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irqdomain: Let irq_domain_mapping display hierarchical domains

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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 <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20170512115538.10767-2-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Marc Zyngier
2017-05-12 12:55:35 +01:00
committed by Thomas Gleixner
parent 08332893e3
commit fe17a42e70
1 changed files with 43 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
kernel/irq/irqdomain.c
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@@ -746,13 +746,54 @@ unsigned int irq_find_mapping(struct irq_domain *domain,
EXPORT_SYMBOL_GPL(irq_find_mapping); EXPORT_SYMBOL_GPL(irq_find_mapping);
#ifdef CONFIG_IRQ_DOMAIN_DEBUG #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) static int virq_debug_show(struct seq_file *m, void *private)
{ {
unsigned long flags; unsigned long flags;
struct irq_desc *desc; struct irq_desc *desc;
struct irq_domain *domain; struct irq_domain *domain;
struct radix_tree_iter iter; struct radix_tree_iter iter;
void *data, **slot; void **slot;
int i; int i;
seq_printf(m, " %-16s %-6s %-10s %-10s %s\n", 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; continue;
raw_spin_lock_irqsave(&desc->lock, flags); raw_spin_lock_irqsave(&desc->lock, flags);
domain = desc->irq_data.domain; virq_debug_show_one(m, desc);
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);
}
raw_spin_unlock_irqrestore(&desc->lock, flags); raw_spin_unlock_irqrestore(&desc->lock, flags);
} }