr);
+ if (rc)
+ printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+ "release file\n");
+
return 0;
}
__initcall(pseries_dlpar_init);
--
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