x86/irq: Make irqstats array based

Having the x86 specific interrupt statistics as a data structure with
individual members instead of an array is just stupid as it requires
endless copy and paste in arch_show_interrupts() and arch_irq_stat_cpu(),
where the latter does not even take the latest interrupt additions into
account. The resulting #ifdef orgy is just disgusting.

Convert it to an array of counters, which does not make a difference in the
actual interrupt hotpath increment as the array index is constant and
therefore not any different than the member based access.

But in arch_show_interrupts() and arch_irq_stat_cpu() this just turns into
a loop, which reduces the text size by ~2k (~12%):

   text	   data	    bss	    dec	    hex	filename
  19643	  15250	    904	  35797	   8bd5	../build/arch/x86/kernel/irq.o
  17355	  15250	    904	  33509	   82e5	../build/arch/x86/kernel/irq.o

Adding a new vector or software counter only requires to update the table
and everything just works. Using the core provided emit function which
speeds up 0 outputs makes it significantly faster.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Radu Rendec <radu@rendec.net>
Link: https://patch.msgid.link/20260517194931.196070643@kernel.org

2 files changed, 3 insertions, 3 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 639904911444..6599e8004d94 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1045,7 +1045,7 @@ static void local_apic_timer_interrupt(void)
 	/*
 	 * the NMI deadlock-detector uses this.
 	 */
-	inc_irq_stat(apic_timer_irqs);
+	inc_irq_stat(APIC_TIMER);
 
 	evt->event_handler(evt);
 }
@@ -2114,7 +2114,7 @@ static noinline void handle_spurious_interrupt(u8 vector)
 
 	trace_spurious_apic_entry(vector);
 
-	inc_irq_stat(irq_spurious_count);
+	inc_irq_stat(SPURIOUS);
 
 	/*
 	 * If this is a spurious interrupt then do not acknowledge
diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c
index 98a57cb4aa86..3635c4d7b7f5 100644
--- a/arch/x86/kernel/apic/ipi.c
+++ b/arch/x86/kernel/apic/ipi.c
@@ -120,7 +120,7 @@ u32 apic_mem_wait_icr_idle_timeout(void)
 	for (cnt = 0; cnt < 1000; cnt++) {
 		if (!(apic_read(APIC_ICR) & APIC_ICR_BUSY))
 			return 0;
-		inc_irq_stat(icr_read_retry_count);
+		inc_irq_stat(ICR_READ_RETRY);
 		udelay(100);
 	}
 	return APIC_ICR_BUSY;