Re: [PATCH 5/5 v2] kernel handling of CPU DLPAR
From: Nathan Fontenot <hidden>
Date: 2009-10-13 18:15:42
Also in:
lkml
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. Updated to include #ifdef CONFIG_HOTPLUG_CPU around the cpu hotplug specific bits so that it will build without CONFIG_HOTPLUG_CPU defined. Signed-off-by: Nathan Fontenot <redacted> --- Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c ===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c 2009-10-13 13:08:22.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c 2009-10-13 13:09:00.000000000 -0500@@ -1,11 +1,11 @@ /* - * dlpar.c - support for dynamic reconfiguration (including PCI - * Hotplug and Dynamic Logical Partitioning on RPA platforms). + * dlpar.c - support for dynamic reconfiguration (including PCI, + * Memory, and CPU Hotplug and Dynamic Logical Partitioning on + * PAPR platforms). * * Copyright (C) 2009 Nathan Fontenot * Copyright (C) 2009 IBM Corporation * - * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation.
@@ -19,6 +19,7 @@ #include <linux/memory_hotplug.h> #include <linux/sysdev.h> #include <linux/sysfs.h> +#include <linux/cpu.h> #include <asm/prom.h>
@@ -408,6 +409,82 @@ return 0; } +#ifdef CONFIG_HOTPLUG_CPU +static ssize_t cpu_probe_store(struct class *class, const char *buf, + size_t count) +{ + struct device_node *dn; + unsigned long drc_index; + char *cpu_name; + int rc; + + rc = strict_strtoul(buf, 0, &drc_index); + if (rc) + 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); + if (!cpu_name) { + free_cc_nodes(dn); + release_drc(drc_index); + return -ENOMEM; + } + + 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; +} + +#endif /* CONFIG_HOTPLUG_CPU */ + #ifdef CONFIG_MEMORY_HOTPLUG static struct property *clone_property(struct property *old_prop)
@@ -553,6 +630,13 @@ static struct class_attribute class_attr_mem_release = __ATTR(release, S_IWUSR, NULL, memory_release_store); +#endif /* CONFIG_MEMORY_HOTPLUG */ + +#ifdef CONFIG_HOTPLUG_CPU +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); #endif static int pseries_dlpar_init(void)
@@ -567,6 +651,18 @@ "release file\n"); #endif +#ifdef CONFIG_HOTPLUG_CPU + if (sysfs_create_file(&cpu_sysdev_class.kset.kobj, + &class_attr_cpu_probe.attr)) + printk(KERN_INFO "DLPAR: Could not create sysfs cpu " + "probe file\n"); + + if (sysfs_create_file(&cpu_sysdev_class.kset.kobj, + &class_attr_cpu_release.attr)) + printk(KERN_INFO "DLPAR: Could not create sysfs cpu " + "release file\n"); +#endif + return 0; } device_initcall(pseries_dlpar_init);