core-transaction.c

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/*
 * Core IEEE1394 transaction logic
 *
 * Copyright (C) 2004-2006 Kristian Hoegsberg <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/bug.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/idr.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rculist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#include <asm/byteorder.h>

#include "core.h"

#define HEADER_PRI(pri)         ((pri) << 0)
#define HEADER_TCODE(tcode)     ((tcode) << 4)
#define HEADER_RETRY(retry)     ((retry) << 8)
#define HEADER_TLABEL(tlabel)       ((tlabel) << 10)
#define HEADER_DESTINATION(destination) ((destination) << 16)
#define HEADER_SOURCE(source)       ((source) << 16)
#define HEADER_RCODE(rcode)     ((rcode) << 12)
#define HEADER_OFFSET_HIGH(offset_high) ((offset_high) << 0)
#define HEADER_DATA_LENGTH(length)  ((length) << 16)
#define HEADER_EXTENDED_TCODE(tcode)    ((tcode) << 0)

#define HEADER_GET_TCODE(q)     (((q) >> 4) & 0x0f)
#define HEADER_GET_TLABEL(q)        (((q) >> 10) & 0x3f)
#define HEADER_GET_RCODE(q)     (((q) >> 12) & 0x0f)
#define HEADER_GET_DESTINATION(q)   (((q) >> 16) & 0xffff)
#define HEADER_GET_SOURCE(q)        (((q) >> 16) & 0xffff)
#define HEADER_GET_OFFSET_HIGH(q)   (((q) >> 0) & 0xffff)
#define HEADER_GET_DATA_LENGTH(q)   (((q) >> 16) & 0xffff)
#define HEADER_GET_EXTENDED_TCODE(q)    (((q) >> 0) & 0xffff)

#define HEADER_DESTINATION_IS_BROADCAST(q) \
    (((q) & HEADER_DESTINATION(0x3f)) == HEADER_DESTINATION(0x3f))

#define PHY_PACKET_CONFIG   0x0
#define PHY_PACKET_LINK_ON  0x1
#define PHY_PACKET_SELF_ID  0x2

#define PHY_CONFIG_GAP_COUNT(gap_count) (((gap_count) << 16) | (1 << 22))
#define PHY_CONFIG_ROOT_ID(node_id) ((((node_id) & 0x3f) << 24) | (1 << 23))
#define PHY_IDENTIFIER(id)      ((id) << 30)

/* returns 0 if the split timeout handler is already running */
static int try_cancel_split_timeout(struct fw_transaction *t)
{
    if (t->is_split_transaction)
        return del_timer(&t->split_timeout_timer);
    else
        return 1;
}

static int close_transaction(struct fw_transaction *transaction,
                 struct fw_card *card, int rcode)
{
    struct fw_transaction *t;
    unsigned long flags;

    spin_lock_irqsave(&card->lock, flags);
    list_for_each_entry(t, &card->transaction_list, link) {
        if (t == transaction) {
            if (!try_cancel_split_timeout(t)) {
                spin_unlock_irqrestore(&card->lock, flags);
                goto timed_out;
            }
            list_del_init(&t->link);
            card->tlabel_mask &= ~(1ULL << t->tlabel);
            break;
        }
    }
    spin_unlock_irqrestore(&card->lock, flags);

    if (&t->link != &card->transaction_list) {
        t->callback(card, rcode, NULL, 0, t->callback_data);
        return 0;
    }

 timed_out:
    return -ENOENT;
}

/*
 * Only valid for transactions that are potentially pending (ie have
 * been sent).
 */
int fw_cancel_transaction(struct fw_card *card,
              struct fw_transaction *transaction)
{
    /*
     * Cancel the packet transmission if it's still queued.  That
     * will call the packet transmission callback which cancels
     * the transaction.
     */

    if (card->driver->cancel_packet(card, &transaction->packet) == 0)
        return 0;

    /*
     * If the request packet has already been sent, we need to see
     * if the transaction is still pending and remove it in that case.
     */

    return close_transaction(transaction, card, RCODE_CANCELLED);
}
EXPORT_SYMBOL(fw_cancel_transaction);

static void split_transaction_timeout_callback(unsigned long data)
{
    struct fw_transaction *t = (struct fw_transaction *)data;
    struct fw_card *card = t->card;
    unsigned long flags;

    spin_lock_irqsave(&card->lock, flags);
    if (list_empty(&t->link)) {
        spin_unlock_irqrestore(&card->lock, flags);
        return;
    }
    list_del(&t->link);
    card->tlabel_mask &= ~(1ULL << t->tlabel);
    spin_unlock_irqrestore(&card->lock, flags);

    t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
}

static void start_split_transaction_timeout(struct fw_transaction *t,
                        struct fw_card *card)
{
    unsigned long flags;

    spin_lock_irqsave(&card->lock, flags);

    if (list_empty(&t->link) || WARN_ON(t->is_split_transaction)) {
        spin_unlock_irqrestore(&card->lock, flags);
        return;
    }

    t->is_split_transaction = true;
    mod_timer(&t->split_timeout_timer,
          jiffies + card->split_timeout_jiffies);

    spin_unlock_irqrestore(&card->lock, flags);
}

static void transmit_complete_callback(struct fw_packet *packet,
                       struct fw_card *card, int status)
{
    struct fw_transaction *t =
        container_of(packet, struct fw_transaction, packet);

    switch (status) {
    case ACK_COMPLETE:
        close_transaction(t, card, RCODE_COMPLETE);
        break;
    case ACK_PENDING:
        start_split_transaction_timeout(t, card);
        break;
    case ACK_BUSY_X:
    case ACK_BUSY_A:
    case ACK_BUSY_B:
        close_transaction(t, card, RCODE_BUSY);
        break;
    case ACK_DATA_ERROR:
        close_transaction(t, card, RCODE_DATA_ERROR);
        break;
    case ACK_TYPE_ERROR:
        close_transaction(t, card, RCODE_TYPE_ERROR);
        break;
    default:
        /*
         * In this case the ack is really a juju specific
         * rcode, so just forward that to the callback.
         */
        close_transaction(t, card, status);
        break;
    }
}

static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
        int destination_id, int source_id, int generation, int speed,
        unsigned long long offset, void *payload, size_t length)
{
    int ext_tcode;

    if (tcode == TCODE_STREAM_DATA) {
        packet->header[0] =
            HEADER_DATA_LENGTH(length) |
            destination_id |
            HEADER_TCODE(TCODE_STREAM_DATA);
        packet->header_length = 4;
        packet->payload = payload;
        packet->payload_length = length;

        goto common;
    }

    if (tcode > 0x10) {
        ext_tcode = tcode & ~0x10;
        tcode = TCODE_LOCK_REQUEST;
    } else
        ext_tcode = 0;

    packet->header[0] =
        HEADER_RETRY(RETRY_X) |
        HEADER_TLABEL(tlabel) |
        HEADER_TCODE(tcode) |
        HEADER_DESTINATION(destination_id);
    packet->header[1] =
        HEADER_OFFSET_HIGH(offset >> 32) | HEADER_SOURCE(source_id);
    packet->header[2] =
        offset;

    switch (tcode) {
    case TCODE_WRITE_QUADLET_REQUEST:
        packet->header[3] = *(u32 *)payload;
        packet->header_length = 16;
        packet->payload_length = 0;
        break;

    case TCODE_LOCK_REQUEST:
    case TCODE_WRITE_BLOCK_REQUEST:
        packet->header[3] =
            HEADER_DATA_LENGTH(length) |
            HEADER_EXTENDED_TCODE(ext_tcode);
        packet->header_length = 16;
        packet->payload = payload;
        packet->payload_length = length;
        break;

    case TCODE_READ_QUADLET_REQUEST:
        packet->header_length = 12;
        packet->payload_length = 0;
        break;

    case TCODE_READ_BLOCK_REQUEST:
        packet->header[3] =
            HEADER_DATA_LENGTH(length) |
            HEADER_EXTENDED_TCODE(ext_tcode);
        packet->header_length = 16;
        packet->payload_length = 0;
        break;

    default:
        WARN(1, "wrong tcode %d\n", tcode);
    }
 common:
    packet->speed = speed;
    packet->generation = generation;
    packet->ack = 0;
    packet->payload_mapped = false;
}

static int allocate_tlabel(struct fw_card *card)
{
    int tlabel;

    tlabel = card->current_tlabel;
    while (card->tlabel_mask & (1ULL << tlabel)) {
        tlabel = (tlabel + 1) & 0x3f;
        if (tlabel == card->current_tlabel)
            return -EBUSY;
    }

    card->current_tlabel = (tlabel + 1) & 0x3f;
    card->tlabel_mask |= 1ULL << tlabel;

    return tlabel;
}

void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
             int destination_id, int generation, int speed,
             unsigned long long offset, void *payload, size_t length,
             fw_transaction_callback_t callback, void *callback_data)
{
    unsigned long flags;
    int tlabel;

    /*
     * Allocate tlabel from the bitmap and put the transaction on
     * the list while holding the card spinlock.
     */

    spin_lock_irqsave(&card->lock, flags);

    tlabel = allocate_tlabel(card);
    if (tlabel < 0) {
        spin_unlock_irqrestore(&card->lock, flags);
        callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
        return;
    }

    t->node_id = destination_id;
    t->tlabel = tlabel;
    t->card = card;
    t->is_split_transaction = false;
    setup_timer(&t->split_timeout_timer,
            split_transaction_timeout_callback, (unsigned long)t);
    t->callback = callback;
    t->callback_data = callback_data;

    fw_fill_request(&t->packet, tcode, t->tlabel,
            destination_id, card->node_id, generation,
            speed, offset, payload, length);
    t->packet.callback = transmit_complete_callback;

    list_add_tail(&t->link, &card->transaction_list);

    spin_unlock_irqrestore(&card->lock, flags);

    card->driver->send_request(card, &t->packet);
}
EXPORT_SYMBOL(fw_send_request);

struct transaction_callback_data {
    struct completion done;
    void *payload;
    int rcode;
};

static void transaction_callback(struct fw_card *card, int rcode,
                 void *payload, size_t length, void *data)
{
    struct transaction_callback_data *d = data;

    if (rcode == RCODE_COMPLETE)
        memcpy(d->payload, payload, length);
    d->rcode = rcode;
    complete(&d->done);
}

int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
               int generation, int speed, unsigned long long offset,
               void *payload, size_t length)
{
    struct transaction_callback_data d;
    struct fw_transaction t;

    init_timer_on_stack(&t.split_timeout_timer);
    init_completion(&d.done);
    d.payload = payload;
    fw_send_request(card, &t, tcode, destination_id, generation, speed,
            offset, payload, length, transaction_callback, &d);
    wait_for_completion(&d.done);
    destroy_timer_on_stack(&t.split_timeout_timer);

    return d.rcode;
}
EXPORT_SYMBOL(fw_run_transaction);

static DEFINE_MUTEX(phy_config_mutex);
static DECLARE_COMPLETION(phy_config_done);

static void transmit_phy_packet_callback(struct fw_packet *packet,
                     struct fw_card *card, int status)
{
    complete(&phy_config_done);
}

static struct fw_packet phy_config_packet = {
    .header_length  = 12,
    .header[0]  = TCODE_LINK_INTERNAL << 4,
    .payload_length = 0,
    .speed      = SCODE_100,
    .callback   = transmit_phy_packet_callback,
};

void fw_send_phy_config(struct fw_card *card,
            int node_id, int generation, int gap_count)
{
    long timeout = DIV_ROUND_UP(HZ, 10);
    u32 data = PHY_IDENTIFIER(PHY_PACKET_CONFIG);

    if (node_id != FW_PHY_CONFIG_NO_NODE_ID)
        data |= PHY_CONFIG_ROOT_ID(node_id);

    if (gap_count == FW_PHY_CONFIG_CURRENT_GAP_COUNT) {
        gap_count = card->driver->read_phy_reg(card, 1);
        if (gap_count < 0)
            return;

        gap_count &= 63;
        if (gap_count == 63)
            return;
    }
    data |= PHY_CONFIG_GAP_COUNT(gap_count);

    mutex_lock(&phy_config_mutex);

    phy_config_packet.header[1] = data;
    phy_config_packet.header[2] = ~data;
    phy_config_packet.generation = generation;
    INIT_COMPLETION(phy_config_done);

    card->driver->send_request(card, &phy_config_packet);
    wait_for_completion_timeout(&phy_config_done, timeout);

    mutex_unlock(&phy_config_mutex);
}

static struct fw_address_handler *lookup_overlapping_address_handler(
    struct list_head *list, unsigned long long offset, size_t length)
{
    struct fw_address_handler *handler;

    list_for_each_entry_rcu(handler, list, link) {
        if (handler->offset < offset + length &&
            offset < handler->offset + handler->length)
            return handler;
    }

    return NULL;
}

static bool is_enclosing_handler(struct fw_address_handler *handler,
                 unsigned long long offset, size_t length)
{
    return handler->offset <= offset &&
        offset + length <= handler->offset + handler->length;
}

static struct fw_address_handler *lookup_enclosing_address_handler(
    struct list_head *list, unsigned long long offset, size_t length)
{
    struct fw_address_handler *handler;

    list_for_each_entry_rcu(handler, list, link) {
        if (is_enclosing_handler(handler, offset, length))
            return handler;
    }

    return NULL;
}

static DEFINE_SPINLOCK(address_handler_list_lock);
static LIST_HEAD(address_handler_list);

const struct fw_address_region fw_high_memory_region =
    { .start = 0x000100000000ULL, .end = 0xffffe0000000ULL,  };
EXPORT_SYMBOL(fw_high_memory_region);

static const struct fw_address_region low_memory_region =
    { .start = 0x000000000000ULL, .end = 0x000100000000ULL,  };

#if 0
const struct fw_address_region fw_private_region =
    { .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
const struct fw_address_region fw_csr_region =
    { .start = CSR_REGISTER_BASE,
      .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM_END,  };
const struct fw_address_region fw_unit_space_region =
    { .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
#endif  /*  0  */

static bool is_in_fcp_region(u64 offset, size_t length)
{
    return offset >= (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
        offset + length <= (CSR_REGISTER_BASE | CSR_FCP_END);
}

int fw_core_add_address_handler(struct fw_address_handler *handler,
                const struct fw_address_region *region)
{
    struct fw_address_handler *other;
    int ret = -EBUSY;

    if (region->start & 0xffff000000000003ULL ||
        region->start >= region->end ||
        region->end   > 0x0001000000000000ULL ||
        handler->length & 3 ||
        handler->length == 0)
        return -EINVAL;

    spin_lock(&address_handler_list_lock);

    handler->offset = region->start;
    while (handler->offset + handler->length <= region->end) {
        if (is_in_fcp_region(handler->offset, handler->length))
            other = NULL;
        else
            other = lookup_overlapping_address_handler
                    (&address_handler_list,
                     handler->offset, handler->length);
        if (other != NULL) {
            handler->offset += other->length;
        } else {
            list_add_tail_rcu(&handler->link, &address_handler_list);
            ret = 0;
            break;
        }
    }

    spin_unlock(&address_handler_list_lock);

    return ret;
}
EXPORT_SYMBOL(fw_core_add_address_handler);

void fw_core_remove_address_handler(struct fw_address_handler *handler)
{
    spin_lock(&address_handler_list_lock);
    list_del_rcu(&handler->link);
    spin_unlock(&address_handler_list_lock);
    synchronize_rcu();
}
EXPORT_SYMBOL(fw_core_remove_address_handler);

struct fw_request {
    struct fw_packet response;
    u32 request_header[4];
    int ack;
    u32 length;
    u32 data[0];
};

static void free_response_callback(struct fw_packet *packet,
                   struct fw_card *card, int status)
{
    struct fw_request *request;

    request = container_of(packet, struct fw_request, response);
    kfree(request);
}

int fw_get_response_length(struct fw_request *r)
{
    int tcode, ext_tcode, data_length;

    tcode = HEADER_GET_TCODE(r->request_header[0]);

    switch (tcode) {
    case TCODE_WRITE_QUADLET_REQUEST:
    case TCODE_WRITE_BLOCK_REQUEST:
        return 0;

    case TCODE_READ_QUADLET_REQUEST:
        return 4;

    case TCODE_READ_BLOCK_REQUEST:
        data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
        return data_length;

    case TCODE_LOCK_REQUEST:
        ext_tcode = HEADER_GET_EXTENDED_TCODE(r->request_header[3]);
        data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
        switch (ext_tcode) {
        case EXTCODE_FETCH_ADD:
        case EXTCODE_LITTLE_ADD:
            return data_length;
        default:
            return data_length / 2;
        }

    default:
        WARN(1, "wrong tcode %d\n", tcode);
        return 0;
    }
}

void fw_fill_response(struct fw_packet *response, u32 *request_header,
              int rcode, void *payload, size_t length)
{
    int tcode, tlabel, extended_tcode, source, destination;

    tcode          = HEADER_GET_TCODE(request_header[0]);
    tlabel         = HEADER_GET_TLABEL(request_header[0]);
    source         = HEADER_GET_DESTINATION(request_header[0]);
    destination    = HEADER_GET_SOURCE(request_header[1]);
    extended_tcode = HEADER_GET_EXTENDED_TCODE(request_header[3]);

    response->header[0] =
        HEADER_RETRY(RETRY_1) |
        HEADER_TLABEL(tlabel) |
        HEADER_DESTINATION(destination);
    response->header[1] =
        HEADER_SOURCE(source) |
        HEADER_RCODE(rcode);
    response->header[2] = 0;

    switch (tcode) {
    case TCODE_WRITE_QUADLET_REQUEST:
    case TCODE_WRITE_BLOCK_REQUEST:
        response->header[0] |= HEADER_TCODE(TCODE_WRITE_RESPONSE);
        response->header_length = 12;
        response->payload_length = 0;
        break;

    case TCODE_READ_QUADLET_REQUEST:
        response->header[0] |=
            HEADER_TCODE(TCODE_READ_QUADLET_RESPONSE);
        if (payload != NULL)
            response->header[3] = *(u32 *)payload;
        else
            response->header[3] = 0;
        response->header_length = 16;
        response->payload_length = 0;
        break;

    case TCODE_READ_BLOCK_REQUEST:
    case TCODE_LOCK_REQUEST:
        response->header[0] |= HEADER_TCODE(tcode + 2);
        response->header[3] =
            HEADER_DATA_LENGTH(length) |
            HEADER_EXTENDED_TCODE(extended_tcode);
        response->header_length = 16;
        response->payload = payload;
        response->payload_length = length;
        break;

    default:
        WARN(1, "wrong tcode %d\n", tcode);
    }

    response->payload_mapped = false;
}
EXPORT_SYMBOL(fw_fill_response);

static u32 compute_split_timeout_timestamp(struct fw_card *card,
                       u32 request_timestamp)
{
    unsigned int cycles;
    u32 timestamp;

    cycles = card->split_timeout_cycles;
    cycles += request_timestamp & 0x1fff;

    timestamp = request_timestamp & ~0x1fff;
    timestamp += (cycles / 8000) << 13;
    timestamp |= cycles % 8000;

    return timestamp;
}

static struct fw_request *allocate_request(struct fw_card *card,
                       struct fw_packet *p)
{
    struct fw_request *request;
    u32 *data, length;
    int request_tcode;

    request_tcode = HEADER_GET_TCODE(p->header[0]);
    switch (request_tcode) {
    case TCODE_WRITE_QUADLET_REQUEST:
        data = &p->header[3];
        length = 4;
        break;

    case TCODE_WRITE_BLOCK_REQUEST:
    case TCODE_LOCK_REQUEST:
        data = p->payload;
        length = HEADER_GET_DATA_LENGTH(p->header[3]);
        break;

    case TCODE_READ_QUADLET_REQUEST:
        data = NULL;
        length = 4;
        break;

    case TCODE_READ_BLOCK_REQUEST:
        data = NULL;
        length = HEADER_GET_DATA_LENGTH(p->header[3]);
        break;

    default:
        fw_notice(card, "ERROR - corrupt request received - %08x %08x %08x\n",
             p->header[0], p->header[1], p->header[2]);
        return NULL;
    }

    request = kmalloc(sizeof(*request) + length, GFP_ATOMIC);
    if (request == NULL)
        return NULL;

    request->response.speed = p->speed;
    request->response.timestamp =
            compute_split_timeout_timestamp(card, p->timestamp);
    request->response.generation = p->generation;
    request->response.ack = 0;
    request->response.callback = free_response_callback;
    request->ack = p->ack;
    request->length = length;
    if (data)
        memcpy(request->data, data, length);

    memcpy(request->request_header, p->header, sizeof(p->header));

    return request;
}

void fw_send_response(struct fw_card *card,
              struct fw_request *request, int rcode)
{
    if (WARN_ONCE(!request, "invalid for FCP address handlers"))
        return;

    /* unified transaction or broadcast transaction: don't respond */
    if (request->ack != ACK_PENDING ||
        HEADER_DESTINATION_IS_BROADCAST(request->request_header[0])) {
        kfree(request);
        return;
    }

    if (rcode == RCODE_COMPLETE)
        fw_fill_response(&request->response, request->request_header,
                 rcode, request->data,
                 fw_get_response_length(request));
    else
        fw_fill_response(&request->response, request->request_header,
                 rcode, NULL, 0);

    card->driver->send_response(card, &request->response);
}
EXPORT_SYMBOL(fw_send_response);

int fw_get_request_speed(struct fw_request *request)
{
    return request->response.speed;
}
EXPORT_SYMBOL(fw_get_request_speed);

static void handle_exclusive_region_request(struct fw_card *card,
                        struct fw_packet *p,
                        struct fw_request *request,
                        unsigned long long offset)
{
    struct fw_address_handler *handler;
    int tcode, destination, source;

    destination = HEADER_GET_DESTINATION(p->header[0]);
    source      = HEADER_GET_SOURCE(p->header[1]);
    tcode       = HEADER_GET_TCODE(p->header[0]);
    if (tcode == TCODE_LOCK_REQUEST)
        tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);

    rcu_read_lock();
    handler = lookup_enclosing_address_handler(&address_handler_list,
                           offset, request->length);
    if (handler)
        handler->address_callback(card, request,
                      tcode, destination, source,
                      p->generation, offset,
                      request->data, request->length,
                      handler->callback_data);
    rcu_read_unlock();

    if (!handler)
        fw_send_response(card, request, RCODE_ADDRESS_ERROR);
}

static void handle_fcp_region_request(struct fw_card *card,
                      struct fw_packet *p,
                      struct fw_request *request,
                      unsigned long long offset)
{
    struct fw_address_handler *handler;
    int tcode, destination, source;

    if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
         offset != (CSR_REGISTER_BASE | CSR_FCP_RESPONSE)) ||
        request->length > 0x200) {
        fw_send_response(card, request, RCODE_ADDRESS_ERROR);

        return;
    }

    tcode       = HEADER_GET_TCODE(p->header[0]);
    destination = HEADER_GET_DESTINATION(p->header[0]);
    source      = HEADER_GET_SOURCE(p->header[1]);

    if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
        tcode != TCODE_WRITE_BLOCK_REQUEST) {
        fw_send_response(card, request, RCODE_TYPE_ERROR);

        return;
    }

    rcu_read_lock();
    list_for_each_entry_rcu(handler, &address_handler_list, link) {
        if (is_enclosing_handler(handler, offset, request->length))
            handler->address_callback(card, NULL, tcode,
                          destination, source,
                          p->generation, offset,
                          request->data,
                          request->length,
                          handler->callback_data);
    }
    rcu_read_unlock();

    fw_send_response(card, request, RCODE_COMPLETE);
}

void fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
{
    struct fw_request *request;
    unsigned long long offset;

    if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
        return;

    if (TCODE_IS_LINK_INTERNAL(HEADER_GET_TCODE(p->header[0]))) {
        fw_cdev_handle_phy_packet(card, p);
        return;
    }

    request = allocate_request(card, p);
    if (request == NULL) {
        /* FIXME: send statically allocated busy packet. */
        return;
    }

    offset = ((u64)HEADER_GET_OFFSET_HIGH(p->header[1]) << 32) |
        p->header[2];

    if (!is_in_fcp_region(offset, request->length))
        handle_exclusive_region_request(card, p, request, offset);
    else
        handle_fcp_region_request(card, p, request, offset);

}
EXPORT_SYMBOL(fw_core_handle_request);

void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
{
    struct fw_transaction *t;
    unsigned long flags;
    u32 *data;
    size_t data_length;
    int tcode, tlabel, source, rcode;

    tcode   = HEADER_GET_TCODE(p->header[0]);
    tlabel  = HEADER_GET_TLABEL(p->header[0]);
    source  = HEADER_GET_SOURCE(p->header[1]);
    rcode   = HEADER_GET_RCODE(p->header[1]);

    spin_lock_irqsave(&card->lock, flags);
    list_for_each_entry(t, &card->transaction_list, link) {
        if (t->node_id == source && t->tlabel == tlabel) {
            if (!try_cancel_split_timeout(t)) {
                spin_unlock_irqrestore(&card->lock, flags);
                goto timed_out;
            }
            list_del_init(&t->link);
            card->tlabel_mask &= ~(1ULL << t->tlabel);
            break;
        }
    }
    spin_unlock_irqrestore(&card->lock, flags);

    if (&t->link == &card->transaction_list) {
 timed_out:
        fw_notice(card, "unsolicited response (source %x, tlabel %x)\n",
              source, tlabel);
        return;
    }

    /*
     * FIXME: sanity check packet, is length correct, does tcodes
     * and addresses match.
     */

    switch (tcode) {
    case TCODE_READ_QUADLET_RESPONSE:
        data = (u32 *) &p->header[3];
        data_length = 4;
        break;

    case TCODE_WRITE_RESPONSE:
        data = NULL;
        data_length = 0;
        break;

    case TCODE_READ_BLOCK_RESPONSE:
    case TCODE_LOCK_RESPONSE:
        data = p->payload;
        data_length = HEADER_GET_DATA_LENGTH(p->header[3]);
        break;

    default:
        /* Should never happen, this is just to shut up gcc. */
        data = NULL;
        data_length = 0;
        break;
    }

    /*
     * The response handler may be executed while the request handler
     * is still pending.  Cancel the request handler.
     */
    card->driver->cancel_packet(card, &t->packet);

    t->callback(card, rcode, data, data_length, t->callback_data);
}
EXPORT_SYMBOL(fw_core_handle_response);

const char *fw_rcode_string(int rcode)
{
    static const char *const names[] = {
        [RCODE_COMPLETE]       = "no error",
        [RCODE_CONFLICT_ERROR] = "conflict error",
        [RCODE_DATA_ERROR]     = "data error",
        [RCODE_TYPE_ERROR]     = "type error",
        [RCODE_ADDRESS_ERROR]  = "address error",
        [RCODE_SEND_ERROR]     = "send error",
        [RCODE_CANCELLED]      = "timeout",
        [RCODE_BUSY]           = "busy",
        [RCODE_GENERATION]     = "bus reset",
        [RCODE_NO_ACK]         = "no ack",
    };

    if ((unsigned int)rcode < ARRAY_SIZE(names) && names[rcode])
        return names[rcode];
    else
        return "unknown";
}
EXPORT_SYMBOL(fw_rcode_string);

static const struct fw_address_region topology_map_region =
    { .start = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP,
      .end   = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP_END, };

static void handle_topology_map(struct fw_card *card, struct fw_request *request,
        int tcode, int destination, int source, int generation,
        unsigned long long offset, void *payload, size_t length,
        void *callback_data)
{
    int start;

    if (!TCODE_IS_READ_REQUEST(tcode)) {
        fw_send_response(card, request, RCODE_TYPE_ERROR);
        return;
    }

    if ((offset & 3) > 0 || (length & 3) > 0) {
        fw_send_response(card, request, RCODE_ADDRESS_ERROR);
        return;
    }

    start = (offset - topology_map_region.start) / 4;
    memcpy(payload, &card->topology_map[start], length);

    fw_send_response(card, request, RCODE_COMPLETE);
}

static struct fw_address_handler topology_map = {
    .length         = 0x400,
    .address_callback   = handle_topology_map,
};

static const struct fw_address_region registers_region =
    { .start = CSR_REGISTER_BASE,
      .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM, };

static void update_split_timeout(struct fw_card *card)
{
    unsigned int cycles;

    cycles = card->split_timeout_hi * 8000 + (card->split_timeout_lo >> 19);

    /* minimum per IEEE 1394, maximum which doesn't overflow OHCI */
    cycles = clamp(cycles, 800u, 3u * 8000u);

    card->split_timeout_cycles = cycles;
    card->split_timeout_jiffies = DIV_ROUND_UP(cycles * HZ, 8000);
}

static void handle_registers(struct fw_card *card, struct fw_request *request,
        int tcode, int destination, int source, int generation,
        unsigned long long offset, void *payload, size_t length,
        void *callback_data)
{
    int reg = offset & ~CSR_REGISTER_BASE;
    __be32 *data = payload;
    int rcode = RCODE_COMPLETE;
    unsigned long flags;

    switch (reg) {
    case CSR_PRIORITY_BUDGET:
        if (!card->priority_budget_implemented) {
            rcode = RCODE_ADDRESS_ERROR;
            break;
        }
        /* else fall through */

    case CSR_NODE_IDS:
        /*
         * per IEEE 1394-2008 8.3.22.3, not IEEE 1394.1-2004 3.2.8
         * and 9.6, but interoperable with IEEE 1394.1-2004 bridges
         */
        /* fall through */

    case CSR_STATE_CLEAR:
    case CSR_STATE_SET:
    case CSR_CYCLE_TIME:
    case CSR_BUS_TIME:
    case CSR_BUSY_TIMEOUT:
        if (tcode == TCODE_READ_QUADLET_REQUEST)
            *data = cpu_to_be32(card->driver->read_csr(card, reg));
        else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
            card->driver->write_csr(card, reg, be32_to_cpu(*data));
        else
            rcode = RCODE_TYPE_ERROR;
        break;

    case CSR_RESET_START:
        if (tcode == TCODE_WRITE_QUADLET_REQUEST)
            card->driver->write_csr(card, CSR_STATE_CLEAR,
                        CSR_STATE_BIT_ABDICATE);
        else
            rcode = RCODE_TYPE_ERROR;
        break;

    case CSR_SPLIT_TIMEOUT_HI:
        if (tcode == TCODE_READ_QUADLET_REQUEST) {
            *data = cpu_to_be32(card->split_timeout_hi);
        } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
            spin_lock_irqsave(&card->lock, flags);
            card->split_timeout_hi = be32_to_cpu(*data) & 7;
            update_split_timeout(card);
            spin_unlock_irqrestore(&card->lock, flags);
        } else {
            rcode = RCODE_TYPE_ERROR;
        }
        break;

    case CSR_SPLIT_TIMEOUT_LO:
        if (tcode == TCODE_READ_QUADLET_REQUEST) {
            *data = cpu_to_be32(card->split_timeout_lo);
        } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
            spin_lock_irqsave(&card->lock, flags);
            card->split_timeout_lo =
                    be32_to_cpu(*data) & 0xfff80000;
            update_split_timeout(card);
            spin_unlock_irqrestore(&card->lock, flags);
        } else {
            rcode = RCODE_TYPE_ERROR;
        }
        break;

    case CSR_MAINT_UTILITY:
        if (tcode == TCODE_READ_QUADLET_REQUEST)
            *data = card->maint_utility_register;
        else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
            card->maint_utility_register = *data;
        else
            rcode = RCODE_TYPE_ERROR;
        break;

    case CSR_BROADCAST_CHANNEL:
        if (tcode == TCODE_READ_QUADLET_REQUEST)
            *data = cpu_to_be32(card->broadcast_channel);
        else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
            card->broadcast_channel =
                (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
                BROADCAST_CHANNEL_INITIAL;
        else
            rcode = RCODE_TYPE_ERROR;
        break;

    case CSR_BUS_MANAGER_ID:
    case CSR_BANDWIDTH_AVAILABLE:
    case CSR_CHANNELS_AVAILABLE_HI:
    case CSR_CHANNELS_AVAILABLE_LO:
        /*
         * FIXME: these are handled by the OHCI hardware and
         * the stack never sees these request. If we add
         * support for a new type of controller that doesn't
         * handle this in hardware we need to deal with these
         * transactions.
         */
        BUG();
        break;

    default:
        rcode = RCODE_ADDRESS_ERROR;
        break;
    }

    fw_send_response(card, request, rcode);
}

static struct fw_address_handler registers = {
    .length         = 0x400,
    .address_callback   = handle_registers,
};

static void handle_low_memory(struct fw_card *card, struct fw_request *request,
        int tcode, int destination, int source, int generation,
        unsigned long long offset, void *payload, size_t length,
        void *callback_data)
{
    /*
     * This catches requests not handled by the physical DMA unit,
     * i.e., wrong transaction types or unauthorized source nodes.
     */
    fw_send_response(card, request, RCODE_TYPE_ERROR);
}

static struct fw_address_handler low_memory = {
    .length         = 0x000100000000ULL,
    .address_callback   = handle_low_memory,
};

MODULE_AUTHOR("Kristian Hoegsberg <[email protected]>");
MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
MODULE_LICENSE("GPL");

static const u32 vendor_textual_descriptor[] = {
    /* textual descriptor leaf () */
    0x00060000,
    0x00000000,
    0x00000000,
    0x4c696e75,     /* L i n u */
    0x78204669,     /* x   F i */
    0x72657769,     /* r e w i */
    0x72650000,     /* r e     */
};

static const u32 model_textual_descriptor[] = {
    /* model descriptor leaf () */
    0x00030000,
    0x00000000,
    0x00000000,
    0x4a756a75,     /* J u j u */
};

static struct fw_descriptor vendor_id_descriptor = {
    .length = ARRAY_SIZE(vendor_textual_descriptor),
    .immediate = 0x03d00d1e,
    .key = 0x81000000,
    .data = vendor_textual_descriptor,
};

static struct fw_descriptor model_id_descriptor = {
    .length = ARRAY_SIZE(model_textual_descriptor),
    .immediate = 0x17000001,
    .key = 0x81000000,
    .data = model_textual_descriptor,
};

static int __init fw_core_init(void)
{
    int ret;

    fw_workqueue = alloc_workqueue("firewire",
                       WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
    if (!fw_workqueue)
        return -ENOMEM;

    ret = bus_register(&fw_bus_type);
    if (ret < 0) {
        destroy_workqueue(fw_workqueue);
        return ret;
    }

    fw_cdev_major = register_chrdev(0, "firewire", &fw_device_ops);
    if (fw_cdev_major < 0) {
        bus_unregister(&fw_bus_type);
        destroy_workqueue(fw_workqueue);
        return fw_cdev_major;
    }

    fw_core_add_address_handler(&topology_map, &topology_map_region);
    fw_core_add_address_handler(&registers, &registers_region);
    fw_core_add_address_handler(&low_memory, &low_memory_region);
    fw_core_add_descriptor(&vendor_id_descriptor);
    fw_core_add_descriptor(&model_id_descriptor);

    return 0;
}

static void __exit fw_core_cleanup(void)
{
    unregister_chrdev(fw_cdev_major, "firewire");
    bus_unregister(&fw_bus_type);
    destroy_workqueue(fw_workqueue);
    idr_destroy(&fw_device_idr);
}

module_init(fw_core_init);
module_exit(fw_core_cleanup);