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From:   guoren@kernel.org
To:     palmerdabbelt@google.com, paul.walmsley@sifive.com,
        anup@brainfault.org, greentime.hu@sifive.com, zong.li@sifive.com,
        atish.patra@wdc.com, tglx@linutronix.de, jason@lakedaemon.net,
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Cc:     linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        guoren@kernel.org, Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH 2/3] irqchip/irq-sifive-plic: Fixup couldn't broadcast to multi CPUs
Date:   Fri, 23 Oct 2020 10:17:24 +0000
Message-Id: <1603448245-79429-2-git-send-email-guoren@kernel.org>
In-Reply-To: <1603448245-79429-1-git-send-email-guoren@kernel.org>
References: <1603448245-79429-1-git-send-email-guoren@kernel.org>
Precedence: bulk

From: Guo Ren <guoren@linux.alibaba.com>

If "echo 3 > /proc/irq/1/smp_affinity", we want irq 1 could be
broadcast to CPU0 & CPU1 and one of them would pick up the irq
handler.

But current implementation couldn't let multi CPUs process the
same IRQ concurrent.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
 drivers/irqchip/irq-sifive-plic.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 2e56576..0003322 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -114,15 +114,12 @@ static inline void plic_irq_toggle(const struct cpumask *mask,
 static void plic_irq_unmask(struct irq_data *d)
 {
 	struct cpumask amask;
-	unsigned int cpu;
 	struct plic_priv *priv = irq_get_chip_data(d->irq);
 
 	cpumask_and(&amask, &priv->lmask, cpu_online_mask);
-	cpu = cpumask_any_and(irq_data_get_affinity_mask(d),
-					   &amask);
-	if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
-		return;
-	plic_irq_toggle(cpumask_of(cpu), d, 1);
+	cpumask_and(&amask, &amask, irq_data_get_affinity_mask(d));
+
+	plic_irq_toggle(&amask, d, 1);
 }
 
 static void plic_irq_mask(struct irq_data *d)
@@ -136,24 +133,16 @@ static void plic_irq_mask(struct irq_data *d)
 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_get_chip_data(d->irq);
 
 	cpumask_and(&amask, &priv->lmask, mask_val);
+	cpumask_and(&amask, &amask, cpu_online_mask);
 
-	if (force)
-		cpu = cpumask_first(&amask);
-	else
-		cpu = cpumask_any_and(&amask, cpu_online_mask);
-
-	if (cpu >= nr_cpu_ids)
-		return -EINVAL;
+	irq_data_update_effective_affinity(d, &amask);
 
 	plic_irq_toggle(&priv->lmask, d, 0);
-	plic_irq_toggle(cpumask_of(cpu), d, 1);
-
-	irq_data_update_effective_affinity(d, cpumask_of(cpu));
+	plic_irq_toggle(&amask, d, 1);
 
 	return IRQ_SET_MASK_OK_DONE;
 }
-- 
2.7.4