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authorIngo Molnar <mingo@elte.hu>2006-07-03 00:24:27 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-03 15:27:00 -0700
commitd7e9629de051bb4b1d104588cd97673ad770809e (patch)
tree8d9f8fd16910ef959d39cb6264a3e5da9b8d7bec
parentc01d403b2e3e3f231b18ebd07ad64ecbe6a258a5 (diff)
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[PATCH] lockdep: add local_irq_enable_in_hardirq() API
Introduce local_irq_enable_in_hardirq() API. It is currently aliased to local_irq_enable(), hence has no functional effects. This API will be used by lockdep, but even without lockdep this will better document places in the kernel where a hardirq context enables hardirqs. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/interrupt.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 2c5452c1d7b..73463fbb38e 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -80,6 +80,23 @@ extern int request_irq(unsigned int,
unsigned long, const char *, void *);
extern void free_irq(unsigned int, void *);
+/*
+ * On lockdep we dont want to enable hardirqs in hardirq
+ * context. Use local_irq_enable_in_hardirq() to annotate
+ * kernel code that has to do this nevertheless (pretty much
+ * the only valid case is for old/broken hardware that is
+ * insanely slow).
+ *
+ * NOTE: in theory this might break fragile code that relies
+ * on hardirq delivery - in practice we dont seem to have such
+ * places left. So the only effect should be slightly increased
+ * irqs-off latencies.
+ */
+#ifdef CONFIG_LOCKDEP
+# define local_irq_enable_in_hardirq() do { } while (0)
+#else
+# define local_irq_enable_in_hardirq() local_irq_enable()
+#endif
#ifdef CONFIG_GENERIC_HARDIRQS
extern void disable_irq_nosync(unsigned int irq);