/*
 * QEMU PowerPC PowerNV (POWER8) PHB3 model
 *
 * Copyright (c) 2014-2020, IBM Corporation.
 *
 * This code is licensed under the GPL version 2 or later. See the
 * COPYING file in the top-level directory.
 */
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/log.h"
#include "target/ppc/cpu.h"
#include "hw/ppc/fdt.h"
#include "hw/pci-host/pnv_phb3_regs.h"
#include "hw/pci-host/pnv_phb3.h"
#include "hw/ppc/pnv.h"
#include "hw/ppc/pnv_xscom.h"
#include "hw/pci/pci_bridge.h"
#include "hw/pci/pci_bus.h"

#include <libfdt.h>

#define phb3_pbcq_error(pbcq, fmt, ...)                                 \
    qemu_log_mask(LOG_GUEST_ERROR, "phb3_pbcq[%d:%d]: " fmt "\n",       \
                  (pbcq)->phb->chip_id, (pbcq)->phb->phb_id, ## __VA_ARGS__)

static uint64_t pnv_pbcq_nest_xscom_read(void *opaque, hwaddr addr,
                                         unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t offset = addr >> 3;

    return pbcq->nest_regs[offset];
}

static uint64_t pnv_pbcq_pci_xscom_read(void *opaque, hwaddr addr,
                                        unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t offset = addr >> 3;

    return pbcq->pci_regs[offset];
}

static uint64_t pnv_pbcq_spci_xscom_read(void *opaque, hwaddr addr,
                                         unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t offset = addr >> 3;

    if (offset == PBCQ_SPCI_ASB_DATA) {
        return pnv_phb3_reg_read(pbcq->phb,
                                 pbcq->spci_regs[PBCQ_SPCI_ASB_ADDR], 8);
    }
    return pbcq->spci_regs[offset];
}

static void pnv_pbcq_update_map(PnvPBCQState *pbcq)
{
    uint64_t bar_en = pbcq->nest_regs[PBCQ_NEST_BAR_EN];
    uint64_t bar, mask, size;

    /*
     * NOTE: This will really not work well if those are remapped
     * after the PHB has created its sub regions. We could do better
     * if we had a way to resize regions but we don't really care
     * that much in practice as the stuff below really only happens
     * once early during boot
     */

    /* Handle unmaps */
    if (memory_region_is_mapped(&pbcq->mmbar0) &&
        !(bar_en & PBCQ_NEST_BAR_EN_MMIO0)) {
        memory_region_del_subregion(get_system_memory(), &pbcq->mmbar0);
    }
    if (memory_region_is_mapped(&pbcq->mmbar1) &&
        !(bar_en & PBCQ_NEST_BAR_EN_MMIO1)) {
        memory_region_del_subregion(get_system_memory(), &pbcq->mmbar1);
    }
    if (memory_region_is_mapped(&pbcq->phbbar) &&
        !(bar_en & PBCQ_NEST_BAR_EN_PHB)) {
        memory_region_del_subregion(get_system_memory(), &pbcq->phbbar);
    }

    /* Update PHB */
    pnv_phb3_update_regions(pbcq->phb);

    /* Handle maps */
    if (!memory_region_is_mapped(&pbcq->mmbar0) &&
        (bar_en & PBCQ_NEST_BAR_EN_MMIO0)) {
        bar = pbcq->nest_regs[PBCQ_NEST_MMIO_BAR0] >> 14;
        mask = pbcq->nest_regs[PBCQ_NEST_MMIO_MASK0];
        size = ((~mask) >> 14) + 1;
        memory_region_init(&pbcq->mmbar0, OBJECT(pbcq), "pbcq-mmio0", size);
        memory_region_add_subregion(get_system_memory(), bar, &pbcq->mmbar0);
        pbcq->mmio0_base = bar;
        pbcq->mmio0_size = size;
    }
    if (!memory_region_is_mapped(&pbcq->mmbar1) &&
        (bar_en & PBCQ_NEST_BAR_EN_MMIO1)) {
        bar = pbcq->nest_regs[PBCQ_NEST_MMIO_BAR1] >> 14;
        mask = pbcq->nest_regs[PBCQ_NEST_MMIO_MASK1];
        size = ((~mask) >> 14) + 1;
        memory_region_init(&pbcq->mmbar1, OBJECT(pbcq), "pbcq-mmio1", size);
        memory_region_add_subregion(get_system_memory(), bar, &pbcq->mmbar1);
        pbcq->mmio1_base = bar;
        pbcq->mmio1_size = size;
    }
    if (!memory_region_is_mapped(&pbcq->phbbar)
        && (bar_en & PBCQ_NEST_BAR_EN_PHB)) {
        bar = pbcq->nest_regs[PBCQ_NEST_PHB_BAR] >> 14;
        size = 0x1000;
        memory_region_init(&pbcq->phbbar, OBJECT(pbcq), "pbcq-phb", size);
        memory_region_add_subregion(get_system_memory(), bar, &pbcq->phbbar);
    }

    /* Update PHB */
    pnv_phb3_update_regions(pbcq->phb);
}

static void pnv_pbcq_nest_xscom_write(void *opaque, hwaddr addr,
                                uint64_t val, unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t reg = addr >> 3;

    switch (reg) {
    case PBCQ_NEST_MMIO_BAR0:
    case PBCQ_NEST_MMIO_BAR1:
    case PBCQ_NEST_MMIO_MASK0:
    case PBCQ_NEST_MMIO_MASK1:
        if (pbcq->nest_regs[PBCQ_NEST_BAR_EN] &
            (PBCQ_NEST_BAR_EN_MMIO0 |
             PBCQ_NEST_BAR_EN_MMIO1)) {
            phb3_pbcq_error(pbcq, "Changing enabled BAR unsupported");
        }
        pbcq->nest_regs[reg] = val & 0xffffffffc0000000ull;
        break;
    case PBCQ_NEST_PHB_BAR:
        if (pbcq->nest_regs[PBCQ_NEST_BAR_EN] & PBCQ_NEST_BAR_EN_PHB) {
            phb3_pbcq_error(pbcq, "Changing enabled BAR unsupported");
        }
        pbcq->nest_regs[reg] = val & 0xfffffffffc000000ull;
        break;
    case PBCQ_NEST_BAR_EN:
        pbcq->nest_regs[reg] = val & 0xf800000000000000ull;
        pnv_pbcq_update_map(pbcq);
        pnv_phb3_remap_irqs(pbcq->phb);
        break;
    case PBCQ_NEST_IRSN_COMPARE:
    case PBCQ_NEST_IRSN_MASK:
        pbcq->nest_regs[reg] = val & PBCQ_NEST_IRSN_COMP;
        pnv_phb3_remap_irqs(pbcq->phb);
        break;
    case PBCQ_NEST_LSI_SRC_ID:
        pbcq->nest_regs[reg] = val & PBCQ_NEST_LSI_SRC;
        pnv_phb3_remap_irqs(pbcq->phb);
        break;
    default:
        phb3_pbcq_error(pbcq, "%s @0x%"HWADDR_PRIx"=%"PRIx64, __func__,
                        addr, val);
    }
}

static void pnv_pbcq_pci_xscom_write(void *opaque, hwaddr addr,
                                     uint64_t val, unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t reg = addr >> 3;

    switch (reg) {
    case PBCQ_PCI_BAR2:
        pbcq->pci_regs[reg] = val & 0xfffffffffc000000ull;
        pnv_pbcq_update_map(pbcq);
        break;
    default:
        phb3_pbcq_error(pbcq, "%s @0x%"HWADDR_PRIx"=%"PRIx64, __func__,
                        addr, val);
    }
}

static void pnv_pbcq_spci_xscom_write(void *opaque, hwaddr addr,
                                uint64_t val, unsigned size)
{
    PnvPBCQState *pbcq = PNV_PBCQ(opaque);
    uint32_t reg = addr >> 3;

    switch (reg) {
    case PBCQ_SPCI_ASB_ADDR:
        pbcq->spci_regs[reg] = val & 0xfff;
        break;
    case PBCQ_SPCI_ASB_STATUS:
        pbcq->spci_regs[reg] &= ~val;
        break;
    case PBCQ_SPCI_ASB_DATA:
        pnv_phb3_reg_write(pbcq->phb, pbcq->spci_regs[PBCQ_SPCI_ASB_ADDR],
                           val, 8);
        break;
    case PBCQ_SPCI_AIB_CAPP_EN:
    case PBCQ_SPCI_CAPP_SEC_TMR:
        break;
    default:
        phb3_pbcq_error(pbcq, "%s @0x%"HWADDR_PRIx"=%"PRIx64, __func__,
                        addr, val);
    }
}

static const MemoryRegionOps pnv_pbcq_nest_xscom_ops = {
    .read = pnv_pbcq_nest_xscom_read,
    .write = pnv_pbcq_nest_xscom_write,
    .valid.min_access_size = 8,
    .valid.max_access_size = 8,
    .impl.min_access_size = 8,
    .impl.max_access_size = 8,
    .endianness = DEVICE_BIG_ENDIAN,
};

static const MemoryRegionOps pnv_pbcq_pci_xscom_ops = {
    .read = pnv_pbcq_pci_xscom_read,
    .write = pnv_pbcq_pci_xscom_write,
    .valid.min_access_size = 8,
    .valid.max_access_size = 8,
    .impl.min_access_size = 8,
    .impl.max_access_size = 8,
    .endianness = DEVICE_BIG_ENDIAN,
};

static const MemoryRegionOps pnv_pbcq_spci_xscom_ops = {
    .read = pnv_pbcq_spci_xscom_read,
    .write = pnv_pbcq_spci_xscom_write,
    .valid.min_access_size = 8,
    .valid.max_access_size = 8,
    .impl.min_access_size = 8,
    .impl.max_access_size = 8,
    .endianness = DEVICE_BIG_ENDIAN,
};

static void pnv_pbcq_default_bars(PnvPBCQState *pbcq)
{
    uint64_t mm0, mm1, reg;
    PnvPHB3 *phb = pbcq->phb;

    mm0 = 0x3d00000000000ull + 0x4000000000ull * phb->chip_id +
            0x1000000000ull * phb->phb_id;
    mm1 = 0x3ff8000000000ull + 0x0200000000ull * phb->chip_id +
            0x0080000000ull * phb->phb_id;
    reg = 0x3fffe40000000ull + 0x0000400000ull * phb->chip_id +
            0x0000100000ull * phb->phb_id;

    pbcq->nest_regs[PBCQ_NEST_MMIO_BAR0] = mm0 << 14;
    pbcq->nest_regs[PBCQ_NEST_MMIO_BAR1] = mm1 << 14;
    pbcq->nest_regs[PBCQ_NEST_PHB_BAR] = reg << 14;
    pbcq->nest_regs[PBCQ_NEST_MMIO_MASK0] = 0x3fff000000000ull << 14;
    pbcq->nest_regs[PBCQ_NEST_MMIO_MASK1] = 0x3ffff80000000ull << 14;
    pbcq->pci_regs[PBCQ_PCI_BAR2] = reg << 14;
}

static void pnv_pbcq_realize(DeviceState *dev, Error **errp)
{
    PnvPBCQState *pbcq = PNV_PBCQ(dev);
    PnvPHB3 *phb;
    char name[32];

    assert(pbcq->phb);
    phb = pbcq->phb;

    /* TODO: Fix OPAL to do that: establish default BAR values */
    pnv_pbcq_default_bars(pbcq);

    /* Initialize the XSCOM region for the PBCQ registers */
    snprintf(name, sizeof(name), "xscom-pbcq-nest-%d.%d",
             phb->chip_id, phb->phb_id);
    pnv_xscom_region_init(&pbcq->xscom_nest_regs, OBJECT(dev),
                          &pnv_pbcq_nest_xscom_ops, pbcq, name,
                          PNV_XSCOM_PBCQ_NEST_SIZE);
    snprintf(name, sizeof(name), "xscom-pbcq-pci-%d.%d",
             phb->chip_id, phb->phb_id);
    pnv_xscom_region_init(&pbcq->xscom_pci_regs, OBJECT(dev),
                          &pnv_pbcq_pci_xscom_ops, pbcq, name,
                          PNV_XSCOM_PBCQ_PCI_SIZE);
    snprintf(name, sizeof(name), "xscom-pbcq-spci-%d.%d",
             phb->chip_id, phb->phb_id);
    pnv_xscom_region_init(&pbcq->xscom_spci_regs, OBJECT(dev),
                          &pnv_pbcq_spci_xscom_ops, pbcq, name,
                          PNV_XSCOM_PBCQ_SPCI_SIZE);
}

static int pnv_pbcq_dt_xscom(PnvXScomInterface *dev, void *fdt,
                             int xscom_offset)
{
    const char compat[] = "ibm,power8-pbcq";
    PnvPHB3 *phb = PNV_PBCQ(dev)->phb;
    char *name;
    int offset;
    uint32_t lpc_pcba = PNV_XSCOM_PBCQ_NEST_BASE + 0x400 * phb->phb_id;
    uint32_t reg[] = {
        cpu_to_be32(lpc_pcba),
        cpu_to_be32(PNV_XSCOM_PBCQ_NEST_SIZE),
        cpu_to_be32(PNV_XSCOM_PBCQ_PCI_BASE + 0x400 * phb->phb_id),
        cpu_to_be32(PNV_XSCOM_PBCQ_PCI_SIZE),
        cpu_to_be32(PNV_XSCOM_PBCQ_SPCI_BASE + 0x040 * phb->phb_id),
        cpu_to_be32(PNV_XSCOM_PBCQ_SPCI_SIZE)
    };

    name = g_strdup_printf("pbcq@%x", lpc_pcba);
    offset = fdt_add_subnode(fdt, xscom_offset, name);
    _FDT(offset);
    g_free(name);

    _FDT((fdt_setprop(fdt, offset, "reg", reg, sizeof(reg))));

    _FDT((fdt_setprop_cell(fdt, offset, "ibm,phb-index", phb->phb_id)));
    _FDT((fdt_setprop_cell(fdt, offset, "ibm,chip-id", phb->chip_id)));
    _FDT((fdt_setprop(fdt, offset, "compatible", compat,
                      sizeof(compat))));
    return 0;
}

static void phb3_pbcq_instance_init(Object *obj)
{
    PnvPBCQState *pbcq = PNV_PBCQ(obj);

    object_property_add_link(obj, "phb", TYPE_PNV_PHB3,
                             (Object **)&pbcq->phb,
                             object_property_allow_set_link,
                             OBJ_PROP_LINK_STRONG);
}

static void pnv_pbcq_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    PnvXScomInterfaceClass *xdc = PNV_XSCOM_INTERFACE_CLASS(klass);

    xdc->dt_xscom = pnv_pbcq_dt_xscom;

    dc->realize = pnv_pbcq_realize;
    dc->user_creatable = false;
}

static const TypeInfo pnv_pbcq_type_info = {
    .name          = TYPE_PNV_PBCQ,
    .parent        = TYPE_DEVICE,
    .instance_size = sizeof(PnvPBCQState),
    .instance_init = phb3_pbcq_instance_init,
    .class_init    = pnv_pbcq_class_init,
    .interfaces    = (InterfaceInfo[]) {
        { TYPE_PNV_XSCOM_INTERFACE },
        { }
    }
};

static void pnv_pbcq_register_types(void)
{
    type_register_static(&pnv_pbcq_type_info);
}

type_init(pnv_pbcq_register_types)
