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/*

 * IEEE 1394 for Linux

 *

 * Transaction support.

 *

 * Copyright (C) 1999 Andreas E. Bombe

 *

 * This code is licensed under the GPL.  See the file COPYING in the root

 * directory of the kernel sources for details.

 */

#include <linux/bitops.h>

#include <linux/compiler.h>

#include <linux/hardirq.h>

#include <linux/spinlock.h>

#include <linux/string.h>

#include <linux/sched.h>  /* because linux/wait.h is broken if CONFIG_SMP=n */

#include <linux/wait.h>

#include <asm/bug.h>

#include <asm/errno.h>

#include <asm/system.h>

#include "ieee1394.h"

#include "ieee1394_types.h"

#include "hosts.h"

#include "ieee1394_core.h"

#include "ieee1394_transactions.h"

#define PREP_ASYNC_HEAD_ADDRESS(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) | (addr >> 32); \

        packet->header[2] = addr & 0xffffffff

#ifndef HPSB_DEBUG_TLABELS

static

#endif

DEFINE_SPINLOCK(hpsb_tlabel_lock);

static DECLARE_WAIT_QUEUE_HEAD(tlabel_wq);

static void fill_async_readquad(struct hpsb_packet *packet, u64 addr)

{

        PREP_ASYNC_HEAD_ADDRESS(TCODE_READQ);

        packet->header_size = 12;

        packet->data_size = 0;

        packet->expect_response = 1;

}

static void fill_async_readblock(struct hpsb_packet *packet, u64 addr,

                                 int length)

{

        PREP_ASYNC_HEAD_ADDRESS(TCODE_READB);

        packet->header[3] = length << 16;

        packet->header_size = 16;

        packet->data_size = 0;

        packet->expect_response = 1;

}

static void fill_async_writequad(struct hpsb_packet *packet, u64 addr,

                                 quadlet_t data)

{

        PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEQ);

        packet->header[3] = data;

        packet->header_size = 16;

        packet->data_size = 0;

        packet->expect_response = 1;

}

static void fill_async_writeblock(struct hpsb_packet *packet, u64 addr,

                                  int length)

{

        PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEB);

        packet->header[3] = length << 16;

        packet->header_size = 16;

        packet->expect_response = 1;

        packet->data_size = length + (length % 4 ? 4 - (length % 4) : 0);

}

static void fill_async_lock(struct hpsb_packet *packet, u64 addr, int extcode,

                            int length)

{

        PREP_ASYNC_HEAD_ADDRESS(TCODE_LOCK_REQUEST);

        packet->header[3] = (length << 16) | extcode;

        packet->header_size = 16;

        packet->data_size = length;

        packet->expect_response = 1;

}

static void fill_phy_packet(struct hpsb_packet *packet, quadlet_t data)

{

        packet->header[0] = data;

        packet->header[1] = ~data;

        packet->header_size = 8;

        packet->data_size = 0;

        packet->expect_response = 0;

        packet->type = hpsb_raw;        /* No CRC added */

        packet->speed_code = IEEE1394_SPEED_100;        /* Force speed to be 100Mbps */

}

static void fill_async_stream_packet(struct hpsb_packet *packet, int length,

                                     int channel, int tag, int sync)

{

        packet->header[0] = (length << 16) | (tag << 14) | (channel << 8)

            | (TCODE_STREAM_DATA << 4) | sync;

        packet->header_size = 4;

        packet->data_size = length;

        packet->type = hpsb_async;

        packet->tcode = TCODE_ISO_DATA;

}

/* same as hpsb_get_tlabel, except that it returns immediately */

static int hpsb_get_tlabel_atomic(struct hpsb_packet *packet)

{

        unsigned long flags, *tp;

        u8 *next;

        int tlabel, n = NODEID_TO_NODE(packet->node_id);

        /* Broadcast transactions are complete once the request has been sent.

         * Use the same transaction label for all broadcast transactions. */

        if (unlikely(n == ALL_NODES)) {

                packet->tlabel = 0;

                return 0;

        }

        tp = packet->host->tl_pool[n].map;

        next = &packet->host->next_tl[n];

        spin_lock_irqsave(&hpsb_tlabel_lock, flags);

        tlabel = find_next_zero_bit(tp, 64, *next);

        if (tlabel > 63)

                tlabel = find_first_zero_bit(tp, 64);

        if (tlabel > 63) {

                spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);

                return -EAGAIN;

        }

        __set_bit(tlabel, tp);

        *next = (tlabel + 1) & 63;

        spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);

        packet->tlabel = tlabel;

        return 0;

}

/**

 * hpsb_get_tlabel - allocate a transaction label

 * @packet: the packet whose tlabel and tl_pool we set

 *

 * Every asynchronous transaction on the 1394 bus needs a transaction

 * label to match the response to the request.  This label has to be

 * different from any other transaction label in an outstanding request to

 * the same node to make matching possible without ambiguity.

 *

 * There are 64 different tlabels, so an allocated tlabel has to be freed

 * with hpsb_free_tlabel() after the transaction is complete (unless it's

 * reused again for the same target node).

 *

 * Return value: Zero on success, otherwise non-zero. A non-zero return

 * generally means there are no available tlabels. If this is called out

 * of interrupt or atomic context, then it will sleep until can return a

 * tlabel or a signal is received.

 */

int hpsb_get_tlabel(struct hpsb_packet *packet)

{

        if (irqs_disabled() || in_atomic())

                return hpsb_get_tlabel_atomic(packet);

        /* NB: The macro wait_event_interruptible() is called with a condition

         * argument with side effect.  This is only possible because the side

         * effect does not occur until the condition became true, and

         * wait_event_interruptible() won't evaluate the condition again after

         * that. */

        return wait_event_interruptible(tlabel_wq,

                                        !hpsb_get_tlabel_atomic(packet));

}

/**

 * hpsb_free_tlabel - free an allocated transaction label

 * @packet: packet whose tlabel and tl_pool needs to be cleared

 *

 * Frees the transaction label allocated with hpsb_get_tlabel().  The

 * tlabel has to be freed after the transaction is complete (i.e. response

 * was received for a split transaction or packet was sent for a unified

 * transaction).

 *

 * A tlabel must not be freed twice.

 */

void hpsb_free_tlabel(struct hpsb_packet *packet)

{

        unsigned long flags, *tp;

        int tlabel, n = NODEID_TO_NODE(packet->node_id);

        if (unlikely(n == ALL_NODES))

                return;

        tp = packet->host->tl_pool[n].map;

        tlabel = packet->tlabel;

        BUG_ON(tlabel > 63 || tlabel < 0);

        spin_lock_irqsave(&hpsb_tlabel_lock, flags);

        BUG_ON(!__test_and_clear_bit(tlabel, tp));

        spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);

        wake_up_interruptible(&tlabel_wq);

}

/**

 * hpsb_packet_success - Make sense of the ack and reply codes

 *

 * Make sense of the ack and reply codes and return more convenient error codes:

 * 0 = success.  -%EBUSY = node is busy, try again.  -%EAGAIN = error which can

 * probably resolved by retry.  -%EREMOTEIO = node suffers from an internal

 * error.  -%EACCES = this transaction is not allowed on requested address.

 * -%EINVAL = invalid address at node.

 */

int hpsb_packet_success(struct hpsb_packet *packet)

{

        switch (packet->ack_code) {

        case ACK_PENDING:

                switch ((packet->header[1] >> 12) & 0xf) {

                case RCODE_COMPLETE:

                        return 0;

                case RCODE_CONFLICT_ERROR:

                        return -EAGAIN;

                case RCODE_DATA_ERROR:

                        return -EREMOTEIO;

                case RCODE_TYPE_ERROR:

                        return -EACCES;

                case RCODE_ADDRESS_ERROR:

                        return -EINVAL;

                default:

                        HPSB_ERR("received reserved rcode %d from node %d",

                                 (packet->header[1] >> 12) & 0xf,

                                 packet->node_id);

                        return -EAGAIN;

                }

        case ACK_BUSY_X:

        case ACK_BUSY_A:

        case ACK_BUSY_B:

                return -EBUSY;

        case ACK_TYPE_ERROR:

                return -EACCES;

        case ACK_COMPLETE:

                if (packet->tcode == TCODE_WRITEQ

                    || packet->tcode == TCODE_WRITEB) {

                        return 0;

                } else {

                        HPSB_ERR("impossible ack_complete from node %d "

                                 "(tcode %d)", packet->node_id, packet->tcode);

                        return -EAGAIN;

                }

        case ACK_DATA_ERROR:

                if (packet->tcode == TCODE_WRITEB

                    || packet->tcode == TCODE_LOCK_REQUEST) {

                        return -EAGAIN;

                } else {

                        HPSB_ERR("impossible ack_data_error from node %d "

                                 "(tcode %d)", packet->node_id, packet->tcode);

                        return -EAGAIN;

                }

        case ACK_ADDRESS_ERROR:

                return -EINVAL;

        case ACK_TARDY:

        case ACK_CONFLICT_ERROR:

        case ACKX_NONE:

        case ACKX_SEND_ERROR:

        case ACKX_ABORTED:

        case ACKX_TIMEOUT:

                /* error while sending */

                return -EAGAIN;

        default:

                HPSB_ERR("got invalid ack %d from node %d (tcode %d)",

                         packet->ack_code, packet->node_id, packet->tcode);

                return -EAGAIN;

        }

}

struct hpsb_packet *hpsb_make_readpacket(struct hpsb_host *host, nodeid_t node,

                                         u64 addr, size_t length)

{

        struct hpsb_packet *packet;

        if (length == 0)

                return NULL;

        packet = hpsb_alloc_packet(length);

        if (!packet)

                return NULL;

        packet->host = host;

        packet->node_id = node;

        if (hpsb_get_tlabel(packet)) {

                hpsb_free_packet(packet);

                return NULL;

        }

        if (length == 4)

                fill_async_readquad(packet, addr);

        else

                fill_async_readblock(packet, addr, length);

        return packet;

}

struct hpsb_packet *hpsb_make_writepacket(struct hpsb_host *host, nodeid_t node,

                                          u64 addr, quadlet_t * buffer,

                                          size_t length)

{

        struct hpsb_packet *packet;

        if (length == 0)

                return NULL;

        packet = hpsb_alloc_packet(length);

        if (!packet)

                return NULL;

        if (length % 4) {       /* zero padding bytes */

                packet->data[length >> 2] = 0;

        }

        packet->host = host;

        packet->node_id = node;

        if (hpsb_get_tlabel(packet)) {

                hpsb_free_packet(packet);

                return NULL;

        }

        if (length == 4) {

                fill_async_writequad(packet, addr, buffer ? *buffer : 0);

        } else {

                fill_async_writeblock(packet, addr, length);

                if (buffer)

                        memcpy(packet->data, buffer, length);

        }

        return packet;

}

struct hpsb_packet *hpsb_make_streampacket(struct hpsb_host *host, u8 * buffer,

                                           int length, int channel, int tag,

                                           int sync)

{

        struct hpsb_packet *packet;

        if (length == 0)

                return NULL;

        packet = hpsb_alloc_packet(length);

        if (!packet)

                return NULL;

        if (length % 4) {       /* zero padding bytes */

                packet->data[length >> 2] = 0;

        }

        packet->host = host;

        /* Because it is too difficult to determine all PHY speeds and link

         * speeds here, we use S100... */

        packet->speed_code = IEEE1394_SPEED_100;

        /* ...and prevent hpsb_send_packet() from overriding it. */

        packet->node_id = LOCAL_BUS | ALL_NODES;

        if (hpsb_get_tlabel(packet)) {

                hpsb_free_packet(packet);

                return NULL;

        }

        fill_async_stream_packet(packet, length, channel, tag, sync);

        if (buffer)

                memcpy(packet->data, buffer, length);

        return packet;

}

struct hpsb_packet *hpsb_make_lockpacket(struct hpsb_host *host, nodeid_t node,

                                         u64 addr, int extcode,

                                         quadlet_t * data, quadlet_t arg)

{

        struct hpsb_packet *p;

        u32 length;

        p = hpsb_alloc_packet(8);

        if (!p)

                return NULL;

        p->host = host;

        p->node_id = node;

        if (hpsb_get_tlabel(p)) {

                hpsb_free_packet(p);

                return NULL;

        }

        switch (extcode) {

        case EXTCODE_FETCH_ADD:

        case EXTCODE_LITTLE_ADD:

                length = 4;

                if (data)

                        p->data[0] = *data;

                break;

        default:

                length = 8;

                if (data) {

                        p->data[0] = arg;

                        p->data[1] = *data;

                }

                break;

        }

        fill_async_lock(p, addr, extcode, length);

        return p;

}

struct hpsb_packet *hpsb_make_lock64packet(struct hpsb_host *host,

                                           nodeid_t node, u64 addr, int extcode,

                                           octlet_t * data, octlet_t arg)

{

        struct hpsb_packet *p;

        u32 length;

        p = hpsb_alloc_packet(16);

        if (!p)

                return NULL;

        p->host = host;

        p->node_id = node;

        if (hpsb_get_tlabel(p)) {

                hpsb_free_packet(p);

                return NULL;

        }

        switch (extcode) {

        case EXTCODE_FETCH_ADD:

        case EXTCODE_LITTLE_ADD:

                length = 8;

                if (data) {

                        p->data[0] = *data >> 32;

                        p->data[1] = *data & 0xffffffff;

                }

                break;

        default:

                length = 16;

                if (data) {

                        p->data[0] = arg >> 32;

                        p->data[1] = arg & 0xffffffff;

                        p->data[2] = *data >> 32;

                        p->data[3] = *data & 0xffffffff;

                }

                break;

        }

        fill_async_lock(p, addr, extcode, length);

        return p;

}

struct hpsb_packet *hpsb_make_phypacket(struct hpsb_host *host, quadlet_t data)

{

        struct hpsb_packet *p;

        p = hpsb_alloc_packet(0);

        if (!p)

                return NULL;

        p->host = host;

        fill_phy_packet(p, data);

        return p;

}

/*

 * FIXME - these functions should probably read from / write to user space to

 * avoid in kernel buffers for user space callers

 */

/**

 * hpsb_read - generic read function

 *

 * Recognizes the local node ID and act accordingly.  Automatically uses a

 * quadlet read request if @length == 4 and and a block read request otherwise.

 * It does not yet support lengths that are not a multiple of 4.

 *

 * You must explicitly specifiy the @generation for which the node ID is valid,

 * to avoid sending packets to the wrong nodes when we race with a bus reset.

 */

int hpsb_read(struct hpsb_host *host, nodeid_t node, unsigned int generation,

              u64 addr, quadlet_t * buffer, size_t length)

{

        struct hpsb_packet *packet;

        int retval = 0;

        if (length == 0)

                return -EINVAL;

        BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet

        packet = hpsb_make_readpacket(host, node, addr, length);

        if (!packet) {

                return -ENOMEM;

        }

        packet->generation = generation;

        retval = hpsb_send_packet_and_wait(packet);

        if (retval < 0)

                goto hpsb_read_fail;

        retval = hpsb_packet_success(packet);

        if (retval == 0) {

                if (length == 4) {

                        *buffer = packet->header[3];

                } else {

                        memcpy(buffer, packet->data, length);

                }

        }

      hpsb_read_fail:

        hpsb_free_tlabel(packet);

        hpsb_free_packet(packet);

        return retval;

}

/**

 * hpsb_write - generic write function

 *

 * Recognizes the local node ID and act accordingly.  Automatically uses a

 * quadlet write request if @length == 4 and and a block write request

 * otherwise.  It does not yet support lengths that are not a multiple of 4.

 *

 * You must explicitly specifiy the @generation for which the node ID is valid,

 * to avoid sending packets to the wrong nodes when we race with a bus reset.

 */

int hpsb_write(struct hpsb_host *host, nodeid_t node, unsigned int generation,

               u64 addr, quadlet_t * buffer, size_t length)

{

        struct hpsb_packet *packet;

        int retval;

        if (length == 0)

                return -EINVAL;

        BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet

        packet = hpsb_make_writepacket(host, node, addr, buffer, length);

        if (!packet)

                return -ENOMEM;

        packet->generation = generation;

        retval = hpsb_send_packet_and_wait(packet);

        if (retval < 0)

                goto hpsb_write_fail;

        retval = hpsb_packet_success(packet);

      hpsb_write_fail:

        hpsb_free_tlabel(packet);

        hpsb_free_packet(packet);

        return retval;

}

#if 0

int hpsb_lock(struct hpsb_host *host, nodeid_t node, unsigned int generation,

              u64 addr, int extcode, quadlet_t * data, quadlet_t arg)

{

        struct hpsb_packet *packet;

        int retval = 0;

        BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet

        packet = hpsb_make_lockpacket(host, node, addr, extcode, data, arg);

        if (!packet)

                return -ENOMEM;

        packet->generation = generation;

        retval = hpsb_send_packet_and_wait(packet);

        if (retval < 0)

                goto hpsb_lock_fail;

        retval = hpsb_packet_success(packet);

        if (retval == 0) {

                *data = packet->data[0];

        }

      hpsb_lock_fail:

        hpsb_free_tlabel(packet);

        hpsb_free_packet(packet);

        return retval;

}

int hpsb_send_gasp(struct hpsb_host *host, int channel, unsigned int generation,

                   quadlet_t * buffer, size_t length, u32 specifier_id,

                   unsigned int version)

{

        struct hpsb_packet *packet;

        int retval = 0;

        u16 specifier_id_hi = (specifier_id & 0x00ffff00) >> 8;

        u8 specifier_id_lo = specifier_id & 0xff;

        HPSB_VERBOSE("Send GASP: channel = %d, length = %Zd", channel, length);

        length += 8;

        packet = hpsb_make_streampacket(host, NULL, length, channel, 3, 0);

        if (!packet)

                return -ENOMEM;

        packet->data[0] = cpu_to_be32((host->node_id << 16) | specifier_id_hi);

        packet->data[1] =

            cpu_to_be32((specifier_id_lo << 24) | (version & 0x00ffffff));

        memcpy(&(packet->data[2]), buffer, length - 8);

        packet->generation = generation;

        packet->no_waiter = 1;

        retval = hpsb_send_packet(packet);

        if (retval < 0)

                hpsb_free_packet(packet);

        return retval;

}

#endif                          /*  0  */