/*
 * Copyright (c) 2012 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <linux/netdevice.h>

#include "brcmu_wifi.h"
#include "brcmu_utils.h"

#include "core.h"
#include "debug.h"
#include "tracepoint.h"
#include "fwsignal.h"
#include "fweh.h"
#include "fwil.h"

/**
 * struct brcm_ethhdr - broadcom specific ether header.
 *
 * @subtype: subtype for this packet.
 * @length: TODO: length of appended data.
 * @version: version indication.
 * @oui: OUI of this packet.
 * @usr_subtype: subtype for this OUI.
 */
struct brcm_ethhdr {
        __be16 subtype;
        __be16 length;
        u8 version;
        u8 oui[3];
        __be16 usr_subtype;
} __packed;

struct brcmf_event_msg_be {
        __be16 version;
        __be16 flags;
        __be32 event_type;
        __be32 status;
        __be32 reason;
        __be32 auth_type;
        __be32 datalen;
        u8 addr[ETH_ALEN];
        char ifname[IFNAMSIZ];
        u8 ifidx;
        u8 bsscfgidx;
} __packed;

/**
 * struct brcmf_event - contents of broadcom event packet.
 *
 * @eth: standard ether header.
 * @hdr: broadcom specific ether header.
 * @msg: common part of the actual event message.
 */
struct brcmf_event {
        struct ethhdr eth;
        struct brcm_ethhdr hdr;
        struct brcmf_event_msg_be msg;
} __packed;

/**
 * struct brcmf_fweh_queue_item - event item on event queue.
 *
 * @q: list element for queuing.
 * @code: event code.
 * @ifidx: interface index related to this event.
 * @ifaddr: ethernet address for interface.
 * @emsg: common parameters of the firmware event message.
 * @data: event specific data part of the firmware event.
 */
struct brcmf_fweh_queue_item {
        struct list_head q;
        enum brcmf_fweh_event_code code;
        u8 ifidx;
        u8 ifaddr[ETH_ALEN];
        struct brcmf_event_msg_be emsg;
        u8 data[0];
};

/**
 * struct brcmf_fweh_event_name - code, name mapping entry.
 */
struct brcmf_fweh_event_name {
        enum brcmf_fweh_event_code code;
        const char *name;
};

#ifdef DEBUG
#define BRCMF_ENUM_DEF(id, val) \
        { val, #id },

/* array for mapping code to event name */
static struct brcmf_fweh_event_name fweh_event_names[] = {
        BRCMF_FWEH_EVENT_ENUM_DEFLIST
};
#undef BRCMF_ENUM_DEF

/**
 * brcmf_fweh_event_name() - returns name for given event code.
 *
 * @code: code to lookup.
 */
static const char *brcmf_fweh_event_name(enum brcmf_fweh_event_code code)
{
        int i;
        for (i = 0; i < ARRAY_SIZE(fweh_event_names); i++) {
                if (fweh_event_names[i].code == code)
                        return fweh_event_names[i].name;
        }
        return "unknown";
}
#else
static const char *brcmf_fweh_event_name(enum brcmf_fweh_event_code code)
{
        return "nodebug";
}
#endif

/**
 * brcmf_fweh_queue_event() - create and queue event.
 *
 * @fweh: firmware event handling info.
 * @event: event queue entry.
 */
static void brcmf_fweh_queue_event(struct brcmf_fweh_info *fweh,
                                   struct brcmf_fweh_queue_item *event)
{
        ulong flags;

        spin_lock_irqsave(&fweh->evt_q_lock, flags);
        list_add_tail(&event->q, &fweh->event_q);
        spin_unlock_irqrestore(&fweh->evt_q_lock, flags);
        schedule_work(&fweh->event_work);
}

static int brcmf_fweh_call_event_handler(struct brcmf_if *ifp,
                                         enum brcmf_fweh_event_code code,
                                         struct brcmf_event_msg *emsg,
                                         void *data)
{
        struct brcmf_fweh_info *fweh;
        int err = -EINVAL;

        if (ifp) {
                fweh = &ifp->drvr->fweh;

                /* handle the event if valid interface and handler */
                if (fweh->evt_handler[code])
                        err = fweh->evt_handler[code](ifp, emsg, data);
                else
                        brcmf_err("unhandled event %d ignored\n", code);
        } else {
                brcmf_err("no interface object\n");
        }
        return err;
}

/**
 * brcmf_fweh_handle_if_event() - handle IF event.
 *
 * @drvr: driver information object.
 * @item: queue entry.
 * @ifpp: interface object (may change upon ADD action).
 */
static void brcmf_fweh_handle_if_event(struct brcmf_pub *drvr,
                                       struct brcmf_event_msg *emsg,
                                       void *data)
{
        struct brcmf_if_event *ifevent = data;
        struct brcmf_if *ifp;
        int err = 0;

        brcmf_dbg(EVENT, "action: %u idx: %u bsscfg: %u flags: %u role: %u\n",
                  ifevent->action, ifevent->ifidx, ifevent->bssidx,
                  ifevent->flags, ifevent->role);

        /* The P2P Device interface event must not be ignored
         * contrary to what firmware tells us. The only way to
         * distinguish the P2P Device is by looking at the ifidx
         * and bssidx received.
         */
        if (!(ifevent->ifidx == 0 && ifevent->bssidx == 1) &&
            (ifevent->flags & BRCMF_E_IF_FLAG_NOIF)) {
                brcmf_dbg(EVENT, "event can be ignored\n");
                return;
        }
        if (ifevent->ifidx >= BRCMF_MAX_IFS) {
                brcmf_err("invalid interface index: %u\n",
                          ifevent->ifidx);
                return;
        }

        ifp = drvr->iflist[ifevent->bssidx];

        if (ifevent->action == BRCMF_E_IF_ADD) {
                brcmf_dbg(EVENT, "adding %s (%pM)\n", emsg->ifname,
                          emsg->addr);
                ifp = brcmf_add_if(drvr, ifevent->bssidx, ifevent->ifidx,
                                   emsg->ifname, emsg->addr);
                if (IS_ERR(ifp))
                        return;
                brcmf_fws_add_interface(ifp);
                if (!drvr->fweh.evt_handler[BRCMF_E_IF])
                        if (brcmf_net_attach(ifp, false) < 0)
                                return;
        }

        if (ifp && ifevent->action == BRCMF_E_IF_CHANGE)
                brcmf_fws_reset_interface(ifp);

        err = brcmf_fweh_call_event_handler(ifp, emsg->event_code, emsg, data);

        if (ifp && ifevent->action == BRCMF_E_IF_DEL)
                brcmf_remove_interface(drvr, ifevent->bssidx);
}

/**
 * brcmf_fweh_dequeue_event() - get event from the queue.
 *
 * @fweh: firmware event handling info.
 */
static struct brcmf_fweh_queue_item *
brcmf_fweh_dequeue_event(struct brcmf_fweh_info *fweh)
{
        struct brcmf_fweh_queue_item *event = NULL;
        ulong flags;

        spin_lock_irqsave(&fweh->evt_q_lock, flags);
        if (!list_empty(&fweh->event_q)) {
                event = list_first_entry(&fweh->event_q,
                                         struct brcmf_fweh_queue_item, q);
                list_del(&event->q);
        }
        spin_unlock_irqrestore(&fweh->evt_q_lock, flags);

        return event;
}

/**
 * brcmf_fweh_event_worker() - firmware event worker.
 *
 * @work: worker object.
 */
static void brcmf_fweh_event_worker(struct work_struct *work)
{
        struct brcmf_pub *drvr;
        struct brcmf_if *ifp;
        struct brcmf_fweh_info *fweh;
        struct brcmf_fweh_queue_item *event;
        int err = 0;
        struct brcmf_event_msg_be *emsg_be;
        struct brcmf_event_msg emsg;

        fweh = container_of(work, struct brcmf_fweh_info, event_work);
        drvr = container_of(fweh, struct brcmf_pub, fweh);

        while ((event = brcmf_fweh_dequeue_event(fweh))) {
                brcmf_dbg(EVENT, "event %s (%u) ifidx %u bsscfg %u addr %pM\n",
                          brcmf_fweh_event_name(event->code), event->code,
                          event->emsg.ifidx, event->emsg.bsscfgidx,
                          event->emsg.addr);

                /* convert event message */
                emsg_be = &event->emsg;
                emsg.version = be16_to_cpu(emsg_be->version);
                emsg.flags = be16_to_cpu(emsg_be->flags);
                emsg.event_code = event->code;
                emsg.status = be32_to_cpu(emsg_be->status);
                emsg.reason = be32_to_cpu(emsg_be->reason);
                emsg.auth_type = be32_to_cpu(emsg_be->auth_type);
                emsg.datalen = be32_to_cpu(emsg_be->datalen);
                memcpy(emsg.addr, emsg_be->addr, ETH_ALEN);
                memcpy(emsg.ifname, emsg_be->ifname, sizeof(emsg.ifname));
                emsg.ifidx = emsg_be->ifidx;
                emsg.bsscfgidx = emsg_be->bsscfgidx;

                brcmf_dbg(EVENT, "  version %u flags %u status %u reason %u\n",
                          emsg.version, emsg.flags, emsg.status, emsg.reason);
                brcmf_dbg_hex_dump(BRCMF_EVENT_ON(), event->data,
                                   min_t(u32, emsg.datalen, 64),
                                   "event payload, len=%d\n", emsg.datalen);

                /* special handling of interface event */
                if (event->code == BRCMF_E_IF) {
                        brcmf_fweh_handle_if_event(drvr, &emsg, event->data);
                        goto event_free;
                }

                if ((event->code == BRCMF_E_TDLS_PEER_EVENT) &&
                    (emsg.bsscfgidx == 1))
                        ifp = drvr->iflist[0];
                else
                        ifp = drvr->iflist[emsg.bsscfgidx];
                err = brcmf_fweh_call_event_handler(ifp, event->code, &emsg,
                                                    event->data);
                if (err) {
                        brcmf_err("event handler failed (%d)\n",
                                  event->code);
                        err = 0;
                }
event_free:
                kfree(event);
        }
}

/**
 * brcmf_fweh_attach() - initialize firmware event handling.
 *
 * @drvr: driver information object.
 */
void brcmf_fweh_attach(struct brcmf_pub *drvr)
{
        struct brcmf_fweh_info *fweh = &drvr->fweh;
        INIT_WORK(&fweh->event_work, brcmf_fweh_event_worker);
        spin_lock_init(&fweh->evt_q_lock);
        INIT_LIST_HEAD(&fweh->event_q);
}

/**
 * brcmf_fweh_detach() - cleanup firmware event handling.
 *
 * @drvr: driver information object.
 */
void brcmf_fweh_detach(struct brcmf_pub *drvr)
{
        struct brcmf_fweh_info *fweh = &drvr->fweh;
        struct brcmf_if *ifp = drvr->iflist[0];
        s8 eventmask[BRCMF_EVENTING_MASK_LEN];

        if (ifp) {
                /* clear all events */
                memset(eventmask, 0, BRCMF_EVENTING_MASK_LEN);
                (void)brcmf_fil_iovar_data_set(ifp, "event_msgs",
                                               eventmask,
                                               BRCMF_EVENTING_MASK_LEN);
        }
        /* cancel the worker */
        cancel_work_sync(&fweh->event_work);
        WARN_ON(!list_empty(&fweh->event_q));
        memset(fweh->evt_handler, 0, sizeof(fweh->evt_handler));
}

/**
 * brcmf_fweh_register() - register handler for given event code.
 *
 * @drvr: driver information object.
 * @code: event code.
 * @handler: handler for the given event code.
 */
int brcmf_fweh_register(struct brcmf_pub *drvr, enum brcmf_fweh_event_code code,
                        brcmf_fweh_handler_t handler)
{
        if (drvr->fweh.evt_handler[code]) {
                brcmf_err("event code %d already registered\n", code);
                return -ENOSPC;
        }
        drvr->fweh.evt_handler[code] = handler;
        brcmf_dbg(TRACE, "event handler registered for %s\n",
                  brcmf_fweh_event_name(code));
        return 0;
}

/**
 * brcmf_fweh_unregister() - remove handler for given code.
 *
 * @drvr: driver information object.
 * @code: event code.
 */
void brcmf_fweh_unregister(struct brcmf_pub *drvr,
                           enum brcmf_fweh_event_code code)
{
        brcmf_dbg(TRACE, "event handler cleared for %s\n",
                  brcmf_fweh_event_name(code));
        drvr->fweh.evt_handler[code] = NULL;
}

/**
 * brcmf_fweh_activate_events() - enables firmware events registered.
 *
 * @ifp: primary interface object.
 */
int brcmf_fweh_activate_events(struct brcmf_if *ifp)
{
        int i, err;
        s8 eventmask[BRCMF_EVENTING_MASK_LEN];

        for (i = 0; i < BRCMF_E_LAST; i++) {
                if (ifp->drvr->fweh.evt_handler[i]) {
                        brcmf_dbg(EVENT, "enable event %s\n",
                                  brcmf_fweh_event_name(i));
                        setbit(eventmask, i);
                }
        }

        /* want to handle IF event as well */
        brcmf_dbg(EVENT, "enable event IF\n");
        setbit(eventmask, BRCMF_E_IF);

        err = brcmf_fil_iovar_data_set(ifp, "event_msgs",
                                       eventmask, BRCMF_EVENTING_MASK_LEN);
        if (err)
                brcmf_err("Set event_msgs error (%d)\n", err);

        return err;
}

/**
 * brcmf_fweh_process_event() - process skb as firmware event.
 *
 * @drvr: driver information object.
 * @event_packet: event packet to process.
 *
 * If the packet buffer contains a firmware event message it will
 * dispatch the event to a registered handler (using worker).
 */
void brcmf_fweh_process_event(struct brcmf_pub *drvr,
                              struct brcmf_event *event_packet)
{
        enum brcmf_fweh_event_code code;
        struct brcmf_fweh_info *fweh = &drvr->fweh;
        struct brcmf_fweh_queue_item *event;
        gfp_t alloc_flag = GFP_KERNEL;
        void *data;
        u32 datalen;

        /* get event info */
        code = get_unaligned_be32(&event_packet->msg.event_type);
        datalen = get_unaligned_be32(&event_packet->msg.datalen);
        data = &event_packet[1];

        if (code >= BRCMF_E_LAST)
                return;

        if (code != BRCMF_E_IF && !fweh->evt_handler[code])
                return;

        if (in_interrupt())
                alloc_flag = GFP_ATOMIC;

        event = kzalloc(sizeof(*event) + datalen, alloc_flag);
        if (!event)
                return;

        event->code = code;
        event->ifidx = event_packet->msg.ifidx;

        /* use memcpy to get aligned event message */
        memcpy(&event->emsg, &event_packet->msg, sizeof(event->emsg));
        memcpy(event->data, data, datalen);
        memcpy(event->ifaddr, event_packet->eth.h_dest, ETH_ALEN);

        brcmf_fweh_queue_event(fweh, event);
}