From 23d0b8b053391afe15c9667d80de77ca88e18b8b Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Wed, 4 Oct 2006 02:16:49 -0700
Subject: [PATCH] genirq: irq: generalize the check for HARDIRQ_BITS

This patch adds support for systems that cannot receive every interrupt on a
single cpu simultaneously, in the check to see if we have enough HARDIRQ_BITS.

MAX_HARDIRQS_PER_CPU becomes the count of the maximum number of hardare
generated interrupts per cpu.

On architectures that support per cpu interrupt delivery this can be a
significant space savings and scalability bonus.

This patch adds support for systems that cannot receive every interrupt on

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 include/asm-x86_64/hardirq.h | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'include/asm-x86_64')

diff --git a/include/asm-x86_64/hardirq.h b/include/asm-x86_64/hardirq.h
index 64a65ce2f41..95d5e090ed8 100644
--- a/include/asm-x86_64/hardirq.h
+++ b/include/asm-x86_64/hardirq.h
@@ -6,6 +6,9 @@
 #include <asm/pda.h>
 #include <asm/apic.h>
 
+/* We can have at most NR_VECTORS irqs routed to a cpu at a time */
+#define MAX_HARDIRQS_PER_CPU NR_VECTORS
+
 #define __ARCH_IRQ_STAT 1
 
 #define local_softirq_pending() read_pda(__softirq_pending)
-- 
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