--- /dev/null
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/cpu.h>
+#include <asm/system.h>
+#include <asm/prom.h>
+#include <asm/rtas.h>
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+#include <asm/vdso_datapage.h>
+#include <asm/pSeries_reconfig.h>
+#include "xics.h"
+
+/* This version can't take the spinlock, because it never returns */
+static struct rtas_args rtas_stop_self_args = {
+ .token = RTAS_UNKNOWN_SERVICE,
+ .nargs = 0,
+ .nret = 1,
+ .rets = &rtas_stop_self_args.args[0],
+};
+
+static void rtas_stop_self(void)
+{
+ struct rtas_args *args = &rtas_stop_self_args;
+
+ local_irq_disable();
+
+ BUG_ON(args->token == RTAS_UNKNOWN_SERVICE);
+
+ printk("cpu %u (hwid %u) Ready to die...\n",
+ smp_processor_id(), hard_smp_processor_id());
+ enter_rtas(__pa(args));
+
+ panic("Alas, I survived.\n");
+}
+
+static void pseries_mach_cpu_die(void)
+{
+ local_irq_disable();
+ idle_task_exit();
+ xics_teardown_cpu(0);
+ rtas_stop_self();
+ /* Should never get here... */
+ BUG();
+ for(;;);
+}
+
+static int qcss_tok; /* query-cpu-stopped-state token */
+
+/* Get state of physical CPU.
+ * Return codes:
+ * 0 - The processor is in the RTAS stopped state
+ * 1 - stop-self is in progress
+ * 2 - The processor is not in the RTAS stopped state
+ * -1 - Hardware Error
+ * -2 - Hardware Busy, Try again later.
+ */
+static int query_cpu_stopped(unsigned int pcpu)
+{
+ int cpu_status, status;
+
+ status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
+ if (status != 0) {
+ printk(KERN_ERR
+ "RTAS query-cpu-stopped-state failed: %i\n", status);
+ return status;
+ }
+
+ return cpu_status;
+}
+
+static int pseries_cpu_disable(void)
+{
+ int cpu = smp_processor_id();
+
+ cpu_clear(cpu, cpu_online_map);
+ vdso_data->processorCount--;
+
+ /*fix boot_cpuid here*/
+ if (cpu == boot_cpuid)
+ boot_cpuid = any_online_cpu(cpu_online_map);
+
+ /* FIXME: abstract this to not be platform specific later on */
+ xics_migrate_irqs_away();
+ return 0;
+}
+
+static void pseries_cpu_die(unsigned int cpu)
+{
+ int tries;
+ int cpu_status;
+ unsigned int pcpu = get_hard_smp_processor_id(cpu);
+
+ for (tries = 0; tries < 25; tries++) {
+ cpu_status = query_cpu_stopped(pcpu);
+ if (cpu_status == 0 || cpu_status == -1)
+ break;
+ msleep(200);
+ }
+ if (cpu_status != 0) {
+ printk("Querying DEAD? cpu %i (%i) shows %i\n",
+ cpu, pcpu, cpu_status);
+ }
+
+ /* Isolation and deallocation are definatly done by
+ * drslot_chrp_cpu. If they were not they would be
+ * done here. Change isolate state to Isolate and
+ * change allocation-state to Unusable.
+ */
+ paca[cpu].cpu_start = 0;
+}
+
+/*
+ * Update cpu_present_map and paca(s) for a new cpu node. The wrinkle
+ * here is that a cpu device node may represent up to two 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)
+{
+ unsigned int cpu;
+ cpumask_t candidate_map, tmp = CPU_MASK_NONE;
+ int err = -ENOSPC, len, nthreads, i;
+ const u32 *intserv;
+
+ intserv = get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return 0;
+
+ nthreads = len / sizeof(u32);
+ for (i = 0; i < nthreads; i++)
+ cpu_set(i, tmp);
+
+ lock_cpu_hotplug();
+
+ BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
+
+ /* Get a bitmap of unoccupied slots. */
+ cpus_xor(candidate_map, cpu_possible_map, cpu_present_map);
+ if (cpus_empty(candidate_map)) {
+ /* If we get here, it most likely means that NR_CPUS is
+ * less than the partition's max processors setting.
+ */
+ printk(KERN_ERR "Cannot add cpu %s; this system configuration"
+ " supports %d logical cpus.\n", np->full_name,
+ cpus_weight(cpu_possible_map));
+ goto out_unlock;
+ }
+
+ while (!cpus_empty(tmp))
+ if (cpus_subset(tmp, candidate_map))
+ /* Found a range where we can insert the new cpu(s) */
+ break;
+ else
+ cpus_shift_left(tmp, tmp, nthreads);
+
+ if (cpus_empty(tmp)) {
+ printk(KERN_ERR "Unable to find space in cpu_present_map for"
+ " processor %s with %d thread(s)\n", np->name,
+ nthreads);
+ goto out_unlock;
+ }
+
+ for_each_cpu_mask(cpu, tmp) {
+ BUG_ON(cpu_isset(cpu, cpu_present_map));
+ cpu_set(cpu, cpu_present_map);
+ set_hard_smp_processor_id(cpu, *intserv++);
+ }
+ err = 0;
+out_unlock:
+ unlock_cpu_hotplug();
+ return err;
+}
+
+/*
+ * 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 u32 *intserv;
+
+ intserv = get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return;
+
+ nthreads = len / sizeof(u32);
+
+ lock_cpu_hotplug();
+ for (i = 0; i < nthreads; i++) {
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != intserv[i])
+ continue;
+ BUG_ON(cpu_online(cpu));
+ cpu_clear(cpu, cpu_present_map);
+ set_hard_smp_processor_id(cpu, -1);
+ break;
+ }
+ if (cpu == NR_CPUS)
+ printk(KERN_WARNING "Could not find cpu to remove "
+ "with physical id 0x%x\n", intserv[i]);
+ }
+ unlock_cpu_hotplug();
+}
+
+static int pseries_smp_notifier(struct notifier_block *nb,
+ unsigned long action, void *node)
+{
+ int err = NOTIFY_OK;
+
+ switch (action) {
+ case PSERIES_RECONFIG_ADD:
+ if (pseries_add_processor(node))
+ err = NOTIFY_BAD;
+ break;
+ case PSERIES_RECONFIG_REMOVE:
+ pseries_remove_processor(node);
+ break;
+ default:
+ err = NOTIFY_DONE;
+ break;
+ }
+ return err;
+}
+
+static struct notifier_block pseries_smp_nb = {
+ .notifier_call = pseries_smp_notifier,
+};
+
+static int __init pseries_cpu_hotplug_init(void)
+{
+ rtas_stop_self_args.token = rtas_token("stop-self");
+ qcss_tok = rtas_token("query-cpu-stopped-state");
+
+ if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE ||
+ qcss_tok == RTAS_UNKNOWN_SERVICE) {
+ printk(KERN_INFO "CPU Hotplug not supported by firmware "
+ "- disabling.\n");
+ return 0;
+ }
+
+ ppc_md.cpu_die = pseries_mach_cpu_die;
+ smp_ops->cpu_disable = pseries_cpu_disable;
+ smp_ops->cpu_die = pseries_cpu_die;
+
+ /* Processors can be added/removed only on LPAR */
+ if (firmware_has_feature(FW_FEATURE_LPAR))
+ pSeries_reconfig_notifier_register(&pseries_smp_nb);
+
+ return 0;
+}
+arch_initcall(pseries_cpu_hotplug_init);
git://git.onelab.eu / linux-2.6.git / blobdiff