From fe8bd18ffea5327344d4ec2bf11f47951212abd0 Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
Date: Mon, 19 Dec 2016 14:20:56 +0000
Subject: MIPS: Introduce irq_stack

Allocate a per-cpu irq stack for use within interrupt handlers.

Also add a utility function on_irq_stack to determine if a given stack
pointer is within the irq stack for that cpu.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Acked-by: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14740/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/include/asm/irq.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'arch/mips/include/asm/irq.h')

diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 6bf10e796553..956db6e201d1 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -17,6 +17,18 @@
 
 #include <irq.h>
 
+#define IRQ_STACK_SIZE			THREAD_SIZE
+
+extern void *irq_stack[NR_CPUS];
+
+static inline bool on_irq_stack(int cpu, unsigned long sp)
+{
+	unsigned long low = (unsigned long)irq_stack[cpu];
+	unsigned long high = low + IRQ_STACK_SIZE;
+
+	return (low <= sp && sp <= high);
+}
+
 #ifdef CONFIG_I8259
 static inline int irq_canonicalize(int irq)
 {
-- 
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