/*
 * 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);
        pci_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_and(cpu_mask, cpu_online_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_data_get_msi_desc(data), &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);

        pci_write_msi_msg(irq, &msg);
        cpumask_copy(irq_data_get_affinity_mask(data), 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               = pci_msi_mask_irq,
        .irq_unmask             = pci_msi_unmask_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,
};