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, 4 insertions, 2 deletions

diff --git a/drivers/parisc/dino.c b/drivers/parisc/dino.c
index fd56128525d1..3bc54b30c3a1 100644
--- a/drivers/parisc/dino.c
+++ b/drivers/parisc/dino.c
@@ -298,7 +298,8 @@ struct pci_port_ops dino_port_ops = {
 
 static void dino_disable_irq(unsigned int irq)
 {
-        struct dino_device *dino_dev = irq_desc[irq].chip_data;
+        struct irq_desc *desc = irq_to_desc(irq);
+        struct dino_device *dino_dev = desc->chip_data;
         int local_irq = gsc_find_local_irq(irq, dino_dev->global_irq, DINO_LOCAL_IRQS);
 
         DBG(KERN_WARNING "%s(0x%p, %d)\n", __func__, dino_dev, irq);
@@ -310,7 +311,8 @@ static void dino_disable_irq(unsigned int irq)
 
 static void dino_enable_irq(unsigned int irq)
 {
-        struct dino_device *dino_dev = irq_desc[irq].chip_data;
+        struct irq_desc *desc = irq_to_desc(irq);
+        struct dino_device *dino_dev = desc->chip_data;
         int local_irq = gsc_find_local_irq(irq, dino_dev->global_irq, DINO_LOCAL_IRQS);
         u32 tmp;