From: David Daney <david.da...@cavium.com>
As in f21afc25f9ed (smp.h: Use local_irq_{save,restore}() in !SMP
version of on_each_cpu().), we don't want to enable irqs if they are
not already enabled.
I don't know of any bugs currently caused by this unconditional
local_irq_enable(), but I want to use this function in MIPS/OCTEON
early boot (when we have early_boot_irqs_disabled). This also makes
this function have similar semantics to on_each_cpu() which is good in
itself.
Signed-off-by: David Daney <david.da...@cavium.com>
---
kernel/smp.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/smp.c b/kernel/smp.c
index 91c52ab..97edbbe 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -578,8 +578,10 @@ EXPORT_SYMBOL(on_each_cpu);
*
* If @wait is true, then returns once @func has returned.
*
- * You must not call this function with disabled interrupts or
- * from a hardware interrupt handler or from a bottom half handler.
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler. The
+ * exception is that it may be used during early boot while
+ * early_boot_irqs_disabled is set.
*/
void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
void *info, bool wait)
@@ -588,9 +590,10 @@ void on_each_cpu_mask(const struct cpumask *mask,
smp_call_func_t func,
smp_call_function_many(mask, func, info, wait);
if (cpumask_test_cpu(cpu, mask)) {
- local_irq_disable();
+ unsigned long flags;
+ local_irq_save(flags);
func(info);
- local_irq_enable();
+ local_irq_restore(flags);
}
put_cpu();
}
--
1.7.11.7
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