/*
* arch/s390/kernel/smp.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* based on other smp stuff by
* (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
* (c) 1998 Ingo Molnar
*
* We work with logical cpu numbering everywhere we can. The only
* functions using the real cpu address (got from STAP) are the sigp
* functions. For all other functions we use the identity mapping.
* That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
* used e.g. to find the idle task belonging to a logical cpu. Every array
* in the kernel is sorted by the logical cpu number and not by the physical
* one which is causing all the confusion with __cpu_logical_map and
* cpu_number_map in other architectures.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <linux/smp_lock.h>
#include <linux/delay.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <asm/sigp.h>
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/s390_ext.h>
#include <asm/cpcmd.h>
#include <asm/tlbflush.h>
/* prototypes */
extern int cpu_idle(void * unused);
extern volatile int __cpu_logical_map[];
/*
* An array with a pointer the lowcore of every CPU.
*/
struct _lowcore *lowcore_ptr[NR_CPUS];
cycles_t cacheflush_time=0;
int smp_threads_ready=0; /* Set when the idlers are all forked. */
cpumask_t cpu_online_map;
cpumask_t cpu_possible_map;
unsigned long cache_decay_ticks = 0;
EXPORT_SYMBOL(cpu_online_map);
/*
* Reboot, halt and power_off routines for SMP.
*/
extern char vmhalt_cmd[];
extern char vmpoff_cmd[];
extern void do_reipl(unsigned long devno);
static void smp_ext_bitcall(int, ec_bit_sig);
static void smp_ext_bitcall_others(ec_bit_sig);
/*
* Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
*/
static spinlock_t call_lock = SPIN_LOCK_UNLOCKED;
struct call_data_struct {
void (*func) (void *info);
void *info;
atomic_t started;
atomic_t finished;
int wait;
};
static struct call_data_struct * call_data;
/*
* 'Call function' interrupt callback
*/
static void do_call_function(void)
{
void (*func) (void *info) = call_data->func;
void *info = call_data->info;
int wait = call_data->wait;
atomic_inc(&call_data->started);
(*func)(info);
if (wait)
atomic_inc(&call_data->finished);
}
/*
* 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.
*/
{
struct call_data_struct data;
int cpus = num_online_cpus()-1;
/* FIXME: get cpu lock -hc */
if (cpus <= 0)
return 0;
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_ext_bitcall_others(ec_call_function);
/* Wait for response */
while (atomic_read(&data.started) != cpus)
cpu_relax();
if (wait)
while (atomic_read(&data.finished) != cpus)
cpu_relax();
spin_unlock(&call_lock);
return 0;
}
/*
* Call a function on one CPU
* cpu : the CPU the function should be executed on
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler. You may call it from a bottom half.
*
* It is guaranteed that the called function runs on the specified CPU,
* preemption is disabled.
*/
int smp_call_function_on(void (*func) (void *info), void *info,
int nonatomic, int wait, int cpu)
{
struct call_data_struct data;
int curr_cpu;
if (!cpu_online(cpu))
return -EINVAL;
/* disable preemption for local function call */
curr_cpu = get_cpu();
if (curr_cpu == cpu) {
/* direct call to function */
func(info);
put_cpu();
return 0;
}
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
data.wait = wait;
if (wait)
atomic_set(&data.finished, 0);
spin_lock_bh(&call_lock);
call_data = &data;
smp_ext_bitcall(cpu, ec_call_function);
/* Wait for response */
while (atomic_read(&data.started) != 1)
cpu_relax();
if (wait)
while (atomic_read(&data.finished) != 1)
cpu_relax();
spin_unlock_bh(&call_lock);
put_cpu();
return 0;
}
EXPORT_SYMBOL(smp_call_function_on);
static inline void do_send_stop(void)
{
unsigned long dummy;
int i, rc;
/* stop all processors */
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_online(i) || smp_processor_id() == i)
continue;
do {
rc = signal_processor_ps(&dummy, 0, i, sigp_stop);
} while (rc == sigp_busy);
}
}
static inline void do_store_status(void)
{
unsigned long low_core_addr;
unsigned long dummy;
int i, rc;
/* store status of all processors in their lowcores (real 0) */
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_online(i) || smp_processor_id() == i)
continue;
low_core_addr = (unsigned long) lowcore_ptr[i];
do {
rc = signal_processor_ps(&dummy, low_core_addr, i,
sigp_store_status_at_address);
} while(rc == sigp_busy);
}
}
/*
* this function sends a 'stop' sigp to all other CPUs in the system.
* it goes straight through.
*/
void smp_send_stop(void)
{
/* write magic number to zero page (absolute 0) */
lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
/* stop other processors. */
do_send_stop();
/* store status of other processors. */
do_store_status();
}
/*
* Reboot, halt and power_off routines for SMP.
*/
static cpumask_t cpu_restart_map;
static void do_machine_restart(void * __unused)
{
cpu_clear(smp_processor_id(), cpu_restart_map);
if (smp_processor_id() == 0) {
/* Wait for all other cpus to enter do_machine_restart. */
while (!cpus_empty(cpu_restart_map))
cpu_relax();
/* Store status of other cpus. */
do_store_status();
/*
* Finally call reipl. Because we waited for all other
* cpus to enter this function we know that they do
* not hold any s390irq-locks (the cpus have been
* interrupted by an external interrupt and s390irq
* locks are always held disabled).
*/
if (MACHINE_IS_VM)
cpcmd ("IPL", NULL, 0);
else
do_reipl (0x10000 | S390_lowcore.ipl_device);
}
signal_processor(smp_processor_id(), sigp_stop);
}
void machine_restart_smp(char * __unused)
{
cpu_restart_map = cpu_online_map;
on_each_cpu(do_machine_restart, NULL, 0, 0);
}
static void do_wait_for_stop(void)
{
unsigned long cr[16];
__ctl_store(cr, 0, 15);
cr[0] &= ~0xffff;
cr[6] = 0;
__ctl_load(cr, 0, 15);
for (;;)
enabled_wait();
}
static void do_machine_halt(void * __unused)
{
if (smp_processor_id() == 0) {
smp_send_stop();
if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
cpcmd(vmhalt_cmd, NULL, 0);
signal_processor(smp_processor_id(),
sigp_stop_and_store_status);
}
do_wait_for_stop();
}
void machine_halt_smp(void)
{
on_each_cpu(do_machine_halt, NULL, 0, 0);
}
static void do_machine_power_off(void * __unused)
{
if (smp_processor_id() == 0) {
smp_send_stop();
if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
cpcmd(vmpoff_cmd, NULL, 0);
signal_processor(smp_processor_id(),
sigp_stop_and_store_status);
}
do_wait_for_stop();
}
void machine_power_off_smp(void)
{
on_each_cpu(do_machine_power_off, NULL, 0, 0);
}
/*
* This is the main routine where commands issued by other
* cpus are handled.
*/
void do_ext_call_interrupt(struct pt_regs *regs, __u16 code)
{
unsigned long bits;
/*
* handle bit signal external calls
*
* For the ec_schedule signal we have to do nothing. All the work
* is done automatically when we return from the interrupt.
*/
bits = xchg(&S390_lowcore.ext_call_fast, 0);
if (test_bit(ec_call_function, &bits))
do_call_function();
}
/*
* Send an external call sigp to another cpu and return without waiting
* for its completion.
*/
static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
{
/*
* Set signaling bit in lowcore of target cpu and kick it
*/
set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
while(signal_processor(cpu, sigp_external_call) == sigp_busy)
udelay(10);
}
/*
* Send an external call sigp to every other cpu in the system and
* return without waiting for its completion.
*/
static void smp_ext_bitcall_others(ec_bit_sig sig)
{
int i;
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_online(i) || smp_processor_id() == i)
continue;
/*
* Set signaling bit in lowcore of target cpu and kick it
*/
set_bit(sig, (unsigned long *) &lowcore_ptr[i]->ext_call_fast);
while (signal_processor(i, sigp_external_call) == sigp_busy)
udelay(10);
}
}
#ifndef CONFIG_ARCH_S390X
/*
* this function sends a 'purge tlb' signal to another CPU.
*/
void smp_ptlb_callback(void *info)
{
local_flush_tlb();
}
void smp_ptlb_all(void)
{
on_each_cpu(smp_ptlb_callback, NULL, 0, 1);
}
EXPORT_SYMBOL(smp_ptlb_all);
#endif /* ! CONFIG_ARCH_S390X */
/*
* this function sends a 'reschedule' IPI to another CPU.
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
void smp_send_reschedule(int cpu)
{
smp_ext_bitcall(cpu, ec_schedule);
}
/*
* parameter area for the set/clear control bit callbacks
*/
typedef struct
{
__u16 start_ctl;
__u16 end_ctl;
unsigned long orvals[16];
unsigned long andvals[16];
} ec_creg_mask_parms;
/*
* callback for setting/clearing control bits
*/
void smp_ctl_bit_callback(void *info) {
ec_creg_mask_parms *pp;
unsigned long cregs[16];
int i;
pp = (ec_creg_mask_parms *) info;
__ctl_store(cregs[pp->start_ctl], pp->start_ctl, pp->end_ctl);
for (i = pp->start_ctl; i <= pp->end_ctl; i++)
cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
__ctl_load(cregs[pp->start_ctl], pp->start_ctl, pp->end_ctl);
}
/*
* Set a bit in a control register of all cpus
*/
void smp_ctl_set_bit(int cr, int bit) {
ec_creg_mask_parms parms;
parms.start_ctl = cr;
parms.end_ctl = cr;
parms.orvals[cr] = 1 << bit;
parms.andvals[cr] = -1L;
preempt_disable();
smp_call_function(smp_ctl_bit_callback, &parms, 0, 1);
__ctl_set_bit(cr, bit);
preempt_enable();
}
/*
* Clear a bit in a control register of all cpus
*/
void smp_ctl_clear_bit(int cr, int bit) {
ec_creg_mask_parms parms;
parms.start_ctl = cr;
parms.end_ctl = cr;
parms.orvals[cr] = 0;
parms.andvals[cr] = ~(1L << bit);
preempt_disable();
smp_call_function(smp_ctl_bit_callback, &parms, 0, 1);
__ctl_clear_bit(cr, bit);
preempt_enable();
}
/*
* Lets check how many CPUs we have.
*/
void __init smp_check_cpus(unsigned int max_cpus)
{
int curr_cpu, num_cpus;
__u16 boot_cpu_addr;
boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
current_thread_info()->cpu = 0;
num_cpus = 1;
for (curr_cpu = 0;
curr_cpu <= 65535 && num_cpus < max_cpus; curr_cpu++) {
if ((__u16) curr_cpu == boot_cpu_addr)
continue;
__cpu_logical_map[num_cpus] = (__u16) curr_cpu;
if (signal_processor(num_cpus, sigp_sense) ==
sigp_not_operational)
continue;
cpu_set(num_cpus, cpu_possible_map);
num_cpus++;
}
printk("Detected %d CPU's\n",(int) num_cpus);
printk("Boot cpu address %2X\n", boot_cpu_addr);
}
/*
* Activate a secondary processor.
*/
extern void init_cpu_timer(void);
extern int pfault_init(void);
extern int pfault_token(void);
int __devinit start_secondary(void *cpuvoid)
{
/* Setup the cpu */
cpu_init();
/* init per CPU timer */
init_cpu_timer();
#ifdef CONFIG_PFAULT
/* Enable pfault pseudo page faults on this cpu. */
pfault_init();
#endif
/* Mark this cpu as online */
cpu_set(smp_processor_id(), cpu_online_map);
/* Switch on interrupts */
local_irq_enable();
/* Print info about this processor */
print_cpu_info(&S390_lowcore.cpu_data);
/* cpu_idle will call schedule for us */
return cpu_idle(NULL);
}
static struct task_struct *__devinit fork_by_hand(void)
{
struct pt_regs regs;
/* don't care about the psw and regs settings since we'll never
reschedule the forked task. */
memset(®s,0,sizeof(struct pt_regs));
return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
}
int __cpu_up(unsigned int cpu)
{
struct task_struct *idle;
struct _lowcore *cpu_lowcore;
sigp_ccode ccode;
/*
* Set prefix page for new cpu
*/
ccode = signal_processor_p((unsigned long)(lowcore_ptr[cpu]),
cpu, sigp_set_prefix);
if (ccode){
printk("sigp_set_prefix failed for cpu %d "
"with condition code %d\n",
(int) cpu, (int) ccode);
return -EIO;
}
/* We can't use kernel_thread since we must _avoid_ to reschedule
the child. */
idle = fork_by_hand();
if (IS_ERR(idle)){
printk("failed fork for CPU %d", cpu);
return -EIO;
}
wake_up_forked_process(idle);
/*
* We remove it from the pidhash and the runqueue
* once we got the process:
*/
init_idle(idle, cpu);
unhash_process(idle);
cpu_lowcore = lowcore_ptr[cpu];
cpu_lowcore->save_area[15] = idle->thread.ksp;
cpu_lowcore->kernel_stack = (unsigned long)
idle->thread_info + (THREAD_SIZE);
__ctl_store(cpu_lowcore->cregs_save_area[0], 0, 15);
__asm__ __volatile__("stam 0,15,0(%0)"
: : "a" (&cpu_lowcore->access_regs_save_area)
: "memory");
cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
cpu_lowcore->current_task = (unsigned long) idle;
cpu_lowcore->cpu_data.cpu_nr = cpu;
eieio();
signal_processor(cpu,sigp_restart);
while (!cpu_online(cpu));
return 0;
}
/*
* Cycle through the processors and setup structures.
*/
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned long async_stack;
int i;
/* request the 0x1202 external interrupt */
if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
panic("Couldn't request external interrupt 0x1202");
smp_check_cpus(max_cpus);
memset(lowcore_ptr,0,sizeof(lowcore_ptr));
/*
* Initialize prefix pages and stacks for all possible cpus
*/
print_cpu_info(&S390_lowcore.cpu_data);
for(i = 0; i < NR_CPUS; i++) {
if (!cpu_possible(i))
continue;
lowcore_ptr[i] = (struct _lowcore *)
__get_free_pages(GFP_KERNEL|GFP_DMA,
sizeof(void*) == 8 ? 1 : 0);
async_stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER);
if (lowcore_ptr[i] == NULL || async_stack == 0ULL)
panic("smp_boot_cpus failed to allocate memory\n");
*(lowcore_ptr[i]) = S390_lowcore;
lowcore_ptr[i]->async_stack = async_stack + (ASYNC_SIZE);
}
set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
}
void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), cpu_possible_map);
S390_lowcore.percpu_offset = __per_cpu_offset[smp_processor_id()];
}
void smp_cpus_done(unsigned int max_cpus)
{
}
/*
* the frequency of the profiling timer can be changed
* by writing a multiplier value into /proc/profile.
*
* usually you want to run this on all CPUs ;)
*/
int setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
EXPORT_SYMBOL(cpu_possible_map);
EXPORT_SYMBOL(lowcore_ptr);
EXPORT_SYMBOL(smp_ctl_set_bit);
EXPORT_SYMBOL(smp_ctl_clear_bit);
EXPORT_SYMBOL(smp_call_function);
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