x86, ioapic: Improve handling of i8259A irq init

/* irq_cfg is indexed by the sum of all RTEs in all I/O APICs. */

#ifdef CONFIG_SPARSE_IRQ

static struct irq_cfg irq_cfgx[] = {

static struct irq_cfg irq_cfgx[NR_IRQS_LEGACY];

#else

static struct irq_cfg irq_cfgx[NR_IRQS] = {

static struct irq_cfg irq_cfgx[NR_IRQS];

#endif

	[0]  = { .vector = IRQ0_VECTOR,  },

	[1]  = { .vector = IRQ1_VECTOR,  },

	[2]  = { .vector = IRQ2_VECTOR,  },

	[3]  = { .vector = IRQ3_VECTOR,  },

	[4]  = { .vector = IRQ4_VECTOR,  },

	[5]  = { .vector = IRQ5_VECTOR,  },

	[6]  = { .vector = IRQ6_VECTOR,  },

	[7]  = { .vector = IRQ7_VECTOR,  },

	[8]  = { .vector = IRQ8_VECTOR,  },

	[9]  = { .vector = IRQ9_VECTOR,  },

	[10] = { .vector = IRQ10_VECTOR, },

	[11] = { .vector = IRQ11_VECTOR, },

	[12] = { .vector = IRQ12_VECTOR, },

	[13] = { .vector = IRQ13_VECTOR, },

	[14] = { .vector = IRQ14_VECTOR, },

	[15] = { .vector = IRQ15_VECTOR, },

};

void __init io_apic_disable_legacy(void)

{

	node= cpu_to_node(boot_cpu_id);

	for (i = 0; i < count; i++) {

		if (i < nr_legacy_irqs)

			cfg[i].vector = IRQ0_VECTOR + i;

		desc = irq_to_desc(i);

		desc->chip_data = &cfg[i];

		zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node);