Received-SPF: pass (google.com: domain of linux-kernel+bounces-154691-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
From: Dawei Li <dawei.li@shingroup.cn>
To: davem@davemloft.net,
	andreas@gaisler.com
Cc: sparclinux@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	sam@ravnborg.org,
	Dawei Li <dawei.li@shingroup.cn>
Subject: [PATCH v3 6/6] sparc/leon: Remove on-stack cpumask var
Date: Tue, 23 Apr 2024 16:30:43 +0800
Message-Id: <20240423083043.3735921-7-dawei.li@shingroup.cn>
In-Reply-To: <20240423083043.3735921-1-dawei.li@shingroup.cn>
References: <20240423083043.3735921-1-dawei.li@shingroup.cn>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Feedback-ID: bizesmtpsz:shingroup.cn:qybglogicsvrgz:qybglogicsvrgz5a-1

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_subset() and cpumask_first_and() to avoid the need for a
temporary cpumask on the stack.

Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
---
 arch/sparc/kernel/leon_kernel.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c
index 4c61da491fee..a43cf794bb1e 100644
--- a/arch/sparc/kernel/leon_kernel.c
+++ b/arch/sparc/kernel/leon_kernel.c
@@ -106,13 +106,12 @@ unsigned long leon_get_irqmask(unsigned int irq)
 #ifdef CONFIG_SMP
 static int irq_choose_cpu(const struct cpumask *affinity)
 {
-	cpumask_t mask;
+	unsigned int cpu = cpumask_first_and(affinity, cpu_online_mask);
 
-	cpumask_and(&mask, cpu_online_mask, affinity);
-	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
+	if (cpumask_subset(cpu_online_mask, affinity) || cpu >= nr_cpu_ids)
 		return boot_cpu_id;
 	else
-		return cpumask_first(&mask);
+		return cpu;
 }
 #else
 #define irq_choose_cpu(affinity) boot_cpu_id
-- 
2.27.0