genirq: Create irq_data

Low level chip functions need access to irq_desc->handler_data,
irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq
number to the low level functions, so they need to lookup irq_desc.
With sparse irq this means a radix tree lookup.

We could hand down irq_desc itself, but low level chip functions have
no need to fiddle with it directly and we want to restrict access to
irq_desc further.

Preparatory patch for new chip functions.

Note, that the ugly anon union/struct is there to avoid a full tree
wide clean up for now. This is not going to last 3 years like __do_IRQ()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.645542300@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 19 insertions, 20 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 27e5c6911223..099d4fc368c3 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -75,12 +75,10 @@ EXPORT_SYMBOL_GPL(nr_irqs);
 #ifdef CONFIG_SPARSE_IRQ
 
 static struct irq_desc irq_desc_init = {
-        .irq        = -1,
-        .status     = IRQ_DISABLED,
-        .chip       = &no_irq_chip,
-        .handle_irq = handle_bad_irq,
-        .depth      = 1,
-        .lock       = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+        .status         = IRQ_DISABLED,
+        .handle_irq     = handle_bad_irq,
+        .depth          = 1,
+        .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
 };
 
 void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
@@ -105,7 +103,7 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
         memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
 
         raw_spin_lock_init(&desc->lock);
-        desc->irq = irq;
+        desc->irq_data.irq = irq;
 #ifdef CONFIG_SMP
         desc->node = node;
 #endif
@@ -151,12 +149,10 @@ void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
 
 static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
         [0 ... NR_IRQS_LEGACY-1] = {
-                .irq        = -1,
-                .status     = IRQ_DISABLED,
-                .chip       = &no_irq_chip,
-                .handle_irq = handle_bad_irq,
-                .depth      = 1,
-                .lock       = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+                .status         = IRQ_DISABLED,
+                .handle_irq     = handle_bad_irq,
+                .depth          = 1,
+                .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
         }
 };
 
@@ -183,8 +179,11 @@ int __init early_irq_init(void)
         kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *
                                           sizeof(int), GFP_NOWAIT, node);
 
+        irq_desc_init.irq_data.chip = &no_irq_chip;
+
         for (i = 0; i < legacy_count; i++) {
-                desc[i].irq = i;
+                desc[i].irq_data.irq = i;
+                desc[i].irq_data.chip = &no_irq_chip;
 #ifdef CONFIG_SMP
                 desc[i].node = node;
 #endif
@@ -241,11 +240,10 @@ out_unlock:
 
 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
         [0 ... NR_IRQS-1] = {
-                .status = IRQ_DISABLED,
-                .chip = &no_irq_chip,
-                .handle_irq = handle_bad_irq,
-                .depth = 1,
-                .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
+                .status         = IRQ_DISABLED,
+                .handle_irq     = handle_bad_irq,
+                .depth          = 1,
+                .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
         }
 };
 
@@ -264,7 +262,8 @@ int __init early_irq_init(void)
         count = ARRAY_SIZE(irq_desc);
 
         for (i = 0; i < count; i++) {
-                desc[i].irq = i;
+                desc[i].irq_data.irq = i;
+                desc[i].irq_data.chip = &no_irq_chip;
                 alloc_desc_masks(&desc[i], 0, true);
                 init_desc_masks(&desc[i]);
                 desc[i].kstat_irqs = kstat_irqs_all[i];