msi_sn.c

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2006 Silicon Graphics, Inc.  All Rights Reserved.
 */

#include <linux/types.h>
#include <linux/irq.h>
#include <linux/pci.h>
#include <linux/cpumask.h>
#include <linux/msi.h>
#include <linux/slab.h>

#include <asm/sn/addrs.h>
#include <asm/sn/intr.h>
#include <asm/sn/pcibus_provider_defs.h>
#include <asm/sn/pcidev.h>
#include <asm/sn/nodepda.h>

struct sn_msi_info {
    u64 pci_addr;
    struct sn_irq_info *sn_irq_info;
};

static struct sn_msi_info sn_msi_info[NR_IRQS];

static struct irq_chip sn_msi_chip;

void sn_teardown_msi_irq(unsigned int irq)
{
    nasid_t nasid;
    int widget;
    struct pci_dev *pdev;
    struct pcidev_info *sn_pdev;
    struct sn_irq_info *sn_irq_info;
    struct pcibus_bussoft *bussoft;
    struct sn_pcibus_provider *provider;

    sn_irq_info = sn_msi_info[irq].sn_irq_info;
    if (sn_irq_info == NULL || sn_irq_info->irq_int_bit >= 0)
        return;

    sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
    pdev = sn_pdev->pdi_linux_pcidev;
    provider = SN_PCIDEV_BUSPROVIDER(pdev);

    (*provider->dma_unmap)(pdev,
                   sn_msi_info[irq].pci_addr,
                   PCI_DMA_FROMDEVICE);
    sn_msi_info[irq].pci_addr = 0;

    bussoft = SN_PCIDEV_BUSSOFT(pdev);
    nasid = NASID_GET(bussoft->bs_base);
    widget = (nasid & 1) ?
            TIO_SWIN_WIDGETNUM(bussoft->bs_base) :
            SWIN_WIDGETNUM(bussoft->bs_base);

    sn_intr_free(nasid, widget, sn_irq_info);
    sn_msi_info[irq].sn_irq_info = NULL;

    destroy_irq(irq);
}

int sn_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *entry)
{
    struct msi_msg msg;
    int widget;
    int status;
    nasid_t nasid;
    u64 bus_addr;
    struct sn_irq_info *sn_irq_info;
    struct pcibus_bussoft *bussoft = SN_PCIDEV_BUSSOFT(pdev);
    struct sn_pcibus_provider *provider = SN_PCIDEV_BUSPROVIDER(pdev);
    int irq;

    if (!entry->msi_attrib.is_64)
        return -EINVAL;

    if (bussoft == NULL)
        return -EINVAL;

    if (provider == NULL || provider->dma_map_consistent == NULL)
        return -EINVAL;

    irq = create_irq();
    if (irq < 0)
        return irq;

    /*
     * Set up the vector plumbing.  Let the prom (via sn_intr_alloc)
     * decide which cpu to direct this msi at by default.
     */

    nasid = NASID_GET(bussoft->bs_base);
    widget = (nasid & 1) ?
            TIO_SWIN_WIDGETNUM(bussoft->bs_base) :
            SWIN_WIDGETNUM(bussoft->bs_base);

    sn_irq_info = kzalloc(sizeof(struct sn_irq_info), GFP_KERNEL);
    if (! sn_irq_info) {
        destroy_irq(irq);
        return -ENOMEM;
    }

    status = sn_intr_alloc(nasid, widget, sn_irq_info, irq, -1, -1);
    if (status) {
        kfree(sn_irq_info);
        destroy_irq(irq);
        return -ENOMEM;
    }

    sn_irq_info->irq_int_bit = -1;      /* mark this as an MSI irq */
    sn_irq_fixup(pdev, sn_irq_info);

    /* Prom probably should fill these in, but doesn't ... */
    sn_irq_info->irq_bridge_type = bussoft->bs_asic_type;
    sn_irq_info->irq_bridge = (void *)bussoft->bs_base;

    /*
     * Map the xio address into bus space
     */
    bus_addr = (*provider->dma_map_consistent)(pdev,
                    sn_irq_info->irq_xtalkaddr,
                    sizeof(sn_irq_info->irq_xtalkaddr),
                    SN_DMA_MSI|SN_DMA_ADDR_XIO);
    if (! bus_addr) {
        sn_intr_free(nasid, widget, sn_irq_info);
        kfree(sn_irq_info);
        destroy_irq(irq);
        return -ENOMEM;
    }

    sn_msi_info[irq].sn_irq_info = sn_irq_info;
    sn_msi_info[irq].pci_addr = bus_addr;

    msg.address_hi = (u32)(bus_addr >> 32);
    msg.address_lo = (u32)(bus_addr & 0x00000000ffffffff);

    /*
     * In the SN platform, bit 16 is a "send vector" bit which
     * must be present in order to move the vector through the system.
     */
    msg.data = 0x100 + irq;

    irq_set_msi_desc(irq, entry);
    write_msi_msg(irq, &msg);
    irq_set_chip_and_handler(irq, &sn_msi_chip, handle_edge_irq);

    return 0;
}

#ifdef CONFIG_SMP
static int sn_set_msi_irq_affinity(struct irq_data *data,
                   const struct cpumask *cpu_mask, bool force)
{
    struct msi_msg msg;
    int slice;
    nasid_t nasid;
    u64 bus_addr;
    struct pci_dev *pdev;
    struct pcidev_info *sn_pdev;
    struct sn_irq_info *sn_irq_info;
    struct sn_irq_info *new_irq_info;
    struct sn_pcibus_provider *provider;
    unsigned int cpu, irq = data->irq;

    cpu = cpumask_first(cpu_mask);
    sn_irq_info = sn_msi_info[irq].sn_irq_info;
    if (sn_irq_info == NULL || sn_irq_info->irq_int_bit >= 0)
        return -1;

    /*
     * Release XIO resources for the old MSI PCI address
     */

    get_cached_msi_msg(irq, &msg);
        sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
    pdev = sn_pdev->pdi_linux_pcidev;
    provider = SN_PCIDEV_BUSPROVIDER(pdev);

    bus_addr = (u64)(msg.address_hi) << 32 | (u64)(msg.address_lo);
    (*provider->dma_unmap)(pdev, bus_addr, PCI_DMA_FROMDEVICE);
    sn_msi_info[irq].pci_addr = 0;

    nasid = cpuid_to_nasid(cpu);
    slice = cpuid_to_slice(cpu);

    new_irq_info = sn_retarget_vector(sn_irq_info, nasid, slice);
    sn_msi_info[irq].sn_irq_info = new_irq_info;
    if (new_irq_info == NULL)
        return -1;

    /*
     * Map the xio address into bus space
     */

    bus_addr = (*provider->dma_map_consistent)(pdev,
                    new_irq_info->irq_xtalkaddr,
                    sizeof(new_irq_info->irq_xtalkaddr),
                    SN_DMA_MSI|SN_DMA_ADDR_XIO);

    sn_msi_info[irq].pci_addr = bus_addr;
    msg.address_hi = (u32)(bus_addr >> 32);
    msg.address_lo = (u32)(bus_addr & 0x00000000ffffffff);

    write_msi_msg(irq, &msg);
    cpumask_copy(data->affinity, cpu_mask);

    return 0;
}
#endif /* CONFIG_SMP */

static void sn_ack_msi_irq(struct irq_data *data)
{
    irq_move_irq(data);
    ia64_eoi();
}

static int sn_msi_retrigger_irq(struct irq_data *data)
{
    unsigned int vector = data->irq;
    ia64_resend_irq(vector);

    return 1;
}

static struct irq_chip sn_msi_chip = {
    .name           = "PCI-MSI",
    .irq_mask       = mask_msi_irq,
    .irq_unmask     = unmask_msi_irq,
    .irq_ack        = sn_ack_msi_irq,
#ifdef CONFIG_SMP
    .irq_set_affinity   = sn_set_msi_irq_affinity,
#endif
    .irq_retrigger      = sn_msi_retrigger_irq,
};