/*
* Smp support for ppc.
*
* Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
* deal of code from the sparc and intel versions.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cache.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/residual.h>
#include <asm/time.h>
#include <asm/thread_info.h>
#include <asm/tlbflush.h>
#include <asm/xmon.h>
#include <asm/machdep.h>
volatile int smp_commenced;
int smp_tb_synchronized;
struct cpuinfo_PPC cpu_data[NR_CPUS];
atomic_t ipi_recv;
atomic_t ipi_sent;
cpumask_t cpu_online_map;
cpumask_t cpu_possible_map;
int smp_hw_index[NR_CPUS];
struct thread_info *secondary_ti;
static struct task_struct *idle_tasks[NR_CPUS];
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
/* SMP operations for this machine */
struct smp_ops_t *smp_ops;
/* all cpu mappings are 1-1 -- Cort */
volatile unsigned long cpu_callin_map[NR_CPUS];
int start_secondary(void *);
void smp_call_function_interrupt(void);
static int __smp_call_function(void (*func) (void *info), void *info,
int wait, int target);
/* Low level assembly function used to backup CPU 0 state */
extern void __save_cpu_setup(void);
/* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.
*
* Make sure this matches openpic_request_IPIs in open_pic.c, or what shows up
* in /proc/interrupts will be wrong!!! --Troy */
#define PPC_MSG_CALL_FUNCTION 0
#define PPC_MSG_RESCHEDULE 1
#define PPC_MSG_INVALIDATE_TLB 2
#define PPC_MSG_XMON_BREAK 3
static inline void
smp_message_pass(int target, int msg)
{
if (smp_ops) {
atomic_inc(&ipi_sent);
smp_ops->message_pass(target, msg);
}
}
/*
* Common functions
*/
void smp_message_recv(int msg)
{
atomic_inc(&ipi_recv);
switch( msg ) {
case PPC_MSG_CALL_FUNCTION:
smp_call_function_interrupt();
break;
case PPC_MSG_RESCHEDULE:
set_need_resched();
break;
case PPC_MSG_INVALIDATE_TLB:
_tlbia();
break;
#ifdef CONFIG_XMON
case PPC_MSG_XMON_BREAK:
xmon(get_irq_regs());
break;
#endif /* CONFIG_XMON */
default:
printk("SMP %d: smp_message_recv(): unknown msg %d\n",
smp_processor_id(), msg);
break;
}
}
/*
* 750's don't broadcast tlb invalidates so
* we have to emulate that behavior.
* -- Cort
*/
void smp_send_tlb_invalidate(int cpu)
{
if ( PVR_VER(mfspr(SPRN_PVR)) == 8 )
smp_message_pass(MSG_ALL_BUT_SELF, PPC_MSG_INVALIDATE_TLB);
}
void smp_send_reschedule(int cpu)
{
/*
* This is only used if `cpu' is running an idle task,
* so it will reschedule itself anyway...
*
* This isn't the case anymore since the other CPU could be
* sleeping and won't reschedule until the next interrupt (such
* as the timer).
* -- Cort
*/
/* This is only used if `cpu' is running an idle task,
so it will reschedule itself anyway... */
smp_message_pass(cpu, PPC_MSG_RESCHEDULE);
}
#ifdef CONFIG_XMON
void smp_send_xmon_break(int cpu)
{
smp_message_pass(cpu, PPC_MSG_XMON_BREAK);
}
#endif /* CONFIG_XMON */
static void stop_this_cpu(void *dummy)
{
local_irq_disable();
while (1)
;
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, NULL, 1, 0);
}
/*
* Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
* Stolen from the i386 version.
*/
static DEFINE_SPINLOCK(call_lock);
static struct call_data_struct {
void (*func) (void *info);
void *info;
atomic_t started;
atomic_t finished;
int wait;
} *call_data;
/*
* this function sends a 'generic call function' IPI to all other CPUs
* in the system.
*/
int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait)
/*
* [SUMMARY] Run a function on all other CPUs.
* <func> The function to run. This must be fast and non-blocking.
* <info> An arbitrary pointer to pass to the function.
* <nonatomic> currently unused.
* <wait> If true, wait (atomically) until function has completed on other CPUs.
* [RETURNS] 0 on success, else a negative status code. Does not return until
* remote CPUs are nearly ready to execute <<func>> or are or have executed.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
{
/* FIXME: get cpu lock with hotplug cpus, or change this to
bitmask. --RR */
if (num_online_cpus() <= 1)
return 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
return __smp_call_function(func, info, wait, MSG_ALL_BUT_SELF);
}
static int __smp_call_function(void (*func) (void *info), void *info,
int wait, int target)
{
struct call_data_struct data;
int ret = -1;
int timeout;
int ncpus = 1;
if (target == MSG_ALL_BUT_SELF)
ncpus = num_online_cpus() - 1;
else if (target == MSG_ALL)
ncpus = num_online_cpus();
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
data.wait = wait;
if (wait)
atomic_set(&data.finished, 0);
spin_lock(&call_lock);
call_data = &data;
/* Send a message to all other CPUs and wait for them to respond */
smp_message_pass(target, PPC_MSG_CALL_FUNCTION);
/* Wait for response */
timeout = 1000000;
while (atomic_read(&data.started) != ncpus) {
if (--timeout == 0) {
printk("smp_call_function on cpu %d: other cpus not responding (%d)\n",
smp_processor_id(), atomic_read(&data.started));
goto out;
}
barrier();
udelay(1);
}
if (wait) {
timeout = 1000000;
while (atomic_read(&data.finished) != ncpus) {
if (--timeout == 0) {
printk("smp_call_function on cpu %d: other cpus not finishing (%d/%d)\n",
smp_processor_id(), atomic_read(&data.finished), atomic_read(&data.started));
goto out;
}
barrier();
udelay(1);
}
}
ret = 0;
out:
spin_unlock(&call_lock);
return ret;
}
void smp_call_function_interrupt(void)
{
void (*func) (void *info) = call_data->func;
void *info = call_data->info;
int wait = call_data->wait;
/*
* Notify initiating CPU that I've grabbed the data and am
* about to execute the function
*/
atomic_inc(&call_data->started);
/*
* At this point the info structure may be out of scope unless wait==1
*/
(*func)(info);
if (wait)
atomic_inc(&call_data->finished);
}
static void __devinit smp_store_cpu_info(int id)
{
struct cpuinfo_PPC *c = &cpu_data[id];
/* assume bogomips are same for everything */
c->loops_per_jiffy = loops_per_jiffy;
c->pvr = mfspr(SPRN_PVR);
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int num_cpus, i, cpu;
struct task_struct *p;
/* Fixup boot cpu */
smp_store_cpu_info(smp_processor_id());
cpu_callin_map[smp_processor_id()] = 1;
if (smp_ops == NULL) {
printk("SMP not supported on this machine.\n");
return;
}
/* Probe platform for CPUs: always linear. */
num_cpus = smp_ops->probe();
if (num_cpus < 2)
smp_tb_synchronized = 1;
for (i = 0; i < num_cpus; ++i)
cpu_set(i, cpu_possible_map);
/* Backup CPU 0 state */
__save_cpu_setup();
for_each_possible_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
/* create a process for the processor */
p = fork_idle(cpu);
if (IS_ERR(p))
panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
task_thread_info(p)->cpu = cpu;
idle_tasks[cpu] = p;
}
}
void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), cpu_possible_map);
}
int __init setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
/* Processor coming up starts here */
int __devinit start_secondary(void *unused)
{
int cpu;
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
cpu = smp_processor_id();
smp_store_cpu_info(cpu);
set_dec(tb_ticks_per_jiffy);
preempt_disable();
cpu_callin_map[cpu] = 1;
printk("CPU %d done callin...\n", cpu);
smp_ops->setup_cpu(cpu);
printk("CPU %d done setup...\n", cpu);
smp_ops->take_timebase();
printk("CPU %d done timebase take...\n", cpu);
spin_lock(&call_lock);
cpu_set(cpu, cpu_online_map);
spin_unlock(&call_lock);
local_irq_enable();
cpu_idle();
return 0;
}
int __cpu_up(unsigned int cpu)
{
char buf[32];
int c;
secondary_ti = task_thread_info(idle_tasks[cpu]);
mb();
/*
* There was a cache flush loop here to flush the cache
* to memory for the first 8MB of RAM. The cache flush
* has been pushed into the kick_cpu function for those
* platforms that need it.
*/
/* wake up cpu */
smp_ops->kick_cpu(cpu);
/*
* wait to see if the cpu made a callin (is actually up).
* use this value that I found through experimentation.
* -- Cort
*/
for (c = 1000; c && !cpu_callin_map[cpu]; c--)
udelay(100);
if (!cpu_callin_map[cpu]) {
sprintf(buf, "didn't find cpu %u", cpu);
if (ppc_md.progress) ppc_md.progress(buf, 0x360+cpu);
printk("Processor %u is stuck.\n", cpu);
return -ENOENT;
}
sprintf(buf, "found cpu %u", cpu);
if (ppc_md.progress) ppc_md.progress(buf, 0x350+cpu);
printk("Processor %d found.\n", cpu);
smp_ops->give_timebase();
/* Wait until cpu puts itself in the online map */
while (!cpu_online(cpu))
cpu_relax();
return 0;
}
void smp_cpus_done(unsigned int max_cpus)
{
smp_ops->setup_cpu(0);
}
