[PATCH 6/11] arm: convert to generic helpers for IPI function calls

Jens Axboe
2008-04-22T07:59:50Z

This converts arm to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single(). Not tested
at all, not even compiled.

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
arch/arm/Kconfig | 5 ++
arch/arm/kernel/smp.c | 148 ++++---------------------------------------------
2 files changed, 16 insertions(+), 137 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d8d2532..b34cedb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -79,6 +79,11 @@ config GENERIC_HARDIRQS
bool
default y

+config GENERIC_SMP_HELPERS
+ bool
+ depends on SMP
+ default y
+
config STACKTRACE_SUPPORT
bool
default y
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index eefae1d..9c85329 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -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);
@@ -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)
+void arch_send_call_function_ipi(cpumask_t mask)
{
- 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;
+ send_ipi_message(mask, IPI_CALL_FUNC);
}

-int smp_call_function(void (*func)(void *info), void *info, int retry,
- int wait)
+void arch_send_call_function_single_ipi(int cpu)
{
- return smp_call_function_on_cpu(func, info, retry, wait,
- cpu_online_map);
+ send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
}
-EXPORT_SYMBOL_GPL(smp_call_function);
-
-int smp_call_function_single(int cpu, void (*func)(void *info), void *info,
- int retry, int wait)
-{
- /* 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;
-}
-EXPORT_SYMBOL_GPL(smp_call_function_single);

void show_ipi_list(struct seq_file *p)
{
@@ -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);

/*
@@ -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:
+ generic_smp_call_function_single_interrupt();
break;

case IPI_CPU_STOP:
@@ -669,7 +543,7 @@ on_each_cpu_mask(void (*func)(void *), void *info, int retry, int wait,

preempt_disable();

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

--
1.5.5.49.gf43e2