kernel-ark/kernel/irq/numa_migrate.c
Ingo Molnar 793f7b12a0 sparseirq: fix desc->lock init
Impact: cleanup

init_one_irq_desc() does not initialize the desc->lock properly -
you cannot init a lock by memcpying some other lock on it.

This happens to work right now (because irq_desc_init is never in use),
but it's a dangerous construct nevertheless, so fix it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-27 09:29:22 +01:00

120 lines
2.6 KiB
C

/*
* NUMA irq-desc migration code
*
* Migrate IRQ data structures (irq_desc, chip_data, etc.) over to
* the new "home node" of the IRQ.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include "internals.h"
static void init_copy_kstat_irqs(struct irq_desc *old_desc,
struct irq_desc *desc,
int cpu, int nr)
{
unsigned long bytes;
init_kstat_irqs(desc, cpu, nr);
if (desc->kstat_irqs != old_desc->kstat_irqs) {
/* Compute how many bytes we need per irq and allocate them */
bytes = nr * sizeof(unsigned int);
memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes);
}
}
static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
{
if (old_desc->kstat_irqs == desc->kstat_irqs)
return;
kfree(old_desc->kstat_irqs);
old_desc->kstat_irqs = NULL;
}
static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
struct irq_desc *desc, int cpu)
{
memcpy(desc, old_desc, sizeof(struct irq_desc));
spin_lock_init(&desc->lock);
desc->cpu = cpu;
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
arch_init_copy_chip_data(old_desc, desc, cpu);
}
static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
{
free_kstat_irqs(old_desc, desc);
arch_free_chip_data(old_desc, desc);
}
static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
int cpu)
{
struct irq_desc *desc;
unsigned int irq;
unsigned long flags;
int node;
irq = old_desc->irq;
spin_lock_irqsave(&sparse_irq_lock, flags);
/* We have to check it to avoid races with another CPU */
desc = irq_desc_ptrs[irq];
if (desc && old_desc != desc)
goto out_unlock;
node = cpu_to_node(cpu);
desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
if (!desc) {
printk(KERN_ERR "irq %d: can not get new irq_desc for migration.\n", irq);
/* still use old one */
desc = old_desc;
goto out_unlock;
}
init_copy_one_irq_desc(irq, old_desc, desc, cpu);
irq_desc_ptrs[irq] = desc;
/* free the old one */
free_one_irq_desc(old_desc, desc);
kfree(old_desc);
out_unlock:
spin_unlock_irqrestore(&sparse_irq_lock, flags);
return desc;
}
struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
{
int old_cpu;
int node, old_node;
/* those all static, do move them */
if (desc->irq < NR_IRQS_LEGACY)
return desc;
old_cpu = desc->cpu;
if (old_cpu != cpu) {
node = cpu_to_node(cpu);
old_node = cpu_to_node(old_cpu);
if (old_node != node)
desc = __real_move_irq_desc(desc, cpu);
else
desc->cpu = cpu;
}
return desc;
}