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-rw-r--r--arch/powerpc/platforms/pseries/hotplug-cpu.c901
1 files changed, 901 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
new file mode 100644
index 000000000..e62835a12
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -0,0 +1,901 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pseries CPU Hotplug infrastructure.
+ *
+ * Split out from arch/powerpc/platforms/pseries/setup.c
+ * arch/powerpc/kernel/rtas.c, and arch/powerpc/platforms/pseries/smp.c
+ *
+ * Peter Bergner, IBM March 2001.
+ * Copyright (C) 2001 IBM.
+ * Dave Engebretsen, Peter Bergner, and
+ * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
+ * Plus various changes from other IBM teams...
+ *
+ * Copyright (C) 2006 Michael Ellerman, IBM Corporation
+ */
+
+#define pr_fmt(fmt) "pseries-hotplug-cpu: " fmt
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/sched.h> /* for idle_task_exit */
+#include <linux/sched/hotplug.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <asm/prom.h>
+#include <asm/rtas.h>
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+#include <asm/vdso_datapage.h>
+#include <asm/xics.h>
+#include <asm/xive.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/topology.h>
+
+#include "pseries.h"
+
+/* This version can't take the spinlock, because it never returns */
+static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE;
+
+/*
+ * Record the CPU ids used on each nodes.
+ * Protected by cpu_add_remove_lock.
+ */
+static cpumask_var_t node_recorded_ids_map[MAX_NUMNODES];
+
+static void rtas_stop_self(void)
+{
+ static struct rtas_args args;
+
+ local_irq_disable();
+
+ BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
+
+ rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL);
+
+ panic("Alas, I survived.\n");
+}
+
+static void pseries_cpu_offline_self(void)
+{
+ unsigned int hwcpu = hard_smp_processor_id();
+
+ local_irq_disable();
+ idle_task_exit();
+ if (xive_enabled())
+ xive_teardown_cpu();
+ else
+ xics_teardown_cpu();
+
+ unregister_slb_shadow(hwcpu);
+ unregister_vpa(hwcpu);
+ rtas_stop_self();
+
+ /* Should never get here... */
+ BUG();
+ for(;;);
+}
+
+static int pseries_cpu_disable(void)
+{
+ int cpu = smp_processor_id();
+
+ set_cpu_online(cpu, false);
+ vdso_data->processorCount--;
+
+ /*fix boot_cpuid here*/
+ if (cpu == boot_cpuid)
+ boot_cpuid = cpumask_any(cpu_online_mask);
+
+ /* FIXME: abstract this to not be platform specific later on */
+ if (xive_enabled())
+ xive_smp_disable_cpu();
+ else
+ xics_migrate_irqs_away();
+
+ cleanup_cpu_mmu_context();
+
+ return 0;
+}
+
+/*
+ * pseries_cpu_die: Wait for the cpu to die.
+ * @cpu: logical processor id of the CPU whose death we're awaiting.
+ *
+ * This function is called from the context of the thread which is performing
+ * the cpu-offline. Here we wait for long enough to allow the cpu in question
+ * to self-destroy so that the cpu-offline thread can send the CPU_DEAD
+ * notifications.
+ *
+ * OTOH, pseries_cpu_offline_self() is called by the @cpu when it wants to
+ * self-destruct.
+ */
+static void pseries_cpu_die(unsigned int cpu)
+{
+ int cpu_status = 1;
+ unsigned int pcpu = get_hard_smp_processor_id(cpu);
+ unsigned long timeout = jiffies + msecs_to_jiffies(120000);
+
+ while (true) {
+ cpu_status = smp_query_cpu_stopped(pcpu);
+ if (cpu_status == QCSS_STOPPED ||
+ cpu_status == QCSS_HARDWARE_ERROR)
+ break;
+
+ if (time_after(jiffies, timeout)) {
+ pr_warn("CPU %i (hwid %i) didn't die after 120 seconds\n",
+ cpu, pcpu);
+ timeout = jiffies + msecs_to_jiffies(120000);
+ }
+
+ cond_resched();
+ }
+
+ if (cpu_status == QCSS_HARDWARE_ERROR) {
+ pr_warn("CPU %i (hwid %i) reported error while dying\n",
+ cpu, pcpu);
+ }
+
+ paca_ptrs[cpu]->cpu_start = 0;
+}
+
+/**
+ * find_cpu_id_range - found a linear ranger of @nthreads free CPU ids.
+ * @nthreads : the number of threads (cpu ids)
+ * @assigned_node : the node it belongs to or NUMA_NO_NODE if free ids from any
+ * node can be peek.
+ * @cpu_mask: the returned CPU mask.
+ *
+ * Returns 0 on success.
+ */
+static int find_cpu_id_range(unsigned int nthreads, int assigned_node,
+ cpumask_var_t *cpu_mask)
+{
+ cpumask_var_t candidate_mask;
+ unsigned int cpu, node;
+ int rc = -ENOSPC;
+
+ if (!zalloc_cpumask_var(&candidate_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ cpumask_clear(*cpu_mask);
+ for (cpu = 0; cpu < nthreads; cpu++)
+ cpumask_set_cpu(cpu, *cpu_mask);
+
+ BUG_ON(!cpumask_subset(cpu_present_mask, cpu_possible_mask));
+
+ /* Get a bitmap of unoccupied slots. */
+ cpumask_xor(candidate_mask, cpu_possible_mask, cpu_present_mask);
+
+ if (assigned_node != NUMA_NO_NODE) {
+ /*
+ * Remove free ids previously assigned on the other nodes. We
+ * can walk only online nodes because once a node became online
+ * it is not turned offlined back.
+ */
+ for_each_online_node(node) {
+ if (node == assigned_node)
+ continue;
+ cpumask_andnot(candidate_mask, candidate_mask,
+ node_recorded_ids_map[node]);
+ }
+ }
+
+ if (cpumask_empty(candidate_mask))
+ goto out;
+
+ while (!cpumask_empty(*cpu_mask)) {
+ if (cpumask_subset(*cpu_mask, candidate_mask))
+ /* Found a range where we can insert the new cpu(s) */
+ break;
+ cpumask_shift_left(*cpu_mask, *cpu_mask, nthreads);
+ }
+
+ if (!cpumask_empty(*cpu_mask))
+ rc = 0;
+
+out:
+ free_cpumask_var(candidate_mask);
+ return rc;
+}
+
+/*
+ * Update cpu_present_mask and paca(s) for a new cpu node. The wrinkle
+ * here is that a cpu device node may represent multiple logical cpus
+ * in the SMT case. We must honor the assumption in other code that
+ * the logical ids for sibling SMT threads x and y are adjacent, such
+ * that x^1 == y and y^1 == x.
+ */
+static int pseries_add_processor(struct device_node *np)
+{
+ int len, nthreads, node, cpu, assigned_node;
+ int rc = 0;
+ cpumask_var_t cpu_mask;
+ const __be32 *intserv;
+
+ intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return 0;
+
+ nthreads = len / sizeof(u32);
+
+ if (!alloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ /*
+ * Fetch from the DT nodes read by dlpar_configure_connector() the NUMA
+ * node id the added CPU belongs to.
+ */
+ node = of_node_to_nid(np);
+ if (node < 0 || !node_possible(node))
+ node = first_online_node;
+
+ BUG_ON(node == NUMA_NO_NODE);
+ assigned_node = node;
+
+ cpu_maps_update_begin();
+
+ rc = find_cpu_id_range(nthreads, node, &cpu_mask);
+ if (rc && nr_node_ids > 1) {
+ /*
+ * Try again, considering the free CPU ids from the other node.
+ */
+ node = NUMA_NO_NODE;
+ rc = find_cpu_id_range(nthreads, NUMA_NO_NODE, &cpu_mask);
+ }
+
+ if (rc) {
+ pr_err("Cannot add cpu %pOF; this system configuration"
+ " supports %d logical cpus.\n", np, num_possible_cpus());
+ goto out;
+ }
+
+ for_each_cpu(cpu, cpu_mask) {
+ BUG_ON(cpu_present(cpu));
+ set_cpu_present(cpu, true);
+ set_hard_smp_processor_id(cpu, be32_to_cpu(*intserv++));
+ }
+
+ /* Record the newly used CPU ids for the associate node. */
+ cpumask_or(node_recorded_ids_map[assigned_node],
+ node_recorded_ids_map[assigned_node], cpu_mask);
+
+ /*
+ * If node is set to NUMA_NO_NODE, CPU ids have be reused from
+ * another node, remove them from its mask.
+ */
+ if (node == NUMA_NO_NODE) {
+ cpu = cpumask_first(cpu_mask);
+ pr_warn("Reusing free CPU ids %d-%d from another node\n",
+ cpu, cpu + nthreads - 1);
+ for_each_online_node(node) {
+ if (node == assigned_node)
+ continue;
+ cpumask_andnot(node_recorded_ids_map[node],
+ node_recorded_ids_map[node],
+ cpu_mask);
+ }
+ }
+
+out:
+ cpu_maps_update_done();
+ free_cpumask_var(cpu_mask);
+ return rc;
+}
+
+/*
+ * Update the present map for a cpu node which is going away, and set
+ * the hard id in the paca(s) to -1 to be consistent with boot time
+ * convention for non-present cpus.
+ */
+static void pseries_remove_processor(struct device_node *np)
+{
+ unsigned int cpu;
+ int len, nthreads, i;
+ const __be32 *intserv;
+ u32 thread;
+
+ intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return;
+
+ nthreads = len / sizeof(u32);
+
+ cpu_maps_update_begin();
+ for (i = 0; i < nthreads; i++) {
+ thread = be32_to_cpu(intserv[i]);
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != thread)
+ continue;
+ BUG_ON(cpu_online(cpu));
+ set_cpu_present(cpu, false);
+ set_hard_smp_processor_id(cpu, -1);
+ update_numa_cpu_lookup_table(cpu, -1);
+ break;
+ }
+ if (cpu >= nr_cpu_ids)
+ printk(KERN_WARNING "Could not find cpu to remove "
+ "with physical id 0x%x\n", thread);
+ }
+ cpu_maps_update_done();
+}
+
+static int dlpar_offline_cpu(struct device_node *dn)
+{
+ int rc = 0;
+ unsigned int cpu;
+ int len, nthreads, i;
+ const __be32 *intserv;
+ u32 thread;
+
+ intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return -EINVAL;
+
+ nthreads = len / sizeof(u32);
+
+ cpu_maps_update_begin();
+ for (i = 0; i < nthreads; i++) {
+ thread = be32_to_cpu(intserv[i]);
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != thread)
+ continue;
+
+ if (!cpu_online(cpu))
+ break;
+
+ /*
+ * device_offline() will return -EBUSY (via cpu_down()) if there
+ * is only one CPU left. Check it here to fail earlier and with a
+ * more informative error message, while also retaining the
+ * cpu_add_remove_lock to be sure that no CPUs are being
+ * online/offlined during this check.
+ */
+ if (num_online_cpus() == 1) {
+ pr_warn("Unable to remove last online CPU %pOFn\n", dn);
+ rc = -EBUSY;
+ goto out_unlock;
+ }
+
+ cpu_maps_update_done();
+ rc = device_offline(get_cpu_device(cpu));
+ if (rc)
+ goto out;
+ cpu_maps_update_begin();
+ break;
+ }
+ if (cpu == num_possible_cpus()) {
+ pr_warn("Could not find cpu to offline with physical id 0x%x\n",
+ thread);
+ }
+ }
+out_unlock:
+ cpu_maps_update_done();
+
+out:
+ return rc;
+}
+
+static int dlpar_online_cpu(struct device_node *dn)
+{
+ int rc = 0;
+ unsigned int cpu;
+ int len, nthreads, i;
+ const __be32 *intserv;
+ u32 thread;
+
+ intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return -EINVAL;
+
+ nthreads = len / sizeof(u32);
+
+ cpu_maps_update_begin();
+ for (i = 0; i < nthreads; i++) {
+ thread = be32_to_cpu(intserv[i]);
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != thread)
+ continue;
+
+ if (!topology_is_primary_thread(cpu)) {
+ if (cpu_smt_control != CPU_SMT_ENABLED)
+ break;
+ if (!topology_smt_thread_allowed(cpu))
+ break;
+ }
+
+ cpu_maps_update_done();
+ find_and_update_cpu_nid(cpu);
+ rc = device_online(get_cpu_device(cpu));
+ if (rc) {
+ dlpar_offline_cpu(dn);
+ goto out;
+ }
+ cpu_maps_update_begin();
+
+ break;
+ }
+ if (cpu == num_possible_cpus())
+ printk(KERN_WARNING "Could not find cpu to online "
+ "with physical id 0x%x\n", thread);
+ }
+ cpu_maps_update_done();
+
+out:
+ return rc;
+
+}
+
+static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
+{
+ struct device_node *child = NULL;
+ u32 my_drc_index;
+ bool found;
+ int rc;
+
+ /* Assume cpu doesn't exist */
+ found = false;
+
+ for_each_child_of_node(parent, child) {
+ rc = of_property_read_u32(child, "ibm,my-drc-index",
+ &my_drc_index);
+ if (rc)
+ continue;
+
+ if (my_drc_index == drc_index) {
+ of_node_put(child);
+ found = true;
+ break;
+ }
+ }
+
+ return found;
+}
+
+static bool drc_info_valid_index(struct device_node *parent, u32 drc_index)
+{
+ struct property *info;
+ struct of_drc_info drc;
+ const __be32 *value;
+ u32 index;
+ int count, i, j;
+
+ info = of_find_property(parent, "ibm,drc-info", NULL);
+ if (!info)
+ return false;
+
+ value = of_prop_next_u32(info, NULL, &count);
+
+ /* First value of ibm,drc-info is number of drc-info records */
+ if (value)
+ value++;
+ else
+ return false;
+
+ for (i = 0; i < count; i++) {
+ if (of_read_drc_info_cell(&info, &value, &drc))
+ return false;
+
+ if (strncmp(drc.drc_type, "CPU", 3))
+ break;
+
+ if (drc_index > drc.last_drc_index)
+ continue;
+
+ index = drc.drc_index_start;
+ for (j = 0; j < drc.num_sequential_elems; j++) {
+ if (drc_index == index)
+ return true;
+
+ index += drc.sequential_inc;
+ }
+ }
+
+ return false;
+}
+
+static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
+{
+ bool found = false;
+ int rc, index;
+
+ if (of_property_present(parent, "ibm,drc-info"))
+ return drc_info_valid_index(parent, drc_index);
+
+ /* Note that the format of the ibm,drc-indexes array is
+ * the number of entries in the array followed by the array
+ * of drc values so we start looking at index = 1.
+ */
+ index = 1;
+ while (!found) {
+ u32 drc;
+
+ rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
+ index++, &drc);
+
+ if (rc)
+ break;
+
+ if (drc == drc_index)
+ found = true;
+ }
+
+ return found;
+}
+
+static int pseries_cpuhp_attach_nodes(struct device_node *dn)
+{
+ struct of_changeset cs;
+ int ret;
+
+ /*
+ * This device node is unattached but may have siblings; open-code the
+ * traversal.
+ */
+ for (of_changeset_init(&cs); dn != NULL; dn = dn->sibling) {
+ ret = of_changeset_attach_node(&cs, dn);
+ if (ret)
+ goto out;
+ }
+
+ ret = of_changeset_apply(&cs);
+out:
+ of_changeset_destroy(&cs);
+ return ret;
+}
+
+static ssize_t dlpar_cpu_add(u32 drc_index)
+{
+ struct device_node *dn, *parent;
+ int rc, saved_rc;
+
+ pr_debug("Attempting to add CPU, drc index: %x\n", drc_index);
+
+ parent = of_find_node_by_path("/cpus");
+ if (!parent) {
+ pr_warn("Failed to find CPU root node \"/cpus\"\n");
+ return -ENODEV;
+ }
+
+ if (dlpar_cpu_exists(parent, drc_index)) {
+ of_node_put(parent);
+ pr_warn("CPU with drc index %x already exists\n", drc_index);
+ return -EINVAL;
+ }
+
+ if (!valid_cpu_drc_index(parent, drc_index)) {
+ of_node_put(parent);
+ pr_warn("Cannot find CPU (drc index %x) to add.\n", drc_index);
+ return -EINVAL;
+ }
+
+ rc = dlpar_acquire_drc(drc_index);
+ if (rc) {
+ pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n",
+ rc, drc_index);
+ of_node_put(parent);
+ return -EINVAL;
+ }
+
+ dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
+ if (!dn) {
+ pr_warn("Failed call to configure-connector, drc index: %x\n",
+ drc_index);
+ dlpar_release_drc(drc_index);
+ of_node_put(parent);
+ return -EINVAL;
+ }
+
+ rc = pseries_cpuhp_attach_nodes(dn);
+
+ /* Regardless we are done with parent now */
+ of_node_put(parent);
+
+ if (rc) {
+ saved_rc = rc;
+ pr_warn("Failed to attach node %pOFn, rc: %d, drc index: %x\n",
+ dn, rc, drc_index);
+
+ rc = dlpar_release_drc(drc_index);
+ if (!rc)
+ dlpar_free_cc_nodes(dn);
+
+ return saved_rc;
+ }
+
+ update_numa_distance(dn);
+
+ rc = dlpar_online_cpu(dn);
+ if (rc) {
+ saved_rc = rc;
+ pr_warn("Failed to online cpu %pOFn, rc: %d, drc index: %x\n",
+ dn, rc, drc_index);
+
+ rc = dlpar_detach_node(dn);
+ if (!rc)
+ dlpar_release_drc(drc_index);
+
+ return saved_rc;
+ }
+
+ pr_debug("Successfully added CPU %pOFn, drc index: %x\n", dn,
+ drc_index);
+ return rc;
+}
+
+static unsigned int pseries_cpuhp_cache_use_count(const struct device_node *cachedn)
+{
+ unsigned int use_count = 0;
+ struct device_node *dn, *tn;
+
+ WARN_ON(!of_node_is_type(cachedn, "cache"));
+
+ for_each_of_cpu_node(dn) {
+ tn = of_find_next_cache_node(dn);
+ of_node_put(tn);
+ if (tn == cachedn)
+ use_count++;
+ }
+
+ for_each_node_by_type(dn, "cache") {
+ tn = of_find_next_cache_node(dn);
+ of_node_put(tn);
+ if (tn == cachedn)
+ use_count++;
+ }
+
+ return use_count;
+}
+
+static int pseries_cpuhp_detach_nodes(struct device_node *cpudn)
+{
+ struct device_node *dn;
+ struct of_changeset cs;
+ int ret = 0;
+
+ of_changeset_init(&cs);
+ ret = of_changeset_detach_node(&cs, cpudn);
+ if (ret)
+ goto out;
+
+ dn = cpudn;
+ while ((dn = of_find_next_cache_node(dn))) {
+ if (pseries_cpuhp_cache_use_count(dn) > 1) {
+ of_node_put(dn);
+ break;
+ }
+
+ ret = of_changeset_detach_node(&cs, dn);
+ of_node_put(dn);
+ if (ret)
+ goto out;
+ }
+
+ ret = of_changeset_apply(&cs);
+out:
+ of_changeset_destroy(&cs);
+ return ret;
+}
+
+static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
+{
+ int rc;
+
+ pr_debug("Attempting to remove CPU %pOFn, drc index: %x\n",
+ dn, drc_index);
+
+ rc = dlpar_offline_cpu(dn);
+ if (rc) {
+ pr_warn("Failed to offline CPU %pOFn, rc: %d\n", dn, rc);
+ return -EINVAL;
+ }
+
+ rc = dlpar_release_drc(drc_index);
+ if (rc) {
+ pr_warn("Failed to release drc (%x) for CPU %pOFn, rc: %d\n",
+ drc_index, dn, rc);
+ dlpar_online_cpu(dn);
+ return rc;
+ }
+
+ rc = pseries_cpuhp_detach_nodes(dn);
+ if (rc) {
+ int saved_rc = rc;
+
+ pr_warn("Failed to detach CPU %pOFn, rc: %d", dn, rc);
+
+ rc = dlpar_acquire_drc(drc_index);
+ if (!rc)
+ dlpar_online_cpu(dn);
+
+ return saved_rc;
+ }
+
+ pr_debug("Successfully removed CPU, drc index: %x\n", drc_index);
+ return 0;
+}
+
+static struct device_node *cpu_drc_index_to_dn(u32 drc_index)
+{
+ struct device_node *dn;
+ u32 my_index;
+ int rc;
+
+ for_each_node_by_type(dn, "cpu") {
+ rc = of_property_read_u32(dn, "ibm,my-drc-index", &my_index);
+ if (rc)
+ continue;
+
+ if (my_index == drc_index)
+ break;
+ }
+
+ return dn;
+}
+
+static int dlpar_cpu_remove_by_index(u32 drc_index)
+{
+ struct device_node *dn;
+ int rc;
+
+ dn = cpu_drc_index_to_dn(drc_index);
+ if (!dn) {
+ pr_warn("Cannot find CPU (drc index %x) to remove\n",
+ drc_index);
+ return -ENODEV;
+ }
+
+ rc = dlpar_cpu_remove(dn, drc_index);
+ of_node_put(dn);
+ return rc;
+}
+
+int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
+{
+ u32 drc_index;
+ int rc;
+
+ drc_index = hp_elog->_drc_u.drc_index;
+
+ lock_device_hotplug();
+
+ switch (hp_elog->action) {
+ case PSERIES_HP_ELOG_ACTION_REMOVE:
+ if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) {
+ rc = dlpar_cpu_remove_by_index(drc_index);
+ /*
+ * Setting the isolation state of an UNISOLATED/CONFIGURED
+ * device to UNISOLATE is a no-op, but the hypervisor can
+ * use it as a hint that the CPU removal failed.
+ */
+ if (rc)
+ dlpar_unisolate_drc(drc_index);
+ }
+ else
+ rc = -EINVAL;
+ break;
+ case PSERIES_HP_ELOG_ACTION_ADD:
+ if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
+ rc = dlpar_cpu_add(drc_index);
+ else
+ rc = -EINVAL;
+ break;
+ default:
+ pr_err("Invalid action (%d) specified\n", hp_elog->action);
+ rc = -EINVAL;
+ break;
+ }
+
+ unlock_device_hotplug();
+ return rc;
+}
+
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+
+static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+{
+ u32 drc_index;
+ int rc;
+
+ rc = kstrtou32(buf, 0, &drc_index);
+ if (rc)
+ return -EINVAL;
+
+ rc = dlpar_cpu_add(drc_index);
+
+ return rc ? rc : count;
+}
+
+static ssize_t dlpar_cpu_release(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;
+
+ rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index);
+ if (rc) {
+ of_node_put(dn);
+ return -EINVAL;
+ }
+
+ rc = dlpar_cpu_remove(dn, drc_index);
+ of_node_put(dn);
+
+ return rc ? rc : count;
+}
+
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
+static int pseries_smp_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct of_reconfig_data *rd = data;
+ int err = 0;
+
+ switch (action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ err = pseries_add_processor(rd->dn);
+ break;
+ case OF_RECONFIG_DETACH_NODE:
+ pseries_remove_processor(rd->dn);
+ break;
+ }
+ return notifier_from_errno(err);
+}
+
+static struct notifier_block pseries_smp_nb = {
+ .notifier_call = pseries_smp_notifier,
+};
+
+void __init pseries_cpu_hotplug_init(void)
+{
+ int qcss_tok;
+
+ rtas_stop_self_token = rtas_function_token(RTAS_FN_STOP_SELF);
+ qcss_tok = rtas_function_token(RTAS_FN_QUERY_CPU_STOPPED_STATE);
+
+ if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE ||
+ qcss_tok == RTAS_UNKNOWN_SERVICE) {
+ printk(KERN_INFO "CPU Hotplug not supported by firmware "
+ "- disabling.\n");
+ return;
+ }
+
+ smp_ops->cpu_offline_self = pseries_cpu_offline_self;
+ smp_ops->cpu_disable = pseries_cpu_disable;
+ smp_ops->cpu_die = pseries_cpu_die;
+}
+
+static int __init pseries_dlpar_init(void)
+{
+ unsigned int node;
+
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
+ ppc_md.cpu_probe = dlpar_cpu_probe;
+ ppc_md.cpu_release = dlpar_cpu_release;
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
+
+ /* Processors can be added/removed only on LPAR */
+ if (firmware_has_feature(FW_FEATURE_LPAR)) {
+ for_each_node(node) {
+ if (!alloc_cpumask_var_node(&node_recorded_ids_map[node],
+ GFP_KERNEL, node))
+ return -ENOMEM;
+
+ /* Record ids of CPU added at boot time */
+ cpumask_copy(node_recorded_ids_map[node],
+ cpumask_of_node(node));
+ }
+
+ of_reconfig_notifier_register(&pseries_smp_nb);
+ }
+
+ return 0;
+}
+machine_arch_initcall(pseries, pseries_dlpar_init);