x86: put timer_rand_state pointer into irq_desc
irq_timer_state[] is a NR_IRQS sized array that is a side-by array to
the real irq_desc[] array.
Integrate that field into the (now dynamic) irq_desc dynamic array and
save some RAM.
v2: keep the old way to support arch not support irq_desc
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1610aa6..60c9c7e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -558,7 +558,7 @@
unsigned dont_count_entropy:1;
};
-static struct timer_rand_state input_timer_state;
+#ifndef CONFIG_HAVE_SPARSE_IRQ
#ifdef CONFIG_HAVE_DYN_ARRAY
static struct timer_rand_state **irq_timer_state;
@@ -567,6 +567,51 @@
static struct timer_rand_state *irq_timer_state[NR_IRQS];
#endif
+static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+ if (irq >= nr_irqs)
+ return NULL;
+
+ return irq_timer_state[irq];
+}
+
+static void set_timer_rand_state(unsigned int irq, struct timer_rand_state *state)
+{
+ if (irq >= nr_irqs)
+ return;
+
+ irq_timer_state[irq] = state;
+}
+
+#else
+
+static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+ struct irq_desc *desc;
+
+ desc = irq_to_desc(irq);
+
+ if (!desc)
+ return NULL;
+
+ return desc->timer_rand_state;
+}
+
+static void set_timer_rand_state(unsigned int irq, struct timer_rand_state *state)
+{
+ struct irq_desc *desc;
+
+ desc = irq_to_desc(irq);
+
+ if (!desc)
+ return;
+
+ desc->timer_rand_state = state;
+}
+#endif
+
+static struct timer_rand_state input_timer_state;
+
/*
* This function adds entropy to the entropy "pool" by using timing
* delays. It uses the timer_rand_state structure to make an estimate
@@ -654,11 +699,15 @@
void add_interrupt_randomness(int irq)
{
- if (irq >= nr_irqs || irq_timer_state[irq] == NULL)
+ struct timer_rand_state *state;
+
+ state = get_timer_rand_state(irq);
+
+ 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
@@ -918,7 +967,14 @@
{
struct timer_rand_state *state;
- if (irq >= nr_irqs || irq_timer_state[irq])
+#ifndef CONFIG_HAVE_SPARSE_IRQ
+ if (irq >= nr_irqs)
+ return;
+#endif
+
+ state = get_timer_rand_state(irq);
+
+ if (state)
return;
/*
@@ -927,7 +983,7 @@
*/
state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
if (state)
- irq_timer_state[irq] = state;
+ set_timer_rand_state(irq, state);
}
#ifdef CONFIG_BLOCK
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 80b8200..60c856a 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -127,6 +127,7 @@
const char *typename;
};
+struct timer_rand_state;
/**
* struct irq_desc - interrupt descriptor
*
@@ -155,6 +156,7 @@
unsigned int irq;
#ifdef CONFIG_HAVE_SPARSE_IRQ
struct irq_desc *next;
+ struct timer_rand_state *timer_rand_state;
#endif
irq_flow_handler_t handle_irq;
struct irq_chip *chip;