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arm: convert to generic helpers for IPI function calls
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This converts arm to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single().

Fixups and testing done by Catalin Marinas <[email protected]>

Cc: Russell King <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
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Jens Axboe committed Jun 26, 2008
1 parent c524a1d commit f6dd9fa
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Showing 3 changed files with 19 additions and 142 deletions.
1 change: 1 addition & 0 deletions arch/arm/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -650,6 +650,7 @@ source "kernel/time/Kconfig"
config SMP
bool "Symmetric Multi-Processing (EXPERIMENTAL)"
depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP)
select USE_GENERIC_SMP_HELPERS
help
This enables support for systems with more than one CPU. If you have
a system with only one CPU, like most personal computers, say N. If
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157 changes: 15 additions & 142 deletions arch/arm/kernel/smp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -68,20 +68,10 @@ enum ipi_msg_type {
IPI_TIMER,
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
IPI_CPU_STOP,
};

struct smp_call_struct {
void (*func)(void *info);
void *info;
int wait;
cpumask_t pending;
cpumask_t unfinished;
};

static struct smp_call_struct * volatile smp_call_function_data;
static DEFINE_SPINLOCK(smp_call_function_lock);

int __cpuinit __cpu_up(unsigned int cpu)
{
struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
Expand Down Expand Up @@ -366,114 +356,15 @@ static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
local_irq_restore(flags);
}

/*
* You must not call this function with disabled interrupts, from a
* hardware interrupt handler, nor from a bottom half handler.
*/
static int smp_call_function_on_cpu(void (*func)(void *info), void *info,
int retry, int wait, cpumask_t callmap)
{
struct smp_call_struct data;
unsigned long timeout;
int ret = 0;

data.func = func;
data.info = info;
data.wait = wait;

cpu_clear(smp_processor_id(), callmap);
if (cpus_empty(callmap))
goto out;

data.pending = callmap;
if (wait)
data.unfinished = callmap;

/*
* try to get the mutex on smp_call_function_data
*/
spin_lock(&smp_call_function_lock);
smp_call_function_data = &data;

send_ipi_message(callmap, IPI_CALL_FUNC);

timeout = jiffies + HZ;
while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
barrier();

/*
* did we time out?
*/
if (!cpus_empty(data.pending)) {
/*
* this may be causing our panic - report it
*/
printk(KERN_CRIT
"CPU%u: smp_call_function timeout for %p(%p)\n"
" callmap %lx pending %lx, %swait\n",
smp_processor_id(), func, info, *cpus_addr(callmap),
*cpus_addr(data.pending), wait ? "" : "no ");

/*
* TRACE
*/
timeout = jiffies + (5 * HZ);
while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
barrier();

if (cpus_empty(data.pending))
printk(KERN_CRIT " RESOLVED\n");
else
printk(KERN_CRIT " STILL STUCK\n");
}

/*
* whatever happened, we're done with the data, so release it
*/
smp_call_function_data = NULL;
spin_unlock(&smp_call_function_lock);

if (!cpus_empty(data.pending)) {
ret = -ETIMEDOUT;
goto out;
}

if (wait)
while (!cpus_empty(data.unfinished))
barrier();
out:

return 0;
}

int smp_call_function(void (*func)(void *info), void *info, int retry,
int wait)
void arch_send_call_function_ipi(cpumask_t mask)
{
return smp_call_function_on_cpu(func, info, retry, wait,
cpu_online_map);
send_ipi_message(mask, IPI_CALL_FUNC);
}
EXPORT_SYMBOL_GPL(smp_call_function);

int smp_call_function_single(int cpu, void (*func)(void *info), void *info,
int retry, int wait)
void arch_send_call_function_single_ipi(int cpu)
{
/* prevent preemption and reschedule on another processor */
int current_cpu = get_cpu();
int ret = 0;

if (cpu == current_cpu) {
local_irq_disable();
func(info);
local_irq_enable();
} else
ret = smp_call_function_on_cpu(func, info, retry, wait,
cpumask_of_cpu(cpu));

put_cpu();

return ret;
send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
}
EXPORT_SYMBOL_GPL(smp_call_function_single);

void show_ipi_list(struct seq_file *p)
{
Expand Down Expand Up @@ -521,27 +412,6 @@ asmlinkage void __exception do_local_timer(struct pt_regs *regs)
}
#endif

/*
* ipi_call_function - handle IPI from smp_call_function()
*
* Note that we copy data out of the cross-call structure and then
* let the caller know that we're here and have done with their data
*/
static void ipi_call_function(unsigned int cpu)
{
struct smp_call_struct *data = smp_call_function_data;
void (*func)(void *info) = data->func;
void *info = data->info;
int wait = data->wait;

cpu_clear(cpu, data->pending);

func(info);

if (wait)
cpu_clear(cpu, data->unfinished);
}

static DEFINE_SPINLOCK(stop_lock);

/*
Expand Down Expand Up @@ -611,7 +481,11 @@ asmlinkage void __exception do_IPI(struct pt_regs *regs)
break;

case IPI_CALL_FUNC:
ipi_call_function(cpu);
generic_smp_call_function_interrupt();
break;

case IPI_CALL_FUNC_SINGLE:
generic_smp_call_function_single_interrupt();
break;

case IPI_CPU_STOP:
Expand Down Expand Up @@ -662,14 +536,13 @@ int setup_profiling_timer(unsigned int multiplier)
}

static int
on_each_cpu_mask(void (*func)(void *), void *info, int retry, int wait,
cpumask_t mask)
on_each_cpu_mask(void (*func)(void *), void *info, int wait, cpumask_t mask)
{
int ret = 0;

preempt_disable();

ret = smp_call_function_on_cpu(func, info, retry, wait, mask);
ret = smp_call_function_mask(mask, func, info, wait);
if (cpu_isset(smp_processor_id(), mask))
func(info);

Expand Down Expand Up @@ -738,7 +611,7 @@ void flush_tlb_mm(struct mm_struct *mm)
{
cpumask_t mask = mm->cpu_vm_mask;

on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, 1, mask);
on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mask);
}

void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
Expand All @@ -749,7 +622,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
ta.ta_vma = vma;
ta.ta_start = uaddr;

on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, 1, mask);
on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mask);
}

void flush_tlb_kernel_page(unsigned long kaddr)
Expand All @@ -771,7 +644,7 @@ void flush_tlb_range(struct vm_area_struct *vma,
ta.ta_start = start;
ta.ta_end = end;

on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, 1, mask);
on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mask);
}

void flush_tlb_kernel_range(unsigned long start, unsigned long end)
Expand Down
3 changes: 3 additions & 0 deletions include/asm-arm/smp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -101,6 +101,9 @@ extern void platform_cpu_die(unsigned int cpu);
extern int platform_cpu_kill(unsigned int cpu);
extern void platform_cpu_enable(unsigned int cpu);

extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi(cpumask_t mask);

/*
* Local timer interrupt handling function (can be IPI'ed).
*/
Expand Down

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