/*
 * QEMU Alpha DP264/CLIPPER hardware system emulator.
 *
 * Choose CLIPPER IRQ mappings over, say, DP264, MONET, or WEBBRICK
 * variants because CLIPPER doesn't have an SMC669 SuperIO controller
 * that we need to emulate as well.
 */

#include "qemu/osdep.h"
#include "cpu.h"
#include "elf.h"
#include "hw/loader.h"
#include "alpha_sys.h"
#include "qemu/error-report.h"
#include "hw/rtc/mc146818rtc.h"
#include "hw/ide/pci.h"
#include "hw/isa/superio.h"
#include "net/net.h"
#include "qemu/cutils.h"
#include "qemu/datadir.h"

static uint64_t cpu_alpha_superpage_to_phys(void *opaque, uint64_t addr)
{
    if (((addr >> 41) & 3) == 2) {
        addr &= 0xffffffffffull;
    }
    return addr;
}

/* Note that there are at least 3 viewpoints of IRQ numbers on Alpha systems.
    (0) The dev_irq_n lines into the cpu, which we totally ignore,
    (1) The DRIR lines in the typhoon chipset,
    (2) The "vector" aka mangled interrupt number reported by SRM PALcode,
    (3) The interrupt number assigned by the kernel.
   The following function is concerned with (1) only.  */

static int clipper_pci_map_irq(PCIDevice *d, int irq_num)
{
    int slot = d->devfn >> 3;

    assert(irq_num >= 0 && irq_num <= 3);

    return (slot + 1) * 4 + irq_num;
}

static void clipper_init(MachineState *machine)
{
    ram_addr_t ram_size = machine->ram_size;
    const char *kernel_filename = machine->kernel_filename;
    const char *kernel_cmdline = machine->kernel_cmdline;
    const char *initrd_filename = machine->initrd_filename;
    MachineClass *mc = MACHINE_GET_CLASS(machine);
    AlphaCPU *cpus[4];
    PCIBus *pci_bus;
    PCIDevice *pci_dev;
    DeviceState *i82378_dev;
    ISABus *isa_bus;
    qemu_irq rtc_irq;
    qemu_irq isa_irq;
    long size, i;
    char *palcode_filename;
    uint64_t palcode_entry;
    uint64_t kernel_entry, kernel_low;
    unsigned int smp_cpus = machine->smp.cpus;

    /* Create up to 4 cpus.  */
    memset(cpus, 0, sizeof(cpus));
    for (i = 0; i < smp_cpus; ++i) {
        cpus[i] = ALPHA_CPU(cpu_create(machine->cpu_type));
    }

    /*
     * arg0 -> memory size
     * arg1 -> kernel entry point
     * arg2 -> config word
     *
     * Config word: bits 0-5 -> ncpus
     *              bit  6   -> nographics option (for HWRPB CTB)
     *
     * See init_hwrpb() in the PALcode.
     */
    cpus[0]->env.trap_arg0 = ram_size;
    cpus[0]->env.trap_arg1 = 0;
    cpus[0]->env.trap_arg2 = smp_cpus | (!machine->enable_graphics << 6);

    /*
     * Init the chipset.  Because we're using CLIPPER IRQ mappings,
     * the minimum PCI device IdSel is 1.
     */
    pci_bus = typhoon_init(machine->ram, &isa_irq, &rtc_irq, cpus,
                           clipper_pci_map_irq, PCI_DEVFN(1, 0));

    /*
     * Init the PCI -> ISA bridge.
     *
     * Technically, PCI-based Alphas shipped with one of three different
     * PCI-ISA bridges:
     *
     * - Intel i82378 SIO
     * - Cypress CY82c693UB
     * - ALI M1533
     *
     * (An Intel i82375 PCI-EISA bridge was also used on some models.)
     *
     * For simplicity, we model an i82378 here, even though it wouldn't
     * have been on any Tsunami/Typhoon systems; it's close enough, and
     * we don't want to deal with modelling the CY82c693UB (which has
     * incompatible edge/level control registers, plus other peripherals
     * like IDE and USB) or the M1533 (which also has IDE and USB).
     *
     * Importantly, we need to provide a PCI device node for it, otherwise
     * some operating systems won't notice there's an ISA bus to configure.
     */
    i82378_dev = DEVICE(pci_create_simple(pci_bus, PCI_DEVFN(7, 0), "i82378"));
    isa_bus = ISA_BUS(qdev_get_child_bus(i82378_dev, "isa.0"));

    /* Connect the ISA PIC to the Typhoon IRQ used for ISA interrupts. */
    qdev_connect_gpio_out(i82378_dev, 0, isa_irq);

    /* Since we have an SRM-compatible PALcode, use the SRM epoch.  */
    mc146818_rtc_init(isa_bus, 1900, rtc_irq);

    /* VGA setup.  Don't bother loading the bios.  */
    pci_vga_init(pci_bus);

    /* Network setup.  e1000 is good enough, failing Tulip support.  */
    pci_init_nic_devices(pci_bus, mc->default_nic);

    /* Super I/O */
    isa_create_simple(isa_bus, TYPE_SMC37C669_SUPERIO);

    /* IDE disk setup.  */
    pci_dev = pci_create_simple(pci_bus, -1, "cmd646-ide");
    pci_ide_create_devs(pci_dev);

    /* Load PALcode.  Given that this is not "real" cpu palcode,
       but one explicitly written for the emulation, we might as
       well load it directly from and ELF image.  */
    palcode_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
                                      machine->firmware ?: "palcode-clipper");
    if (palcode_filename == NULL) {
        error_report("no palcode provided");
        exit(1);
    }
    size = load_elf(palcode_filename, NULL, cpu_alpha_superpage_to_phys,
                    NULL, &palcode_entry, NULL, NULL, NULL,
                    0, EM_ALPHA, 0, 0);
    if (size < 0) {
        error_report("could not load palcode '%s'", palcode_filename);
        exit(1);
    }
    g_free(palcode_filename);

    /* Start all cpus at the PALcode RESET entry point.  */
    for (i = 0; i < smp_cpus; ++i) {
        cpus[i]->env.pc = palcode_entry;
        cpus[i]->env.palbr = palcode_entry;
    }

    /* Load a kernel.  */
    if (kernel_filename) {
        uint64_t param_offset;

        size = load_elf(kernel_filename, NULL, cpu_alpha_superpage_to_phys,
                        NULL, &kernel_entry, &kernel_low, NULL, NULL,
                        0, EM_ALPHA, 0, 0);
        if (size < 0) {
            error_report("could not load kernel '%s'", kernel_filename);
            exit(1);
        }

        cpus[0]->env.trap_arg1 = kernel_entry;

        param_offset = kernel_low - 0x6000;

        if (kernel_cmdline) {
            pstrcpy_targphys("cmdline", param_offset, 0x100, kernel_cmdline);
        }

        if (initrd_filename) {
            long initrd_base;
            int64_t initrd_size;

            initrd_size = get_image_size(initrd_filename);
            if (initrd_size < 0) {
                error_report("could not load initial ram disk '%s'",
                             initrd_filename);
                exit(1);
            }

            /* Put the initrd image as high in memory as possible.  */
            initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
            load_image_targphys(initrd_filename, initrd_base,
                                ram_size - initrd_base);

            address_space_stq(&address_space_memory, param_offset + 0x100,
                              initrd_base + 0xfffffc0000000000ULL,
                              MEMTXATTRS_UNSPECIFIED,
                              NULL);
            address_space_stq(&address_space_memory, param_offset + 0x108,
                              initrd_size, MEMTXATTRS_UNSPECIFIED, NULL);
        }
    }
}

static void clipper_machine_init(MachineClass *mc)
{
    mc->desc = "Alpha DP264/CLIPPER";
    mc->init = clipper_init;
    mc->block_default_type = IF_IDE;
    mc->max_cpus = 4;
    mc->is_default = true;
    mc->default_cpu_type = ALPHA_CPU_TYPE_NAME("ev67");
    mc->default_ram_id = "ram";
    mc->default_nic = "e1000";
}

DEFINE_MACHINE("clipper", clipper_machine_init)