linux/arch/blackfin/mach-common/smp.c
Steven Miao 177a48fdc8 smp: bf561: and smb_wmb()/smp_rmb() at ipi send/receive
add smb_wmb()/smp_rmb() to keep cache coherent

Signed-off-by: Steven Miao <realmz6@gmail.com>
2013-11-15 18:14:49 +08:00

438 lines
9.9 KiB
C

/*
* 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/clockchips.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 <linux/atomic.h>
#include <asm/cacheflush.h>
#include <asm/irq_handler.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")));
#ifdef CONFIG_ICACHE_FLUSH_L1
unsigned long blackfin_iflush_l1_entry[NR_CPUS];
#endif
struct blackfin_initial_pda initial_pda_coreb;
enum ipi_message_type {
BFIN_IPI_NONE,
BFIN_IPI_TIMER,
BFIN_IPI_RESCHEDULE,
BFIN_IPI_CALL_FUNC,
BFIN_IPI_CALL_FUNC_SINGLE,
BFIN_IPI_CPU_STOP,
};
struct blackfin_flush_data {
unsigned long start;
unsigned long end;
};
void *secondary_stack;
static struct blackfin_flush_data smp_flush_data;
static DEFINE_SPINLOCK(stop_lock);
/* 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_data {
atomic_t count;
atomic_t bits;
};
static DEFINE_PER_CPU(struct ipi_data, bfin_ipi);
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);
set_cpu_online(cpu, false);
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. */
blackfin_dcache_invalidate_range((unsigned long)fdata,
(unsigned long)fdata + sizeof(*fdata));
/* Make sure all write buffers in the data side of the core
* are flushed before trying to invalidate the icache. This
* needs to be after the data flush and before the icache
* flush so that the SSYNC does the right thing in preventing
* the instruction prefetcher from hitting things in cached
* memory at the wrong time -- it runs much further ahead than
* the pipeline.
*/
SSYNC();
/* ipi_flaush_icache is invoked by generic flush_icache_range,
* so call blackfin arch icache flush directly here.
*/
blackfin_icache_flush_range(fdata->start, fdata->end);
}
/* 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;
}
DECLARE_PER_CPU(struct clock_event_device, coretmr_events);
void ipi_timer(void)
{
int cpu = smp_processor_id();
struct clock_event_device *evt = &per_cpu(coretmr_events, cpu);
evt->event_handler(evt);
}
static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
{
struct ipi_data *bfin_ipi_data;
unsigned int cpu = smp_processor_id();
unsigned long pending;
unsigned long msg;
platform_clear_ipi(cpu, IRQ_SUPPLE_1);
smp_rmb();
bfin_ipi_data = &__get_cpu_var(bfin_ipi);
while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) {
msg = 0;
do {
msg = find_next_bit(&pending, BITS_PER_LONG, msg + 1);
switch (msg) {
case BFIN_IPI_TIMER:
ipi_timer();
break;
case BFIN_IPI_RESCHEDULE:
scheduler_ipi();
break;
case BFIN_IPI_CALL_FUNC:
generic_smp_call_function_interrupt();
break;
case BFIN_IPI_CALL_FUNC_SINGLE:
generic_smp_call_function_single_interrupt();
break;
case BFIN_IPI_CPU_STOP:
ipi_cpu_stop(cpu);
break;
default:
goto out;
}
atomic_dec(&bfin_ipi_data->count);
} while (msg < BITS_PER_LONG);
}
out:
return IRQ_HANDLED;
}
static void bfin_ipi_init(void)
{
unsigned int cpu;
struct ipi_data *bfin_ipi_data;
for_each_possible_cpu(cpu) {
bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
atomic_set(&bfin_ipi_data->bits, 0);
atomic_set(&bfin_ipi_data->count, 0);
}
}
void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
{
unsigned int cpu;
struct ipi_data *bfin_ipi_data;
unsigned long flags;
local_irq_save(flags);
for_each_cpu(cpu, cpumask) {
bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
atomic_set_mask((1 << msg), &bfin_ipi_data->bits);
atomic_inc(&bfin_ipi_data->count);
}
local_irq_restore(flags);
smp_wmb();
for_each_cpu(cpu, cpumask)
platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
}
void arch_send_call_function_single_ipi(int cpu)
{
send_ipi(cpumask_of(cpu), BFIN_IPI_CALL_FUNC_SINGLE);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
send_ipi(mask, BFIN_IPI_CALL_FUNC);
}
void smp_send_reschedule(int cpu)
{
send_ipi(cpumask_of(cpu), BFIN_IPI_RESCHEDULE);
return;
}
void smp_send_msg(const struct cpumask *mask, unsigned long type)
{
send_ipi(mask, type);
}
void smp_timer_broadcast(const struct cpumask *mask)
{
smp_send_msg(mask, BFIN_IPI_TIMER);
}
void smp_send_stop(void)
{
cpumask_t callmap;
preempt_disable();
cpumask_copy(&callmap, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &callmap);
if (!cpumask_empty(&callmap))
send_ipi(&callmap, BFIN_IPI_CPU_STOP);
preempt_enable();
return;
}
int __cpu_up(unsigned int cpu, struct task_struct *idle)
{
int ret;
secondary_stack = task_stack_page(idle) + THREAD_SIZE;
ret = platform_boot_secondary(cpu, idle);
secondary_stack = NULL;
return ret;
}
static void setup_secondary(unsigned int cpu)
{
unsigned long ilat;
bfin_write_IMASK(0);
CSYNC();
ilat = bfin_read_ILAT();
CSYNC();
bfin_write_ILAT(ilat);
CSYNC();
/* Enable interrupt levels IVG7-15. IARs have been already
* programmed by the boot CPU. */
bfin_irq_flags |= IMASK_IVG15 |
IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
}
void secondary_start_kernel(void)
{
unsigned int cpu = smp_processor_id();
struct mm_struct *mm = &init_mm;
if (_bfin_swrst & SWRST_DBL_FAULT_B) {
printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
#ifdef CONFIG_DEBUG_DOUBLEFAULT
printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n",
initial_pda_coreb.seqstat_doublefault & SEQSTAT_EXCAUSE,
initial_pda_coreb.retx_doublefault);
printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %pF\n",
initial_pda_coreb.dcplb_doublefault_addr);
printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %pF\n",
initial_pda_coreb.icplb_doublefault_addr);
#endif
printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
initial_pda_coreb.retx);
}
/*
* We want the D-cache to be enabled early, in case the atomic
* support code emulates cache coherence (see
* __ARCH_SYNC_CORE_DCACHE).
*/
init_exception_vectors();
local_irq_disable();
/* Attach the new idle task to the global mm. */
atomic_inc(&mm->mm_users);
atomic_inc(&mm->mm_count);
current->active_mm = mm;
preempt_disable();
setup_secondary(cpu);
platform_secondary_init(cpu);
/* setup local core timer */
bfin_local_timer_setup();
local_irq_enable();
bfin_setup_caches(cpu);
notify_cpu_starting(cpu);
/*
* Calibrate loops per jiffy value.
* IRQs need to be enabled here - D-cache can be invalidated
* in timer irq handler, so core B can read correct jiffies.
*/
calibrate_delay();
/* We are done with local CPU inits, unblock the boot CPU. */
set_cpu_online(cpu, true);
cpu_startup_entry(CPUHP_ONLINE);
}
void __init smp_prepare_boot_cpu(void)
{
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
platform_prepare_cpus(max_cpus);
bfin_ipi_init();
platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
}
void __init smp_cpus_done(unsigned int max_cpus)
{
unsigned long bogosum = 0;
unsigned int cpu;
for_each_online_cpu(cpu)
bogosum += loops_per_jiffy;
printk(KERN_INFO "SMP: Total of %d processors activated "
"(%lu.%02lu BogoMIPS).\n",
num_online_cpus(),
bogosum / (500000/HZ),
(bogosum / (5000/HZ)) % 100);
}
void smp_icache_flush_range_others(unsigned long start, unsigned long end)
{
smp_flush_data.start = start;
smp_flush_data.end = end;
preempt_disable();
if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1))
printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
preempt_enable();
}
EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
#ifdef __ARCH_SYNC_CORE_ICACHE
unsigned long icache_invld_count[NR_CPUS];
void resync_core_icache(void)
{
unsigned int cpu = get_cpu();
blackfin_invalidate_entire_icache();
icache_invld_count[cpu]++;
put_cpu();
}
EXPORT_SYMBOL(resync_core_icache);
#endif
#ifdef __ARCH_SYNC_CORE_DCACHE
unsigned long dcache_invld_count[NR_CPUS];
unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
void resync_core_dcache(void)
{
unsigned int cpu = get_cpu();
blackfin_invalidate_entire_dcache();
dcache_invld_count[cpu]++;
put_cpu();
}
EXPORT_SYMBOL(resync_core_dcache);
#endif
#ifdef CONFIG_HOTPLUG_CPU
int __cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
if (cpu == 0)
return -EPERM;
set_cpu_online(cpu, false);
return 0;
}
static DECLARE_COMPLETION(cpu_killed);
int __cpu_die(unsigned int cpu)
{
return wait_for_completion_timeout(&cpu_killed, 5000);
}
void cpu_die(void)
{
complete(&cpu_killed);
atomic_dec(&init_mm.mm_users);
atomic_dec(&init_mm.mm_count);
local_irq_disable();
platform_cpu_die();
}
#endif