Save sram context after changing MPU, DSP or core clocks

[linux-ginger.git] / drivers / ieee1394 / ieee1394_core.c

/*
 * IEEE 1394 for Linux
 *
 * Core support: hpsb_packet management, packet handling and forwarding to
 *               highlevel or lowlevel code
 *
 * Copyright (C) 1999, 2000 Andreas E. Bombe
 *                     2002 Manfred Weihs <weihs@ict.tuwien.ac.at>
 *
 * This code is licensed under the GPL.  See the file COPYING in the root
 * directory of the kernel sources for details.
 *
 *
 * Contributions:
 *
 * Manfred Weihs <weihs@ict.tuwien.ac.at>
 *        loopback functionality in hpsb_send_packet
 *        allow highlevel drivers to disable automatic response generation
 *              and to generate responses themselves (deferred)
 *
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/bitops.h>
#include <linux/kdev_t.h>
#include <linux/freezer.h>
#include <linux/suspend.h>
#include <linux/kthread.h>
#include <linux/preempt.h>
#include <linux/time.h>

#include <asm/system.h>
#include <asm/byteorder.h>

#include "ieee1394_types.h"
#include "ieee1394.h"
#include "hosts.h"
#include "ieee1394_core.h"
#include "highlevel.h"
#include "ieee1394_transactions.h"
#include "csr.h"
#include "nodemgr.h"
#include "dma.h"
#include "iso.h"
#include "config_roms.h"

/*
 * Disable the nodemgr detection and config rom reading functionality.
 */
static int disable_nodemgr;
module_param(disable_nodemgr, int, 0444);
MODULE_PARM_DESC(disable_nodemgr, "Disable nodemgr functionality.");

/* Disable Isochronous Resource Manager functionality */
int hpsb_disable_irm = 0;
module_param_named(disable_irm, hpsb_disable_irm, bool, 0444);
MODULE_PARM_DESC(disable_irm,
                 "Disable Isochronous Resource Manager functionality.");

/* We are GPL, so treat us special */
MODULE_LICENSE("GPL");

/* Some globals used */
const char *hpsb_speedto_str[] = { "S100", "S200", "S400", "S800", "S1600", "S3200" };
struct class *hpsb_protocol_class;

#ifdef CONFIG_IEEE1394_VERBOSEDEBUG
static void dump_packet(const char *text, quadlet_t *data, int size, int speed)
{
        int i;

        size /= 4;
        size = (size > 4 ? 4 : size);

        printk(KERN_DEBUG "ieee1394: %s", text);
        if (speed > -1 && speed < 6)
                printk(" at %s", hpsb_speedto_str[speed]);
        printk(":");
        for (i = 0; i < size; i++)
                printk(" %08x", data[i]);
        printk("\n");
}
#else
#define dump_packet(a,b,c,d) do {} while (0)
#endif

static void abort_requests(struct hpsb_host *host);
static void queue_packet_complete(struct hpsb_packet *packet);


/**
 * hpsb_set_packet_complete_task - set task that runs when a packet completes
 * @packet: the packet whose completion we want the task added to
 * @routine: function to call
 * @data: data (if any) to pass to the above function
 *
 * Set the task that runs when a packet completes. You cannot call this more
 * than once on a single packet before it is sent.
 *
 * Typically, the complete @routine is responsible to call hpsb_free_packet().
 */
void hpsb_set_packet_complete_task(struct hpsb_packet *packet,
                                   void (*routine)(void *), void *data)
{
        WARN_ON(packet->complete_routine != NULL);
        packet->complete_routine = routine;
        packet->complete_data = data;
        return;
}

/**
 * hpsb_alloc_packet - allocate new packet structure
 * @data_size: size of the data block to be allocated, in bytes
 *
 * This function allocates, initializes and returns a new &struct hpsb_packet.
 * It can be used in interrupt context.  A header block is always included and
 * initialized with zeros.  Its size is big enough to contain all possible 1394
 * headers.  The data block is only allocated if @data_size is not zero.
 *
 * For packets for which responses will be received the @data_size has to be big
 * enough to contain the response's data block since no further allocation
 * occurs at response matching time.
 *
 * The packet's generation value will be set to the current generation number
 * for ease of use.  Remember to overwrite it with your own recorded generation
 * number if you can not be sure that your code will not race with a bus reset.
 *
 * Return value: A pointer to a &struct hpsb_packet or NULL on allocation
 * failure.
 */
struct hpsb_packet *hpsb_alloc_packet(size_t data_size)
{
        struct hpsb_packet *packet;

        data_size = ((data_size + 3) & ~3);

        packet = kzalloc(sizeof(*packet) + data_size, GFP_ATOMIC);
        if (!packet)
                return NULL;

        packet->state = hpsb_unused;
        packet->generation = -1;
        INIT_LIST_HEAD(&packet->driver_list);
        INIT_LIST_HEAD(&packet->queue);
        atomic_set(&packet->refcnt, 1);

        if (data_size) {
                packet->data = packet->embedded_data;
                packet->allocated_data_size = data_size;
        }
        return packet;
}

/**
 * hpsb_free_packet - free packet and data associated with it
 * @packet: packet to free (is NULL safe)
 *
 * Frees @packet->data only if it was allocated through hpsb_alloc_packet().
 */
void hpsb_free_packet(struct hpsb_packet *packet)
{
        if (packet && atomic_dec_and_test(&packet->refcnt)) {
                BUG_ON(!list_empty(&packet->driver_list) ||
                       !list_empty(&packet->queue));
                kfree(packet);
        }
}

/**
 * hpsb_reset_bus - initiate bus reset on the given host
 * @host: host controller whose bus to reset
 * @type: one of enum reset_types
 *
 * Returns 1 if bus reset already in progress, 0 otherwise.
 */
int hpsb_reset_bus(struct hpsb_host *host, int type)
{
        if (!host->in_bus_reset) {
                host->driver->devctl(host, RESET_BUS, type);
                return 0;
        } else {
                return 1;
        }
}

/**
 * hpsb_read_cycle_timer - read cycle timer register and system time
 * @host: host whose isochronous cycle timer register is read
 * @cycle_timer: address of bitfield to return the register contents
 * @local_time: address to return the system time
 *
 * The format of * @cycle_timer, is described in OHCI 1.1 clause 5.13. This
 * format is also read from non-OHCI controllers. * @local_time contains the
 * system time in microseconds since the Epoch, read at the moment when the
 * cycle timer was read.
 *
 * Return value: 0 for success or error number otherwise.
 */
int hpsb_read_cycle_timer(struct hpsb_host *host, u32 *cycle_timer,
                          u64 *local_time)
{
        int ctr;
        struct timeval tv;
        unsigned long flags;

        if (!host || !cycle_timer || !local_time)
                return -EINVAL;

        preempt_disable();
        local_irq_save(flags);

        ctr = host->driver->devctl(host, GET_CYCLE_COUNTER, 0);
        if (ctr)
                do_gettimeofday(&tv);

        local_irq_restore(flags);
        preempt_enable();

        if (!ctr)
                return -EIO;
        *cycle_timer = ctr;
        *local_time = tv.tv_sec * 1000000ULL + tv.tv_usec;
        return 0;
}

/**
 * hpsb_bus_reset - notify a bus reset to the core
 *
 * For host driver module usage.  Safe to use in interrupt context, although
 * quite complex; so you may want to run it in the bottom rather than top half.
 *
 * Returns 1 if bus reset already in progress, 0 otherwise.
 */
int hpsb_bus_reset(struct hpsb_host *host)
{
        if (host->in_bus_reset) {
                HPSB_NOTICE("%s called while bus reset already in progress",
                            __func__);
                return 1;
        }

        abort_requests(host);
        host->in_bus_reset = 1;
        host->irm_id = -1;
        host->is_irm = 0;
        host->busmgr_id = -1;
        host->is_busmgr = 0;
        host->is_cycmst = 0;
        host->node_count = 0;
        host->selfid_count = 0;

        return 0;
}


/*
 * Verify num_of_selfids SelfIDs and return number of nodes.  Return zero in
 * case verification failed.
 */
static int check_selfids(struct hpsb_host *host)
{
        int nodeid = -1;
        int rest_of_selfids = host->selfid_count;
        struct selfid *sid = (struct selfid *)host->topology_map;
        struct ext_selfid *esid;
        int esid_seq = 23;

        host->nodes_active = 0;

        while (rest_of_selfids--) {
                if (!sid->extended) {
                        nodeid++;
                        esid_seq = 0;

                        if (sid->phy_id != nodeid) {
                                HPSB_INFO("SelfIDs failed monotony check with "
                                          "%d", sid->phy_id);
                                return 0;
                        }

                        if (sid->link_active) {
                                host->nodes_active++;
                                if (sid->contender)
                                        host->irm_id = LOCAL_BUS | sid->phy_id;
                        }
                } else {
                        esid = (struct ext_selfid *)sid;

                        if ((esid->phy_id != nodeid)
                            || (esid->seq_nr != esid_seq)) {
                                HPSB_INFO("SelfIDs failed monotony check with "
                                          "%d/%d", esid->phy_id, esid->seq_nr);
                                return 0;
                        }
                        esid_seq++;
                }
                sid++;
        }

        esid = (struct ext_selfid *)(sid - 1);
        while (esid->extended) {
                if ((esid->porta == SELFID_PORT_PARENT) ||
                    (esid->portb == SELFID_PORT_PARENT) ||
                    (esid->portc == SELFID_PORT_PARENT) ||
                    (esid->portd == SELFID_PORT_PARENT) ||
                    (esid->porte == SELFID_PORT_PARENT) ||
                    (esid->portf == SELFID_PORT_PARENT) ||
                    (esid->portg == SELFID_PORT_PARENT) ||
                    (esid->porth == SELFID_PORT_PARENT)) {
                        HPSB_INFO("SelfIDs failed root check on "
                                  "extended SelfID");
                        return 0;
                }
                esid--;
        }

        sid = (struct selfid *)esid;
        if ((sid->port0 == SELFID_PORT_PARENT) ||
            (sid->port1 == SELFID_PORT_PARENT) ||
            (sid->port2 == SELFID_PORT_PARENT)) {
                HPSB_INFO("SelfIDs failed root check");
                return 0;
        }

        host->node_count = nodeid + 1;
        return 1;
}

static void build_speed_map(struct hpsb_host *host, int nodecount)
{
        u8 cldcnt[nodecount];
        u8 *map = host->speed_map;
        u8 *speedcap = host->speed;
        u8 local_link_speed = host->csr.lnk_spd;
        struct selfid *sid;
        struct ext_selfid *esid;
        int i, j, n;

        for (i = 0; i < (nodecount * 64); i += 64) {
                for (j = 0; j < nodecount; j++) {
                        map[i+j] = IEEE1394_SPEED_MAX;
                }
        }

        for (i = 0; i < nodecount; i++) {
                cldcnt[i] = 0;
        }

        /* find direct children count and speed */
        for (sid = (struct selfid *)&host->topology_map[host->selfid_count-1],
                     n = nodecount - 1;
             (void *)sid >= (void *)host->topology_map; sid--) {
                if (sid->extended) {
                        esid = (struct ext_selfid *)sid;

                        if (esid->porta == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->portb == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->portc == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->portd == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->porte == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->portf == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->portg == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (esid->porth == SELFID_PORT_CHILD) cldcnt[n]++;
                } else {
                        if (sid->port0 == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (sid->port1 == SELFID_PORT_CHILD) cldcnt[n]++;
                        if (sid->port2 == SELFID_PORT_CHILD) cldcnt[n]++;

                        speedcap[n] = sid->speed;
                        if (speedcap[n] > local_link_speed)
                                speedcap[n] = local_link_speed;
                        n--;
                }
        }

        /* set self mapping */
        for (i = 0; i < nodecount; i++) {
                map[64*i + i] = speedcap[i];
        }

        /* fix up direct children count to total children count;
         * also fix up speedcaps for sibling and parent communication */
        for (i = 1; i < nodecount; i++) {
                for (j = cldcnt[i], n = i - 1; j > 0; j--) {
                        cldcnt[i] += cldcnt[n];
                        speedcap[n] = min(speedcap[n], speedcap[i]);
                        n -= cldcnt[n] + 1;
                }
        }

        for (n = 0; n < nodecount; n++) {
                for (i = n - cldcnt[n]; i <= n; i++) {
                        for (j = 0; j < (n - cldcnt[n]); j++) {
                                map[j*64 + i] = map[i*64 + j] =
                                        min(map[i*64 + j], speedcap[n]);
                        }
                        for (j = n + 1; j < nodecount; j++) {
                                map[j*64 + i] = map[i*64 + j] =
                                        min(map[i*64 + j], speedcap[n]);
                        }
                }
        }

        /* assume a maximum speed for 1394b PHYs, nodemgr will correct it */
        if (local_link_speed > SELFID_SPEED_UNKNOWN)
                for (i = 0; i < nodecount; i++)
                        if (speedcap[i] == SELFID_SPEED_UNKNOWN)
                                speedcap[i] = local_link_speed;
}


/**
 * hpsb_selfid_received - hand over received selfid packet to the core
 *
 * For host driver module usage.  Safe to use in interrupt context.
 *
 * The host driver should have done a successful complement check (second
 * quadlet is complement of first) beforehand.
 */
void hpsb_selfid_received(struct hpsb_host *host, quadlet_t sid)
{
        if (host->in_bus_reset) {
                HPSB_VERBOSE("Including SelfID 0x%x", sid);
                host->topology_map[host->selfid_count++] = sid;
        } else {
                HPSB_NOTICE("Spurious SelfID packet (0x%08x) received from bus %d",
                            sid, NODEID_TO_BUS(host->node_id));
        }
}

/**
 * hpsb_selfid_complete - notify completion of SelfID stage to the core
 *
 * For host driver module usage.  Safe to use in interrupt context, although
 * quite complex; so you may want to run it in the bottom rather than top half.
 *
 * Notify completion of SelfID stage to the core and report new physical ID
 * and whether host is root now.
 */
void hpsb_selfid_complete(struct hpsb_host *host, int phyid, int isroot)
{
        if (!host->in_bus_reset)
                HPSB_NOTICE("SelfID completion called outside of bus reset!");

        host->node_id = LOCAL_BUS | phyid;
        host->is_root = isroot;

        if (!check_selfids(host)) {
                if (host->reset_retries++ < 20) {
                        /* selfid stage did not complete without error */
                        HPSB_NOTICE("Error in SelfID stage, resetting");
                        host->in_bus_reset = 0;
                        /* this should work from ohci1394 now... */
                        hpsb_reset_bus(host, LONG_RESET);
                        return;
                } else {
                        HPSB_NOTICE("Stopping out-of-control reset loop");
                        HPSB_NOTICE("Warning - topology map and speed map will not be valid");
                        host->reset_retries = 0;
                }
        } else {
                host->reset_retries = 0;
                build_speed_map(host, host->node_count);
        }

        HPSB_VERBOSE("selfid_complete called with successful SelfID stage "
                     "... irm_id: 0x%X node_id: 0x%X",host->irm_id,host->node_id);

        /* irm_id is kept up to date by check_selfids() */
        if (host->irm_id == host->node_id) {
                host->is_irm = 1;
        } else {
                host->is_busmgr = 0;
                host->is_irm = 0;
        }

        if (isroot) {
                host->driver->devctl(host, ACT_CYCLE_MASTER, 1);
                host->is_cycmst = 1;
        }
        atomic_inc(&host->generation);
        host->in_bus_reset = 0;
        highlevel_host_reset(host);
}

static DEFINE_SPINLOCK(pending_packets_lock);

/**
 * hpsb_packet_sent - notify core of sending a packet
 *
 * For host driver module usage.  Safe to call from within a transmit packet
 * routine.
 *
 * Notify core of sending a packet.  Ackcode is the ack code returned for async
 * transmits or ACKX_SEND_ERROR if the transmission failed completely; ACKX_NONE
 * for other cases (internal errors that don't justify a panic).
 */
void hpsb_packet_sent(struct hpsb_host *host, struct hpsb_packet *packet,
                      int ackcode)
{
        unsigned long flags;

        spin_lock_irqsave(&pending_packets_lock, flags);

        packet->ack_code = ackcode;

        if (packet->no_waiter || packet->state == hpsb_complete) {
                /* if packet->no_waiter, must not have a tlabel allocated */
                spin_unlock_irqrestore(&pending_packets_lock, flags);
                hpsb_free_packet(packet);
                return;
        }

        atomic_dec(&packet->refcnt);    /* drop HC's reference */
        /* here the packet must be on the host->pending_packets queue */

        if (ackcode != ACK_PENDING || !packet->expect_response) {
                packet->state = hpsb_complete;
                list_del_init(&packet->queue);
                spin_unlock_irqrestore(&pending_packets_lock, flags);
                queue_packet_complete(packet);
                return;
        }

        packet->state = hpsb_pending;
        packet->sendtime = jiffies;

        spin_unlock_irqrestore(&pending_packets_lock, flags);

        mod_timer(&host->timeout, jiffies + host->timeout_interval);
}

/**
 * hpsb_send_phy_config - transmit a PHY configuration packet on the bus
 * @host: host that PHY config packet gets sent through
 * @rootid: root whose force_root bit should get set (-1 = don't set force_root)
 * @gapcnt: gap count value to set (-1 = don't set gap count)
 *
 * This function sends a PHY config packet on the bus through the specified
 * host.
 *
 * Return value: 0 for success or negative error number otherwise.
 */
int hpsb_send_phy_config(struct hpsb_host *host, int rootid, int gapcnt)
{
        struct hpsb_packet *packet;
        quadlet_t d = 0;
        int retval = 0;

        if (rootid >= ALL_NODES || rootid < -1 || gapcnt > 0x3f || gapcnt < -1 ||
           (rootid == -1 && gapcnt == -1)) {
                HPSB_DEBUG("Invalid Parameter: rootid = %d   gapcnt = %d",
                           rootid, gapcnt);
                return -EINVAL;
        }

        if (rootid != -1)
                d |= PHYPACKET_PHYCONFIG_R | rootid << PHYPACKET_PORT_SHIFT;
        if (gapcnt != -1)
                d |= PHYPACKET_PHYCONFIG_T | gapcnt << PHYPACKET_GAPCOUNT_SHIFT;

        packet = hpsb_make_phypacket(host, d);
        if (!packet)
                return -ENOMEM;

        packet->generation = get_hpsb_generation(host);
        retval = hpsb_send_packet_and_wait(packet);
        hpsb_free_packet(packet);

        return retval;
}

/**
 * hpsb_send_packet - transmit a packet on the bus
 * @packet: packet to send
 *
 * The packet is sent through the host specified in the packet->host field.
 * Before sending, the packet's transmit speed is automatically determined
 * using the local speed map when it is an async, non-broadcast packet.
 *
 * Possibilities for failure are that host is either not initialized, in bus
 * reset, the packet's generation number doesn't match the current generation
 * number or the host reports a transmit error.
 *
 * Return value: 0 on success, negative errno on failure.
 */
int hpsb_send_packet(struct hpsb_packet *packet)
{
        struct hpsb_host *host = packet->host;

        if (host->is_shutdown)
                return -EINVAL;
        if (host->in_bus_reset ||
            (packet->generation != get_hpsb_generation(host)))
                return -EAGAIN;

        packet->state = hpsb_queued;

        /* This just seems silly to me */
        WARN_ON(packet->no_waiter && packet->expect_response);

        if (!packet->no_waiter || packet->expect_response) {
                unsigned long flags;

                atomic_inc(&packet->refcnt);
                /* Set the initial "sendtime" to 10 seconds from now, to
                   prevent premature expiry.  If a packet takes more than
                   10 seconds to hit the wire, we have bigger problems :) */
                packet->sendtime = jiffies + 10 * HZ;
                spin_lock_irqsave(&pending_packets_lock, flags);
                list_add_tail(&packet->queue, &host->pending_packets);
                spin_unlock_irqrestore(&pending_packets_lock, flags);
        }

        if (packet->node_id == host->node_id) {
                /* it is a local request, so handle it locally */

                quadlet_t *data;
                size_t size = packet->data_size + packet->header_size;

                data = kmalloc(size, GFP_ATOMIC);
                if (!data) {
                        HPSB_ERR("unable to allocate memory for concatenating header and data");
                        return -ENOMEM;
                }

                memcpy(data, packet->header, packet->header_size);

                if (packet->data_size)
                        memcpy(((u8*)data) + packet->header_size, packet->data, packet->data_size);

                dump_packet("send packet local", packet->header, packet->header_size, -1);

                hpsb_packet_sent(host, packet, packet->expect_response ? ACK_PENDING : ACK_COMPLETE);
                hpsb_packet_received(host, data, size, 0);

                kfree(data);

                return 0;
        }

        if (packet->type == hpsb_async &&
            NODEID_TO_NODE(packet->node_id) != ALL_NODES)
                packet->speed_code =
                        host->speed[NODEID_TO_NODE(packet->node_id)];

        dump_packet("send packet", packet->header, packet->header_size, packet->speed_code);

        return host->driver->transmit_packet(host, packet);
}

/* We could just use complete() directly as the packet complete
 * callback, but this is more typesafe, in the sense that we get a
 * compiler error if the prototype for complete() changes. */

static void complete_packet(void *data)
{
        complete((struct completion *) data);
}

/**
 * hpsb_send_packet_and_wait - enqueue packet, block until transaction completes
 * @packet: packet to send
 *
 * Return value: 0 on success, negative errno on failure.
 */
int hpsb_send_packet_and_wait(struct hpsb_packet *packet)
{
        struct completion done;
        int retval;

        init_completion(&done);
        hpsb_set_packet_complete_task(packet, complete_packet, &done);
        retval = hpsb_send_packet(packet);
        if (retval == 0)
                wait_for_completion(&done);

        return retval;
}

static void send_packet_nocare(struct hpsb_packet *packet)
{
        if (hpsb_send_packet(packet) < 0) {
                hpsb_free_packet(packet);
        }
}

static size_t packet_size_to_data_size(size_t packet_size, size_t header_size,
                                       size_t buffer_size, int tcode)
{
        size_t ret = packet_size <= header_size ? 0 : packet_size - header_size;

        if (unlikely(ret > buffer_size))
                ret = buffer_size;

        if (unlikely(ret + header_size != packet_size))
                HPSB_ERR("unexpected packet size %zd (tcode %d), bug?",
                         packet_size, tcode);
        return ret;
}

static void handle_packet_response(struct hpsb_host *host, int tcode,
                                   quadlet_t *data, size_t size)
{
        struct hpsb_packet *packet;
        int tlabel = (data[0] >> 10) & 0x3f;
        size_t header_size;
        unsigned long flags;

        spin_lock_irqsave(&pending_packets_lock, flags);

        list_for_each_entry(packet, &host->pending_packets, queue)
                if (packet->tlabel == tlabel &&
                    packet->node_id == (data[1] >> 16))
                        goto found;

        spin_unlock_irqrestore(&pending_packets_lock, flags);
        HPSB_DEBUG("unsolicited response packet received - %s",
                   "no tlabel match");
        dump_packet("contents", data, 16, -1);
        return;

found:
        switch (packet->tcode) {
        case TCODE_WRITEQ:
        case TCODE_WRITEB:
                if (unlikely(tcode != TCODE_WRITE_RESPONSE))
                        break;
                header_size = 12;
                size = 0;
                goto dequeue;

        case TCODE_READQ:
                if (unlikely(tcode != TCODE_READQ_RESPONSE))
                        break;
                header_size = 16;
                size = 0;
                goto dequeue;

        case TCODE_READB:
                if (unlikely(tcode != TCODE_READB_RESPONSE))
                        break;
                header_size = 16;
                size = packet_size_to_data_size(size, header_size,
                                                packet->allocated_data_size,
                                                tcode);
                goto dequeue;

        case TCODE_LOCK_REQUEST:
                if (unlikely(tcode != TCODE_LOCK_RESPONSE))
                        break;
                header_size = 16;
                size = packet_size_to_data_size(min(size, (size_t)(16 + 8)),
                                                header_size,
                                                packet->allocated_data_size,
                                                tcode);
                goto dequeue;
        }

        spin_unlock_irqrestore(&pending_packets_lock, flags);
        HPSB_DEBUG("unsolicited response packet received - %s",
                   "tcode mismatch");
        dump_packet("contents", data, 16, -1);
        return;

dequeue:
        list_del_init(&packet->queue);
        spin_unlock_irqrestore(&pending_packets_lock, flags);

        if (packet->state == hpsb_queued) {
                packet->sendtime = jiffies;
                packet->ack_code = ACK_PENDING;
        }
        packet->state = hpsb_complete;

        memcpy(packet->header, data, header_size);
        if (size)
                memcpy(packet->data, data + 4, size);

        queue_packet_complete(packet);
}


static struct hpsb_packet *create_reply_packet(struct hpsb_host *host,
                                               quadlet_t *data, size_t dsize)
{
        struct hpsb_packet *p;

        p = hpsb_alloc_packet(dsize);
        if (unlikely(p == NULL)) {
                /* FIXME - send data_error response */
                HPSB_ERR("out of memory, cannot send response packet");
                return NULL;
        }

        p->type = hpsb_async;
        p->state = hpsb_unused;
        p->host = host;
        p->node_id = data[1] >> 16;
        p->tlabel = (data[0] >> 10) & 0x3f;
        p->no_waiter = 1;

        p->generation = get_hpsb_generation(host);

        if (dsize % 4)
                p->data[dsize / 4] = 0;

        return p;
}

#define PREP_ASYNC_HEAD_RCODE(tc) \
        packet->tcode = tc; \
        packet->header[0] = (packet->node_id << 16) | (packet->tlabel << 10) \
                | (1 << 8) | (tc << 4); \
        packet->header[1] = (packet->host->node_id << 16) | (rcode << 12); \
        packet->header[2] = 0

static void fill_async_readquad_resp(struct hpsb_packet *packet, int rcode,
                              quadlet_t data)
{
        PREP_ASYNC_HEAD_RCODE(TCODE_READQ_RESPONSE);
        packet->header[3] = data;
        packet->header_size = 16;
        packet->data_size = 0;
}

static void fill_async_readblock_resp(struct hpsb_packet *packet, int rcode,
                               int length)
{
        if (rcode != RCODE_COMPLETE)
                length = 0;

        PREP_ASYNC_HEAD_RCODE(TCODE_READB_RESPONSE);
        packet->header[3] = length << 16;
        packet->header_size = 16;
        packet->data_size = length + (length % 4 ? 4 - (length % 4) : 0);
}

static void fill_async_write_resp(struct hpsb_packet *packet, int rcode)
{
        PREP_ASYNC_HEAD_RCODE(TCODE_WRITE_RESPONSE);
        packet->header_size = 12;
        packet->data_size = 0;
}

static void fill_async_lock_resp(struct hpsb_packet *packet, int rcode, int extcode,
                          int length)
{
        if (rcode != RCODE_COMPLETE)
                length = 0;

        PREP_ASYNC_HEAD_RCODE(TCODE_LOCK_RESPONSE);
        packet->header[3] = (length << 16) | extcode;
        packet->header_size = 16;
        packet->data_size = length;
}

static void handle_incoming_packet(struct hpsb_host *host, int tcode,
                                   quadlet_t *data, size_t size,
                                   int write_acked)
{
        struct hpsb_packet *packet;
        int length, rcode, extcode;
        quadlet_t buffer;
        nodeid_t source = data[1] >> 16;
        nodeid_t dest = data[0] >> 16;
        u16 flags = (u16) data[0];
        u64 addr;

        /* FIXME?
         * Out-of-bounds lengths are left for highlevel_read|write to cap. */

        switch (tcode) {
        case TCODE_WRITEQ:
                addr = (((u64)(data[1] & 0xffff)) << 32) | data[2];
                rcode = highlevel_write(host, source, dest, data + 3,
                                        addr, 4, flags);
                goto handle_write_request;

        case TCODE_WRITEB:
                addr = (((u64)(data[1] & 0xffff)) << 32) | data[2];
                rcode = highlevel_write(host, source, dest, data + 4,
                                        addr, data[3] >> 16, flags);
handle_write_request:
                if (rcode < 0 || write_acked ||
                    NODEID_TO_NODE(data[0] >> 16) == NODE_MASK)
                        return;
                /* not a broadcast write, reply */
                packet = create_reply_packet(host, data, 0);
                if (packet) {
                        fill_async_write_resp(packet, rcode);
                        send_packet_nocare(packet);
                }
                return;

        case TCODE_READQ:
                addr = (((u64)(data[1] & 0xffff)) << 32) | data[2];
                rcode = highlevel_read(host, source, &buffer, addr, 4, flags);
                if (rcode < 0)
                        return;

                packet = create_reply_packet(host, data, 0);
                if (packet) {
                        fill_async_readquad_resp(packet, rcode, buffer);
                        send_packet_nocare(packet);
                }
                return;

        case TCODE_READB:
                length = data[3] >> 16;
                packet = create_reply_packet(host, data, length);
                if (!packet)
                        return;

                addr = (((u64)(data[1] & 0xffff)) << 32) | data[2];
                rcode = highlevel_read(host, source, packet->data, addr,
                                       length, flags);
                if (rcode < 0) {
                        hpsb_free_packet(packet);
                        return;
                }
                fill_async_readblock_resp(packet, rcode, length);
                send_packet_nocare(packet);
                return;

        case TCODE_LOCK_REQUEST:
                length = data[3] >> 16;
                extcode = data[3] & 0xffff;
                addr = (((u64)(data[1] & 0xffff)) << 32) | data[2];

                packet = create_reply_packet(host, data, 8);
                if (!packet)
                        return;

                if (extcode == 0 || extcode >= 7) {
                        /* let switch default handle error */
                        length = 0;
                }

                switch (length) {
                case 4:
                        rcode = highlevel_lock(host, source, packet->data, addr,
                                               data[4], 0, extcode, flags);
                        fill_async_lock_resp(packet, rcode, extcode, 4);
                        break;
                case 8:
                        if (extcode != EXTCODE_FETCH_ADD &&
                            extcode != EXTCODE_LITTLE_ADD) {
                                rcode = highlevel_lock(host, source,
                                                       packet->data, addr,
                                                       data[5], data[4],
                                                       extcode, flags);
                                fill_async_lock_resp(packet, rcode, extcode, 4);
                        } else {
                                rcode = highlevel_lock64(host, source,
                                             (octlet_t *)packet->data, addr,
                                             *(octlet_t *)(data + 4), 0ULL,
                                             extcode, flags);
                                fill_async_lock_resp(packet, rcode, extcode, 8);
                        }
                        break;
                case 16:
                        rcode = highlevel_lock64(host, source,
                                                 (octlet_t *)packet->data, addr,
                                                 *(octlet_t *)(data + 6),
                                                 *(octlet_t *)(data + 4),
                                                 extcode, flags);
                        fill_async_lock_resp(packet, rcode, extcode, 8);
                        break;
                default:
                        rcode = RCODE_TYPE_ERROR;
                        fill_async_lock_resp(packet, rcode, extcode, 0);
                }

                if (rcode < 0)
                        hpsb_free_packet(packet);
                else
                        send_packet_nocare(packet);
                return;
        }
}

/**
 * hpsb_packet_received - hand over received packet to the core
 *
 * For host driver module usage.
 *
 * The contents of data are expected to be the full packet but with the CRCs
 * left out (data block follows header immediately), with the header (i.e. the
 * first four quadlets) in machine byte order and the data block in big endian.
 * *@data can be safely overwritten after this call.
 *
 * If the packet is a write request, @write_acked is to be set to true if it was
 * ack_complete'd already, false otherwise.  This argument is ignored for any
 * other packet type.
 */
void hpsb_packet_received(struct hpsb_host *host, quadlet_t *data, size_t size,
                          int write_acked)
{
        int tcode;

        if (unlikely(host->in_bus_reset)) {
                HPSB_DEBUG("received packet during reset; ignoring");
                return;
        }

        dump_packet("received packet", data, size, -1);

        tcode = (data[0] >> 4) & 0xf;

        switch (tcode) {
        case TCODE_WRITE_RESPONSE:
        case TCODE_READQ_RESPONSE:
        case TCODE_READB_RESPONSE:
        case TCODE_LOCK_RESPONSE:
                handle_packet_response(host, tcode, data, size);
                break;

        case TCODE_WRITEQ:
        case TCODE_WRITEB:
        case TCODE_READQ:
        case TCODE_READB:
        case TCODE_LOCK_REQUEST:
                handle_incoming_packet(host, tcode, data, size, write_acked);
                break;

        case TCODE_CYCLE_START:
                /* simply ignore this packet if it is passed on */
                break;

        default:
                HPSB_DEBUG("received packet with bogus transaction code %d",
                           tcode);
                break;
        }
}

static void abort_requests(struct hpsb_host *host)
{
        struct hpsb_packet *packet, *p;
        struct list_head tmp;
        unsigned long flags;

        host->driver->devctl(host, CANCEL_REQUESTS, 0);

        INIT_LIST_HEAD(&tmp);
        spin_lock_irqsave(&pending_packets_lock, flags);
        list_splice_init(&host->pending_packets, &tmp);
        spin_unlock_irqrestore(&pending_packets_lock, flags);

        list_for_each_entry_safe(packet, p, &tmp, queue) {
                list_del_init(&packet->queue);
                packet->state = hpsb_complete;
                packet->ack_code = ACKX_ABORTED;
                queue_packet_complete(packet);
        }
}

void abort_timedouts(unsigned long __opaque)
{
        struct hpsb_host *host = (struct hpsb_host *)__opaque;
        struct hpsb_packet *packet, *p;
        struct list_head tmp;
        unsigned long flags, expire, j;

        spin_lock_irqsave(&host->csr.lock, flags);
        expire = host->csr.expire;
        spin_unlock_irqrestore(&host->csr.lock, flags);

        j = jiffies;
        INIT_LIST_HEAD(&tmp);
        spin_lock_irqsave(&pending_packets_lock, flags);

        list_for_each_entry_safe(packet, p, &host->pending_packets, queue) {
                if (time_before(packet->sendtime + expire, j))
                        list_move_tail(&packet->queue, &tmp);
                else
                        /* Since packets are added to the tail, the oldest
                         * ones are first, always. When we get to one that
                         * isn't timed out, the rest aren't either. */
                        break;
        }
        if (!list_empty(&host->pending_packets))
                mod_timer(&host->timeout, j + host->timeout_interval);

        spin_unlock_irqrestore(&pending_packets_lock, flags);

        list_for_each_entry_safe(packet, p, &tmp, queue) {
                list_del_init(&packet->queue);
                packet->state = hpsb_complete;
                packet->ack_code = ACKX_TIMEOUT;
                queue_packet_complete(packet);
        }
}

static struct task_struct *khpsbpkt_thread;
static LIST_HEAD(hpsbpkt_queue);

static void queue_packet_complete(struct hpsb_packet *packet)
{
        unsigned long flags;

        if (packet->no_waiter) {
                hpsb_free_packet(packet);
                return;
        }
        if (packet->complete_routine != NULL) {
                spin_lock_irqsave(&pending_packets_lock, flags);
                list_add_tail(&packet->queue, &hpsbpkt_queue);
                spin_unlock_irqrestore(&pending_packets_lock, flags);
                wake_up_process(khpsbpkt_thread);
        }
        return;
}

/*
 * Kernel thread which handles packets that are completed.  This way the
 * packet's "complete" function is asynchronously run in process context.
 * Only packets which have a "complete" function may be sent here.
 */
static int hpsbpkt_thread(void *__hi)
{
        struct hpsb_packet *packet, *p;
        struct list_head tmp;
        int may_schedule;

        while (!kthread_should_stop()) {

                INIT_LIST_HEAD(&tmp);
                spin_lock_irq(&pending_packets_lock);
                list_splice_init(&hpsbpkt_queue, &tmp);
                spin_unlock_irq(&pending_packets_lock);

                list_for_each_entry_safe(packet, p, &tmp, queue) {
                        list_del_init(&packet->queue);
                        packet->complete_routine(packet->complete_data);
                }

                set_current_state(TASK_INTERRUPTIBLE);
                spin_lock_irq(&pending_packets_lock);
                may_schedule = list_empty(&hpsbpkt_queue);
                spin_unlock_irq(&pending_packets_lock);
                if (may_schedule)
                        schedule();
                __set_current_state(TASK_RUNNING);
        }
        return 0;
}

static int __init ieee1394_init(void)
{
        int i, ret;

        /* non-fatal error */
        if (hpsb_init_config_roms()) {
                HPSB_ERR("Failed to initialize some config rom entries.\n");
                HPSB_ERR("Some features may not be available\n");
        }

        khpsbpkt_thread = kthread_run(hpsbpkt_thread, NULL, "khpsbpkt");
        if (IS_ERR(khpsbpkt_thread)) {
                HPSB_ERR("Failed to start hpsbpkt thread!\n");
                ret = PTR_ERR(khpsbpkt_thread);
                goto exit_cleanup_config_roms;
        }

        if (register_chrdev_region(IEEE1394_CORE_DEV, 256, "ieee1394")) {
                HPSB_ERR("unable to register character device major %d!\n", IEEE1394_MAJOR);
                ret = -ENODEV;
                goto exit_release_kernel_thread;
        }

        ret = bus_register(&ieee1394_bus_type);
        if (ret < 0) {
                HPSB_INFO("bus register failed");
                goto release_chrdev;
        }

        for (i = 0; fw_bus_attrs[i]; i++) {
                ret = bus_create_file(&ieee1394_bus_type, fw_bus_attrs[i]);
                if (ret < 0) {
                        while (i >= 0) {
                                bus_remove_file(&ieee1394_bus_type,
                                                fw_bus_attrs[i--]);
                        }
                        bus_unregister(&ieee1394_bus_type);
                        goto release_chrdev;
                }
        }

        ret = class_register(&hpsb_host_class);
        if (ret < 0)
                goto release_all_bus;

        hpsb_protocol_class = class_create(THIS_MODULE, "ieee1394_protocol");
        if (IS_ERR(hpsb_protocol_class)) {
                ret = PTR_ERR(hpsb_protocol_class);
                goto release_class_host;
        }

        ret = init_csr();
        if (ret) {
                HPSB_INFO("init csr failed");
                ret = -ENOMEM;
                goto release_class_protocol;
        }

        if (disable_nodemgr) {
                HPSB_INFO("nodemgr and IRM functionality disabled");
                /* We shouldn't contend for IRM with nodemgr disabled, since
                   nodemgr implements functionality required of ieee1394a-2000
                   IRMs */
                hpsb_disable_irm = 1;

                return 0;
        }

        if (hpsb_disable_irm) {
                HPSB_INFO("IRM functionality disabled");
        }

        ret = init_ieee1394_nodemgr();
        if (ret < 0) {
                HPSB_INFO("init nodemgr failed");
                goto cleanup_csr;
        }

        return 0;

cleanup_csr:
        cleanup_csr();
release_class_protocol:
        class_destroy(hpsb_protocol_class);
release_class_host:
        class_unregister(&hpsb_host_class);
release_all_bus:
        for (i = 0; fw_bus_attrs[i]; i++)
                bus_remove_file(&ieee1394_bus_type, fw_bus_attrs[i]);
        bus_unregister(&ieee1394_bus_type);
release_chrdev:
        unregister_chrdev_region(IEEE1394_CORE_DEV, 256);
exit_release_kernel_thread:
        kthread_stop(khpsbpkt_thread);
exit_cleanup_config_roms:
        hpsb_cleanup_config_roms();
        return ret;
}

static void __exit ieee1394_cleanup(void)
{
        int i;

        if (!disable_nodemgr)
                cleanup_ieee1394_nodemgr();

        cleanup_csr();

        class_destroy(hpsb_protocol_class);
        class_unregister(&hpsb_host_class);
        for (i = 0; fw_bus_attrs[i]; i++)
                bus_remove_file(&ieee1394_bus_type, fw_bus_attrs[i]);
        bus_unregister(&ieee1394_bus_type);

        kthread_stop(khpsbpkt_thread);

        hpsb_cleanup_config_roms();

        unregister_chrdev_region(IEEE1394_CORE_DEV, 256);
}

fs_initcall(ieee1394_init);
module_exit(ieee1394_cleanup);

/* Exported symbols */

/** hosts.c **/
EXPORT_SYMBOL(hpsb_alloc_host);
EXPORT_SYMBOL(hpsb_add_host);
EXPORT_SYMBOL(hpsb_resume_host);
EXPORT_SYMBOL(hpsb_remove_host);
EXPORT_SYMBOL(hpsb_update_config_rom_image);

/** ieee1394_core.c **/
EXPORT_SYMBOL(hpsb_speedto_str);
EXPORT_SYMBOL(hpsb_protocol_class);
EXPORT_SYMBOL(hpsb_set_packet_complete_task);
EXPORT_SYMBOL(hpsb_alloc_packet);
EXPORT_SYMBOL(hpsb_free_packet);
EXPORT_SYMBOL(hpsb_send_packet);
EXPORT_SYMBOL(hpsb_reset_bus);
EXPORT_SYMBOL(hpsb_read_cycle_timer);
EXPORT_SYMBOL(hpsb_bus_reset);
EXPORT_SYMBOL(hpsb_selfid_received);
EXPORT_SYMBOL(hpsb_selfid_complete);
EXPORT_SYMBOL(hpsb_packet_sent);
EXPORT_SYMBOL(hpsb_packet_received);
EXPORT_SYMBOL_GPL(hpsb_disable_irm);

/** ieee1394_transactions.c **/
EXPORT_SYMBOL(hpsb_get_tlabel);
EXPORT_SYMBOL(hpsb_free_tlabel);
EXPORT_SYMBOL(hpsb_make_readpacket);
EXPORT_SYMBOL(hpsb_make_writepacket);
EXPORT_SYMBOL(hpsb_make_streampacket);
EXPORT_SYMBOL(hpsb_make_lockpacket);
EXPORT_SYMBOL(hpsb_make_lock64packet);
EXPORT_SYMBOL(hpsb_make_phypacket);
EXPORT_SYMBOL(hpsb_read);
EXPORT_SYMBOL(hpsb_write);
EXPORT_SYMBOL(hpsb_lock);
EXPORT_SYMBOL(hpsb_packet_success);

/** highlevel.c **/
EXPORT_SYMBOL(hpsb_register_highlevel);
EXPORT_SYMBOL(hpsb_unregister_highlevel);
EXPORT_SYMBOL(hpsb_register_addrspace);
EXPORT_SYMBOL(hpsb_unregister_addrspace);
EXPORT_SYMBOL(hpsb_allocate_and_register_addrspace);
EXPORT_SYMBOL(hpsb_get_hostinfo);
EXPORT_SYMBOL(hpsb_create_hostinfo);
EXPORT_SYMBOL(hpsb_destroy_hostinfo);
EXPORT_SYMBOL(hpsb_set_hostinfo_key);
EXPORT_SYMBOL(hpsb_get_hostinfo_bykey);
EXPORT_SYMBOL(hpsb_set_hostinfo);

/** nodemgr.c **/
EXPORT_SYMBOL(hpsb_node_fill_packet);
EXPORT_SYMBOL(hpsb_node_write);
EXPORT_SYMBOL(__hpsb_register_protocol);
EXPORT_SYMBOL(hpsb_unregister_protocol);

/** csr.c **/
EXPORT_SYMBOL(hpsb_update_config_rom);

/** dma.c **/
EXPORT_SYMBOL(dma_prog_region_init);
EXPORT_SYMBOL(dma_prog_region_alloc);
EXPORT_SYMBOL(dma_prog_region_free);
EXPORT_SYMBOL(dma_region_init);
EXPORT_SYMBOL(dma_region_alloc);
EXPORT_SYMBOL(dma_region_free);
EXPORT_SYMBOL(dma_region_sync_for_cpu);
EXPORT_SYMBOL(dma_region_sync_for_device);
EXPORT_SYMBOL(dma_region_mmap);
EXPORT_SYMBOL(dma_region_offset_to_bus);

/** iso.c **/
EXPORT_SYMBOL(hpsb_iso_xmit_init);
EXPORT_SYMBOL(hpsb_iso_recv_init);
EXPORT_SYMBOL(hpsb_iso_xmit_start);
EXPORT_SYMBOL(hpsb_iso_recv_start);
EXPORT_SYMBOL(hpsb_iso_recv_listen_channel);
EXPORT_SYMBOL(hpsb_iso_recv_unlisten_channel);
EXPORT_SYMBOL(hpsb_iso_recv_set_channel_mask);
EXPORT_SYMBOL(hpsb_iso_stop);
EXPORT_SYMBOL(hpsb_iso_shutdown);
EXPORT_SYMBOL(hpsb_iso_xmit_queue_packet);
EXPORT_SYMBOL(hpsb_iso_xmit_sync);
EXPORT_SYMBOL(hpsb_iso_recv_release_packets);
EXPORT_SYMBOL(hpsb_iso_n_ready);
EXPORT_SYMBOL(hpsb_iso_packet_sent);
EXPORT_SYMBOL(hpsb_iso_packet_received);
EXPORT_SYMBOL(hpsb_iso_wake);
EXPORT_SYMBOL(hpsb_iso_recv_flush);

/** csr1212.c **/
EXPORT_SYMBOL(csr1212_attach_keyval_to_directory);
EXPORT_SYMBOL(csr1212_detach_keyval_from_directory);
EXPORT_SYMBOL(csr1212_get_keyval);
EXPORT_SYMBOL(csr1212_new_directory);
EXPORT_SYMBOL(csr1212_parse_keyval);
EXPORT_SYMBOL(csr1212_read);
EXPORT_SYMBOL(csr1212_release_keyval);