[PATCH 03/04] x86: put timer_rand_state pointer into irq_desc

[Yinghai Lu <yhlu.kernel@gmail.com>]

so could remove timer_rand_state pointer array

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

Index: linux-2.6/drivers/char/random.c
===================================================================
--- linux-2.6.orig/drivers/char/random.c
+++ linux-2.6/drivers/char/random.c
@@ -559,13 +559,6 @@ struct timer_rand_state {
 
 static struct timer_rand_state input_timer_state;
 
-#ifdef CONFIG_HAVE_DYN_ARRAY
-static struct timer_rand_state **irq_timer_state;
-DEFINE_DYN_ARRAY(irq_timer_state, sizeof(struct timer_rand_state *), nr_irqs, PAGE_SIZE, NULL);
-#else
-static struct timer_rand_state *irq_timer_state[NR_IRQS];
-#endif
-
 /*
  * This function adds entropy to the entropy "pool" by using timing
  * delays.  It uses the timer_rand_state structure to make an estimate
@@ -653,11 +646,20 @@ EXPORT_SYMBOL_GPL(add_input_randomness);
 
 void add_interrupt_randomness(int irq)
 {
-	if (irq >= nr_irqs || irq_timer_state[irq] == NULL)
+	struct timer_rand_state *state;
+	struct irq_desc *desc;
+
+	if (irq >= nr_irqs)
+		return;
+
+	desc = get_irq_desc(irq);
+	state = desc->timer_rand_state;
+
+	if (state == NULL)
 		return;
 
 	DEBUG_ENT("irq event %d\n", irq);
-	add_timer_randomness(irq_timer_state[irq], 0x100 + irq);
+	add_timer_randomness(state, 0x100 + irq);
 }
 
 #ifdef CONFIG_BLOCK
@@ -916,8 +918,15 @@ module_init(rand_initialize);
 void rand_initialize_irq(int irq)
 {
 	struct timer_rand_state *state;
+	struct irq_desc *desc;
+
+	if (irq >= nr_irqs)
+		return;
 
-	if (irq >= nr_irqs || irq_timer_state[irq])
+	desc = get_irq_desc(irq);
+	state = desc->timer_rand_state;
+
+	if (state)
 		return;
 
 	/*
@@ -926,7 +935,7 @@ void rand_initialize_irq(int irq)
 	 */
 	state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
 	if (state)
-		irq_timer_state[irq] = state;
+		desc->timer_rand_state = state;
 }
 
 #ifdef CONFIG_BLOCK
Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -129,6 +129,7 @@ struct irq_chip {
 	const char	*typename;
 };
 
+struct timer_rand_state;
 /**
  * struct irq_desc - interrupt descriptor
  *
@@ -158,6 +159,7 @@ struct irq_desc {
 	unsigned int		irq;
 	struct irq_desc		*next;
 #endif
+	struct timer_rand_state *timer_rand_state;
 	irq_flow_handler_t	handle_irq;
 	struct irq_chip		*chip;
 	struct msi_desc		*msi_desc;