msi.c

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/*
 * Copyright 2011 Michael Ellerman, IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/irq.h>
#include <linux/interrupt.h>

#include "msi.h"
#include "ics.h"
#include "wsp_pci.h"

/* Magic addresses for 32 & 64-bit MSIs with hardcoded MVE 0 */
#define MSI_ADDR_32     0xFFFF0000ul
#define MSI_ADDR_64     0x1000000000000000ul

int wsp_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
    struct pci_controller *phb;
    struct msi_desc *entry;
    struct msi_msg msg;
    unsigned int virq;
    int hwirq;

    phb = pci_bus_to_host(dev->bus);
    if (!phb)
        return -ENOENT;

    entry = list_first_entry(&dev->msi_list, struct msi_desc, list);
    if (entry->msi_attrib.is_64) {
        msg.address_lo = 0;
        msg.address_hi = MSI_ADDR_64 >> 32;
    } else {
        msg.address_lo = MSI_ADDR_32;
        msg.address_hi = 0;
    }

    list_for_each_entry(entry, &dev->msi_list, list) {
        hwirq = wsp_ics_alloc_irq(phb->dn, 1);
        if (hwirq < 0) {
            dev_warn(&dev->dev, "wsp_msi: hwirq alloc failed!\n");
            return hwirq;
        }

        virq = irq_create_mapping(NULL, hwirq);
        if (virq == NO_IRQ) {
            dev_warn(&dev->dev, "wsp_msi: virq alloc failed!\n");
            return -1;
        }

        dev_dbg(&dev->dev, "wsp_msi: allocated irq %#x/%#x\n",
            hwirq, virq);

        wsp_ics_set_msi_chip(virq);
        irq_set_msi_desc(virq, entry);
        msg.data = hwirq & XIVE_ADDR_MASK;
        write_msi_msg(virq, &msg);
    }

    return 0;
}

void wsp_teardown_msi_irqs(struct pci_dev *dev)
{
    struct pci_controller *phb;
    struct msi_desc *entry;
    int hwirq;

    phb = pci_bus_to_host(dev->bus);

    dev_dbg(&dev->dev, "wsp_msi: tearing down msi irqs\n");

    list_for_each_entry(entry, &dev->msi_list, list) {
        if (entry->irq == NO_IRQ)
            continue;

        irq_set_msi_desc(entry->irq, NULL);
        wsp_ics_set_std_chip(entry->irq);

        hwirq = virq_to_hw(entry->irq);
        /* In this order to avoid racing with irq_create_mapping() */
        irq_dispose_mapping(entry->irq);
        wsp_ics_free_irq(phb->dn, hwirq);
    }
}

void wsp_setup_phb_msi(struct pci_controller *phb)
{
    /* Create a single MVE at offset 0 that matches everything */
    out_be64(phb->cfg_data + PCIE_REG_IODA_ADDR, PCIE_REG_IODA_AD_TBL_MVT);
    out_be64(phb->cfg_data + PCIE_REG_IODA_DATA0, 1ull << 63);

    ppc_md.setup_msi_irqs = wsp_setup_msi_irqs;
    ppc_md.teardown_msi_irqs = wsp_teardown_msi_irqs;
}