generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[]

add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.

Preallocate 32 irq_desc, and irq_desc() will try to get more.

( No change in functionality is expected anywhere, except the odd build
  failure where we missed a code site or where a crossing commit itroduces
  new irq_desc[] usage. )

v2: according to Eric, change get_irq_desc() to irq_desc()

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 5 deletions

diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index c689e9851a80..c45ab718cf07 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -39,7 +39,7 @@ unsigned long probe_irq_on(void)
          * flush such a longstanding irq before considering it as spurious.
          */
         for (i = nr_irqs-1; i > 0; i--) {
-                desc = irq_desc + i;
+                desc = irq_to_desc(i);
 
                 spin_lock_irq(&desc->lock);
                 if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
@@ -69,7 +69,7 @@ unsigned long probe_irq_on(void)
          * happened in the previous stage, it may have masked itself)
          */
         for (i = nr_irqs-1; i > 0; i--) {
-                desc = irq_desc + i;
+                desc = irq_to_desc(i);
 
                 spin_lock_irq(&desc->lock);
                 if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
@@ -92,7 +92,7 @@ unsigned long probe_irq_on(void)
         for (i = 0; i < nr_irqs; i++) {
                 unsigned int status;
 
-                desc = irq_desc + i;
+                desc = irq_to_desc(i);
                 spin_lock_irq(&desc->lock);
                 status = desc->status;
 
@@ -131,7 +131,7 @@ unsigned int probe_irq_mask(unsigned long val)
 
         mask = 0;
         for (i = 0; i < nr_irqs; i++) {
-                struct irq_desc *desc = irq_desc + i;
+                struct irq_desc *desc = irq_to_desc(i);
                 unsigned int status;
 
                 spin_lock_irq(&desc->lock);
@@ -174,7 +174,7 @@ int probe_irq_off(unsigned long val)
         int i, irq_found = 0, nr_irqs = 0;
 
         for (i = 0; i < nr_irqs; i++) {
-                struct irq_desc *desc = irq_desc + i;
+                struct irq_desc *desc = irq_to_desc(i);
                 unsigned int status;
 
                 spin_lock_irq(&desc->lock);