/*
 * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
 *
 * PAPR Inter-VM Logical Lan, aka ibmveth
 *
 * Copyright (c) 2010,2011 David Gibson, IBM Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */
#include "hw/hw.h"
#include "net/net.h"
#include "hw/qdev.h"
#include "hw/ppc/spapr.h"
#include "hw/ppc/spapr_vio.h"

#include <libfdt.h>

#define ETH_ALEN        6
#define MAX_PACKET_SIZE 65536

/*#define DEBUG*/

#ifdef DEBUG
#define dprintf(fmt...) do { fprintf(stderr, fmt); } while (0)
#else
#define dprintf(fmt...)
#endif

/*
 * Virtual LAN device
 */

typedef uint64_t vlan_bd_t;

#define VLAN_BD_VALID        0x8000000000000000ULL
#define VLAN_BD_TOGGLE       0x4000000000000000ULL
#define VLAN_BD_NO_CSUM      0x0200000000000000ULL
#define VLAN_BD_CSUM_GOOD    0x0100000000000000ULL
#define VLAN_BD_LEN_MASK     0x00ffffff00000000ULL
#define VLAN_BD_LEN(bd)      (((bd) & VLAN_BD_LEN_MASK) >> 32)
#define VLAN_BD_ADDR_MASK    0x00000000ffffffffULL
#define VLAN_BD_ADDR(bd)     ((bd) & VLAN_BD_ADDR_MASK)

#define VLAN_VALID_BD(addr, len) (VLAN_BD_VALID | \
                                  (((len) << 32) & VLAN_BD_LEN_MASK) |  \
                                  (addr & VLAN_BD_ADDR_MASK))

#define VLAN_RXQC_TOGGLE     0x80
#define VLAN_RXQC_VALID      0x40
#define VLAN_RXQC_NO_CSUM    0x02
#define VLAN_RXQC_CSUM_GOOD  0x01

#define VLAN_RQ_ALIGNMENT    16
#define VLAN_RXQ_BD_OFF      0
#define VLAN_FILTER_BD_OFF   8
#define VLAN_RX_BDS_OFF      16
#define VLAN_MAX_BUFS        ((SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF) / 8)

#define TYPE_VIO_SPAPR_VLAN_DEVICE "spapr-vlan"
#define VIO_SPAPR_VLAN_DEVICE(obj) \
     OBJECT_CHECK(VIOsPAPRVLANDevice, (obj), TYPE_VIO_SPAPR_VLAN_DEVICE)

typedef struct VIOsPAPRVLANDevice {
    VIOsPAPRDevice sdev;
    NICConf nicconf;
    NICState *nic;
    int isopen;
    target_ulong buf_list;
    int add_buf_ptr, use_buf_ptr, rx_bufs;
    target_ulong rxq_ptr;
} VIOsPAPRVLANDevice;

static int spapr_vlan_can_receive(NetClientState *nc)
{
    VIOsPAPRVLANDevice *dev = qemu_get_nic_opaque(nc);

    return (dev->isopen && dev->rx_bufs > 0);
}

static ssize_t spapr_vlan_receive(NetClientState *nc, const uint8_t *buf,
                                  size_t size)
{
    VIOsPAPRVLANDevice *dev = qemu_get_nic_opaque(nc);
    VIOsPAPRDevice *sdev = VIO_SPAPR_DEVICE(dev);
    vlan_bd_t rxq_bd = vio_ldq(sdev, dev->buf_list + VLAN_RXQ_BD_OFF);
    vlan_bd_t bd;
    int buf_ptr = dev->use_buf_ptr;
    uint64_t handle;
    uint8_t control;

    dprintf("spapr_vlan_receive() [%s] rx_bufs=%d\n", sdev->qdev.id,
            dev->rx_bufs);

    if (!dev->isopen) {
        return -1;
    }

    if (!dev->rx_bufs) {
        return -1;
    }

    do {
        buf_ptr += 8;
        if (buf_ptr >= SPAPR_TCE_PAGE_SIZE) {
            buf_ptr = VLAN_RX_BDS_OFF;
        }

        bd = vio_ldq(sdev, dev->buf_list + buf_ptr);
        dprintf("use_buf_ptr=%d bd=0x%016llx\n",
                buf_ptr, (unsigned long long)bd);
    } while ((!(bd & VLAN_BD_VALID) || (VLAN_BD_LEN(bd) < (size + 8)))
             && (buf_ptr != dev->use_buf_ptr));

    if (!(bd & VLAN_BD_VALID) || (VLAN_BD_LEN(bd) < (size + 8))) {
        /* Failed to find a suitable buffer */
        return -1;
    }

    /* Remove the buffer from the pool */
    dev->rx_bufs--;
    dev->use_buf_ptr = buf_ptr;
    vio_stq(sdev, dev->buf_list + dev->use_buf_ptr, 0);

    dprintf("Found buffer: ptr=%d num=%d\n", dev->use_buf_ptr, dev->rx_bufs);

    /* Transfer the packet data */
    if (spapr_vio_dma_write(sdev, VLAN_BD_ADDR(bd) + 8, buf, size) < 0) {
        return -1;
    }

    dprintf("spapr_vlan_receive: DMA write completed\n");

    /* Update the receive queue */
    control = VLAN_RXQC_TOGGLE | VLAN_RXQC_VALID;
    if (rxq_bd & VLAN_BD_TOGGLE) {
        control ^= VLAN_RXQC_TOGGLE;
    }

    handle = vio_ldq(sdev, VLAN_BD_ADDR(bd));
    vio_stq(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 8, handle);
    vio_stl(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 4, size);
    vio_sth(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 2, 8);
    vio_stb(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr, control);

    dprintf("wrote rxq entry (ptr=0x%llx): 0x%016llx 0x%016llx\n",
            (unsigned long long)dev->rxq_ptr,
            (unsigned long long)vio_ldq(sdev, VLAN_BD_ADDR(rxq_bd) +
                                        dev->rxq_ptr),
            (unsigned long long)vio_ldq(sdev, VLAN_BD_ADDR(rxq_bd) +
                                        dev->rxq_ptr + 8));

    dev->rxq_ptr += 16;
    if (dev->rxq_ptr >= VLAN_BD_LEN(rxq_bd)) {
        dev->rxq_ptr = 0;
        vio_stq(sdev, dev->buf_list + VLAN_RXQ_BD_OFF, rxq_bd ^ VLAN_BD_TOGGLE);
    }

    if (sdev->signal_state & 1) {
        qemu_irq_pulse(spapr_vio_qirq(sdev));
    }

    return size;
}

static void spapr_vlan_cleanup(NetClientState *nc)
{
    VIOsPAPRVLANDevice *dev = qemu_get_nic_opaque(nc);

    dev->nic = NULL;
}

static NetClientInfo net_spapr_vlan_info = {
    .type = NET_CLIENT_OPTIONS_KIND_NIC,
    .size = sizeof(NICState),
    .can_receive = spapr_vlan_can_receive,
    .receive = spapr_vlan_receive,
    .cleanup = spapr_vlan_cleanup,
};

static void spapr_vlan_reset(VIOsPAPRDevice *sdev)
{
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);

    dev->buf_list = 0;
    dev->rx_bufs = 0;
    dev->isopen = 0;
}

static int spapr_vlan_init(VIOsPAPRDevice *sdev)
{
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);

    qemu_macaddr_default_if_unset(&dev->nicconf.macaddr);

    dev->nic = qemu_new_nic(&net_spapr_vlan_info, &dev->nicconf,
                            object_get_typename(OBJECT(sdev)), sdev->qdev.id, dev);
    qemu_format_nic_info_str(qemu_get_queue(dev->nic), dev->nicconf.macaddr.a);

    return 0;
}

void spapr_vlan_create(VIOsPAPRBus *bus, NICInfo *nd)
{
    DeviceState *dev;

    dev = qdev_create(&bus->bus, "spapr-vlan");

    qdev_set_nic_properties(dev, nd);

    qdev_init_nofail(dev);
}

static int spapr_vlan_devnode(VIOsPAPRDevice *dev, void *fdt, int node_off)
{
    VIOsPAPRVLANDevice *vdev = VIO_SPAPR_VLAN_DEVICE(dev);
    uint8_t padded_mac[8] = {0, 0};
    int ret;

    /* Some old phyp versions give the mac address in an 8-byte
     * property.  The kernel driver has an insane workaround for this;
     * rather than doing the obvious thing and checking the property
     * length, it checks whether the first byte has 0b10 in the low
     * bits.  If a correct 6-byte property has a different first byte
     * the kernel will get the wrong mac address, overrunning its
     * buffer in the process (read only, thank goodness).
     *
     * Here we workaround the kernel workaround by always supplying an
     * 8-byte property, with the mac address in the last six bytes */
    memcpy(&padded_mac[2], &vdev->nicconf.macaddr, ETH_ALEN);
    ret = fdt_setprop(fdt, node_off, "local-mac-address",
                      padded_mac, sizeof(padded_mac));
    if (ret < 0) {
        return ret;
    }

    ret = fdt_setprop_cell(fdt, node_off, "ibm,mac-address-filters", 0);
    if (ret < 0) {
        return ret;
    }

    return 0;
}

static int check_bd(VIOsPAPRVLANDevice *dev, vlan_bd_t bd,
                    target_ulong alignment)
{
    if ((VLAN_BD_ADDR(bd) % alignment)
        || (VLAN_BD_LEN(bd) % alignment)) {
        return -1;
    }

    if (!spapr_vio_dma_valid(&dev->sdev, VLAN_BD_ADDR(bd),
                             VLAN_BD_LEN(bd), DMA_DIRECTION_FROM_DEVICE)
        || !spapr_vio_dma_valid(&dev->sdev, VLAN_BD_ADDR(bd),
                                VLAN_BD_LEN(bd), DMA_DIRECTION_TO_DEVICE)) {
        return -1;
    }

    return 0;
}

static target_ulong h_register_logical_lan(PowerPCCPU *cpu,
                                           sPAPREnvironment *spapr,
                                           target_ulong opcode,
                                           target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong buf_list = args[1];
    target_ulong rec_queue = args[2];
    target_ulong filter_list = args[3];
    VIOsPAPRDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
    vlan_bd_t filter_list_bd;

    if (!dev) {
        return H_PARAMETER;
    }

    if (dev->isopen) {
        hcall_dprintf("H_REGISTER_LOGICAL_LAN called twice without "
                      "H_FREE_LOGICAL_LAN\n");
        return H_RESOURCE;
    }

    if (check_bd(dev, VLAN_VALID_BD(buf_list, SPAPR_TCE_PAGE_SIZE),
                 SPAPR_TCE_PAGE_SIZE) < 0) {
        hcall_dprintf("Bad buf_list 0x" TARGET_FMT_lx "\n", buf_list);
        return H_PARAMETER;
    }

    filter_list_bd = VLAN_VALID_BD(filter_list, SPAPR_TCE_PAGE_SIZE);
    if (check_bd(dev, filter_list_bd, SPAPR_TCE_PAGE_SIZE) < 0) {
        hcall_dprintf("Bad filter_list 0x" TARGET_FMT_lx "\n", filter_list);
        return H_PARAMETER;
    }

    if (!(rec_queue & VLAN_BD_VALID)
        || (check_bd(dev, rec_queue, VLAN_RQ_ALIGNMENT) < 0)) {
        hcall_dprintf("Bad receive queue\n");
        return H_PARAMETER;
    }

    dev->buf_list = buf_list;
    sdev->signal_state = 0;

    rec_queue &= ~VLAN_BD_TOGGLE;

    /* Initialize the buffer list */
    vio_stq(sdev, buf_list, rec_queue);
    vio_stq(sdev, buf_list + 8, filter_list_bd);
    spapr_vio_dma_set(sdev, buf_list + VLAN_RX_BDS_OFF, 0,
                      SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF);
    dev->add_buf_ptr = VLAN_RX_BDS_OFF - 8;
    dev->use_buf_ptr = VLAN_RX_BDS_OFF - 8;
    dev->rx_bufs = 0;
    dev->rxq_ptr = 0;

    /* Initialize the receive queue */
    spapr_vio_dma_set(sdev, VLAN_BD_ADDR(rec_queue), 0, VLAN_BD_LEN(rec_queue));

    dev->isopen = 1;
    qemu_flush_queued_packets(qemu_get_queue(dev->nic));

    return H_SUCCESS;
}


static target_ulong h_free_logical_lan(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                       target_ulong opcode, target_ulong *args)
{
    target_ulong reg = args[0];
    VIOsPAPRDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);

    if (!dev) {
        return H_PARAMETER;
    }

    if (!dev->isopen) {
        hcall_dprintf("H_FREE_LOGICAL_LAN called without "
                      "H_REGISTER_LOGICAL_LAN\n");
        return H_RESOURCE;
    }

    spapr_vlan_reset(sdev);
    return H_SUCCESS;
}

static target_ulong h_add_logical_lan_buffer(PowerPCCPU *cpu,
                                             sPAPREnvironment *spapr,
                                             target_ulong opcode,
                                             target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong buf = args[1];
    VIOsPAPRDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
    vlan_bd_t bd;

    dprintf("H_ADD_LOGICAL_LAN_BUFFER(0x" TARGET_FMT_lx
            ", 0x" TARGET_FMT_lx ")\n", reg, buf);

    if (!sdev) {
        hcall_dprintf("Bad device\n");
        return H_PARAMETER;
    }

    if ((check_bd(dev, buf, 4) < 0)
        || (VLAN_BD_LEN(buf) < 16)) {
        hcall_dprintf("Bad buffer enqueued\n");
        return H_PARAMETER;
    }

    if (!dev->isopen || dev->rx_bufs >= VLAN_MAX_BUFS) {
        return H_RESOURCE;
    }

    do {
        dev->add_buf_ptr += 8;
        if (dev->add_buf_ptr >= SPAPR_TCE_PAGE_SIZE) {
            dev->add_buf_ptr = VLAN_RX_BDS_OFF;
        }

        bd = vio_ldq(sdev, dev->buf_list + dev->add_buf_ptr);
    } while (bd & VLAN_BD_VALID);

    vio_stq(sdev, dev->buf_list + dev->add_buf_ptr, buf);

    dev->rx_bufs++;

    dprintf("h_add_logical_lan_buffer():  Added buf  ptr=%d  rx_bufs=%d"
            " bd=0x%016llx\n", dev->add_buf_ptr, dev->rx_bufs,
            (unsigned long long)buf);

    return H_SUCCESS;
}

static target_ulong h_send_logical_lan(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                       target_ulong opcode, target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong *bufs = args + 1;
    target_ulong continue_token = args[7];
    VIOsPAPRDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
    unsigned total_len;
    uint8_t *lbuf, *p;
    int i, nbufs;
    int ret;

    dprintf("H_SEND_LOGICAL_LAN(0x" TARGET_FMT_lx ", <bufs>, 0x"
            TARGET_FMT_lx ")\n", reg, continue_token);

    if (!sdev) {
        return H_PARAMETER;
    }

    dprintf("rxbufs = %d\n", dev->rx_bufs);

    if (!dev->isopen) {
        return H_DROPPED;
    }

    if (continue_token) {
        return H_HARDWARE; /* FIXME actually handle this */
    }

    total_len = 0;
    for (i = 0; i < 6; i++) {
        dprintf("   buf desc: 0x" TARGET_FMT_lx "\n", bufs[i]);
        if (!(bufs[i] & VLAN_BD_VALID)) {
            break;
        }
        total_len += VLAN_BD_LEN(bufs[i]);
    }

    nbufs = i;
    dprintf("h_send_logical_lan() %d buffers, total length 0x%x\n",
            nbufs, total_len);

    if (total_len == 0) {
        return H_SUCCESS;
    }

    if (total_len > MAX_PACKET_SIZE) {
        /* Don't let the guest force too large an allocation */
        return H_RESOURCE;
    }

    lbuf = alloca(total_len);
    p = lbuf;
    for (i = 0; i < nbufs; i++) {
        ret = spapr_vio_dma_read(sdev, VLAN_BD_ADDR(bufs[i]),
                                 p, VLAN_BD_LEN(bufs[i]));
        if (ret < 0) {
            return ret;
        }

        p += VLAN_BD_LEN(bufs[i]);
    }

    qemu_send_packet(qemu_get_queue(dev->nic), lbuf, total_len);

    return H_SUCCESS;
}

static target_ulong h_multicast_ctrl(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                     target_ulong opcode, target_ulong *args)
{
    target_ulong reg = args[0];
    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);

    if (!dev) {
        return H_PARAMETER;
    }

    return H_SUCCESS;
}

static Property spapr_vlan_properties[] = {
    DEFINE_SPAPR_PROPERTIES(VIOsPAPRVLANDevice, sdev),
    DEFINE_NIC_PROPERTIES(VIOsPAPRVLANDevice, nicconf),
    DEFINE_PROP_END_OF_LIST(),
};

static void spapr_vlan_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);

    k->init = spapr_vlan_init;
    k->reset = spapr_vlan_reset;
    k->devnode = spapr_vlan_devnode;
    k->dt_name = "l-lan";
    k->dt_type = "network";
    k->dt_compatible = "IBM,l-lan";
    k->signal_mask = 0x1;
    dc->props = spapr_vlan_properties;
    k->rtce_window_size = 0x10000000;
}

static const TypeInfo spapr_vlan_info = {
    .name          = TYPE_VIO_SPAPR_VLAN_DEVICE,
    .parent        = TYPE_VIO_SPAPR_DEVICE,
    .instance_size = sizeof(VIOsPAPRVLANDevice),
    .class_init    = spapr_vlan_class_init,
};

static void spapr_vlan_register_types(void)
{
    spapr_register_hypercall(H_REGISTER_LOGICAL_LAN, h_register_logical_lan);
    spapr_register_hypercall(H_FREE_LOGICAL_LAN, h_free_logical_lan);
    spapr_register_hypercall(H_SEND_LOGICAL_LAN, h_send_logical_lan);
    spapr_register_hypercall(H_ADD_LOGICAL_LAN_BUFFER,
                             h_add_logical_lan_buffer);
    spapr_register_hypercall(H_MULTICAST_CTRL, h_multicast_ctrl);
    type_register_static(&spapr_vlan_info);
}

type_init(spapr_vlan_register_types)