[net-next-2.6.git] / arch / powerpc / platforms / pseries / smp.c

/*
 * SMP support for pSeries machines.
 *
 * Dave Engebretsen, Peter Bergner, and
 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
 *
 * Plus various changes from other IBM teams...
 *
 *      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/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cache.h>
#include <linux/err.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>

#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/system.h>
#include <asm/rtas.h>
#include <asm/pSeries_reconfig.h>
#include <asm/mpic.h>
#include <asm/vdso_datapage.h>
#include <asm/cputhreads.h>

#include "plpar_wrappers.h"
#include "pseries.h"
#include "xics.h"
#include "offline_states.h"


/*
 * The Primary thread of each non-boot processor was started from the OF client
 * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop.
 */
static cpumask_var_t of_spin_mask;

/* Query where a cpu is now.  Return codes #defined in plpar_wrappers.h */
int smp_query_cpu_stopped(unsigned int pcpu)
{
	int cpu_status, status;
	int qcss_tok = rtas_token("query-cpu-stopped-state");

	if (qcss_tok == RTAS_UNKNOWN_SERVICE) {
		printk(KERN_INFO "Firmware doesn't support "
				"query-cpu-stopped-state\n");
		return QCSS_HARDWARE_ERROR;
	}

	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;
}

/**
 * smp_startup_cpu() - start the given cpu
 *
 * At boot time, there is nothing to do for primary threads which were
 * started from Open Firmware.  For anything else, call RTAS with the
 * appropriate start location.
 *
 * Returns:
 *	0	- failure
 *	1	- success
 */
static inline int __devinit smp_startup_cpu(unsigned int lcpu)
{
	int status;
	unsigned long start_here = __pa((u32)*((unsigned long *)
					       generic_secondary_smp_init));
	unsigned int pcpu;
	int start_cpu;

	if (cpumask_test_cpu(lcpu, of_spin_mask))
		/* Already started by OF and sitting in spin loop */
		return 1;

	pcpu = get_hard_smp_processor_id(lcpu);

	/* Check to see if the CPU out of FW already for kexec */
	if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){
		cpumask_set_cpu(lcpu, of_spin_mask);
		return 1;
	}

	/* Fixup atomic count: it exited inside IRQ handler. */
	task_thread_info(paca[lcpu].__current)->preempt_count	= 0;

	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
		goto out;

	/* 
	 * If the RTAS start-cpu token does not exist then presume the
	 * cpu is already spinning.
	 */
	start_cpu = rtas_token("start-cpu");
	if (start_cpu == RTAS_UNKNOWN_SERVICE)
		return 1;

	status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu);
	if (status != 0) {
		printk(KERN_ERR "start-cpu failed: %i\n", status);
		return 0;
	}

out:
	return 1;
}

#ifdef CONFIG_XICS
static void __devinit smp_xics_setup_cpu(int cpu)
{
	if (cpu != boot_cpuid)
		xics_setup_cpu();

	if (firmware_has_feature(FW_FEATURE_SPLPAR))
		vpa_init(cpu);

	cpumask_clear_cpu(cpu, of_spin_mask);
	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
	set_default_offline_state(cpu);

}
#endif /* CONFIG_XICS */

static void __devinit smp_pSeries_kick_cpu(int nr)
{
	long rc;
	unsigned long hcpuid;
	BUG_ON(nr < 0 || nr >= NR_CPUS);

	if (!smp_startup_cpu(nr))
		return;

	/*
	 * The processor is currently spinning, waiting for the
	 * cpu_start field to become non-zero After we set cpu_start,
	 * the processor will continue on to secondary_start
	 */
	paca[nr].cpu_start = 1;

	set_preferred_offline_state(nr, CPU_STATE_ONLINE);

	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
		hcpuid = get_hard_smp_processor_id(nr);
		rc = plpar_hcall_norets(H_PROD, hcpuid);
		if (rc != H_SUCCESS)
			printk(KERN_ERR "Error: Prod to wake up processor %d "
						"Ret= %ld\n", nr, rc);
	}
}

static int smp_pSeries_cpu_bootable(unsigned int nr)
{
	/* Special case - we inhibit secondary thread startup
	 * during boot if the user requests it.
	 */
	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
			return 0;
		if (smt_enabled_at_boot
		    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
			return 0;
	}

	return 1;
}
#ifdef CONFIG_MPIC
static struct smp_ops_t pSeries_mpic_smp_ops = {
	.message_pass	= smp_mpic_message_pass,
	.probe		= smp_mpic_probe,
	.kick_cpu	= smp_pSeries_kick_cpu,
	.setup_cpu	= smp_mpic_setup_cpu,
};
#endif
#ifdef CONFIG_XICS
static struct smp_ops_t pSeries_xics_smp_ops = {
	.message_pass	= smp_xics_message_pass,
	.probe		= smp_xics_probe,
	.kick_cpu	= smp_pSeries_kick_cpu,
	.setup_cpu	= smp_xics_setup_cpu,
	.cpu_bootable	= smp_pSeries_cpu_bootable,
};
#endif

/* This is called very early */
static void __init smp_init_pseries(void)
{
	int i;

	pr_debug(" -> smp_init_pSeries()\n");

	alloc_bootmem_cpumask_var(&of_spin_mask);

	/* Mark threads which are still spinning in hold loops. */
	if (cpu_has_feature(CPU_FTR_SMT)) {
		for_each_present_cpu(i) { 
			if (cpu_thread_in_core(i) == 0)
				cpumask_set_cpu(i, of_spin_mask);
		}
	} else {
		cpumask_copy(of_spin_mask, cpu_present_mask);
	}

	cpumask_clear_cpu(boot_cpuid, of_spin_mask);

	/* Non-lpar has additional take/give timebase */
	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
		smp_ops->give_timebase = rtas_give_timebase;
		smp_ops->take_timebase = rtas_take_timebase;
	}

	pr_debug(" <- smp_init_pSeries()\n");
}

#ifdef CONFIG_MPIC
void __init smp_init_pseries_mpic(void)
{
	smp_ops = &pSeries_mpic_smp_ops;

	smp_init_pseries();
}
#endif

void __init smp_init_pseries_xics(void)
{
	smp_ops = &pSeries_xics_smp_ops;

	smp_init_pseries();
}
Commit	Line	Data
1da177e4	1	/*
69a80d3f	2	* SMP support for pSeries machines.
1da177e4 LT	3	*
	4	* Dave Engebretsen, Peter Bergner, and
	5	* Mike Corrigan {engebret\|bergner\|mikec}@us.ibm.com
	6	*
	7	* Plus various changes from other IBM teams...
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
1da177e4	15
1da177e4 LT	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/sched.h>
	19	#include <linux/smp.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/delay.h>
	22	#include <linux/init.h>
	23	#include <linux/spinlock.h>
	24	#include <linux/cache.h>
	25	#include <linux/err.h>
	26	#include <linux/sysdev.h>
	27	#include <linux/cpu.h>
	28
	29	#include <asm/ptrace.h>
	30	#include <asm/atomic.h>
	31	#include <asm/irq.h>
	32	#include <asm/page.h>
	33	#include <asm/pgtable.h>
	34	#include <asm/io.h>
	35	#include <asm/prom.h>
	36	#include <asm/smp.h>
	37	#include <asm/paca.h>
1da177e4	38	#include <asm/machdep.h>
1da177e4	39	#include <asm/cputable.h>
1ababe11	40	#include <asm/firmware.h>
1da177e4 LT	41	#include <asm/system.h>
1da177e4 LT	42	#include <asm/rtas.h>
1da177e4	43	#include <asm/pSeries_reconfig.h>
bbeb3f4c	44	#include <asm/mpic.h>
271c3f35	45	#include <asm/vdso_datapage.h>
8d089085	46	#include <asm/cputhreads.h>
1da177e4	47
a1218720	48	#include "plpar_wrappers.h"
8feaeca2	49	#include "pseries.h"
d13f7208	50	#include "xics.h"
3aa565f5	51	#include "offline_states.h"
a1218720	52
1da177e4 LT	53
1da177e4 LT	54	/*
6a75a6b8 MM	55	* The Primary thread of each non-boot processor was started from the OF client
6a75a6b8 MM	56	* interface by prom_hold_cpus and is spinning on secondary_hold_spinloop.
1da177e4	57	*/
af831e1e	58	static cpumask_var_t of_spin_mask;
1da177e4	59
f8b67691 MN	60	/* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */
	61	int smp_query_cpu_stopped(unsigned int pcpu)
	62	{
	63	int cpu_status, status;
	64	int qcss_tok = rtas_token("query-cpu-stopped-state");
	65
	66	if (qcss_tok == RTAS_UNKNOWN_SERVICE) {
	67	printk(KERN_INFO "Firmware doesn't support "
	68	"query-cpu-stopped-state\n");
	69	return QCSS_HARDWARE_ERROR;
	70	}
	71
	72	status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
	73	if (status != 0) {
	74	printk(KERN_ERR
	75	"RTAS query-cpu-stopped-state failed: %i\n", status);
	76	return status;
	77	}
	78
	79	return cpu_status;
	80	}
	81
1da177e4 LT	82	/**
	83	* smp_startup_cpu() - start the given cpu
	84	*
	85	* At boot time, there is nothing to do for primary threads which were
	86	* started from Open Firmware. For anything else, call RTAS with the
	87	* appropriate start location.
	88	*
	89	* Returns:
	90	* 0 - failure
	91	* 1 - success
	92	*/
	93	static inline int __devinit smp_startup_cpu(unsigned int lcpu)
	94	{
	95	int status;
	96	unsigned long start_here = __pa((u32)((unsigned long )
f39b7a55	97	generic_secondary_smp_init));
1da177e4	98	unsigned int pcpu;
1ed2fd2d	99	int start_cpu;
1da177e4	100
af831e1e	101	if (cpumask_test_cpu(lcpu, of_spin_mask))
1da177e4 LT	102	/* Already started by OF and sitting in spin loop */
	103	return 1;
	104
	105	pcpu = get_hard_smp_processor_id(lcpu);
	106
aef40e87 MN	107	/* Check to see if the CPU out of FW already for kexec */
aef40e87 MN	108	if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){
af831e1e	109	cpumask_set_cpu(lcpu, of_spin_mask);
aef40e87 MN	110	return 1;
	111	}
	112
1da177e4	113	/* Fixup atomic count: it exited inside IRQ handler. */
b5e2fc1c	114	task_thread_info(paca[lcpu].__current)->preempt_count = 0;
1da177e4	115
3aa565f5 GS	116	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
	117	goto out;
	118
1ed2fd2d AB	119	/*
	120	* If the RTAS start-cpu token does not exist then presume the
	121	* cpu is already spinning.
	122	*/
	123	start_cpu = rtas_token("start-cpu");
	124	if (start_cpu == RTAS_UNKNOWN_SERVICE)
	125	return 1;
	126
496b7a51	127	status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu);
1da177e4 LT	128	if (status != 0) {
	129	printk(KERN_ERR "start-cpu failed: %i\n", status);
	130	return 0;
	131	}
1ed2fd2d	132
3aa565f5	133	out:
1da177e4 LT	134	return 1;
	135	}
	136
cebf589c	137	#ifdef CONFIG_XICS
1da177e4 LT	138	static void __devinit smp_xics_setup_cpu(int cpu)
	139	{
	140	if (cpu != boot_cpuid)
	141	xics_setup_cpu();
	142
1ababe11	143	if (firmware_has_feature(FW_FEATURE_SPLPAR))
1da177e4 LT	144	vpa_init(cpu);
1da177e4 LT	145
af831e1e	146	cpumask_clear_cpu(cpu, of_spin_mask);
3aa565f5 GS	147	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
3aa565f5 GS	148	set_default_offline_state(cpu);
1da177e4	149
1da177e4	150	}
cebf589c	151	#endif /* CONFIG_XICS */
1da177e4	152
1da177e4 LT	153	static void __devinit smp_pSeries_kick_cpu(int nr)
1da177e4 LT	154	{
3aa565f5 GS	155	long rc;
3aa565f5 GS	156	unsigned long hcpuid;
1da177e4 LT	157	BUG_ON(nr < 0 \|\| nr >= NR_CPUS);
	158
	159	if (!smp_startup_cpu(nr))
	160	return;
	161
	162	/*
	163	* The processor is currently spinning, waiting for the
	164	* cpu_start field to become non-zero After we set cpu_start,
	165	* the processor will continue on to secondary_start
	166	*/
	167	paca[nr].cpu_start = 1;
3aa565f5 GS	168
	169	set_preferred_offline_state(nr, CPU_STATE_ONLINE);
	170
	171	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
	172	hcpuid = get_hard_smp_processor_id(nr);
	173	rc = plpar_hcall_norets(H_PROD, hcpuid);
	174	if (rc != H_SUCCESS)
5a2ad98e JP	175	printk(KERN_ERR "Error: Prod to wake up processor %d "
5a2ad98e JP	176	"Ret= %ld\n", nr, rc);
3aa565f5	177	}
1da177e4 LT	178	}
	179
	180	static int smp_pSeries_cpu_bootable(unsigned int nr)
	181	{
	182	/* Special case - we inhibit secondary thread startup
6a75a6b8	183	* during boot if the user requests it.
1da177e4	184	*/
954e6da5 NF	185	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
	186	if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
	187	return 0;
	188	if (smt_enabled_at_boot
	189	&& cpu_thread_in_core(nr) >= smt_enabled_at_boot)
	190	return 0;
	191	}
1da177e4 LT	192
	193	return 1;
	194	}
cebf589c	195	#ifdef CONFIG_MPIC
1da177e4 LT	196	static struct smp_ops_t pSeries_mpic_smp_ops = {
	197	.message_pass = smp_mpic_message_pass,
	198	.probe = smp_mpic_probe,
	199	.kick_cpu = smp_pSeries_kick_cpu,
	200	.setup_cpu = smp_mpic_setup_cpu,
	201	};
cebf589c AB	202	#endif
cebf589c AB	203	#ifdef CONFIG_XICS
1da177e4 LT	204	static struct smp_ops_t pSeries_xics_smp_ops = {
	205	.message_pass = smp_xics_message_pass,
	206	.probe = smp_xics_probe,
	207	.kick_cpu = smp_pSeries_kick_cpu,
	208	.setup_cpu = smp_xics_setup_cpu,
	209	.cpu_bootable = smp_pSeries_cpu_bootable,
	210	};
cebf589c	211	#endif
1da177e4 LT	212
1da177e4 LT	213	/* This is called very early */
0ebfff14	214	static void __init smp_init_pseries(void)
1da177e4 LT	215	{
	216	int i;
	217
f7ebf352	218	pr_debug(" -> smp_init_pSeries()\n");
1da177e4	219
af831e1e AB	220	alloc_bootmem_cpumask_var(&of_spin_mask);
af831e1e AB	221
1da177e4	222	/* Mark threads which are still spinning in hold loops. */
0231c290 AB	223	if (cpu_has_feature(CPU_FTR_SMT)) {
0231c290 AB	224	for_each_present_cpu(i) {
6a75a6b8	225	if (cpu_thread_in_core(i) == 0)
af831e1e	226	cpumask_set_cpu(i, of_spin_mask);
1da177e4	227	}
0231c290	228	} else {
af831e1e	229	cpumask_copy(of_spin_mask, cpu_present_mask);
0231c290	230	}
1da177e4	231
af831e1e	232	cpumask_clear_cpu(boot_cpuid, of_spin_mask);
1da177e4 LT	233
	234	/* Non-lpar has additional take/give timebase */
	235	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
c4007a2f BH	236	smp_ops->give_timebase = rtas_give_timebase;
c4007a2f BH	237	smp_ops->take_timebase = rtas_take_timebase;
1da177e4 LT	238	}
1da177e4 LT	239
f7ebf352	240	pr_debug(" <- smp_init_pSeries()\n");
1da177e4 LT	241	}
1da177e4 LT	242
0ebfff14 BH	243	#ifdef CONFIG_MPIC
	244	void __init smp_init_pseries_mpic(void)
	245	{
	246	smp_ops = &pSeries_mpic_smp_ops;
	247
	248	smp_init_pseries();
	249	}
	250	#endif
	251
	252	void __init smp_init_pseries_xics(void)
	253	{
	254	smp_ops = &pSeries_xics_smp_ops;
	255
	256	smp_init_pseries();
	257	}