linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * MSI framework for platform devices

 *

 * Copyright (C) 2015 ARM Limited, All Rights Reserved.

 * Author: Marc Zyngier <marc.zyngier@arm.com>

 */

​

#include <linux/device.h>

#include <linux/idr.h>

#include <linux/irq.h>

#include <linux/irqdomain.h>

#include <linux/msi.h>

#include <linux/slab.h>

​

#define DEV_ID_SHIFT    21

#define MAX_DEV_MSIS    (1 << (32 - DEV_ID_SHIFT))

​

/*

 * Internal data structure containing a (made up, but unique) devid

 * and the callback to write the MSI message.

 */

struct platform_msi_priv_data {

    struct device       *dev;

    void            *host_data;

    msi_alloc_info_t    arg;

    irq_write_msi_msg_t write_msg;

    int         devid;

};

​

/* The devid allocator */

static DEFINE_IDA(platform_msi_devid_ida);

​

#ifdef GENERIC_MSI_DOMAIN_OPS

/*

 * Convert an msi_desc to a globaly unique identifier (per-device

 * devid + msi_desc position in the msi_list).

 */

static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)

{

    u32 devid;

​

    devid = desc->platform.msi_priv_data->devid;

​

    return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.msi_index;

}

​

static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)

{

    arg->desc = desc;

    arg->hwirq = platform_msi_calc_hwirq(desc);

}

​

static int platform_msi_init(struct irq_domain *domain,

                 struct msi_domain_info *info,

                 unsigned int virq, irq_hw_number_t hwirq,

                 msi_alloc_info_t *arg)

{

    return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,

                         info->chip, info->chip_data);

}

#else

#define platform_msi_set_desc       NULL