From fe17a42e704a64477b15bb2cf8366fe3e5119aff Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 May 2017 12:55:35 +0100 Subject: [PATCH] irqdomain: Let irq_domain_mapping display hierarchical domains Hierarchical domains seem to be hard to grasp, and a number of aspiring kernel hackers find them utterly discombobulating. In order to ease their pain, let's make them appear in /sys/kernel/debug/irq_domain_mapping, such as the following: 96 0x81808 MSI 0x (null) RADIX MSI 96+ 0x00063 GICv2m 0xffff8003ee116980 RADIX GICv2m 96+ 0x00063 GICv2 0xffff00000916bfd8 LINEAR GICv2 [output compressed to fit in a commit log] This shows that IRQ96 is implemented by a stack of three domains, the + sign indicating the stacking. Signed-off-by: Marc Zyngier Link: http://lkml.kernel.org/r/20170512115538.10767-2-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- kernel/irq/irqdomain.c | 68 ++++++++++++++++++++++++++---------------- 1 file changed, 43 insertions(+), 25 deletions(-) diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 31805f237396..1f6cd2cacf74 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -746,13 +746,54 @@ unsigned int irq_find_mapping(struct irq_domain *domain, EXPORT_SYMBOL_GPL(irq_find_mapping); #ifdef CONFIG_IRQ_DOMAIN_DEBUG +static void virq_debug_show_one(struct seq_file *m, struct irq_desc *desc) +{ + struct irq_domain *domain; + struct irq_data *data; + + domain = desc->irq_data.domain; + data = &desc->irq_data; + + while (domain) { + unsigned int irq = data->irq; + unsigned long hwirq = data->hwirq; + struct irq_chip *chip; + bool direct; + + if (data == &desc->irq_data) + seq_printf(m, "%5d ", irq); + else + seq_printf(m, "%5d+ ", irq); + seq_printf(m, "0x%05lx ", hwirq); + + chip = irq_data_get_irq_chip(data); + seq_printf(m, "%-15s ", (chip && chip->name) ? chip->name : "none"); + + seq_printf(m, data ? "0x%p " : " %p ", + irq_data_get_irq_chip_data(data)); + + seq_printf(m, " %c ", (desc->action && desc->action->handler) ? '*' : ' '); + direct = (irq == hwirq) && (irq < domain->revmap_direct_max_irq); + seq_printf(m, "%6s%-8s ", + (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX", + direct ? "(DIRECT)" : ""); + seq_printf(m, "%s\n", domain->name); +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + domain = domain->parent; + data = data->parent_data; +#else + domain = NULL; +#endif + } +} + static int virq_debug_show(struct seq_file *m, void *private) { unsigned long flags; struct irq_desc *desc; struct irq_domain *domain; struct radix_tree_iter iter; - void *data, **slot; + void **slot; int i; seq_printf(m, " %-16s %-6s %-10s %-10s %s\n", @@ -782,30 +823,7 @@ static int virq_debug_show(struct seq_file *m, void *private) continue; raw_spin_lock_irqsave(&desc->lock, flags); - domain = desc->irq_data.domain; - - if (domain) { - struct irq_chip *chip; - int hwirq = desc->irq_data.hwirq; - bool direct; - - seq_printf(m, "%5d ", i); - seq_printf(m, "0x%05x ", hwirq); - - chip = irq_desc_get_chip(desc); - seq_printf(m, "%-15s ", (chip && chip->name) ? chip->name : "none"); - - data = irq_desc_get_chip_data(desc); - seq_printf(m, data ? "0x%p " : " %p ", data); - - seq_printf(m, " %c ", (desc->action && desc->action->handler) ? '*' : ' '); - direct = (i == hwirq) && (i < domain->revmap_direct_max_irq); - seq_printf(m, "%6s%-8s ", - (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX", - direct ? "(DIRECT)" : ""); - seq_printf(m, "%s\n", desc->irq_data.domain->name); - } - + virq_debug_show_one(m, desc); raw_spin_unlock_irqrestore(&desc->lock, flags); } -- 2.20.1