[patch 37/52] x86/vector: Add vector domain debugfs support

Thomas Gleixner
2017-09-13T21:35:14Z

[-- Attachment #1: x86-vector--Add-vector-domain-debugfs-support.patch --]
[-- Type: text/plain, Size: 2762 bytes --]

Add the debug callback for the vector domain, which gives a detailed
information about vector usage if invoked for the domain by using rhe
matrix allocator debug function and vector/target information when invoked
for a particular interrupt.

Extra information foir the Vector domain:

Online bitmaps: 32
Global available: 6352
Global reserved: 5
Total allocated: 20
System: 41: 0-19,32,50,128,238-255
| CPU | avl | man | act | vectors
0 183 4 19 33-48,51-53
1 199 4 1 33
2 199 4 0

Extra information for interrupts:

Vector: 42
Target: 4

This allows a detailed analysis of the vector usage and the association to
interrupts and devices.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/apic/vector.c | 50 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -11,6 +11,7 @@
* published by the Free Software Foundation.
*/
#include <linux/interrupt.h>
+#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/compiler.h>
#include <linux/slab.h>
@@ -373,9 +374,54 @@ static int x86_vector_alloc_irqs(struct
return err;
}

+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d,
+ struct irq_data *irqd, int ind)
+{
+ unsigned int cpu, vec, prev_cpu, prev_vec;
+ struct apic_chip_data *apicd;
+ unsigned long flags;
+ int irq;
+
+ if (!irqd) {
+ irq_matrix_debug_show(m, vector_matrix, ind);
+ return;
+ }
+
+ irq = irqd->irq;
+ if (irq < nr_legacy_irqs() && !test_bit(irq, &io_apic_irqs)) {
+ seq_printf(m, "%*sVector: %5d\n", ind, "", ISA_IRQ_VECTOR(irq));
+ seq_printf(m, "%*sTarget: Legacy PIC all CPUs\n", ind, "");
+ return;
+ }
+
+ apicd = irqd->chip_data;
+ if (!apicd) {
+ seq_printf(m, "%*sVector: Not assigned\n", ind, "");
+ return;
+ }
+
+ raw_spin_lock_irqsave(&vector_lock, flags);
+ cpu = apicd->cpu;
+ vec = apicd->cfg.vector;
+ prev_cpu = apicd->prev_cpu;
+ prev_vec = apicd->cfg.old_vector;
+ raw_spin_unlock_irqrestore(&vector_lock, flags);
+ seq_printf(m, "%*sVector: %5u\n", ind, "", vec);
+ seq_printf(m, "%*sTarget: %5u\n", ind, "", cpu);
+ if (prev_vec) {
+ seq_printf(m, "%*sPrevious vector: %5u\n", ind, "", prev_vec);
+ seq_printf(m, "%*sPrevious target: %5u\n", ind, "", prev_cpu);
+ }
+}
+#endif
+
static const struct irq_domain_ops x86_vector_domain_ops = {
- .alloc = x86_vector_alloc_irqs,
- .free = x86_vector_free_irqs,
+ .alloc = x86_vector_alloc_irqs,
+ .free = x86_vector_free_irqs,
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+ .debug_show = x86_vector_debug_show,
+#endif
};

int __init arch_probe_nr_irqs(void)