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

From: Jens Axboe
Date: Tue Apr 22 2008 - 14:55:57 EST


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 <catalin.marinas@xxxxxxx>

Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx>
---
arch/arm/Kconfig | 1 +
arch/arm/kernel/smp.c | 157 +++++--------------------------------------------
2 files changed, 16 insertions(+), 142 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d8d2532..fed48c4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -663,6 +663,7 @@ 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
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index eefae1d..6344466 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)
-{
- 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)
{
@@ -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_SINGLE:
+ generic_smp_call_function_single_interrupt();
break;

case IPI_CPU_STOP:
@@ -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);

@@ -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)
@@ -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)
@@ -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)
--
1.5.5.1.57.g5909c

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/