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author | Yinghai Lu <yinghai@kernel.org> | 2008-12-05 18:58:31 -0800 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 14:31:51 +0100 |
commit | 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch) | |
tree | 239251bad791fd60af8c0f2ba365b7188395c83f /include/linux/random.h | |
parent | 218d11a8b071b23b76c484fd5f72a4fe3306801e (diff) | |
download | linux-stable-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.gz linux-stable-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.bz2 linux-stable-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.zip |
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.h | 51 |
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); |