genirq: Provide config option to disable deprecated code

This option covers now the old chip functions and the irq_desc data
fields which are moving to struct irq_data. More stuff will follow.

Pretty handy for testing a conversion, whether something broke or not.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>

6 files changed, 39 insertions, 6 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 0c83cbd2df4e..82ed8231394a 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -155,6 +155,7 @@ struct irq_data {
  */
 struct irq_chip {
         const char      *name;
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
         unsigned int    (*startup)(unsigned int irq);
         void            (*shutdown)(unsigned int irq);
         void            (*enable)(unsigned int irq);
@@ -175,7 +176,7 @@ struct irq_chip {
 
         void            (*bus_lock)(unsigned int irq);
         void            (*bus_sync_unlock)(unsigned int irq);
-
+#endif
         unsigned int    (*irq_startup)(struct irq_data *data);
         void            (*irq_shutdown)(struct irq_data *data);
         void            (*irq_enable)(struct irq_data *data);
@@ -225,6 +226,9 @@ struct irq_2_iommu;
  */
 struct irq_desc {
 
+#ifdef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
+        struct irq_data         irq_data;
+#else
         /*
          * This union will go away, once we fixed the direct access to
          * irq_desc all over the place. The direct fields are a 1:1
@@ -247,6 +251,8 @@ struct irq_desc {
 #endif
                 };
         };
+#endif
+
         struct timer_rand_state *timer_rand_state;
         unsigned int            *kstat_irqs;
         irq_flow_handler_t      handle_irq;
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index e0fc6cd78aa0..a42c0191d71a 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -12,6 +12,10 @@ config GENERIC_HARDIRQS
 config GENERIC_HARDIRQS_NO__DO_IRQ
        def_bool y
 
+# Select this to disable the deprecated stuff
+config GENERIC_HARDIRQS_NO_DEPRECATED
+       def_bool n
+
 # Options selectable by the architecture code
 config HAVE_SPARSE_IRQ
        def_bool n
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index f2c4d28c508a..323547983f15 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -324,6 +324,7 @@ static void default_shutdown(struct irq_data *data)
         desc->status |= IRQ_MASKED;
 }
 
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 /* Temporary migration helpers */
 static void compat_irq_mask(struct irq_data *data)
 {
@@ -400,12 +401,14 @@ static void compat_bus_sync_unlock(struct irq_data *data)
 {
         data->chip->bus_sync_unlock(data->irq);
 }
+#endif
 
 /*
  * Fixup enable/disable function pointers
  */
 void irq_chip_set_defaults(struct irq_chip *chip)
 {
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
         /*
          * Compat fixup functions need to be before we set the
          * defaults for enable/disable/startup/shutdown
@@ -418,7 +421,7 @@ void irq_chip_set_defaults(struct irq_chip *chip)
                 chip->irq_shutdown = compat_irq_shutdown;
         if (chip->startup)
                 chip->irq_startup = compat_irq_startup;
-
+#endif
         /*
          * The real defaults
          */
@@ -437,6 +440,8 @@ void irq_chip_set_defaults(struct irq_chip *chip)
         if (!chip->irq_shutdown)
                 chip->irq_shutdown = chip->irq_disable != default_disable ?
                         chip->irq_disable : default_shutdown;
+
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
         if (!chip->end)
                 chip->end = dummy_irq_chip.end;
 
@@ -465,6 +470,7 @@ void irq_chip_set_defaults(struct irq_chip *chip)
                 chip->irq_set_wake = compat_irq_set_wake;
         if (chip->retrigger)
                 chip->irq_retrigger = compat_irq_retrigger;
+#endif
 }
 
 static inline void mask_ack_irq(struct irq_desc *desc)
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 8d0697f892a2..3fcef37154a1 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -309,7 +309,12 @@ static unsigned int noop_ret(struct irq_data *data)
         return 0;
 }
 
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 static void compat_noop(unsigned int irq) { }
+#define END_INIT .end = compat_noop
+#else
+#define END_INIT
+#endif
 
 /*
  * Generic no controller implementation
@@ -321,7 +326,7 @@ struct irq_chip no_irq_chip = {
         .irq_enable     = noop,
         .irq_disable    = noop,
         .irq_ack        = ack_bad,
-        .end            = compat_noop,
+        END_INIT
 };
 
 /*
@@ -337,7 +342,7 @@ struct irq_chip dummy_irq_chip = {
         .irq_ack        = noop,
         .irq_mask       = noop,
         .irq_unmask     = noop,
-        .end            = compat_noop,
+        END_INIT
 };
 
 /*
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index ecafbfee5b12..b905f0ab1bb2 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -42,6 +42,16 @@ extern int irq_select_affinity_usr(unsigned int irq);
 
 extern void irq_set_thread_affinity(struct irq_desc *desc);
 
+#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
+static inline void irq_end(unsigned int irq, struct irq_desc *desc)
+{
+        if (desc->irq_data.chip && desc->irq_data.chip->end)
+                desc->irq_data.chip->end(irq);
+}
+#else
+static inline void irq_end(unsigned int irq, struct irq_desc *desc) { }
+#endif
+
 /* Inline functions for support of irq chips on slow busses */
 static inline void chip_bus_lock(struct irq_desc *desc)
 {
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 9ee704d3a23c..3089d3b9d5f3 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -14,6 +14,8 @@
 #include <linux/moduleparam.h>
 #include <linux/timer.h>
 
+#include "internals.h"
+
 static int irqfixup __read_mostly;
 
 #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10)
@@ -78,8 +80,8 @@ static int try_one_irq(int irq, struct irq_desc *desc)
          * If we did actual work for the real IRQ line we must let the
          * IRQ controller clean up too
          */
-        if (work && desc->irq_data.chip && desc->irq_data.chip->end)
-                desc->irq_data.chip->end(irq);
+        if (work)
+                irq_end(irq, desc);
         raw_spin_unlock(&desc->lock);
 
         return ok;