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authorYinghai Lu <yinghai@kernel.org>2008-12-06 05:58:31 +0300
committerIngo Molnar <mingo@elte.hu>2008-12-08 16:31:51 +0300
commit0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch)
tree239251bad791fd60af8c0f2ba365b7188395c83f /include/linux/random.h
parent218d11a8b071b23b76c484fd5f72a4fe3306801e (diff)
downloadlinux-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.xz
sparse irq_desc[] array: core kernel and x86 changes
Impact: new feature Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with NR_CPUS set to large values. The goal is to be able to scale up to much larger NR_IRQS value without impacting the (important) common case. To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of irq_desc pointers. When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc, this also makes the IRQ descriptors NUMA-local (to the site that calls request_irq()). This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now uses desc->chip_data for x86 to store irq_cfg. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/random.h')
-rw-r--r--include/linux/random.h51
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/random.h b/include/linux/random.h
index 36f125c0c603..ad9daa2374d5 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -44,6 +44,57 @@ struct rand_pool_info {
extern void rand_initialize_irq(int irq);
+struct timer_rand_state;
+#ifndef CONFIG_SPARSE_IRQ
+
+extern struct timer_rand_state *irq_timer_state[];
+
+extern int nr_irqs;
+static inline struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+ if (irq >= nr_irqs)
+ return NULL;
+
+ return irq_timer_state[irq];
+}
+
+static inline void set_timer_rand_state(unsigned int irq, struct timer_rand_state *state)
+{
+ if (irq >= nr_irqs)
+ return;
+
+ irq_timer_state[irq] = state;
+}
+
+#else
+
+#include <linux/irq.h>
+static inline 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 inline 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
+
+
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value);
extern void add_interrupt_randomness(int irq);