[tip:irq/core] genirq: Remove IRQF_DISABLED from core code

tip-bot for Thomas Gleixner
2010-04-13T19:35:22Z

Commit-ID: 6932bf37bed45ce8ed531928b1b0f98162fe6df6
Gitweb: http://git.kernel.org/tip/6932bf37bed45ce8ed531928b1b0f98162fe6df6
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri, 26 Mar 2010 00:06:55 +0000
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 13 Apr 2010 16:36:40 +0200

genirq: Remove IRQF_DISABLED from core code

Remove all code which is related to IRQF_DISABLED from the core kernel
code. IRQF_DISABLED still exists as a flag, but becomes a NOOP and
will be removed after a grace period. That way we can easily revert to
the previous behaviour by just restoring the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>
LKML-Reference: <20100326000405.991244690@linutronix.de>
---
Documentation/feature-removal-schedule.txt | 7 ++++++
include/linux/interrupt.h | 3 +-
kernel/irq/manage.c | 30 ----------------------------
3 files changed, 9 insertions(+), 31 deletions(-)

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index ed511af..9c31c2e 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -589,3 +589,10 @@ Why: Useful in 2003, implementation is a hack.
Generally invoked by accident today.
Seen as doing more harm than good.
Who: Len Brown <len.brown@intel.com>
+
+----------------------------
+
+What: IRQF_DISABLED
+When: 2.6.36
+Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
+Who: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index d7e7a76..e6d2f44 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -39,7 +39,8 @@
* These flags used only by the kernel as part of the
* irq handling routines.
*
- * IRQF_DISABLED - keep irqs disabled when calling the action handler
+ * IRQF_DISABLED - keep irqs disabled when calling the action handler.
+ * DEPRECATED. This flag is a NOOP and scheduled to be removed
* IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
* IRQF_SHARED - allow sharing the irq among several devices
* IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 84f3227..444d5a8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -757,16 +757,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
if (new->flags & IRQF_ONESHOT)
desc->status |= IRQ_ONESHOT;

- /*
- * Force MSI interrupts to run with interrupts
- * disabled. The multi vector cards can cause stack
- * overflows due to nested interrupts when enough of
- * them are directed to a core and fire at the same
- * time.
- */
- if (desc->msi_desc)
- new->flags |= IRQF_DISABLED;
-
if (!(desc->status & IRQ_NOAUTOEN)) {
desc->depth = 0;
desc->status &= ~IRQ_DISABLED;
@@ -1027,7 +1017,6 @@ EXPORT_SYMBOL(free_irq);
* Flags:
*
* IRQF_SHARED Interrupt is shared
- * IRQF_DISABLED Disable local interrupts while processing
* IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
* IRQF_TRIGGER_* Specify active edge(s) or level
*
@@ -1041,25 +1030,6 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
int retval;

/*
- * handle_IRQ_event() always ignores IRQF_DISABLED except for
- * the _first_ irqaction (sigh). That can cause oopsing, but
- * the behavior is classified as "will not fix" so we need to
- * start nudging drivers away from using that idiom.
- */
- if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) ==
- (IRQF_SHARED|IRQF_DISABLED)) {
- pr_warning(
- "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
- irq, devname);
- }
-
-#ifdef CONFIG_LOCKDEP
- /*
- * Lockdep wants atomic interrupt handlers:
- */
- irqflags |= IRQF_DISABLED;
-#endif
- /*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
* which interrupt is which (messes up the interrupt freeing