[PATCH] genirq: rename desc->handler to desc->chip

This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch.  But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly.  The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 18 insertions, 18 deletions

diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
index d58c1c5c903a..abb4cb1c831e 100644
--- a/arch/ia64/kernel/iosapic.c
+++ b/arch/ia64/kernel/iosapic.c
@@ -660,13 +660,13 @@ register_intr (unsigned int gsi, int vector, unsigned char delivery,
                 irq_type = &irq_type_iosapic_level;
 
         idesc = irq_descp(vector);
-        if (idesc->handler != irq_type) {
-                if (idesc->handler != &no_irq_type)
+        if (idesc->chip != irq_type) {
+                if (idesc->chip != &no_irq_type)
                         printk(KERN_WARNING
                                "%s: changing vector %d from %s to %s\n",
                                __FUNCTION__, vector,
-                               idesc->handler->typename, irq_type->typename);
-                idesc->handler = irq_type;
+                               idesc->chip->typename, irq_type->typename);
+                idesc->chip = irq_type;
         }
         return 0;
 }
@@ -903,7 +903,7 @@ iosapic_unregister_intr (unsigned int gsi)
                         BUG_ON(iosapic_intr_info[vector].count);
 
                         /* Clear the interrupt controller descriptor */
-                        idesc->handler = &no_irq_type;
+                        idesc->chip = &no_irq_type;
 
                         /* Clear the interrupt information */
                         memset(&iosapic_intr_info[vector], 0,
diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
index 9c72ea3f6432..2645153dba8a 100644
--- a/arch/ia64/kernel/irq.c
+++ b/arch/ia64/kernel/irq.c
@@ -76,7 +76,7 @@ int show_interrupts(struct seq_file *p, void *v)
                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
                 }
 #endif
-                seq_printf(p, " %14s", irq_desc[i].handler->typename);
+                seq_printf(p, " %14s", irq_desc[i].chip->typename);
                 seq_printf(p, "  %s", action->name);
 
                 for (action=action->next; action; action = action->next)
@@ -144,15 +144,15 @@ static void migrate_irqs(void)
                         /*
                          * Al three are essential, currently WARN_ON.. maybe panic?
                          */
-                        if (desc->handler && desc->handler->disable &&
-                                desc->handler->enable && desc->handler->set_affinity) {
-                                desc->handler->disable(irq);
-                                desc->handler->set_affinity(irq, mask);
-                                desc->handler->enable(irq);
+                        if (desc->chip && desc->chip->disable &&
+                                desc->chip->enable && desc->chip->set_affinity) {
+                                desc->chip->disable(irq);
+                                desc->chip->set_affinity(irq, mask);
+                                desc->chip->enable(irq);
                         } else {
-                                WARN_ON((!(desc->handler) || !(desc->handler->disable) ||
-                                                !(desc->handler->enable) ||
-                                                !(desc->handler->set_affinity)));
+                                WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
+                                                !(desc->chip->enable) ||
+                                                !(desc->chip->set_affinity)));
                         }
                 }
         }
diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index ef9a2b49307a..6d8fc9498ed9 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -251,7 +251,7 @@ register_percpu_irq (ia64_vector vec, struct irqaction *action)
                 if (irq_to_vector(irq) == vec) {
                         desc = irq_descp(irq);
                         desc->status |= IRQ_PER_CPU;
-                        desc->handler = &irq_type_ia64_lsapic;
+                        desc->chip = &irq_type_ia64_lsapic;
                         if (action)
                                 setup_irq(irq, action);
                 }
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index 44e9547878ac..d69288055599 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -684,9 +684,9 @@ int migrate_platform_irqs(unsigned int cpu)
                          * polling before making changes.
                          */
                         if (desc) {
-                                desc->handler->disable(ia64_cpe_irq);
-                                desc->handler->set_affinity(ia64_cpe_irq, mask);
-                                desc->handler->enable(ia64_cpe_irq);
+                                desc->chip->disable(ia64_cpe_irq);
+                                desc->chip->set_affinity(ia64_cpe_irq, mask);
+                                desc->chip->enable(ia64_cpe_irq);
                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
                         }
                 }