path: root/drivers/pci/intr_remapping.c

#include <linux/interrupt.h>
#include <linux/dmar.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/pci.h>
#include <linux/irq.h>
#include <asm/io_apic.h>
#include <asm/smp.h>
#include <asm/cpu.h>
#include <linux/intel-iommu.h>
#include "intr_remapping.h"
#include <acpi/acpi.h>
#include <asm/pci-direct.h>
#include "pci.h"

static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
static int ir_ioapic_num;
int intr_remapping_enabled;

static int disable_intremap;
static __init int setup_nointremap(char *str)
{
	disable_intremap = 1;
	return 0;
}
early_param("nointremap", setup_nointremap);

struct irq_2_iommu {
	struct intel_iommu *iommu;
	u16 irte_index;
	u16 sub_handle;
	u8  irte_mask;
};

#ifdef CONFIG_GENERIC_HARDIRQS
static struct irq_2_iommu *get_one_free_irq_2_iommu(int node)
{
	struct irq_2_iommu *iommu;

	iommu = kzalloc_node(sizeof(*iommu), GFP_ATOMIC, node);
	printk(KERN_DEBUG "alloc irq_2_iommu on node %d\n", node);

	return iommu;
}

static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
{
	struct irq_desc *desc;

	desc = irq_to_desc(irq);

	if (WARN_ON_ONCE(!desc))
		return NULL;

	return desc->irq_2_iommu;
}

static struct irq_2_iommu *irq_2_iommu_alloc_node(unsigned int irq, int node)
{
	struct irq_desc *desc;
	struct irq_2_iommu *irq_iommu;

	/*
	 * alloc irq desc if not allocated already.
	 */
	desc = irq_to_desc_alloc_node(irq, node);
	if (!desc) {
		printk(KERN_INFO "can not get irq_desc for %d\n", irq);
		return NULL;
	}

	irq_iommu = desc->irq_2_iommu;

	if (!irq_iommu)
		desc->irq_2_iommu = get_one_free_irq_2_iommu(node);

	return desc->irq_2_iommu;
}

static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
{
	return irq_2_iommu_alloc_node(irq, cpu_to_node(boot_cpu_id));
}

#else /* !CONFIG_SPARSE_IRQ */

static struct irq_2_iommu irq_2_iommuX[NR_IRQS];

static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
{
	if (irq < nr_irqs)
		return &irq_2_iommuX[irq];

	return NULL;
}
static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
{
	return irq_2_iommu(irq);
}
#endif

static DEFINE_SPINLOCK(irq_2_ir_lock);

static struct irq_2_iommu *valid_irq_2_iommu(unsigned int irq)
{
	struct irq_2_iommu *irq_iommu;

	irq_iommu = irq_2_iommu(irq);

	if (!irq_iommu)
		return NULL;

	if (!irq_iommu->iommu)
		return NULL;

	return irq_iommu;
}

int irq_remapped(int irq)
{
	return valid_irq_2_iommu(irq) != NULL;
}

int get_irte(int irq, struct irte *entry)
{
	int index;
	struct irq_2_iommu *irq_iommu;
	unsigned long flags;

	if (!entry)
		return -1;

	spin_lock_irqsave(&irq_2_ir_lock, flags);
	irq_iommu = valid_irq_2_iommu(irq);
	if (!irq_iommu) {
		spin_unlock_irqrestore(&irq_2_ir_lock, flags);
		return -1;
	}

	index = irq_iommu->irte_index + irq_iommu->sub_handle;
	*entry = *(irq_iommu->iommu->ir_table->base + index);

	spin_unlock_irqrestore(&irq_2_ir_lock, flags);
	return 0;
}

int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
{
	struct ir_table *table = iommu->ir_table;
	struct irq_2_iommu *irq_iommu;
	u16 index, start_index;
	unsigned int mask = 0;
	unsigned long flags;
	int i;

	if (!count)
		return -1;

#ifndef CONFIG_SPARSE_IRQ
	/* protect irq_2_iommu_alloc later */
	if (irq >= nr_irqs)
		return -1;
#endif

	/*
	 * start the IRTE search from index 0.
	 */
	index = start_index = 0;

	if (count > 1) {
		count = __roundup_pow_of_two(count);
		mask = ilog2(count);
	}

	if (mask > ecap_max_handle_mask(iommu->ecap)) {
		printk(KERN_ERR
		       "Requested mask %x exceeds the max invalidation handle"
		       " mask value %Lx\n", mask,
		       ecap_max_handle_mask(iommu->ecap));
		return -1;
	}

	spin_lock_irqsave(&irq_2_ir_lock, flags);
	do {
		for (i = index; i < index + count; i++)
			if  (table->base[i].present)
				break;
		/* empty index found */
		if (i == index + count)
			break;

		index = (index + count) % INTR_REMAP_TABLE_ENTRIES;

		if (index == start_index) {
			spin_unlock_irqrestore(&irq_2_ir_lock, flags);
			printk(KERN_ERR "can't allocate an IRTE\n");
			return -1;
		}
	} while (1);

	for