lkml.org 
[lkml]   [2009]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 5/5] kernel handling of CPU DLPAR
    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 <nfont@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);
    >> --
    >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    >> the body of a message to majordomo@vger.kernel.org
    >> More majordomo info at http://vger.kernel.org/majordomo-info.html
    >> Please read the FAQ at http://www.tux.org/lkml/
    >>


    \
     
     \ /
      Last update: 2009-09-14 20:57    [W:0.058 / U:64.088 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site