kernel-ark/arch/ppc64/kernel/pSeries_smp.c
Arnd Bergmann cebf589c82 [PATCH] ppc64: Add driver for BPA interrupt controllers
Add support for the integrated interrupt controller on BPA
CPUs. There is one of those for each SMT thread.

The mapping of interrupt numbers to HW interrupt sources
is described in arch/ppc64/kernel/bpa_iic.h.

This version hardcodes the 'Spider' chip as the secondary
interrupt controller. That is not really generic for the
architecture, but at the moment it is the only secondary
PIC that exists.

A little more work will be needed on this as soon as
we have boards with multiple external interrupt controllers.

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-06-23 09:43:43 +10:00

505 lines
12 KiB
C

/*
* SMP support for pSeries and BPA 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.
*/
#undef DEBUG
#include <linux/config.h>
#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/time.h>
#include <asm/machdep.h>
#include <asm/xics.h>
#include <asm/cputable.h>
#include <asm/system.h>
#include <asm/rtas.h>
#include <asm/plpar_wrappers.h>
#include <asm/pSeries_reconfig.h>
#include "mpic.h"
#include "bpa_iic.h"
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
/*
* The primary thread of each non-boot processor is recorded here before
* smp init.
*/
static cpumask_t of_spin_map;
extern void pSeries_secondary_smp_init(unsigned long);
#ifdef CONFIG_HOTPLUG_CPU
/* 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;
int status, qcss_tok;
qcss_tok = rtas_token("query-cpu-stopped-state");
if (qcss_tok == RTAS_UNKNOWN_SERVICE)
return -1;
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;
}
int pSeries_cpu_disable(void)
{
systemcfg->processorCount--;
/*fix boot_cpuid here*/
if (smp_processor_id() == 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;
}
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;
u32 *intserv;
intserv = (u32 *)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;
u32 *intserv;
intserv = (u32 *)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,
};
#endif /* CONFIG_HOTPLUG_CPU */
/**
* 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 *)
pSeries_secondary_smp_init));
unsigned int pcpu;
if (cpu_isset(lcpu, of_spin_map))
/* Already started by OF and sitting in spin loop */
return 1;
pcpu = get_hard_smp_processor_id(lcpu);
/* Fixup atomic count: it exited inside IRQ handler. */
paca[lcpu].__current->thread_info->preempt_count = 0;
status = rtas_call(rtas_token("start-cpu"), 3, 1, NULL,
pcpu, start_here, lcpu);
if (status != 0) {
printk(KERN_ERR "start-cpu failed: %i\n", status);
return 0;
}
return 1;
}
#ifdef CONFIG_XICS
static inline void smp_xics_do_message(int cpu, int msg)
{
set_bit(msg, &xics_ipi_message[cpu].value);
mb();
xics_cause_IPI(cpu);
}
static void smp_xics_message_pass(int target, int msg)
{
unsigned int i;
if (target < NR_CPUS) {
smp_xics_do_message(target, msg);
} else {
for_each_online_cpu(i) {
if (target == MSG_ALL_BUT_SELF
&& i == smp_processor_id())
continue;
smp_xics_do_message(i, msg);
}
}
}
static int __init smp_xics_probe(void)
{
xics_request_IPIs();
return cpus_weight(cpu_possible_map);
}
static void __devinit smp_xics_setup_cpu(int cpu)
{
if (cpu != boot_cpuid)
xics_setup_cpu();
if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR)
vpa_init(cpu);
cpu_clear(cpu, of_spin_map);
}
#endif /* CONFIG_XICS */
#ifdef CONFIG_BPA_IIC
static void smp_iic_message_pass(int target, int msg)
{
unsigned int i;
if (target < NR_CPUS) {
iic_cause_IPI(target, msg);
} else {
for_each_online_cpu(i) {
if (target == MSG_ALL_BUT_SELF
&& i == smp_processor_id())
continue;
iic_cause_IPI(i, msg);
}
}
}
static int __init smp_iic_probe(void)
{
iic_request_IPIs();
return cpus_weight(cpu_possible_map);
}
static void __devinit smp_iic_setup_cpu(int cpu)
{
if (cpu != boot_cpuid)
iic_setup_cpu();
}
#endif /* CONFIG_BPA_IIC */
static DEFINE_SPINLOCK(timebase_lock);
static unsigned long timebase = 0;
static void __devinit pSeries_give_timebase(void)
{
spin_lock(&timebase_lock);
rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
timebase = get_tb();
spin_unlock(&timebase_lock);
while (timebase)
barrier();
rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
}
static void __devinit pSeries_take_timebase(void)
{
while (!timebase)
barrier();
spin_lock(&timebase_lock);
set_tb(timebase >> 32, timebase & 0xffffffff);
timebase = 0;
spin_unlock(&timebase_lock);
}
static void __devinit smp_pSeries_kick_cpu(int nr)
{
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;
}
static int smp_pSeries_cpu_bootable(unsigned int nr)
{
/* Special case - we inhibit secondary thread startup
* during boot if the user requests it. Odd-numbered
* cpus are assumed to be secondary threads.
*/
if (system_state < SYSTEM_RUNNING &&
cpu_has_feature(CPU_FTR_SMT) &&
!smt_enabled_at_boot && nr % 2 != 0)
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
#ifdef CONFIG_BPA_IIC
static struct smp_ops_t bpa_iic_smp_ops = {
.message_pass = smp_iic_message_pass,
.probe = smp_iic_probe,
.kick_cpu = smp_pSeries_kick_cpu,
.setup_cpu = smp_iic_setup_cpu,
.cpu_bootable = smp_pSeries_cpu_bootable,
};
#endif
/* This is called very early */
void __init smp_init_pSeries(void)
{
int i;
DBG(" -> smp_init_pSeries()\n");
switch (ppc64_interrupt_controller) {
#ifdef CONFIG_MPIC
case IC_OPEN_PIC:
smp_ops = &pSeries_mpic_smp_ops;
break;
#endif
#ifdef CONFIG_XICS
case IC_PPC_XIC:
smp_ops = &pSeries_xics_smp_ops;
break;
#endif
#ifdef CONFIG_BPA_IIC
case IC_BPA_IIC:
smp_ops = &bpa_iic_smp_ops;
break;
#endif
default:
panic("Invalid interrupt controller");
}
#ifdef CONFIG_HOTPLUG_CPU
smp_ops->cpu_disable = pSeries_cpu_disable;
smp_ops->cpu_die = pSeries_cpu_die;
/* Processors can be added/removed only on LPAR */
if (systemcfg->platform == PLATFORM_PSERIES_LPAR)
pSeries_reconfig_notifier_register(&pSeries_smp_nb);
#endif
/* Mark threads which are still spinning in hold loops. */
if (cpu_has_feature(CPU_FTR_SMT)) {
for_each_present_cpu(i) {
if (i % 2 == 0)
/*
* Even-numbered logical cpus correspond to
* primary threads.
*/
cpu_set(i, of_spin_map);
}
} else {
of_spin_map = cpu_present_map;
}
cpu_clear(boot_cpuid, of_spin_map);
/* Non-lpar has additional take/give timebase */
if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
smp_ops->give_timebase = pSeries_give_timebase;
smp_ops->take_timebase = pSeries_take_timebase;
}
DBG(" <- smp_init_pSeries()\n");
}