(repost) cleaning up handling of bad IRQs

(repost) cleaning up handling of bad IRQs

[Enrico Weigelt, metux IT consult]

Hello friends,

 << reposting, since first queue didn't go through completely, due to mailer problem >>

here's a patch queue for cleaning up the IRQ handling. Inspired by a
discussion we had on a previous patch of mine:

    "arch: fix 'unexpected IRQ trap at vector' warnings"
    https://www.spinics.net/lists/kernel/msg3763137.html

Turned out that the whole message, as it is right now, doesn't make much
sense at at all - not just incorrect wording, but also not quite useful
information. And the whole ack_bad_irq() thing deserves a cleanup anyways.

So, I've had a closer look and came to these conclusions:

1. The warning message doesn't need to be duplicated in the per architecture
   ack_bad_irq() functions. All, but one callers already do their own warning.
   Thus just adding a pr_warn() call there, printing out more useful data
   like the hardware IRQ number, and dropping all warnings from all the
   ack_bad_irq() functions.

2. Many of the ack_bad_irq()'s count up the spurious interrupts - lots of
   duplications over the various archs. Some of them using atomic_t, some
   just plain ints. Consolidating this by introducing a global counter
   with inline'd accessors and doing the upcounting in the (currently 3)
   call sites of ack_bad_irq(). After that, step by step changing all
   archs to use the new counter.

3. For all but one arch (x86), ack_bad_irq() became a no-op.

   On x86, it's just a call to ack_APIC_irq(), in order to prevent lockups
   when IRQs missed to be ack'ed on the APIC. Could we perhaps do this in
   some better place ? In that case, ack_bad_irq() could easily be removed
   entirely.

have fun,

--mtx

[PATCH 01/23] kernel: irq: irqdescs: warn on spurious IRQ

[Enrico Weigelt, metux IT consult]

Add a warning on spurious IRQs to __handle_domain_irq(), also telling the
linux IRQ number (if any), the hw IRQ number and the max nr of IRQs.

That's far more informative than the warnings in (some of) the individual
arch's ack_bad_irq()'s. These aren't really helpful since either the
other callers already had printed more detailed information or (when called
by __handle_domain_irq()) the printout just doesn't tell anything useful.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 kernel/irq/irqdesc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index e810eb9906ea..62a381351775 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -681,6 +681,9 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 	 * than crashing, do something sensible.
 	 */
 	if (unlikely(!irq || irq >= nr_irqs)) {
+		if (printk_ratelimit())
+			pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
+				irq, hwirq, nr_irqs);
 		ack_bad_irq(irq);
 		ret = -EINVAL;
 	} else {
-- 
2.11.0

[PATCH 02/23] arch: alpha: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/alpha/kernel/irq.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
index f6d2946edbd2..c1980eea75a6 100644
--- a/arch/alpha/kernel/irq.c
+++ b/arch/alpha/kernel/irq.c
@@ -35,7 +35,6 @@ DEFINE_PER_CPU(unsigned long, irq_pmi_count);
 void ack_bad_irq(unsigned int irq)
 {
 	irq_err_count++;
-	printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
 }
 
 #ifdef CONFIG_SMP 
-- 
2.11.0

[PATCH 03/23] arch: arm: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/arm/include/asm/hw_irq.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/arm/include/asm/hw_irq.h b/arch/arm/include/asm/hw_irq.h
index cecc13214ef1..5305c7e33aee 100644
--- a/arch/arm/include/asm/hw_irq.h
+++ b/arch/arm/include/asm/hw_irq.h
@@ -9,7 +9,6 @@ static inline void ack_bad_irq(int irq)
 {
 	extern unsigned long irq_err_count;
 	irq_err_count++;
-	pr_crit("unexpected IRQ trap at vector %02x\n", irq);
 }
 
 #define ARCH_IRQ_INIT_FLAGS	(IRQ_NOREQUEST | IRQ_NOPROBE)
-- 
2.11.0

[PATCH 04/23] arch: c6x: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/c6x/kernel/irq.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c
index e4c53d185b62..b9f7cfa2ed21 100644
--- a/arch/c6x/kernel/irq.c
+++ b/arch/c6x/kernel/irq.c
@@ -116,7 +116,6 @@ void __init init_IRQ(void)
 
 void ack_bad_irq(int irq)
 {
-	printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
 	irq_err_count++;
 }
 
-- 
2.11.0

[PATCH 05/23] arch: ia64: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o "0x" prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/ia64/include/asm/hardirq.h | 2 +-
 arch/ia64/kernel/irq.c          | 9 ---------
 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/ia64/include/asm/hardirq.h b/arch/ia64/include/asm/hardirq.h
index ccde7c2ba00f..dddaafaf84e0 100644
--- a/arch/ia64/include/asm/hardirq.h
+++ b/arch/ia64/include/asm/hardirq.h
@@ -22,6 +22,6 @@
 
 extern void __iomem *ipi_base_addr;
 
-void ack_bad_irq(unsigned int irq);
+#define ack_bad_irq(irq)
 
 #endif /* _ASM_IA64_HARDIRQ_H */
diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
index ecef17c7c35b..1365c7cf2095 100644
--- a/arch/ia64/kernel/irq.c
+++ b/arch/ia64/kernel/irq.c
@@ -28,15 +28,6 @@
 #include <asm/xtp.h>
 
 /*
- * 'what should we do if we get a hw irq event on an illegal vector'.
- * each architecture has to answer this themselves.
- */
-void ack_bad_irq(unsigned int irq)
-{
-	printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id());
-}
-
-/*
  * Interrupt statistics:
  */
 
-- 
2.11.0

[PATCH 06/23] arch: mips: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/mips/include/asm/hardirq.h | 3 +--
 arch/mips/kernel/irq.c          | 9 ---------
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/mips/include/asm/hardirq.h b/arch/mips/include/asm/hardirq.h
index c977a86c2c65..75444120e6cb 100644
--- a/arch/mips/include/asm/hardirq.h
+++ b/arch/mips/include/asm/hardirq.h
@@ -10,8 +10,7 @@
 #ifndef _ASM_HARDIRQ_H
 #define _ASM_HARDIRQ_H
 
-extern void ack_bad_irq(unsigned int irq);
-#define ack_bad_irq ack_bad_irq
+#define ack_bad_irq(irq)
 
 #include <asm-generic/hardirq.h>
 
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 85b6c60f285d..c98be305fab6 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -27,15 +27,6 @@
 
 void *irq_stack[NR_CPUS];
 
-/*
- * 'what should we do if we get a hw irq event on an illegal vector'.
- * each architecture has to answer this themselves.
- */
-void ack_bad_irq(unsigned int irq)
-{
-	printk("unexpected IRQ # %d\n", irq);
-}
-
 atomic_t irq_err_count;
 
 int arch_show_interrupts(struct seq_file *p, int prec)
-- 
2.11.0

[PATCH 07/23] arch: parisc: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/parisc/include/asm/hardirq.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/include/asm/hardirq.h b/arch/parisc/include/asm/hardirq.h
index fad29aa6f45f..78b581f00bb3 100644
--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -34,6 +34,6 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 #define __ARCH_IRQ_STAT
 #define inc_irq_stat(member)	this_cpu_inc(irq_stat.member)
 #define __inc_irq_stat(member)	__this_cpu_inc(irq_stat.member)
-#define ack_bad_irq(irq) WARN(1, "unexpected IRQ trap at vector %02x\n", irq)
+#define ack_bad_irq(irq)
 
 #endif /* _PARISC_HARDIRQ_H */
-- 
2.11.0

[PATCH 08/23] arch: powerpc: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/powerpc/include/asm/hardirq.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index f133b5930ae1..4138193c2367 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h
@@ -27,10 +27,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 #define __ARCH_IRQ_STAT
 #define __ARCH_IRQ_EXIT_IRQS_DISABLED
 
-static inline void ack_bad_irq(unsigned int irq)
-{
-	printk(KERN_CRIT "unexpected IRQ trap at vector %02x\n", irq);
-}
+#define ack_bad_irq(irq)
 
 extern u64 arch_irq_stat_cpu(unsigned int cpu);
 #define arch_irq_stat_cpu	arch_irq_stat_cpu
-- 
2.11.0

[PATCH 09/23] arch: s390: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/s390/include/asm/hardirq.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/s390/include/asm/hardirq.h b/arch/s390/include/asm/hardirq.h
index dfbc3c6c0674..56d95fcb310a 100644
--- a/arch/s390/include/asm/hardirq.h
+++ b/arch/s390/include/asm/hardirq.h
@@ -21,9 +21,6 @@
 #define __ARCH_HAS_DO_SOFTIRQ
 #define __ARCH_IRQ_EXIT_IRQS_DISABLED
 
-static inline void ack_bad_irq(unsigned int irq)
-{
-	printk(KERN_CRIT "unexpected IRQ trap at vector %02x\n", irq);
-}
+#define ack_bad_irq(irq)
 
 #endif /* __ASM_HARDIRQ_H */
-- 
2.11.0

[PATCH 10/23] arch: sh: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/sh/kernel/irq.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index ab5f790b0cd2..c14a142efe60 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -31,7 +31,6 @@ atomic_t irq_err_count;
 void ack_bad_irq(unsigned int irq)
 {
 	atomic_inc(&irq_err_count);
-	printk("unexpected IRQ trap at vector %02x\n", irq);
 }
 
 #if defined(CONFIG_PROC_FS)
-- 
2.11.0

[PATCH 11/23] arch: sparc: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/sparc/include/asm/hardirq_64.h | 2 +-
 arch/sparc/kernel/irq_64.c          | 5 -----
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/sparc/include/asm/hardirq_64.h b/arch/sparc/include/asm/hardirq_64.h
index 75b92bfe04b5..874151f520de 100644
--- a/arch/sparc/include/asm/hardirq_64.h
+++ b/arch/sparc/include/asm/hardirq_64.h
@@ -14,6 +14,6 @@
 #define local_softirq_pending_ref \
 	__cpu_data.__softirq_pending
 
-void ack_bad_irq(unsigned int irq);
+#define ack_bad_irq(irq)
 
 #endif /* !(__SPARC64_HARDIRQ_H) */
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index 3ec9f1402aad..ea2a52f7fe53 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -284,11 +284,6 @@ static unsigned int sysino_exists(u32 devhandle, unsigned int devino)
 	return irq;
 }
 
-void ack_bad_irq(unsigned int irq)
-{
-	pr_crit("BAD IRQ ack %d\n", irq);
-}
-
 void irq_install_pre_handler(int irq,
 			     void (*func)(unsigned int, void *, void *),
 			     void *arg1, void *arg2)
-- 
2.11.0

[PATCH 12/23] arch: x86: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/x86/kernel/irq.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index c5dd50369e2f..5c66c44b6b60 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -36,9 +36,6 @@ atomic_t irq_err_count;
  */
 void ack_bad_irq(unsigned int irq)
 {
-	if (printk_ratelimit())
-		pr_err("unexpected IRQ trap at vector %02x\n", irq);
-
 	/*
 	 * Currently unexpected vectors happen only on SMP and APIC.
 	 * We _must_ ack these because every local APIC has only N
-- 
2.11.0

[PATCH 13/23] arch: generic: drop misleading warning on spurious IRQ

[Enrico Weigelt, metux IT consult]

The warning in ack_bad_irq() is misleading in several ways:
* the term "vector" isn't quite correct
* the printing format isn't consistent across the archs: some print decimal,
  some hex, some hex w/o 0x prefix.
* the printed linux irq isn't meaningful in all cases - we actually would
  want it to print the hw irq.

Since all call sites already print out more detailed and correct information,
we just don't need to duplicate this in each single arch. So just drop it.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 include/asm-generic/hardirq.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/asm-generic/hardirq.h b/include/asm-generic/hardirq.h
index 7317e8258b48..f5a0240cbf52 100644
--- a/include/asm-generic/hardirq.h
+++ b/include/asm-generic/hardirq.h
@@ -19,7 +19,6 @@ DECLARE_PER_CPU_ALIGNED(irq_cpustat_t, irq_stat);
 #ifndef ack_bad_irq
 static inline void ack_bad_irq(unsigned int irq)
 {
-	printk(KERN_CRIT "unexpected IRQ trap at vector %02x\n", irq);
 }
 #endif
 
-- 
2.11.0

[PATCH 14/23] kernel: generic counter for interrupt errors

[Enrico Weigelt, metux IT consult]

We currently have counters for spurious interrupt spread over all the
individual architectures. Mostly done in the arch's ack_bad_irq(),
sometimes also in arch specific drivers.

It's time to consolidate this code duplication:

  * introduce a global counter and inlined accessors
  * increase the counter in all call sites of ack_bad_irq()
  * subsequent patches will transform the individual archs one by one

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 include/asm-generic/irq-err.h | 17 +++++++++++++++++
 kernel/irq/dummychip.c        |  2 ++
 kernel/irq/handle.c           |  4 ++++
 kernel/irq/irqdesc.c          |  2 ++
 4 files changed, 25 insertions(+)
 create mode 100644 include/asm-generic/irq-err.h

diff --git a/include/asm-generic/irq-err.h b/include/asm-generic/irq-err.h
new file mode 100644
index 000000000000..33c75eb50c10
--- /dev/null
+++ b/include/asm-generic/irq-err.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_GENERIC_IRQ_ERR_H
+#define __ASM_GENERIC_IRQ_ERR_H
+
+extern atomic_t irq_err_counter;
+
+static inline void irq_err_inc(void)
+{
+	atomic_inc(&irq_err_counter);
+}
+
+static inline int irq_err_get(void)
+{
+	return atomic_read(&irq_err_counter);
+}
+
+#endif /* __ASM_GENERIC_IRQ_ERR_H */
diff --git a/kernel/irq/dummychip.c b/kernel/irq/dummychip.c
index 0b0cdf206dc4..93585dab9bd0 100644
--- a/kernel/irq/dummychip.c
+++ b/kernel/irq/dummychip.c
@@ -8,6 +8,7 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/export.h>
+#include <asm-generic/irq-err.h>
 
 #include "internals.h"
 
@@ -20,6 +21,7 @@ static void ack_bad(struct irq_data *data)
 	struct irq_desc *desc = irq_data_to_desc(data);
 
 	print_irq_desc(data->irq, desc);
+	irq_err_inc();
 	ack_bad_irq(data->irq);
 }
 
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 762a928e18f9..ad90f5a56c3a 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -13,11 +13,14 @@
 #include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
+#include <asm-generic/irq-err.h>
 
 #include <trace/events/irq.h>
 
 #include "internals.h"
 
+atomic_t irq_err_counter;
+
 #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
 void (*handle_arch_irq)(struct pt_regs *) __ro_after_init;
 #endif
@@ -34,6 +37,7 @@ void handle_bad_irq(struct irq_desc *desc)
 
 	print_irq_desc(irq, desc);
 	kstat_incr_irqs_this_cpu(desc);
+	irq_err_inc();
 	ack_bad_irq(irq);
 }
 EXPORT_SYMBOL_GPL(handle_bad_irq);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 62a381351775..6192672be4d2 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -16,6 +16,7 @@
 #include <linux/bitmap.h>
 #include <linux/irqdomain.h>
 #include <linux/sysfs.h>
+#include <asm-generic/irq-err.h>
 
 #include "internals.h"
 
@@ -684,6 +685,7 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 		if (printk_ratelimit())
 			pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
 				irq, hwirq, nr_irqs);
+		irq_err_inc();
 		ack_bad_irq(irq);
 		ret = -EINVAL;
 	} else {
-- 
2.11.0

[PATCH 15/23] arch: mips: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/mips/include/asm/hw_irq.h | 4 ----
 arch/mips/kernel/irq-gt641xx.c | 3 ++-
 arch/mips/kernel/irq.c         | 7 +++----
 arch/mips/sni/rm200.c          | 3 ++-
 arch/mips/vr41xx/common/icu.c  | 3 ++-
 arch/mips/vr41xx/common/irq.c  | 5 +++--
 drivers/gpio/gpio-vr41xx.c     | 4 ++--
 7 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/arch/mips/include/asm/hw_irq.h b/arch/mips/include/asm/hw_irq.h
index 9e8ef5994c9c..b75fe2c4377f 100644
--- a/arch/mips/include/asm/hw_irq.h
+++ b/arch/mips/include/asm/hw_irq.h
@@ -8,10 +8,6 @@
 #ifndef __ASM_HW_IRQ_H
 #define __ASM_HW_IRQ_H
 
-#include <linux/atomic.h>
-
-extern atomic_t irq_err_count;
-
 /*
  * interrupt-retrigger: NOP for now. This may not be appropriate for all
  * machines, we'll see ...
diff --git a/arch/mips/kernel/irq-gt641xx.c b/arch/mips/kernel/irq-gt641xx.c
index 93bcf5736a6f..e2c877287bee 100644
--- a/arch/mips/kernel/irq-gt641xx.c
+++ b/arch/mips/kernel/irq-gt641xx.c
@@ -11,6 +11,7 @@
 #include <linux/types.h>
 
 #include <asm/gt64120.h>
+#include <asm-generic/irq-err.h>
 
 #define GT641XX_IRQ_TO_BIT(irq) (1U << (irq - GT641XX_IRQ_BASE))
 
@@ -97,7 +98,7 @@ void gt641xx_irq_dispatch(void)
 		}
 	}
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 }
 
 void __init gt641xx_irq_init(void)
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index c98be305fab6..3ea3e4280648 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -8,6 +8,7 @@
  * Copyright (C) 1992 Linus Torvalds
  * Copyright (C) 1994 - 2000 Ralf Baechle
  */
+#include <asm-generic/irq-err.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/init.h>
@@ -27,17 +28,15 @@
 
 void *irq_stack[NR_CPUS];
 
-atomic_t irq_err_count;
-
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
-	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+	seq_printf(p, "%*s: %10u\n", prec, "ERR", irq_err_get());
 	return 0;
 }
 
 asmlinkage void spurious_interrupt(void)
 {
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 }
 
 void __init init_IRQ(void)
diff --git a/arch/mips/sni/rm200.c b/arch/mips/sni/rm200.c
index d84744ca871d..c61d60a4dcc5 100644
--- a/arch/mips/sni/rm200.c
+++ b/arch/mips/sni/rm200.c
@@ -21,6 +21,7 @@
 #include <asm/sni.h>
 #include <asm/time.h>
 #include <asm/irq_cpu.h>
+#include <asm-generic/irq-err.h>
 
 #define RM200_I8259A_IRQ_BASE 32
 
@@ -270,7 +271,7 @@ void sni_rm200_mask_and_ack_8259A(struct irq_data *d)
 			       "spurious RM200 8259A interrupt: IRQ%d.\n", irq);
 			spurious_irq_mask |= irqmask;
 		}
-		atomic_inc(&irq_err_count);
+		irq_err_inc();
 		/*
 		 * Theoretically we do not have to handle this IRQ,
 		 * but in Linux this does not cause problems and is
diff --git a/arch/mips/vr41xx/common/icu.c b/arch/mips/vr41xx/common/icu.c
index 7b7f25b4b057..462f559ad978 100644
--- a/arch/mips/vr41xx/common/icu.c
+++ b/arch/mips/vr41xx/common/icu.c
@@ -27,6 +27,7 @@
 #include <asm/io.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>
+#include <asm-generic/irq-err.h>
 
 static void __iomem *icu1_base;
 static void __iomem *icu2_base;
@@ -640,7 +641,7 @@ static int icu_get_irq(unsigned int irq)
 
 	printk(KERN_ERR "spurious ICU interrupt: %04x,%04x\n", pend1, pend2);
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 
 	return -1;
 }
diff --git a/arch/mips/vr41xx/common/irq.c b/arch/mips/vr41xx/common/irq.c
index 8f68446ff2d9..b2580de08e25 100644
--- a/arch/mips/vr41xx/common/irq.c
+++ b/arch/mips/vr41xx/common/irq.c
@@ -10,6 +10,7 @@
 
 #include <asm/irq_cpu.h>
 #include <asm/vr41xx/irq.h>
+#include <asm-generic/irq-err.h>
 
 typedef struct irq_cascade {
 	int (*get_irq)(unsigned int);
@@ -46,7 +47,7 @@ static void irq_dispatch(unsigned int irq)
 	irq_cascade_t *cascade;
 
 	if (irq >= NR_IRQS) {
-		atomic_inc(&irq_err_count);
+		irq_err_inc();
 		return;
 	}
 
@@ -66,7 +67,7 @@ static void irq_dispatch(unsigned int irq)
 		ret = cascade->get_irq(irq);
 		irq = ret;
 		if (ret < 0)
-			atomic_inc(&irq_err_count);
+			irq_err_inc();
 		else
 			irq_dispatch(irq);
 		if (!irqd_irq_disabled(idata) && chip->irq_unmask)
diff --git a/drivers/gpio/gpio-vr41xx.c b/drivers/gpio/gpio-vr41xx.c
index 98cd715ccc33..c1dbd933d291 100644
--- a/drivers/gpio/gpio-vr41xx.c
+++ b/drivers/gpio/gpio-vr41xx.c
@@ -18,7 +18,7 @@
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/vr41xx/giu.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>
@@ -217,7 +217,7 @@ static int giu_get_irq(unsigned int irq)
 	printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
 	       maskl, pendl, maskh, pendh);
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 
 	return -EINVAL;
 }
-- 
2.11.0

[PATCH 16/23] arch: alpha: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/alpha/include/asm/hardirq.h |  3 ---
 arch/alpha/include/asm/hw_irq.h  |  2 --
 arch/alpha/kernel/irq.c          | 12 +++---------
 arch/alpha/kernel/irq_alpha.c    |  5 +++--
 arch/alpha/kernel/perf_event.c   |  6 +++---
 5 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/arch/alpha/include/asm/hardirq.h b/arch/alpha/include/asm/hardirq.h
index 5ce5b34e8a1a..0bbc9947e364 100644
--- a/arch/alpha/include/asm/hardirq.h
+++ b/arch/alpha/include/asm/hardirq.h
@@ -2,9 +2,6 @@
 #ifndef _ALPHA_HARDIRQ_H
 #define _ALPHA_HARDIRQ_H
 
-void ack_bad_irq(unsigned int irq);
-#define ack_bad_irq ack_bad_irq
-
 #include <asm-generic/hardirq.h>
 
 #endif /* _ALPHA_HARDIRQ_H */
diff --git a/arch/alpha/include/asm/hw_irq.h b/arch/alpha/include/asm/hw_irq.h
index e2d81ac0d934..0be79f3a6cae 100644
--- a/arch/alpha/include/asm/hw_irq.h
+++ b/arch/alpha/include/asm/hw_irq.h
@@ -2,8 +2,6 @@
 #ifndef _ALPHA_HW_IRQ_H
 #define _ALPHA_HW_IRQ_H
 
-
-extern volatile unsigned long irq_err_count;
 DECLARE_PER_CPU(unsigned long, irq_pmi_count);
 
 #ifdef CONFIG_ALPHA_GENERIC
diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
index c1980eea75a6..2b7dad83e0dc 100644
--- a/arch/alpha/kernel/irq.c
+++ b/arch/alpha/kernel/irq.c
@@ -25,18 +25,12 @@
 #include <linux/seq_file.h>
 #include <linux/profile.h>
 #include <linux/bitops.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/io.h>
 #include <linux/uaccess.h>
 
-volatile unsigned long irq_err_count;
 DEFINE_PER_CPU(unsigned long, irq_pmi_count);
 
-void ack_bad_irq(unsigned int irq)
-{
-	irq_err_count++;
-}
-
 #ifdef CONFIG_SMP 
 static char irq_user_affinity[NR_IRQS];
 
@@ -79,7 +73,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	for_each_online_cpu(j)
 		seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
 	seq_puts(p, "          Performance Monitoring\n");
-	seq_printf(p, "ERR: %10lu\n", irq_err_count);
+	seq_printf(p, "ERR: %10lu\n", irq_err_get());
 	return 0;
 }
 
@@ -109,7 +103,7 @@ handle_irq(int irq)
 	
 	if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
 	    illegal_count < MAX_ILLEGAL_IRQS)) {
-		irq_err_count++;
+		irq_err_inc();
 		illegal_count++;
 		printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
 		       irq);
diff --git a/arch/alpha/kernel/irq_alpha.c b/arch/alpha/kernel/irq_alpha.c
index d17e44c99df9..3b6373cf73d9 100644
--- a/arch/alpha/kernel/irq_alpha.c
+++ b/arch/alpha/kernel/irq_alpha.c
@@ -13,6 +13,7 @@
 #include <asm/dma.h>
 #include <asm/perf_event.h>
 #include <asm/mce.h>
+#include <asm-generic/irq-err.h>
 
 #include "proto.h"
 #include "irq_impl.h"
@@ -30,7 +31,7 @@ EXPORT_SYMBOL(__min_ipl);
 static void
 dummy_perf(unsigned long vector, struct pt_regs *regs)
 {
-	irq_err_count++;
+	irq_err_inc();
 	printk(KERN_CRIT "Performance counter interrupt!\n");
 }
 
@@ -60,7 +61,7 @@ do_entInt(unsigned long type, unsigned long vector,
 		handle_ipi(regs);
 		return;
 #else
-		irq_err_count++;
+		irq_err_inc();
 		printk(KERN_CRIT "Interprocessor interrupt? "
 		       "You must be kidding!\n");
 #endif
diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index e7a59d927d78..d855cece7bb1 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -16,7 +16,7 @@
 #include <linux/kdebug.h>
 #include <linux/mutex.h>
 #include <linux/init.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/hwrpb.h>
 #include <linux/atomic.h>
 #include <asm/irq.h>
@@ -823,7 +823,7 @@ static void alpha_perf_event_irq_handler(unsigned long la_ptr,
 	/* la_ptr is the counter that overflowed. */
 	if (unlikely(la_ptr >= alpha_pmu->num_pmcs)) {
 		/* This should never occur! */
-		irq_err_count++;
+		irq_err_inc();
 		pr_warn("PMI: silly index %ld\n", la_ptr);
 		wrperfmon(PERFMON_CMD_ENABLE, cpuc->idx_mask);
 		return;
@@ -846,7 +846,7 @@ static void alpha_perf_event_irq_handler(unsigned long la_ptr,
 
 	if (unlikely(!event)) {
 		/* This should never occur! */
-		irq_err_count++;
+		irq_err_inc();
 		pr_warn("PMI: No event at index %d!\n", idx);
 		wrperfmon(PERFMON_CMD_ENABLE, cpuc->idx_mask);
 		return;
-- 
2.11.0

[PATCH 17/23] arch: arm: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/arm/include/asm/hardirq.h  | 2 +-
 arch/arm/include/asm/hw_irq.h   | 6 ------
 arch/arm/kernel/irq.c           | 6 ++----
 drivers/irqchip/irq-omap-intc.c | 5 ++---
 4 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h
index 706efafbf972..d9ae8998240d 100644
--- a/arch/arm/include/asm/hardirq.h
+++ b/arch/arm/include/asm/hardirq.h
@@ -5,7 +5,7 @@
 #include <asm/irq.h>
 
 #define __ARCH_IRQ_EXIT_IRQS_DISABLED	1
-#define ack_bad_irq ack_bad_irq
+#define ack_bad_irq(irq)
 
 #include <asm-generic/hardirq.h>
 
diff --git a/arch/arm/include/asm/hw_irq.h b/arch/arm/include/asm/hw_irq.h
index 5305c7e33aee..adbbeb11b930 100644
--- a/arch/arm/include/asm/hw_irq.h
+++ b/arch/arm/include/asm/hw_irq.h
@@ -5,12 +5,6 @@
 #ifndef _ARCH_ARM_HW_IRQ_H
 #define _ARCH_ARM_HW_IRQ_H
 
-static inline void ack_bad_irq(int irq)
-{
-	extern unsigned long irq_err_count;
-	irq_err_count++;
-}
-
 #define ARCH_IRQ_INIT_FLAGS	(IRQ_NOREQUEST | IRQ_NOPROBE)
 
 #endif
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 698b6f636156..72c3b8ce74db 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -32,7 +32,7 @@
 #include <linux/kallsyms.h>
 #include <linux/proc_fs.h>
 #include <linux/export.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/hardware/cache-uniphier.h>
 #include <asm/outercache.h>
@@ -41,8 +41,6 @@
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
 
-unsigned long irq_err_count;
-
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
 #ifdef CONFIG_FIQ
@@ -51,7 +49,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 #ifdef CONFIG_SMP
 	show_ipi_list(p, prec);
 #endif
-	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
+	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_get());
 	return 0;
 }
 
diff --git a/drivers/irqchip/irq-omap-intc.c b/drivers/irqchip/irq-omap-intc.c
index d360a6eddd6d..2682c6e814c2 100644
--- a/drivers/irqchip/irq-omap-intc.c
+++ b/drivers/irqchip/irq-omap-intc.c
@@ -15,7 +15,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/exception.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
@@ -328,7 +328,6 @@ static int __init omap_init_irq(u32 base, struct device_node *node)
 static asmlinkage void __exception_irq_entry
 omap_intc_handle_irq(struct pt_regs *regs)
 {
-	extern unsigned long irq_err_count;
 	u32 irqnr;
 
 	irqnr = intc_readl(INTC_SIR);
@@ -351,7 +350,7 @@ omap_intc_handle_irq(struct pt_regs *regs)
 	 */
 	if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) {
 		pr_err_once("%s: spurious irq!\n", __func__);
-		irq_err_count++;
+		irq_err_inc();
 		omap_ack_irq(NULL);
 		return;
 	}
-- 
2.11.0

[PATCH 18/23] arch: arm64: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/arm64/include/asm/hardirq.h | 9 ++-------
 arch/arm64/kernel/smp.c          | 6 ++----
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
index cbfa7b6f2e09..760922571084 100644
--- a/arch/arm64/include/asm/hardirq.h
+++ b/arch/arm64/include/asm/hardirq.h
@@ -13,7 +13,8 @@
 #include <asm/kvm_arm.h>
 #include <asm/sysreg.h>
 
-#define ack_bad_irq ack_bad_irq
+#define ack_bad_irq(irq)
+
 #include <asm-generic/hardirq.h>
 
 #define __ARCH_IRQ_EXIT_IRQS_DISABLED	1
@@ -85,10 +86,4 @@ do {									\
 		write_sysreg(___hcr, hcr_el2);				\
 } while (0)
 
-static inline void ack_bad_irq(unsigned int irq)
-{
-	extern unsigned long irq_err_count;
-	irq_err_count++;
-}
-
 #endif /* __ASM_HARDIRQ_H */
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 2499b895efea..0edc565ea735 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -33,7 +33,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/kexec.h>
 #include <linux/kvm_host.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/alternative.h>
 #include <asm/atomic.h>
 #include <asm/cacheflush.h>
@@ -798,8 +798,6 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr);
 
-unsigned long irq_err_count;
-
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	unsigned int cpu, i;
@@ -813,7 +811,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "      %s\n", ipi_types[i]);
 	}
 
-	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
+	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_get());
 	return 0;
 }
 
-- 
2.11.0

[PATCH 19/23] arch: c6x: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/c6x/include/asm/hardirq.h |  3 ---
 arch/c6x/include/asm/irq.h     |  2 --
 arch/c6x/kernel/irq.c          | 11 ++---------
 3 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/arch/c6x/include/asm/hardirq.h b/arch/c6x/include/asm/hardirq.h
index f37d07d31040..f70f6113e53a 100644
--- a/arch/c6x/include/asm/hardirq.h
+++ b/arch/c6x/include/asm/hardirq.h
@@ -9,9 +9,6 @@
 #ifndef _ASM_C6X_HARDIRQ_H
 #define _ASM_C6X_HARDIRQ_H
 
-extern void ack_bad_irq(int irq);
-#define ack_bad_irq ack_bad_irq
-
 #include <asm-generic/hardirq.h>
 
 #endif /* _ASM_C6X_HARDIRQ_H */
diff --git a/arch/c6x/include/asm/irq.h b/arch/c6x/include/asm/irq.h
index 9da4d1afd0d7..f42c5747c3ee 100644
--- a/arch/c6x/include/asm/irq.h
+++ b/arch/c6x/include/asm/irq.h
@@ -45,6 +45,4 @@ struct pt_regs;
 
 extern asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs);
 
-extern unsigned long irq_err_count;
-
 #endif /* _ASM_C6X_IRQ_H */
diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c
index b9f7cfa2ed21..9f9d798925de 100644
--- a/arch/c6x/kernel/irq.c
+++ b/arch/c6x/kernel/irq.c
@@ -21,12 +21,10 @@
 #include <linux/of_irq.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/megamod-pic.h>
 #include <asm/special_insns.h>
 
-unsigned long irq_err_count;
-
 static DEFINE_RAW_SPINLOCK(core_irq_lock);
 
 static void mask_core_irq(struct irq_data *data)
@@ -114,13 +112,8 @@ void __init init_IRQ(void)
 	set_creg(ICR, 0xfff0);
 }
 
-void ack_bad_irq(int irq)
-{
-	irq_err_count++;
-}
-
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
-	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
+	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_get());
 	return 0;
 }
-- 
2.11.0

cleanup handling of bad IRQs

[Enrico Weigelt, metux IT consult]

Hello friends,


here's a patch queue for cleaning up the IRQ handling. Inspired by a
discussion we had on a previous patch of mine:

    "arch: fix 'unexpected IRQ trap at vector' warnings"
    https://www.spinics.net/lists/kernel/msg3763137.html

Turned out that the whole message, as it is right now, doesn't make much
sense at at all - not just incorrect wording, but also not quite useful
information. And the whole ack_bad_irq() thing deserves a cleanup anyways.

So, I've had a closer look and came to these conclusions:

1. The warning message doesn't need to be duplicated in the per architecture
   ack_bad_irq() functions. All, but one callers already do their own warning.
   Thus just adding a pr_warn() call there, printing out more useful data
   like the hardware IRQ number, and dropping all warnings from all the
   ack_bad_irq() functions.

2. Many of the ack_bad_irq()'s count up the spurious interrupts - lots of
   duplications over the various archs. Some of them using atomic_t, some
   just plain ints. Consolidating this by introducing a global counter
   with inline'd accessors and doing the upcounting in the (currently 3)
   call sites of ack_bad_irq(). After that, step by step changing all
   archs to use the new counter.

3. For all but one arch (x86), ack_bad_irq() became a no-op.

   On x86, it's just a call to ack_APIC_irq(), in order to prevent lockups
   when IRQs missed to be ack'ed on the APIC. Could we perhaps do this in
   some better place ? In that case, ack_bad_irq() could easily be removed
   entirely.

have fun,

--mtx

[PATCH 15/23] arch: mips: use generic irq error counter

[Enrico Weigelt, metux IT consult]

Use the newly introduced irq error counter, that's already maintained
by all callers of ack_bad_irq(), in order to remove duplicate code.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 arch/mips/include/asm/hw_irq.h | 4 ----
 arch/mips/kernel/irq-gt641xx.c | 3 ++-
 arch/mips/kernel/irq.c         | 7 +++----
 arch/mips/sni/rm200.c          | 3 ++-
 arch/mips/vr41xx/common/icu.c  | 3 ++-
 arch/mips/vr41xx/common/irq.c  | 5 +++--
 drivers/gpio/gpio-vr41xx.c     | 4 ++--
 7 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/arch/mips/include/asm/hw_irq.h b/arch/mips/include/asm/hw_irq.h
index 9e8ef5994c9c..b75fe2c4377f 100644
--- a/arch/mips/include/asm/hw_irq.h
+++ b/arch/mips/include/asm/hw_irq.h
@@ -8,10 +8,6 @@
 #ifndef __ASM_HW_IRQ_H
 #define __ASM_HW_IRQ_H
 
-#include <linux/atomic.h>
-
-extern atomic_t irq_err_count;
-
 /*
  * interrupt-retrigger: NOP for now. This may not be appropriate for all
  * machines, we'll see ...
diff --git a/arch/mips/kernel/irq-gt641xx.c b/arch/mips/kernel/irq-gt641xx.c
index 93bcf5736a6f..e2c877287bee 100644
--- a/arch/mips/kernel/irq-gt641xx.c
+++ b/arch/mips/kernel/irq-gt641xx.c
@@ -11,6 +11,7 @@
 #include <linux/types.h>
 
 #include <asm/gt64120.h>
+#include <asm-generic/irq-err.h>
 
 #define GT641XX_IRQ_TO_BIT(irq) (1U << (irq - GT641XX_IRQ_BASE))
 
@@ -97,7 +98,7 @@ void gt641xx_irq_dispatch(void)
 		}
 	}
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 }
 
 void __init gt641xx_irq_init(void)
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index c98be305fab6..3ea3e4280648 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -8,6 +8,7 @@
  * Copyright (C) 1992 Linus Torvalds
  * Copyright (C) 1994 - 2000 Ralf Baechle
  */
+#include <asm-generic/irq-err.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/init.h>
@@ -27,17 +28,15 @@
 
 void *irq_stack[NR_CPUS];
 
-atomic_t irq_err_count;
-
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
-	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+	seq_printf(p, "%*s: %10u\n", prec, "ERR", irq_err_get());
 	return 0;
 }
 
 asmlinkage void spurious_interrupt(void)
 {
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 }
 
 void __init init_IRQ(void)
diff --git a/arch/mips/sni/rm200.c b/arch/mips/sni/rm200.c
index d84744ca871d..c61d60a4dcc5 100644
--- a/arch/mips/sni/rm200.c
+++ b/arch/mips/sni/rm200.c
@@ -21,6 +21,7 @@
 #include <asm/sni.h>
 #include <asm/time.h>
 #include <asm/irq_cpu.h>
+#include <asm-generic/irq-err.h>
 
 #define RM200_I8259A_IRQ_BASE 32
 
@@ -270,7 +271,7 @@ void sni_rm200_mask_and_ack_8259A(struct irq_data *d)
 			       "spurious RM200 8259A interrupt: IRQ%d.\n", irq);
 			spurious_irq_mask |= irqmask;
 		}
-		atomic_inc(&irq_err_count);
+		irq_err_inc();
 		/*
 		 * Theoretically we do not have to handle this IRQ,
 		 * but in Linux this does not cause problems and is
diff --git a/arch/mips/vr41xx/common/icu.c b/arch/mips/vr41xx/common/icu.c
index 7b7f25b4b057..462f559ad978 100644
--- a/arch/mips/vr41xx/common/icu.c
+++ b/arch/mips/vr41xx/common/icu.c
@@ -27,6 +27,7 @@
 #include <asm/io.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>
+#include <asm-generic/irq-err.h>
 
 static void __iomem *icu1_base;
 static void __iomem *icu2_base;
@@ -640,7 +641,7 @@ static int icu_get_irq(unsigned int irq)
 
 	printk(KERN_ERR "spurious ICU interrupt: %04x,%04x\n", pend1, pend2);
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 
 	return -1;
 }
diff --git a/arch/mips/vr41xx/common/irq.c b/arch/mips/vr41xx/common/irq.c
index 8f68446ff2d9..b2580de08e25 100644
--- a/arch/mips/vr41xx/common/irq.c
+++ b/arch/mips/vr41xx/common/irq.c
@@ -10,6 +10,7 @@
 
 #include <asm/irq_cpu.h>
 #include <asm/vr41xx/irq.h>
+#include <asm-generic/irq-err.h>
 
 typedef struct irq_cascade {
 	int (*get_irq)(unsigned int);
@@ -46,7 +47,7 @@ static void irq_dispatch(unsigned int irq)
 	irq_cascade_t *cascade;
 
 	if (irq >= NR_IRQS) {
-		atomic_inc(&irq_err_count);
+		irq_err_inc();
 		return;
 	}
 
@@ -66,7 +67,7 @@ static void irq_dispatch(unsigned int irq)
 		ret = cascade->get_irq(irq);
 		irq = ret;
 		if (ret < 0)
-			atomic_inc(&irq_err_count);
+			irq_err_inc();
 		else
 			irq_dispatch(irq);
 		if (!irqd_irq_disabled(idata) && chip->irq_unmask)
diff --git a/drivers/gpio/gpio-vr41xx.c b/drivers/gpio/gpio-vr41xx.c
index 98cd715ccc33..c1dbd933d291 100644
--- a/drivers/gpio/gpio-vr41xx.c
+++ b/drivers/gpio/gpio-vr41xx.c
@@ -18,7 +18,7 @@
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
-
+#include <asm-generic/irq-err.h>
 #include <asm/vr41xx/giu.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>
@@ -217,7 +217,7 @@ static int giu_get_irq(unsigned int irq)
 	printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
 	       maskl, pendl, maskh, pendh);
 
-	atomic_inc(&irq_err_count);
+	irq_err_inc();
 
 	return -EINVAL;
 }
-- 
2.11.0