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/*
* IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
*
* Copyright 2007-2009 Analog Devices Inc.
* Philippe Gerum <rpm@xenomai.org>
*
* Licensed under the GPL-2.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/cache.h>
#include <linux/profile.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/cpu.h>
#include <asm/time.h>
#include <linux/err.h>
/*
* Anomaly notes:
* 05000120 - we always define corelock as 32-bit integer in L2
*/
struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
*init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
*init_saved_dcplb_fault_addr_coreb;
#define BFIN_IPI_RESCHEDULE 0
#define BFIN_IPI_CALL_FUNC 1
#define BFIN_IPI_CPU_STOP 2
struct blackfin_flush_data {
unsigned long start;
unsigned long end;
};
void *secondary_stack;
struct smp_call_struct {
void (*func)(void *info);
void *info;
int wait;
cpumask_t *waitmask;
};
static struct blackfin_flush_data smp_flush_data;
static DEFINE_SPINLOCK(stop_lock);
struct ipi_message {
unsigned long type;
struct smp_call_struct call_struct;
};
/* A magic number - stress test shows this is safe for common cases */
#define BFIN_IPI_MSGQ_LEN 5
/* Simple FIFO buffer, overflow leads to panic */
struct ipi_message_queue {
spinlock_t lock;
unsigned long count;
unsigned long head; /* head of the queue */
struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
};
static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
static void ipi_cpu_stop(unsigned int cpu)
{
spin_lock(&stop_lock);
printk(KERN_CRIT "CPU%u: stopping\n", cpu);
dump_stack();
spin_unlock(&stop_lock);
cpu_clear(cpu, cpu_online_map);
local_irq_disable();
while (1)
SSYNC();
}
static void ipi_flush_icache(void *info)
{
struct blackfin_flush_data *fdata = info;
/* Invalidate the memory holding the bounds of the flushed region. */
invalidate_dcache_range((unsigned long)fdata,
(unsigned long)fdata + sizeof(*fdata));
flush_icache_range(fdata->start, fdata->end);
}
static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
{
int wait;
void (*func)(void *info);
void *info;
func = msg->call_struct.func;
info = msg->call_struct.info;
wait = msg->call_struct.wait;
func(info);
if (wait) {
#ifdef __ARCH_SYNC_CORE_DCACHE
/*
* 'wait' usually means synchronization between CPUs.
* Invalidate D cache in case shared data was changed
* by func() to ensure cache coherence.
*/
resync_core_dcache();
#endif
cpu_clear(cpu, *msg->call_struct.waitmask);
}
}
/* Use IRQ_SUPPLE_0 to request reschedule.
* When returning from interrupt to user space,
* there is chance to reschedule */
static irqreturn_t ipi_handler_int0(int irq, void *dev_instance)
{
unsigned int cpu = smp_processor_id();
platform_clear_ipi(cpu, IRQ_SUPPLE_0);
return IRQ_HANDLED;
}
static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
{
struct ipi_message *msg;
struct ipi_message_queue *msg_queue;
unsigned int cpu = smp_processor_id();
unsigned long flags;
platform_clear_ipi(cpu, IRQ_SUPPLE_1);
msg_queue = &__get_cpu_var(ipi_msg_queue);
spin_lock_irqsave(&msg_queue->lock, flags);
while (msg_queue->count) {
msg = &msg_queue->ipi_message[msg_queue->head];
switch (msg->type) {
case BFIN_IPI_CALL_FUNC:
spin_unlock_irqrestore(&msg_queue->lock, flags);
ipi_call_function(cpu, msg);
spin_lock_irqsave(&msg_queue->lock, flags);
break;
case BFIN_IPI_CPU_STOP:
spin_unlock_irqrestore(&msg_queue->lock, flags);
ipi_cpu_stop(cpu);
spin_lock_irqsave(&msg_queue->lock, flags);
break;
default:
printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
cpu, msg->type);
break;
}
msg_queue->head++;
msg_queue->head %= BFIN_IPI_MSGQ_LEN;
msg_queue->count--;
}
spin_unlock_irqrestore(&msg_queue->lock, flags);
return IRQ_HANDLED;
}
static void ipi_queue_init(void)
{
unsigned int cpu;
struct ipi_message_queue *msg_queue;
for_each_possible_cpu(cpu) {
msg_queue = &per_cpu(ipi_msg_queue, cpu);
spin_lock_init(&msg_queue->lock);
msg_queue->count = 0;
msg_queue->head = 0;
}
}
static inline void smp_send_message(cpumask_t callmap, unsigned long type,
void (*func) (void *info), void *info, int wait)
{
unsigned int cpu;
struct ipi_message_queue *msg_queue;
struct ipi_message *msg;
unsigned long flags, next_msg;
cpumask_t waitmask = callmap; /* waitmask is shared by all cpus */
for_each_cpu_mask(cpu, callmap) {
msg_queue = &per_cpu(ipi_msg_queue, cpu);
spin_lock_irqsave(&msg_queue->lock, flags);
if (msg_queue->count < BFIN_IPI_MSGQ_LEN) {
next_msg = (msg_queue->head + msg_queue->count)
% BFIN_IPI_MSGQ_LEN;
msg = &msg_queue->ipi_message[next_msg];
msg->type = type;
if (type == BFIN_IPI_CALL_FUNC) {
msg->call_struct.func = func;
msg->call_struct.info = info;
msg->call_struct.wait = wait;
msg->call_struct.waitmask = &waitmask;
}
msg_queue->count++;
} else
panic("IPI message queue overflow\n");
spin_unlock_irqrestore(&msg_queue->lock, flags);
platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
}
if (wait) {
while (!cpus_empty(waitmask))
blackfin_dcache_invalidate_range(
(unsigned long)(&waitmask),
(unsigned long)(&waitmask));
#ifdef __ARCH_SYNC_CORE_DCACHE
/*
* Invalidate D cache in case shared data was changed by
* other processors to ensure cache coherence.
*/
resync_core_dcache();
#endif
}
}
int smp_call_function(void (*func)(void *info), void *info, int wait)
{
cpumask_t callmap;
callmap = cpu_online_map;
cpu_clear(smp_processor_id(), callmap);
if (cpus_empty(callmap))
return 0;
smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
return 0;
}
EXPORT_SYMBOL_GPL(smp_call_function);
int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
int wait)
{
unsigned int cpu = cpuid;
cpumask_t callmap;
if (cpu_is_offline(cpu))
return 0;
cpus_clear(callmap);
cpu_set(cpu, callmap);
smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
return 0;
}
EXPORT_SYMBOL_GPL(smp_call_function_single);
void smp_send_reschedule(int cpu)
{
/* simply trigger an ipi */
if (cpu_is_offline(cpu))
return;
platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0
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