[PATCH] MIPS: SB1250: Validate and update IRQ affinity

[Florian Fainelli <f.fainelli@gmail.com>]

sb1250_set_affinity() selects the first online CPU in the requested
affinity mask without checking whether such a CPU exists. If the
intersection is empty, the resulting CPU index is invalid and must
not be passed to cpu_logical_map().

Reject affinity masks containing no online CPU with -EINVAL before
accessing the CPU mapping or interrupt mapper registers.

Also update the effective affinity mask to reflect the single logical
CPU selected as the interrupt target.

Fixes: 421d1563c662 ("mips: Validate online cpus in irq_set_affinity() callbacks")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/mips/sibyte/sb1250/irq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
index 2f08ad267a11..d7a656cd7ec0 100644
--- a/arch/mips/sibyte/sb1250/irq.c
+++ b/arch/mips/sibyte/sb1250/irq.c
@@ -76,6 +76,8 @@ static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask,
 	unsigned long flags;
 
 	i = cpumask_first_and(mask, cpu_online_mask);
+	if (i >= nr_cpu_ids)
+		return -EINVAL;
 
 	/* Convert logical CPU to physical CPU */
 	cpu = cpu_logical_map(i);
@@ -103,6 +105,7 @@ static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask,
 		____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
 					R_IMR_INTERRUPT_MASK));
 	}
+	irq_data_update_effective_affinity(d, cpumask_of(i));
 	raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags);
 
 	return 0;
-- 
2.53.0