[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / platforms / pseries / hotplug-cpu.c

/*
 * 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"
#include "plpar_wrappers.h"
#include "offline_states.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 DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =
							CPU_STATE_OFFLINE;
static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;

static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;

static int cede_offline_enabled __read_mostly = 1;

/*
 * Enable/disable cede_offline when available.
 */
static int __init setup_cede_offline(char *str)
{
	if (!strcmp(str, "off"))
		cede_offline_enabled = 0;
	else if (!strcmp(str, "on"))
		cede_offline_enabled = 1;
	else
		return 0;
	return 1;
}

__setup("cede_offline=", setup_cede_offline);

enum cpu_state_vals get_cpu_current_state(int cpu)
{
	return per_cpu(current_state, cpu);
}

void set_cpu_current_state(int cpu, enum cpu_state_vals state)
{
	per_cpu(current_state, cpu) = state;
}

enum cpu_state_vals get_preferred_offline_state(int cpu)
{
	return per_cpu(preferred_offline_state, cpu);
}

void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
{
	per_cpu(preferred_offline_state, cpu) = state;
}

void set_default_offline_state(int cpu)
{
	per_cpu(preferred_offline_state, cpu) = default_offline_state;
}

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)
{
	unsigned int cpu = smp_processor_id();
	unsigned int hwcpu = hard_smp_processor_id();
	u8 cede_latency_hint = 0;

	local_irq_disable();
	idle_task_exit();
	xics_teardown_cpu();

	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
		set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
		if (ppc_md.suspend_disable_cpu)
			ppc_md.suspend_disable_cpu();

		cede_latency_hint = 2;

		get_lppaca()->idle = 1;
		if (!get_lppaca()->shared_proc)
			get_lppaca()->donate_dedicated_cpu = 1;

		while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
			extended_cede_processor(cede_latency_hint);
		}

		if (!get_lppaca()->shared_proc)
			get_lppaca()->donate_dedicated_cpu = 0;
		get_lppaca()->idle = 0;

		if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
			unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));

			/*
			 * Call to start_secondary_resume() will not return.
			 * Kernel stack will be reset and start_secondary()
			 * will be called to continue the online operation.
			 */
			start_secondary_resume();
		}
	}

	/* Requested state is CPU_STATE_OFFLINE at this point */
	WARN_ON(get_preferred_offline_state(cpu) != CPU_STATE_OFFLINE);

	set_cpu_current_state(cpu, CPU_STATE_OFFLINE);
	unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
	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 */
	xics_migrate_irqs_away();
	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_mach_cpu_die() is called by the @cpu when it wants to
 * self-destruct.
 */
static void pseries_cpu_die(unsigned int cpu)
{
	int tries;
	int cpu_status = 1;
	unsigned int pcpu = get_hard_smp_processor_id(cpu);

	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
		cpu_status = 1;
		for (tries = 0; tries < 5000; tries++) {
			if (get_cpu_current_state(cpu) == CPU_STATE_INACTIVE) {
				cpu_status = 0;
				break;
			}
			msleep(1);
		}
	} else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {

		for (tries = 0; tries < 25; tries++) {
			cpu_status = smp_query_cpu_stopped(pcpu);
			if (cpu_status == QCSS_STOPPED ||
			    cpu_status == QCSS_HARDWARE_ERROR)
				break;
			cpu_relax();
		}
	}

	if (cpu_status != 0) {
		printk("Querying DEAD? cpu %i (%i) shows %i\n",
		       cpu, pcpu, cpu_status);
	}

	/* Isolation and deallocation are definitely 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_mask 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_var_t candidate_mask, tmp;
	int err = -ENOSPC, len, nthreads, i;
	const u32 *intserv;

	intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
	if (!intserv)
		return 0;

	zalloc_cpumask_var(&candidate_mask, GFP_KERNEL);
	zalloc_cpumask_var(&tmp, GFP_KERNEL);

	nthreads = len / sizeof(u32);
	for (i = 0; i < nthreads; i++)
		cpumask_set_cpu(i, tmp);

	cpu_maps_update_begin();

	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 (cpumask_empty(candidate_mask)) {
		/* 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,
		       cpumask_weight(cpu_possible_mask));
		goto out_unlock;
	}

	while (!cpumask_empty(tmp))
		if (cpumask_subset(tmp, candidate_mask))
			/* Found a range where we can insert the new cpu(s) */
			break;
		else
			cpumask_shift_left(tmp, tmp, nthreads);

	if (cpumask_empty(tmp)) {
		printk(KERN_ERR "Unable to find space in cpu_present_mask for"
		       " processor %s with %d thread(s)\n", np->name,
		       nthreads);
		goto out_unlock;
	}

	for_each_cpu(cpu, tmp) {
		BUG_ON(cpumask_test_cpu(cpu, cpu_present_mask));
		set_cpu_present(cpu, true);
		set_hard_smp_processor_id(cpu, *intserv++);
	}
	err = 0;
out_unlock:
	cpu_maps_update_done();
	free_cpumask_var(candidate_mask);
	free_cpumask_var(tmp);
	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 = 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++) {
		for_each_present_cpu(cpu) {
			if (get_hard_smp_processor_id(cpu) != intserv[i])
				continue;
			BUG_ON(cpu_online(cpu));
			set_cpu_present(cpu, false);
			set_hard_smp_processor_id(cpu, -1);
			break;
		}
		if (cpu >= nr_cpu_ids)
			printk(KERN_WARNING "Could not find cpu to remove "
			       "with physical id 0x%x\n", intserv[i]);
	}
	cpu_maps_update_done();
}

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,
};

#define MAX_CEDE_LATENCY_LEVELS		4
#define	CEDE_LATENCY_PARAM_LENGTH	10
#define CEDE_LATENCY_PARAM_MAX_LENGTH	\
	(MAX_CEDE_LATENCY_LEVELS * CEDE_LATENCY_PARAM_LENGTH * sizeof(char))
#define CEDE_LATENCY_TOKEN		45

static char cede_parameters[CEDE_LATENCY_PARAM_MAX_LENGTH];

static int parse_cede_parameters(void)
{
	memset(cede_parameters, 0, CEDE_LATENCY_PARAM_MAX_LENGTH);
	return rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
			 NULL,
			 CEDE_LATENCY_TOKEN,
			 __pa(cede_parameters),
			 CEDE_LATENCY_PARAM_MAX_LENGTH);
}

static int __init pseries_cpu_hotplug_init(void)
{
	struct device_node *np;
	const char *typep;
	int cpu;
	int qcss_tok;

	for_each_node_by_name(np, "interrupt-controller") {
		typep = of_get_property(np, "compatible", NULL);
		if (strstr(typep, "open-pic")) {
			of_node_put(np);

			printk(KERN_INFO "CPU Hotplug not supported on "
				"systems using MPIC\n");
			return 0;
		}
	}

	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);
		cpu_maps_update_begin();
		if (cede_offline_enabled && parse_cede_parameters() == 0) {
			default_offline_state = CPU_STATE_INACTIVE;
			for_each_online_cpu(cpu)
				set_default_offline_state(cpu);
		}
		cpu_maps_update_done();
	}

	return 0;
}
arch_initcall(pseries_cpu_hotplug_init);
Commit	Line	Data
0332c2d4 ME	1	/*
	2	* pseries CPU Hotplug infrastructure.
	3	*
413f7c40 ME	4	* Split out from arch/powerpc/platforms/pseries/setup.c
413f7c40 ME	5	* arch/powerpc/kernel/rtas.c, and arch/powerpc/platforms/pseries/smp.c
0332c2d4 ME	6	*
	7	* Peter Bergner, IBM March 2001.
	8	* Copyright (C) 2001 IBM.
413f7c40 ME	9	* Dave Engebretsen, Peter Bergner, and
	10	* Mike Corrigan {engebret\|bergner\|mikec}@us.ibm.com
	11	* Plus various changes from other IBM teams...
0332c2d4 ME	12	*
	13	* Copyright (C) 2006 Michael Ellerman, IBM Corporation
	14	*
	15	* This program is free software; you can redistribute it and/or
	16	* modify it under the terms of the GNU General Public License
	17	* as published by the Free Software Foundation; either version
	18	* 2 of the License, or (at your option) any later version.
	19	*/
	20
	21	#include <linux/kernel.h>
	22	#include <linux/delay.h>
	23	#include <linux/cpu.h>
	24	#include <asm/system.h>
	25	#include <asm/prom.h>
	26	#include <asm/rtas.h>
	27	#include <asm/firmware.h>
	28	#include <asm/machdep.h>
	29	#include <asm/vdso_datapage.h>
	30	#include <asm/pSeries_reconfig.h>
	31	#include "xics.h"
473980a9	32	#include "plpar_wrappers.h"
3aa565f5	33	#include "offline_states.h"
0332c2d4 ME	34
	35	/* This version can't take the spinlock, because it never returns */
	36	static struct rtas_args rtas_stop_self_args = {
	37	.token = RTAS_UNKNOWN_SERVICE,
	38	.nargs = 0,
	39	.nret = 1,
	40	.rets = &rtas_stop_self_args.args[0],
	41	};
	42
3aa565f5 GS	43	static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =
	44	CPU_STATE_OFFLINE;
	45	static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;
	46
	47	static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;
	48
	49	static int cede_offline_enabled __read_mostly = 1;
	50
	51	/*
	52	* Enable/disable cede_offline when available.
	53	*/
	54	static int __init setup_cede_offline(char *str)
	55	{
	56	if (!strcmp(str, "off"))
	57	cede_offline_enabled = 0;
	58	else if (!strcmp(str, "on"))
	59	cede_offline_enabled = 1;
	60	else
	61	return 0;
	62	return 1;
	63	}
	64
	65	__setup("cede_offline=", setup_cede_offline);
	66
	67	enum cpu_state_vals get_cpu_current_state(int cpu)
	68	{
	69	return per_cpu(current_state, cpu);
	70	}
	71
	72	void set_cpu_current_state(int cpu, enum cpu_state_vals state)
	73	{
	74	per_cpu(current_state, cpu) = state;
	75	}
	76
	77	enum cpu_state_vals get_preferred_offline_state(int cpu)
	78	{
	79	return per_cpu(preferred_offline_state, cpu);
	80	}
	81
	82	void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
	83	{
	84	per_cpu(preferred_offline_state, cpu) = state;
	85	}
	86
	87	void set_default_offline_state(int cpu)
	88	{
	89	per_cpu(preferred_offline_state, cpu) = default_offline_state;
	90	}
	91
04da6af9	92	static void rtas_stop_self(void)
0332c2d4 ME	93	{
	94	struct rtas_args *args = &rtas_stop_self_args;
	95
	96	local_irq_disable();
	97
	98	BUG_ON(args->token == RTAS_UNKNOWN_SERVICE);
	99
	100	printk("cpu %u (hwid %u) Ready to die...\n",
	101	smp_processor_id(), hard_smp_processor_id());
	102	enter_rtas(__pa(args));
	103
	104	panic("Alas, I survived.\n");
	105	}
	106
06ba30b6	107	static void pseries_mach_cpu_die(void)
04da6af9	108	{
3aa565f5 GS	109	unsigned int cpu = smp_processor_id();
	110	unsigned int hwcpu = hard_smp_processor_id();
	111	u8 cede_latency_hint = 0;
	112
04da6af9 ME	113	local_irq_disable();
04da6af9 ME	114	idle_task_exit();
c3e8506c	115	xics_teardown_cpu();
3aa565f5 GS	116
	117	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
	118	set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
32d8ad4e BK	119	if (ppc_md.suspend_disable_cpu)
	120	ppc_md.suspend_disable_cpu();
	121
3aa565f5 GS	122	cede_latency_hint = 2;
	123
	124	get_lppaca()->idle = 1;
	125	if (!get_lppaca()->shared_proc)
	126	get_lppaca()->donate_dedicated_cpu = 1;
	127
3aa565f5 GS	128	while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
3aa565f5 GS	129	extended_cede_processor(cede_latency_hint);
3aa565f5 GS	130	}
3aa565f5 GS	131
3aa565f5 GS	132	if (!get_lppaca()->shared_proc)
	133	get_lppaca()->donate_dedicated_cpu = 0;
	134	get_lppaca()->idle = 0;
3aa565f5	135
0212f260 VS	136	if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
0212f260 VS	137	unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
3aa565f5	138
0212f260 VS	139	/*
	140	* Call to start_secondary_resume() will not return.
	141	* Kernel stack will be reset and start_secondary()
	142	* will be called to continue the online operation.
	143	*/
	144	start_secondary_resume();
	145	}
	146	}
3aa565f5	147
0212f260 VS	148	/* Requested state is CPU_STATE_OFFLINE at this point */
0212f260 VS	149	WARN_ON(get_preferred_offline_state(cpu) != CPU_STATE_OFFLINE);
3aa565f5	150
0212f260 VS	151	set_cpu_current_state(cpu, CPU_STATE_OFFLINE);
	152	unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
	153	rtas_stop_self();
3aa565f5	154
04da6af9 ME	155	/* Should never get here... */
	156	BUG();
	157	for(;;);
	158	}
	159
06ba30b6	160	static int pseries_cpu_disable(void)
413f7c40 ME	161	{
	162	int cpu = smp_processor_id();
	163
ea0f1cab	164	set_cpu_online(cpu, false);
413f7c40 ME	165	vdso_data->processorCount--;
	166
	167	/fix boot_cpuid here/
	168	if (cpu == boot_cpuid)
8729faaa	169	boot_cpuid = cpumask_any(cpu_online_mask);
413f7c40 ME	170
	171	/* FIXME: abstract this to not be platform specific later on */
	172	xics_migrate_irqs_away();
	173	return 0;
	174	}
	175
3aa565f5 GS	176	/*
	177	* pseries_cpu_die: Wait for the cpu to die.
	178	* @cpu: logical processor id of the CPU whose death we're awaiting.
	179	*
	180	* This function is called from the context of the thread which is performing
	181	* the cpu-offline. Here we wait for long enough to allow the cpu in question
	182	* to self-destroy so that the cpu-offline thread can send the CPU_DEAD
	183	* notifications.
	184	*
	185	* OTOH, pseries_mach_cpu_die() is called by the @cpu when it wants to
	186	* self-destruct.
	187	*/
06ba30b6	188	static void pseries_cpu_die(unsigned int cpu)
413f7c40 ME	189	{
413f7c40 ME	190	int tries;
3aa565f5	191	int cpu_status = 1;
413f7c40 ME	192	unsigned int pcpu = get_hard_smp_processor_id(cpu);
413f7c40 ME	193
3aa565f5 GS	194	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
3aa565f5 GS	195	cpu_status = 1;
940ce422	196	for (tries = 0; tries < 5000; tries++) {
3aa565f5 GS	197	if (get_cpu_current_state(cpu) == CPU_STATE_INACTIVE) {
	198	cpu_status = 0;
	199	break;
	200	}
940ce422	201	msleep(1);
3aa565f5 GS	202	}
	203	} else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
	204
	205	for (tries = 0; tries < 25; tries++) {
f8b67691 MN	206	cpu_status = smp_query_cpu_stopped(pcpu);
	207	if (cpu_status == QCSS_STOPPED \|\|
	208	cpu_status == QCSS_HARDWARE_ERROR)
3aa565f5 GS	209	break;
	210	cpu_relax();
	211	}
413f7c40	212	}
3aa565f5	213
413f7c40 ME	214	if (cpu_status != 0) {
	215	printk("Querying DEAD? cpu %i (%i) shows %i\n",
	216	cpu, pcpu, cpu_status);
	217	}
	218
25985edc	219	/* Isolation and deallocation are definitely done by
413f7c40 ME	220	* drslot_chrp_cpu. If they were not they would be
	221	* done here. Change isolate state to Isolate and
	222	* change allocation-state to Unusable.
	223	*/
	224	paca[cpu].cpu_start = 0;
	225	}
	226
	227	/*
828a6986	228	* Update cpu_present_mask and paca(s) for a new cpu node. The wrinkle
413f7c40 ME	229	* here is that a cpu device node may represent up to two logical cpus
	230	* in the SMT case. We must honor the assumption in other code that
	231	* the logical ids for sibling SMT threads x and y are adjacent, such
	232	* that x^1 == y and y^1 == x.
	233	*/
06ba30b6	234	static int pseries_add_processor(struct device_node *np)
413f7c40 ME	235	{
413f7c40 ME	236	unsigned int cpu;
8729faaa	237	cpumask_var_t candidate_mask, tmp;
413f7c40 ME	238	int err = -ENOSPC, len, nthreads, i;
	239	const u32 *intserv;
	240
e2eb6392	241	intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
413f7c40 ME	242	if (!intserv)
	243	return 0;
	244
8729faaa AB	245	zalloc_cpumask_var(&candidate_mask, GFP_KERNEL);
	246	zalloc_cpumask_var(&tmp, GFP_KERNEL);
	247
413f7c40 ME	248	nthreads = len / sizeof(u32);
413f7c40 ME	249	for (i = 0; i < nthreads; i++)
8729faaa	250	cpumask_set_cpu(i, tmp);
413f7c40	251
86ef5c9a	252	cpu_maps_update_begin();
413f7c40	253
8729faaa	254	BUG_ON(!cpumask_subset(cpu_present_mask, cpu_possible_mask));
413f7c40 ME	255
413f7c40 ME	256	/* Get a bitmap of unoccupied slots. */
8729faaa AB	257	cpumask_xor(candidate_mask, cpu_possible_mask, cpu_present_mask);
8729faaa AB	258	if (cpumask_empty(candidate_mask)) {
413f7c40 ME	259	/* If we get here, it most likely means that NR_CPUS is
	260	* less than the partition's max processors setting.
	261	*/
	262	printk(KERN_ERR "Cannot add cpu %s; this system configuration"
	263	" supports %d logical cpus.\n", np->full_name,
8729faaa	264	cpumask_weight(cpu_possible_mask));
413f7c40 ME	265	goto out_unlock;
	266	}
	267
8729faaa AB	268	while (!cpumask_empty(tmp))
8729faaa AB	269	if (cpumask_subset(tmp, candidate_mask))
413f7c40 ME	270	/* Found a range where we can insert the new cpu(s) */
	271	break;
	272	else
8729faaa	273	cpumask_shift_left(tmp, tmp, nthreads);
413f7c40	274
8729faaa	275	if (cpumask_empty(tmp)) {
828a6986	276	printk(KERN_ERR "Unable to find space in cpu_present_mask for"
413f7c40 ME	277	" processor %s with %d thread(s)\n", np->name,
	278	nthreads);
	279	goto out_unlock;
	280	}
	281
8729faaa AB	282	for_each_cpu(cpu, tmp) {
8729faaa AB	283	BUG_ON(cpumask_test_cpu(cpu, cpu_present_mask));
ea0f1cab	284	set_cpu_present(cpu, true);
413f7c40 ME	285	set_hard_smp_processor_id(cpu, *intserv++);
	286	}
	287	err = 0;
	288	out_unlock:
86ef5c9a	289	cpu_maps_update_done();
8729faaa AB	290	free_cpumask_var(candidate_mask);
8729faaa AB	291	free_cpumask_var(tmp);
413f7c40 ME	292	return err;
	293	}
	294
	295	/*
	296	* Update the present map for a cpu node which is going away, and set
	297	* the hard id in the paca(s) to -1 to be consistent with boot time
	298	* convention for non-present cpus.
	299	*/
06ba30b6	300	static void pseries_remove_processor(struct device_node *np)
413f7c40 ME	301	{
	302	unsigned int cpu;
	303	int len, nthreads, i;
	304	const u32 *intserv;
	305
e2eb6392	306	intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
413f7c40 ME	307	if (!intserv)
	308	return;
	309
	310	nthreads = len / sizeof(u32);
	311
86ef5c9a	312	cpu_maps_update_begin();
413f7c40 ME	313	for (i = 0; i < nthreads; i++) {
	314	for_each_present_cpu(cpu) {
	315	if (get_hard_smp_processor_id(cpu) != intserv[i])
	316	continue;
	317	BUG_ON(cpu_online(cpu));
ea0f1cab	318	set_cpu_present(cpu, false);
413f7c40 ME	319	set_hard_smp_processor_id(cpu, -1);
	320	break;
	321	}
8729faaa	322	if (cpu >= nr_cpu_ids)
413f7c40 ME	323	printk(KERN_WARNING "Could not find cpu to remove "
	324	"with physical id 0x%x\n", intserv[i]);
	325	}
86ef5c9a	326	cpu_maps_update_done();
413f7c40 ME	327	}
413f7c40 ME	328
06ba30b6 ME	329	static int pseries_smp_notifier(struct notifier_block *nb,
06ba30b6 ME	330	unsigned long action, void *node)
413f7c40 ME	331	{
	332	int err = NOTIFY_OK;
	333
	334	switch (action) {
	335	case PSERIES_RECONFIG_ADD:
06ba30b6	336	if (pseries_add_processor(node))
413f7c40 ME	337	err = NOTIFY_BAD;
	338	break;
	339	case PSERIES_RECONFIG_REMOVE:
06ba30b6	340	pseries_remove_processor(node);
413f7c40 ME	341	break;
	342	default:
	343	err = NOTIFY_DONE;
	344	break;
	345	}
	346	return err;
	347	}
	348
06ba30b6 ME	349	static struct notifier_block pseries_smp_nb = {
06ba30b6 ME	350	.notifier_call = pseries_smp_notifier,
413f7c40 ME	351	};
413f7c40 ME	352
3aa565f5 GS	353	#define MAX_CEDE_LATENCY_LEVELS 4
	354	#define CEDE_LATENCY_PARAM_LENGTH 10
	355	#define CEDE_LATENCY_PARAM_MAX_LENGTH \
	356	(MAX_CEDE_LATENCY_LEVELS * CEDE_LATENCY_PARAM_LENGTH * sizeof(char))
	357	#define CEDE_LATENCY_TOKEN 45
	358
	359	static char cede_parameters[CEDE_LATENCY_PARAM_MAX_LENGTH];
	360
	361	static int parse_cede_parameters(void)
	362	{
3aa565f5	363	memset(cede_parameters, 0, CEDE_LATENCY_PARAM_MAX_LENGTH);
20a8ab97 AB	364	return rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
	365	NULL,
	366	CEDE_LATENCY_TOKEN,
	367	__pa(cede_parameters),
	368	CEDE_LATENCY_PARAM_MAX_LENGTH);
3aa565f5 GS	369	}
3aa565f5 GS	370
0332c2d4 ME	371	static int __init pseries_cpu_hotplug_init(void)
0332c2d4 ME	372	{
64f27585 OJ	373	struct device_node *np;
64f27585 OJ	374	const char *typep;
3aa565f5	375	int cpu;
f8b67691	376	int qcss_tok;
64f27585 OJ	377
	378	for_each_node_by_name(np, "interrupt-controller") {
	379	typep = of_get_property(np, "compatible", NULL);
	380	if (strstr(typep, "open-pic")) {
	381	of_node_put(np);
	382
	383	printk(KERN_INFO "CPU Hotplug not supported on "
	384	"systems using MPIC\n");
	385	return 0;
	386	}
	387	}
	388
0332c2d4	389	rtas_stop_self_args.token = rtas_token("stop-self");
674fa677	390	qcss_tok = rtas_token("query-cpu-stopped-state");
0332c2d4	391
674fa677 ME	392	if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE \|\|
	393	qcss_tok == RTAS_UNKNOWN_SERVICE) {
	394	printk(KERN_INFO "CPU Hotplug not supported by firmware "
	395	"- disabling.\n");
	396	return 0;
	397	}
04da6af9	398
06ba30b6 ME	399	ppc_md.cpu_die = pseries_mach_cpu_die;
	400	smp_ops->cpu_disable = pseries_cpu_disable;
	401	smp_ops->cpu_die = pseries_cpu_die;
413f7c40 ME	402
413f7c40 ME	403	/* Processors can be added/removed only on LPAR */
3aa565f5	404	if (firmware_has_feature(FW_FEATURE_LPAR)) {
06ba30b6	405	pSeries_reconfig_notifier_register(&pseries_smp_nb);
3aa565f5 GS	406	cpu_maps_update_begin();
	407	if (cede_offline_enabled && parse_cede_parameters() == 0) {
	408	default_offline_state = CPU_STATE_INACTIVE;
	409	for_each_online_cpu(cpu)
	410	set_default_offline_state(cpu);
	411	}
	412	cpu_maps_update_done();
	413	}
413f7c40	414
0332c2d4 ME	415	return 0;
	416	}
	417	arch_initcall(pseries_cpu_hotplug_init);