ieee1394_transactions.c

Ieee1394驱动实现

		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  */