linux-imx

// SPDX-License-Identifier: GPL-2.0

​

/*

 * Hyper-V stub IOMMU driver.

 *

 * Copyright (C) 2019, Microsoft, Inc.

 *

 * Author : Lan Tianyu <Tianyu.Lan@microsoft.com>

 */

​

#include <linux/types.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/iommu.h>

#include <linux/module.h>

​

#include <asm/apic.h>

#include <asm/cpu.h>

#include <asm/hw_irq.h>

#include <asm/io_apic.h>

#include <asm/irq_remapping.h>

#include <asm/hypervisor.h>

​

#include "irq_remapping.h"

​

#ifdef CONFIG_IRQ_REMAP

​

/*

 * According 82093AA IO-APIC spec , IO APIC has a 24-entry Interrupt

 * Redirection Table. Hyper-V exposes one single IO-APIC and so define

 * 24 IO APIC remmapping entries.

 */

#define IOAPIC_REMAPPING_ENTRY 24

​

static cpumask_t ioapic_max_cpumask = { CPU_BITS_NONE };

static struct irq_domain *ioapic_ir_domain;

​

static int hyperv_ir_set_affinity(struct irq_data *data,

        const struct cpumask *mask, bool force)

{

    struct irq_data *parent = data->parent_data;

    struct irq_cfg *cfg = irqd_cfg(data);

    struct IO_APIC_route_entry *entry;

    int ret;

​

    /* Return error If new irq affinity is out of ioapic_max_cpumask. */

    if (!cpumask_subset(mask, &ioapic_max_cpumask))

        return -EINVAL;

​

    ret = parent->chip->irq_set_affinity(parent, mask, force);

    if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)

        return ret;

​

    entry = data->chip_data;

    entry->dest = cfg->dest_apicid;

    entry->vector = cfg->vector;

    send_cleanup_vector(cfg);

​

    return 0;

}

​

static struct irq_chip hyperv_ir_chip = {

    .name           = "HYPERV-IR",

    .irq_ack        = apic_ack_irq,

    .irq_set_affinity   = hyperv_ir_set_affinity,

};

​

static int hyperv_irq_remapping_alloc(struct irq_domain *domain,

                     unsigned int virq, unsigned int nr_irqs,

                     void *arg)

{

    struct irq_alloc_info *info = arg;

    struct irq_data *irq_data;

    struct irq_desc *desc;

    int ret = 0;

​

    if (!info || info->type != X86_IRQ_ALLOC_TYPE_IOAPIC || nr_irqs > 1)

        return -EINVAL;

​

    ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);

    if (ret < 0)

        return ret;

​

    irq_data = irq_domain_get_irq_data(domain, virq);

    if (!irq_data) {

        irq_domain_free_irqs_common(domain, virq, nr_irqs);

        return -EINVAL;

    }

​

    irq_data->chip = &hyperv_ir_chip;

​

    /*