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* [PATCH 1/2] irqchip/sifive-plic: Fix PLIC crash on touching offline CPU context
@ 2021-08-03  1:12 guoren
  2021-08-03  1:12 ` [PATCH 2/2] riscv: Improve status in cpu sections of device-tree for cpuhotplug usage guoren
  2021-08-03  5:13 ` [PATCH 1/2] irqchip/sifive-plic: Fix PLIC crash on touching offline CPU context Anup Patel
  0 siblings, 2 replies; 4+ messages in thread
From: guoren @ 2021-08-03  1:12 UTC (permalink / raw)
  To: anup.patel, atish.patra, palmerdabbelt, tglx, maz, guoren
  Cc: linux-riscv, linux-kernel, Guo Ren, Anup Patel, Greentime Hu

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

The current plic driver would touch offline CPU context and cause
bus error in some chip when in CPU hotplug scenario.

This patch fixes up the problem and prevents plic access offline
CPU context in plic_init() & plic_set_affinity().

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Greentime Hu <greentime.hu@sifive.com>
Cc: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-sifive-plic.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index cf74cfa..9c9bb20 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -64,6 +64,7 @@ struct plic_priv {
 	struct cpumask lmask;
 	struct irq_domain *irqdomain;
 	void __iomem *regs;
+	unsigned int nr_irqs;
 };
 
 struct plic_handler {
@@ -150,7 +151,7 @@ static int plic_set_affinity(struct irq_data *d,
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
-	plic_irq_toggle(&priv->lmask, d, 0);
+	plic_irq_toggle(cpu_online_mask, d, 0);
 	plic_irq_toggle(cpumask_of(cpu), d, !irqd_irq_masked(d));
 
 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
@@ -251,15 +252,25 @@ static void plic_set_threshold(struct plic_handler *handler, u32 threshold)
 
 static int plic_dying_cpu(unsigned int cpu)
 {
+	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
+
 	if (plic_parent_irq)
 		disable_percpu_irq(plic_parent_irq);
 
+	handler->present = false;
+
 	return 0;
 }
 
 static int plic_starting_cpu(unsigned int cpu)
 {
 	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
+	irq_hw_number_t hwirq;
+
+	handler->present = true;
+
+	for (hwirq = 1; hwirq <= handler->priv->nr_irqs; hwirq++)
+		plic_toggle(handler, hwirq, 0);
 
 	if (plic_parent_irq)
 		enable_percpu_irq(plic_parent_irq,
@@ -275,7 +286,6 @@ static int __init plic_init(struct device_node *node,
 		struct device_node *parent)
 {
 	int error = 0, nr_contexts, nr_handlers = 0, i;
-	u32 nr_irqs;
 	struct plic_priv *priv;
 	struct plic_handler *handler;
 
@@ -290,8 +300,8 @@ static int __init plic_init(struct device_node *node,
 	}
 
 	error = -EINVAL;
-	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
-	if (WARN_ON(!nr_irqs))
+	of_property_read_u32(node, "riscv,ndev", &priv->nr_irqs);
+	if (WARN_ON(!priv->nr_irqs))
 		goto out_iounmap;
 
 	nr_contexts = of_irq_count(node);
@@ -299,14 +309,13 @@ static int __init plic_init(struct device_node *node,
 		goto out_iounmap;
 
 	error = -ENOMEM;
-	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
+	priv->irqdomain = irq_domain_add_linear(node, priv->nr_irqs + 1,
 			&plic_irqdomain_ops, priv);
 	if (WARN_ON(!priv->irqdomain))
 		goto out_iounmap;
 
 	for (i = 0; i < nr_contexts; i++) {
 		struct of_phandle_args parent;
-		irq_hw_number_t hwirq;
 		int cpu, hartid;
 
 		if (of_irq_parse_one(node, i, &parent)) {
@@ -354,7 +363,8 @@ static int __init plic_init(struct device_node *node,
 		}
 
 		cpumask_set_cpu(cpu, &priv->lmask);
-		handler->present = true;
+		if (cpu == smp_processor_id())
+			handler->present = true;
 		handler->hart_base =
 			priv->regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
 		raw_spin_lock_init(&handler->enable_lock);
@@ -362,8 +372,6 @@ static int __init plic_init(struct device_node *node,
 			priv->regs + ENABLE_BASE + i * ENABLE_PER_HART;
 		handler->priv = priv;
 done:
-		for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
-			plic_toggle(handler, hwirq, 0);
 		nr_handlers++;
 	}
 
-- 
2.7.4


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-08-10  2:43 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-03  1:12 [PATCH 1/2] irqchip/sifive-plic: Fix PLIC crash on touching offline CPU context guoren
2021-08-03  1:12 ` [PATCH 2/2] riscv: Improve status in cpu sections of device-tree for cpuhotplug usage guoren
2021-08-03  5:13 ` [PATCH 1/2] irqchip/sifive-plic: Fix PLIC crash on touching offline CPU context Anup Patel
2021-08-10  2:43   ` Guo Ren

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