[PATCH 6/6] irqchip/sifive-plic: Avoid explicit cpumask allocation on stack

From: Dawei Li
Date: Fri Apr 12 2024 - 07:00:50 EST


In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_first_and_and() to avoid the need for a temporary cpumask on
the stack.

Signed-off-by: Dawei Li <dawei.li@xxxxxxxxxxxx>
---
drivers/irqchip/irq-sifive-plic.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index f3d4cb9e34f7..bf5d2fc6396e 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -164,15 +164,13 @@ static int plic_set_affinity(struct irq_data *d,
const struct cpumask *mask_val, bool force)
{
unsigned int cpu;
- struct cpumask amask;
struct plic_priv *priv = irq_data_get_irq_chip_data(d);

- cpumask_and(&amask, &priv->lmask, mask_val);
-
if (force)
- cpu = cpumask_first(&amask);
+ cpu = cpumask_first_and(&priv->lmask, mask_val);
else
- cpu = cpumask_any_and(&amask, cpu_online_mask);
+ cpu = cpumask_first_and_and(&priv->lmask, mask_val,
+ cpu_online_mask);

if (cpu >= nr_cpu_ids)
return -EINVAL;
--
2.27.0