[PATCH 2/2] parisc: Remove unnecessary NULL check of the kstat_irqs field

[Radu Rendec]

The kstat_irqs field of struct irq_desc is used to store a per-cpu count
of interrupt events. It is initialized in init_desc(), along with all
the other fields in struct irq_desc that need explicit initialization,
and therefore it's always available (non-NULL) for any valid interrupt
descriptor.

On parisc, CONFIG_SPARSE_IRQ is disabled, interrupt descriptors are
allocated statically in the irq_desc[] array, and kstat_irqs is
initialized implicitly to NULL. The kstat_irqs field is initialized
later, for all descriptors, via start_kernel() -> early_irq_init() ->
init_desc().

smp_boot_one_cpu() is used only for CPU hotplugging. On a SMP system,
the boot CPU initializes the interrupt descriptors as described above,
and smp_boot_one_cpu() is called later, for the secondary CPU(s).

The previous patch in this series makes a similar change across the
generic IRQ code in kernel/irq/irqdesc.c, and provides a more detailed
explanation of why kstat_irqs is guaranteed to be non-NULL.

Signed-off-by: Radu Rendec <radu@xxxxxxxxxx>
---
 arch/parisc/kernel/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index b2d12ab728b1..36be17e32948 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -343,7 +343,7 @@ static int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 	for (i = 0; i < NR_IRQS; i++) {
 		struct irq_desc *desc = irq_to_desc(i);
 
-		if (desc && desc->kstat_irqs)
+		if (desc)
 			*per_cpu_ptr(desc->kstat_irqs, cpuid) = (struct irqstat) { };
 	}
 #endif
-- 
2.54.0