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.
> + 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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