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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, zijun_hu <zijun_hu@htc.com>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 241/264] irqchip/gic-v3: Iterate over possible CPUs by for_each_possible_cpu()
Date:   Thu, 23 Jun 2022 18:43:54 +0200
Message-Id: <20220623164350.893321580@linuxfoundation.org>
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From: zijun_hu <zijun_hu@htc.com>

[ Upstream commit 3fad4cdac235c5b13227d0c09854c689ae62c70b ]

get_cpu_number() doesn't use existing helper to iterate over possible
CPUs, It will cause an error in case of discontinuous @cpu_possible_mask
such as 0b11110001, which can result from a core having failed to come
up on a SMP machine.

Fixed by using existing helper for_each_possible_cpu().

Signed-off-by: zijun_hu <zijun_hu@htc.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/irqchip/irq-gic-v3.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 2ab6060031a4..9ae24ffb9b09 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -982,7 +982,7 @@ static int get_cpu_number(struct device_node *dn)
 {
 	const __be32 *cell;
 	u64 hwid;
-	int i;
+	int cpu;
 
 	cell = of_get_property(dn, "reg", NULL);
 	if (!cell)
@@ -996,9 +996,9 @@ static int get_cpu_number(struct device_node *dn)
 	if (hwid & ~MPIDR_HWID_BITMASK)
 		return -1;
 
-	for (i = 0; i < num_possible_cpus(); i++)
-		if (cpu_logical_map(i) == hwid)
-			return i;
+	for_each_possible_cpu(cpu)
+		if (cpu_logical_map(cpu) == hwid)
+			return cpu;
 
 	return -1;
 }
-- 
2.35.1