/*
   * RapidIO enumeration and discovery support
   *
   * Copyright 2005 MontaVista Software, Inc.
   * Matt Porter <mporter@kernel.crashing.org>
   *

   * Copyright 2009 Integrated Device Technology, Inc.
   * Alex Bounine <alexandre.bounine@idt.com>
   * - Added Port-Write/Error Management initialization and handling
   *

   * Copyright 2009 Sysgo AG
   * Thomas Moll <thomas.moll@sysgo.com>
   * - Added Input- Output- enable functionality, to allow full communication
   *

   * 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.
   */

  #include <linux/types.h>
  #include <linux/kernel.h>
  
  #include <linux/delay.h>

  #include <linux/dma-mapping.h>

  #include <linux/init.h>
  #include <linux/rio.h>
  #include <linux/rio_drv.h>
  #include <linux/rio_ids.h>
  #include <linux/rio_regs.h>
  #include <linux/module.h>
  #include <linux/spinlock.h>
  #include <linux/timer.h>

  #include <linux/sched.h>

  #include <linux/jiffies.h>
  #include <linux/slab.h>

  
  #include "rio.h"

  static void rio_init_em(struct rio_dev *rdev);

  static int next_destid = 0;

  static int next_comptag = 1;

  static int rio_mport_phys_table[] = {
  	RIO_EFB_PAR_EP_ID,
  	RIO_EFB_PAR_EP_REC_ID,
  	RIO_EFB_SER_EP_ID,
  	RIO_EFB_SER_EP_REC_ID,
  	-1,
  };

  /**

   * rio_destid_alloc - Allocate next available destID for given network

   * @net: RIO network

   *
   * Returns next available device destination ID for the specified RIO network.
   * Marks allocated ID as one in use.
   * Returns RIO_INVALID_DESTID if new destID is not available.
   */
  static u16 rio_destid_alloc(struct rio_net *net)
  {
  	int destid;
  	struct rio_id_table *idtab = &net->destid_table;
  
  	spin_lock(&idtab->lock);

  	destid = find_first_zero_bit(idtab->table, idtab->max);

  
  	if (destid < idtab->max) {

  		set_bit(destid, idtab->table);
  		destid += idtab->start;
  	} else
  		destid = RIO_INVALID_DESTID;
  
  	spin_unlock(&idtab->lock);
  	return (u16)destid;
  }

  /**

   * rio_destid_reserve - Reserve the specivied destID

   * @net: RIO network
   * @destid: destID to reserve

   *
   * Tries to reserve the specified destID.

   * Returns 0 if successful.

   */
  static int rio_destid_reserve(struct rio_net *net, u16 destid)
  {
  	int oldbit;
  	struct rio_id_table *idtab = &net->destid_table;
  
  	destid -= idtab->start;
  	spin_lock(&idtab->lock);
  	oldbit = test_and_set_bit(destid, idtab->table);
  	spin_unlock(&idtab->lock);
  	return oldbit;
  }

  /**

   * rio_destid_free - free a previously allocated destID

   * @net: RIO network
   * @destid: destID to free

   *
   * Makes the specified destID available for use.
   */
  static void rio_destid_free(struct rio_net *net, u16 destid)
  {
  	struct rio_id_table *idtab = &net->destid_table;
  
  	destid -= idtab->start;
  	spin_lock(&idtab->lock);
  	clear_bit(destid, idtab->table);
  	spin_unlock(&idtab->lock);
  }

  /**

   * rio_destid_first - return first destID in use

   * @net: RIO network

   */
  static u16 rio_destid_first(struct rio_net *net)
  {
  	int destid;
  	struct rio_id_table *idtab = &net->destid_table;
  
  	spin_lock(&idtab->lock);
  	destid = find_first_bit(idtab->table, idtab->max);
  	if (destid >= idtab->max)
  		destid = RIO_INVALID_DESTID;
  	else
  		destid += idtab->start;
  	spin_unlock(&idtab->lock);
  	return (u16)destid;
  }

  /**

   * rio_destid_next - return next destID in use

   * @net: RIO network
   * @from: destination ID from which search shall continue

   */
  static u16 rio_destid_next(struct rio_net *net, u16 from)
  {
  	int destid;
  	struct rio_id_table *idtab = &net->destid_table;
  
  	spin_lock(&idtab->lock);
  	destid = find_next_bit(idtab->table, idtab->max, from);
  	if (destid >= idtab->max)
  		destid = RIO_INVALID_DESTID;
  	else
  		destid += idtab->start;
  	spin_unlock(&idtab->lock);
  	return (u16)destid;
  }

  /**
   * rio_get_device_id - Get the base/extended device id for a device
   * @port: RIO master port
   * @destid: Destination ID of device
   * @hopcount: Hopcount to device
   *
   * Reads the base/extended device id from a device. Returns the
   * 8/16-bit device ID.
   */
  static u16 rio_get_device_id(struct rio_mport *port, u16 destid, u8 hopcount)
  {
  	u32 result;
  
  	rio_mport_read_config_32(port, destid, hopcount, RIO_DID_CSR, &result);

  	return RIO_GET_DID(port->sys_size, result);

  }
  
  /**
   * rio_set_device_id - Set the base/extended device id for a device
   * @port: RIO master port
   * @destid: Destination ID of device
   * @hopcount: Hopcount to device
   * @did: Device ID value to be written
   *
   * Writes the base/extended device id from a device.
   */

  static void rio_set_device_id(struct rio_mport *port, u16 destid, u8 hopcount, u16 did)

  {
  	rio_mport_write_config_32(port, destid, hopcount, RIO_DID_CSR,

  				  RIO_SET_DID(port->sys_size, did));

  }
  
  /**
   * rio_local_set_device_id - Set the base/extended device id for a port
   * @port: RIO master port
   * @did: Device ID value to be written
   *
   * Writes the base/extended device id from a device.
   */
  static void rio_local_set_device_id(struct rio_mport *port, u16 did)
  {

  	rio_local_write_config_32(port, RIO_DID_CSR, RIO_SET_DID(port->sys_size,
  				did));

  }
  
  /**
   * rio_clear_locks- Release all host locks and signal enumeration complete

   * @net: RIO network to run on

   *
   * Marks the component tag CSR on each device with the enumeration
   * complete flag. When complete, it then release the host locks on
   * each device. Returns 0 on success or %-EINVAL on failure.
   */

  static int rio_clear_locks(struct rio_net *net)

  {

  	struct rio_mport *port = net->hport;

  	struct rio_dev *rdev;
  	u32 result;
  	int ret = 0;

  	/* Release host device id locks */
  	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
  				  port->host_deviceid);
  	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
  	if ((result & 0xffff) != 0xffff) {
  		printk(KERN_INFO
  		       "RIO: badness when releasing host lock on master port, result %8.8x
  ",
  		       result);
  		ret = -EINVAL;
  	}

  	list_for_each_entry(rdev, &net->devices, net_list) {

  		rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
  				    port->host_deviceid);
  		rio_read_config_32(rdev, RIO_HOST_DID_LOCK_CSR, &result);
  		if ((result & 0xffff) != 0xffff) {
  			printk(KERN_INFO
  			       "RIO: badness when releasing host lock on vid %4.4x did %4.4x
  ",
  			       rdev->vid, rdev->did);
  			ret = -EINVAL;
  		}

  
  		/* Mark device as discovered and enable master */
  		rio_read_config_32(rdev,
  				   rdev->phys_efptr + RIO_PORT_GEN_CTL_CSR,
  				   &result);
  		result |= RIO_PORT_GEN_DISCOVERED | RIO_PORT_GEN_MASTER;
  		rio_write_config_32(rdev,
  				    rdev->phys_efptr + RIO_PORT_GEN_CTL_CSR,
  				    result);

  	}
  
  	return ret;
  }
  
  /**
   * rio_enum_host- Set host lock and initialize host destination ID
   * @port: Master port to issue transaction
   *
   * Sets the local host master port lock and destination ID register
   * with the host device ID value. The host device ID value is provided
   * by the platform. Returns %0 on success or %-1 on failure.
   */
  static int rio_enum_host(struct rio_mport *port)
  {
  	u32 result;
  
  	/* Set master port host device id lock */
  	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
  				  port->host_deviceid);
  
  	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
  	if ((result & 0xffff) != port->host_deviceid)
  		return -1;
  
  	/* Set master port destid and init destid ctr */
  	rio_local_set_device_id(port, port->host_deviceid);

  	return 0;
  }
  
  /**
   * rio_device_has_destid- Test if a device contains a destination ID register
   * @port: Master port to issue transaction
   * @src_ops: RIO device source operations
   * @dst_ops: RIO device destination operations
   *
   * Checks the provided @src_ops and @dst_ops for the necessary transaction
   * capabilities that indicate whether or not a device will implement a
   * destination ID register. Returns 1 if true or 0 if false.
   */
  static int rio_device_has_destid(struct rio_mport *port, int src_ops,
  				 int dst_ops)
  {

  	u32 mask = RIO_OPS_READ | RIO_OPS_WRITE | RIO_OPS_ATOMIC_TST_SWP | RIO_OPS_ATOMIC_INC | RIO_OPS_ATOMIC_DEC | RIO_OPS_ATOMIC_SET | RIO_OPS_ATOMIC_CLR;
  
  	return !!((src_ops | dst_ops) & mask);

  }
  
  /**
   * rio_release_dev- Frees a RIO device struct
   * @dev: LDM device associated with a RIO device struct
   *
   * Gets the RIO device struct associated a RIO device struct.
   * The RIO device struct is freed.
   */
  static void rio_release_dev(struct device *dev)
  {
  	struct rio_dev *rdev;
  
  	rdev = to_rio_dev(dev);
  	kfree(rdev);
  }
  
  /**
   * rio_is_switch- Tests if a RIO device has switch capabilities
   * @rdev: RIO device
   *
   * Gets the RIO device Processing Element Features register
   * contents and tests for switch capabilities. Returns 1 if
   * the device is a switch or 0 if it is not a switch.
   * The RIO device struct is freed.
   */
  static int rio_is_switch(struct rio_dev *rdev)
  {
  	if (rdev->pef & RIO_PEF_SWITCH)
  		return 1;
  	return 0;
  }
  
  /**

   * rio_setup_device- Allocates and sets up a RIO device
   * @net: RIO network
   * @port: Master port to send transactions
   * @destid: Current destination ID
   * @hopcount: Current hopcount
   * @do_enum: Enumeration/Discovery mode flag
   *
   * Allocates a RIO device and configures fields based on configuration
   * space contents. If device has a destination ID register, a destination
   * ID is either assigned in enumeration mode or read from configuration
   * space in discovery mode.  If the device has switch capabilities, then
   * a switch is allocated and configured appropriately. Returns a pointer
   * to a RIO device on success or NULL on failure.
   *
   */

  static struct rio_dev *rio_setup_device(struct rio_net *net,

  					struct rio_mport *port, u16 destid,
  					u8 hopcount, int do_enum)
  {

  	int ret = 0;

  	struct rio_dev *rdev;

  	struct rio_switch *rswitch = NULL;

  	int result, rdid;

  	size_t size;
  	u32 swpinfo = 0;

  	size = sizeof(struct rio_dev);
  	if (rio_mport_read_config_32(port, destid, hopcount,
  				     RIO_PEF_CAR, &result))
  		return NULL;
  
  	if (result & (RIO_PEF_SWITCH | RIO_PEF_MULTIPORT)) {
  		rio_mport_read_config_32(port, destid, hopcount,
  					 RIO_SWP_INFO_CAR, &swpinfo);
  		if (result & RIO_PEF_SWITCH) {
  			size += (RIO_GET_TOTAL_PORTS(swpinfo) *
  				sizeof(rswitch->nextdev[0])) + sizeof(*rswitch);
  		}
  	}
  
  	rdev = kzalloc(size, GFP_KERNEL);

  	if (!rdev)

  		return NULL;

  	rdev->net = net;

  	rdev->pef = result;
  	rdev->swpinfo = swpinfo;

  	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
  				 &result);
  	rdev->did = result >> 16;
  	rdev->vid = result & 0xffff;
  	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
  				 &rdev->device_rev);
  	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
  				 &result);
  	rdev->asm_did = result >> 16;
  	rdev->asm_vid = result & 0xffff;
  	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
  				 &result);
  	rdev->asm_rev = result >> 16;

  	if (rdev->pef & RIO_PEF_EXT_FEATURES) {

  		rdev->efptr = result & 0xffff;

  		rdev->phys_efptr = rio_mport_get_physefb(port, 0, destid,
  							 hopcount);
  
  		rdev->em_efptr = rio_mport_get_feature(port, 0, destid,
  						hopcount, RIO_EFB_ERR_MGMNT);
  	}

  
  	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
  				 &rdev->src_ops);
  	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
  				 &rdev->dst_ops);

  	if (do_enum) {
  		/* Assign component tag to device */
  		if (next_comptag >= 0x10000) {
  			pr_err("RIO: Component Tag Counter Overflow
  ");
  			goto cleanup;
  		}
  		rio_mport_write_config_32(port, destid, hopcount,
  					  RIO_COMPONENT_TAG_CSR, next_comptag);
  		rdev->comp_tag = next_comptag++;

  		rdev->do_enum = true;

  	}  else {
  		rio_mport_read_config_32(port, destid, hopcount,
  					 RIO_COMPONENT_TAG_CSR,
  					 &rdev->comp_tag);

  	}

  	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)) {
  		if (do_enum) {
  			rio_set_device_id(port, destid, hopcount, next_destid);

  			rdev->destid = next_destid;
  			next_destid = rio_destid_alloc(net);

  		} else
  			rdev->destid = rio_get_device_id(port, destid, hopcount);

  
  		rdev->hopcount = 0xff;
  	} else {
  		/* Switch device has an associated destID which
  		 * will be adjusted later
  		 */
  		rdev->destid = destid;
  		rdev->hopcount = hopcount;
  	}

  
  	/* If a PE has both switch and other functions, show it as a switch */
  	if (rio_is_switch(rdev)) {

  		rswitch = rdev->rswitch;

  		rswitch->port_ok = 0;

  		spin_lock_init(&rswitch->lock);

  		rswitch->route_table = kzalloc(sizeof(u8)*
  					RIO_MAX_ROUTE_ENTRIES(port->sys_size),
  					GFP_KERNEL);

  		if (!rswitch->route_table)
  			goto cleanup;

  		/* Initialize switch route table */

  		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES(port->sys_size);
  				rdid++)

  			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;

  		dev_set_name(&rdev->dev, "%02x:s:%04x", rdev->net->id,

  			     rdev->comp_tag & RIO_CTAG_UDEVID);

  		if (do_enum)
  			rio_route_clr_table(rdev, RIO_GLOBAL_TABLE, 0);

  		list_add_tail(&rswitch->node, &net->switches);

  	} else {
  		if (do_enum)
  			/*Enable Input Output Port (transmitter reviever)*/
  			rio_enable_rx_tx_port(port, 0, destid, hopcount, 0);

  		dev_set_name(&rdev->dev, "%02x:e:%04x", rdev->net->id,

  			     rdev->comp_tag & RIO_CTAG_UDEVID);

  	}

  	rdev->dev.parent = &port->dev;

  	rio_attach_device(rdev);

  
  	device_initialize(&rdev->dev);
  	rdev->dev.release = rio_release_dev;
  	rio_dev_get(rdev);

  	rdev->dma_mask = DMA_BIT_MASK(32);

  	rdev->dev.dma_mask = &rdev->dma_mask;

  	rdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

  	if (rdev->dst_ops & RIO_DST_OPS_DOORBELL)

  		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
  				   0, 0xffff);

  	ret = rio_add_device(rdev);
  	if (ret)
  		goto cleanup;

  	return rdev;

  
  cleanup:

  	if (rswitch)

  		kfree(rswitch->route_table);

  	kfree(rdev);
  	return NULL;

  }
  
  /**
   * rio_sport_is_active- Tests if a switch port has an active connection.
   * @port: Master port to send transaction
   * @destid: Associated destination ID for switch
   * @hopcount: Hopcount to reach switch
   * @sport: Switch port number
   *
   * Reads the port error status CSR for a particular switch port to
   * determine if the port has an active link.  Returns

   * %RIO_PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is

   * inactive.
   */
  static int
  rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
  {

  	u32 result = 0;

  	u32 ext_ftr_ptr;

  	ext_ftr_ptr = rio_mport_get_efb(port, 0, destid, hopcount, 0);

  	while (ext_ftr_ptr) {
  		rio_mport_read_config_32(port, destid, hopcount,
  					 ext_ftr_ptr, &result);
  		result = RIO_GET_BLOCK_ID(result);
  		if ((result == RIO_EFB_SER_EP_FREE_ID) ||
  		    (result == RIO_EFB_SER_EP_FREE_ID_V13P) ||
  		    (result == RIO_EFB_SER_EP_FREC_ID))

  			break;

  
  		ext_ftr_ptr = rio_mport_get_efb(port, 0, destid, hopcount,
  						ext_ftr_ptr);
  	}

  
  	if (ext_ftr_ptr)
  		rio_mport_read_config_32(port, destid, hopcount,
  					 ext_ftr_ptr +
  					 RIO_PORT_N_ERR_STS_CSR(sport),
  					 &result);

  	return result & RIO_PORT_N_ERR_STS_PORT_OK;

  }
  
  /**

   * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
   * @port: Master port to send transaction
   * @hopcount: Number of hops to the device
   *
   * Used during enumeration to read the Host Device ID Lock CSR on a
   * RIO device. Returns the value of the lock register.
   */
  static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
  {
  	u32 result;

  	rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size), hopcount,

  				 RIO_HOST_DID_LOCK_CSR, &result);
  
  	return (u16) (result & 0xffff);
  }
  
  /**

   * rio_enum_peer- Recursively enumerate a RIO network through a master port
   * @net: RIO network being enumerated
   * @port: Master port to send transactions
   * @hopcount: Number of hops into the network

   * @prev: Previous RIO device connected to the enumerated one
   * @prev_port: Port on previous RIO device

   *
   * Recursively enumerates a RIO network.  Transactions are sent via the
   * master port passed in @port.
   */

  static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,

  			 u8 hopcount, struct rio_dev *prev, int prev_port)

  {

  	struct rio_dev *rdev;

  	u32 regval;

  	int tmp;

  	if (rio_mport_chk_dev_access(port,
  			RIO_ANY_DESTID(port->sys_size), hopcount)) {
  		pr_debug("RIO: device access check failed
  ");
  		return -1;
  	}

  	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
  		pr_debug("RIO: PE already discovered by this host
  ");
  		/*
  		 * Already discovered by this host. Add it as another

  		 * link to the existing device.

  		 */

  		rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size),
  				hopcount, RIO_COMPONENT_TAG_CSR, &regval);
  
  		if (regval) {
  			rdev = rio_get_comptag((regval & 0xffff), NULL);
  
  			if (rdev && prev && rio_is_switch(prev)) {
  				pr_debug("RIO: redundant path to %s
  ",
  					 rio_name(rdev));
  				prev->rswitch->nextdev[prev_port] = rdev;
  			}
  		}

  		return 0;
  	}
  
  	/* Attempt to acquire device lock */

  	rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
  				  hopcount,

  				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
  	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
  	       < port->host_deviceid) {
  		/* Delay a bit */
  		mdelay(1);
  		/* Attempt to acquire device lock again */

  		rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
  					  hopcount,

  					  RIO_HOST_DID_LOCK_CSR,
  					  port->host_deviceid);
  	}
  
  	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
  		pr_debug(
  		    "RIO: PE locked by a higher priority host...retreating
  ");
  		return -1;
  	}
  
  	/* Setup new RIO device */

  	rdev = rio_setup_device(net, port, RIO_ANY_DESTID(port->sys_size),
  					hopcount, 1);
  	if (rdev) {

  		/* Add device to the global and bus/net specific list. */
  		list_add_tail(&rdev->net_list, &net->devices);

  		rdev->prev = prev;
  		if (prev && rio_is_switch(prev))
  			prev->rswitch->nextdev[prev_port] = rdev;

  	} else
  		return -1;
  
  	if (rio_is_switch(rdev)) {

  		int sw_destid;
  		int cur_destid;
  		int sw_inport;
  		u16 destid;
  		int port_num;

  		sw_inport = RIO_GET_PORT_NUM(rdev->swpinfo);

  		rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,

  				    port->host_deviceid, sw_inport, 0);

  		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;

  		destid = rio_destid_first(net);
  		while (destid != RIO_INVALID_DESTID && destid < next_destid) {
  			if (destid != port->host_deviceid) {
  				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
  						    destid, sw_inport, 0);
  				rdev->rswitch->route_table[destid] = sw_inport;
  			}
  			destid = rio_destid_next(net, destid + 1);

  		}

  		pr_debug(
  		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports
  ",

  		    rio_name(rdev), rdev->vid, rdev->did,
  		    RIO_GET_TOTAL_PORTS(rdev->swpinfo));

  		sw_destid = next_destid;

  		for (port_num = 0;
  		     port_num < RIO_GET_TOTAL_PORTS(rdev->swpinfo);
  		     port_num++) {

  			if (sw_inport == port_num) {
  				rio_enable_rx_tx_port(port, 0,

  					      RIO_ANY_DESTID(port->sys_size),
  					      hopcount, port_num);

  				rdev->rswitch->port_ok |= (1 << port_num);

  				continue;

  			}

  
  			cur_destid = next_destid;
  
  			if (rio_sport_is_active

  			    (port, RIO_ANY_DESTID(port->sys_size), hopcount,
  			     port_num)) {

  				pr_debug(
  				    "RIO: scanning device on port %d
  ",
  				    port_num);

  				rio_enable_rx_tx_port(port, 0,
  					      RIO_ANY_DESTID(port->sys_size),
  					      hopcount, port_num);

  				rdev->rswitch->port_ok |= (1 << port_num);

  				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,

  						RIO_ANY_DESTID(port->sys_size),

  						port_num, 0);

  				if (rio_enum_peer(net, port, hopcount + 1,
  						  rdev, port_num) < 0)

  					return -1;
  
  				/* Update routing tables */

  				destid = rio_destid_next(net, cur_destid + 1);
  				if (destid != RIO_INVALID_DESTID) {

  					for (destid = cur_destid;

  					     destid < next_destid;) {
  						if (destid != port->host_deviceid) {
  							rio_route_add_entry(rdev,

  								    RIO_GLOBAL_TABLE,
  								    destid,

  								    port_num,
  								    0);

  							rdev->rswitch->
  								route_table[destid] =
  								port_num;
  						}
  						destid = rio_destid_next(net,
  								destid + 1);

  					}

  				}

  			} else {
  				/* If switch supports Error Management,
  				 * set PORT_LOCKOUT bit for unused port
  				 */
  				if (rdev->em_efptr)
  					rio_set_port_lockout(rdev, port_num, 1);
  
  				rdev->rswitch->port_ok &= ~(1 << port_num);

  			}
  		}

  		/* Direct Port-write messages to the enumeratiing host */
  		if ((rdev->src_ops & RIO_SRC_OPS_PORT_WRITE) &&
  		    (rdev->em_efptr)) {
  			rio_write_config_32(rdev,
  					rdev->em_efptr + RIO_EM_PW_TGT_DEVID,
  					(port->host_deviceid << 16) |
  					(port->sys_size << 15));
  		}
  
  		rio_init_em(rdev);

  		/* Check for empty switch */

  		if (next_destid == sw_destid)
  			next_destid = rio_destid_alloc(net);

  		rdev->destid = sw_destid;

  	} else
  		pr_debug("RIO: found %s (vid %4.4x did %4.4x)
  ",
  		    rio_name(rdev), rdev->vid, rdev->did);
  
  	return 0;
  }
  
  /**
   * rio_enum_complete- Tests if enumeration of a network is complete
   * @port: Master port to send transaction
   *

   * Tests the PGCCSR discovered bit for non-zero value (enumeration

   * complete flag). Return %1 if enumeration is complete or %0 if

   * enumeration is incomplete.
   */
  static int rio_enum_complete(struct rio_mport *port)
  {

  	u32 regval;

  	rio_local_read_config_32(port, port->phys_efptr + RIO_PORT_GEN_CTL_CSR,
  				 &regval);

  	return (regval & RIO_PORT_GEN_DISCOVERED) ? 1 : 0;

  }
  
  /**
   * rio_disc_peer- Recursively discovers a RIO network through a master port
   * @net: RIO network being discovered
   * @port: Master port to send transactions
   * @destid: Current destination ID in network
   * @hopcount: Number of hops into the network

   * @prev: previous rio_dev
   * @prev_port: previous port number

   *
   * Recursively discovers a RIO network.  Transactions are sent via the
   * master port passed in @port.
   */

  static int

  rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,

  	      u8 hopcount, struct rio_dev *prev, int prev_port)

  {
  	u8 port_num, route_port;

  	struct rio_dev *rdev;
  	u16 ndestid;
  
  	/* Setup new RIO device */
  	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
  		/* Add device to the global and bus/net specific list. */
  		list_add_tail(&rdev->net_list, &net->devices);

  		rdev->prev = prev;
  		if (prev && rio_is_switch(prev))
  			prev->rswitch->nextdev[prev_port] = rdev;

  	} else
  		return -1;
  
  	if (rio_is_switch(rdev)) {

  		/* Associated destid is how we accessed this switch */

  		rdev->destid = destid;

  		pr_debug(
  		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports
  ",

  		    rio_name(rdev), rdev->vid, rdev->did,
  		    RIO_GET_TOTAL_PORTS(rdev->swpinfo));
  		for (port_num = 0;
  		     port_num < RIO_GET_TOTAL_PORTS(rdev->swpinfo);
  		     port_num++) {

  			if (RIO_GET_PORT_NUM(rdev->swpinfo) == port_num)

  				continue;
  
  			if (rio_sport_is_active
  			    (port, destid, hopcount, port_num)) {
  				pr_debug(
  				    "RIO: scanning device on port %d
  ",
  				    port_num);

  
  				rio_lock_device(port, destid, hopcount, 1000);

  				for (ndestid = 0;
  				     ndestid < RIO_ANY_DESTID(port->sys_size);

  				     ndestid++) {

  					rio_route_get_entry(rdev,

  							    RIO_GLOBAL_TABLE,
  							    ndestid,

  							    &route_port, 0);

  					if (route_port == port_num)
  						break;
  				}

  				if (ndestid == RIO_ANY_DESTID(port->sys_size))
  					continue;

  				rio_unlock_device(port, destid, hopcount);

  				if (rio_disc_peer(net, port, ndestid,
  					hopcount + 1, rdev, port_num) < 0)

  					return -1;
  			}
  		}
  	} else
  		pr_debug("RIO: found %s (vid %4.4x did %4.4x)
  ",
  		    rio_name(rdev), rdev->vid, rdev->did);
  
  	return 0;
  }
  
  /**
   * rio_mport_is_active- Tests if master port link is active
   * @port: Master port to test
   *
   * Reads the port error status CSR for the master port to
   * determine if the port has an active link.  Returns

   * %RIO_PORT_N_ERR_STS_PORT_OK if the  master port is active

   * or %0 if it is inactive.
   */
  static int rio_mport_is_active(struct rio_mport *port)
  {
  	u32 result = 0;
  	u32 ext_ftr_ptr;
  	int *entry = rio_mport_phys_table;
  
  	do {
  		if ((ext_ftr_ptr =
  		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
  			break;
  	} while (*++entry >= 0);
  
  	if (ext_ftr_ptr)
  		rio_local_read_config_32(port,
  					 ext_ftr_ptr +
  					 RIO_PORT_N_ERR_STS_CSR(port->index),
  					 &result);

  	return result & RIO_PORT_N_ERR_STS_PORT_OK;

  }
  
  /**
   * rio_alloc_net- Allocate and configure a new RIO network
   * @port: Master port associated with the RIO network

   * @do_enum: Enumeration/Discovery mode flag
   * @start: logical minimal start id for new net

   *
   * Allocates a RIO network structure, initializes per-network
   * list heads, and adds the associated master port to the
   * network list of associated master ports. Returns a
   * RIO network pointer on success or %NULL on failure.
   */

  static struct rio_net *rio_alloc_net(struct rio_mport *port,

  					       int do_enum, u16 start)

  {
  	struct rio_net *net;

  	net = kzalloc(sizeof(struct rio_net), GFP_KERNEL);

  	if (net && do_enum) {

  		net->destid_table.table = kcalloc(
  			BITS_TO_LONGS(RIO_MAX_ROUTE_ENTRIES(port->sys_size)),

  			sizeof(long),
  			GFP_KERNEL);
  
  		if (net->destid_table.table == NULL) {
  			pr_err("RIO: failed to allocate destID table
  ");
  			kfree(net);
  			net = NULL;
  		} else {
  			net->destid_table.start = start;

  			net->destid_table.max =
  					RIO_MAX_ROUTE_ENTRIES(port->sys_size);
  			spin_lock_init(&net->destid_table.lock);
  		}
  	}

  	if (net) {

  		INIT_LIST_HEAD(&net->node);
  		INIT_LIST_HEAD(&net->devices);

  		INIT_LIST_HEAD(&net->switches);

  		INIT_LIST_HEAD(&net->mports);
  		list_add_tail(&port->nnode, &net->mports);
  		net->hport = port;

  		net->id = port->id;

  	}
  	return net;
  }
  
  /**

   * rio_update_route_tables- Updates route tables in switches

   * @net: RIO network to run update on

   *
   * For each enumerated device, ensure that each switch in a system
   * has correct routing entries. Add routes for devices that where
   * unknown dirung the first enumeration pass through the switch.
   */

  static void rio_update_route_tables(struct rio_net *net)

  {

  	struct rio_dev *rdev, *swrdev;

  	struct rio_switch *rswitch;
  	u8 sport;
  	u16 destid;

  	list_for_each_entry(rdev, &net->devices, net_list) {

  		destid = rdev->destid;

  		list_for_each_entry(rswitch, &net->switches, node) {

  
  			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
  				continue;
  
  			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {

  				swrdev = sw_to_rio_dev(rswitch);

  				/* Skip if destid ends in empty switch*/

  				if (swrdev->destid == destid)

  					continue;

  				sport = RIO_GET_PORT_NUM(swrdev->swpinfo);

  				rio_route_add_entry(swrdev, RIO_GLOBAL_TABLE,
  						    destid, sport, 0);
  				rswitch->route_table[destid] = sport;

  			}
  		}
  	}
  }
  
  /**

   * rio_init_em - Initializes RIO Error Management (for switches)

   * @rdev: RIO device

   *
   * For each enumerated switch, call device-specific error management
   * initialization routine (if supplied by the switch driver).
   */
  static void rio_init_em(struct rio_dev *rdev)
  {
  	if (rio_is_switch(rdev) && (rdev->em_efptr) &&

  	    rdev->rswitch->ops && rdev->rswitch->ops->em_init) {
  		rdev->rswitch->ops->em_init(rdev);

  	}
  }
  
  /**
   * rio_pw_enable - Enables/disables port-write handling by a master port
   * @port: Master port associated with port-write handling
   * @enable:  1=enable,  0=disable
   */
  static void rio_pw_enable(struct rio_mport *port, int enable)
  {
  	if (port->ops->pwenable)
  		port->ops->pwenable(port, enable);
  }
  
  /**

   * rio_enum_mport- Start enumeration through a master port
   * @mport: Master port to send transactions

   * @flags: Enumeration control flags

   *
   * Starts the enumeration process. If somebody has enumerated our
   * master port device, then give up. If not and we have an active
   * link, then start recursive peer enumeration. Returns %0 if
   * enumeration succeeds or %-EBUSY if enumeration fails.
   */

  static int rio_enum_mport(struct rio_mport *mport, u32 flags)

  {
  	struct rio_net *net = NULL;
  	int rc = 0;
  
  	printk(KERN_INFO "RIO: enumerate master port %d, %s
  ", mport->id,
  	       mport->name);

  
  	/*
  	 * To avoid multiple start requests (repeat enumeration is not supported
  	 * by this method) check if enumeration/discovery was performed for this
  	 * mport: if mport was added into the list of mports for a net exit
  	 * with error.
  	 */
  	if (mport->nnode.next || mport->nnode.prev)
  		return -EBUSY;

  	/* If somebody else enumerated our master port device, bail. */
  	if (rio_enum_host(mport) < 0) {
  		printk(KERN_INFO
  		       "RIO: master port %d device has been enumerated by a remote host
  ",
  		       mport->id);
  		rc = -EBUSY;
  		goto out;
  	}
  
  	/* If master port has an active link, allocate net and enum peers */
  	if (rio_mport_is_active(mport)) {

  		net = rio_alloc_net(mport, 1, 0);
  		if (!net) {

  			printk(KERN_ERR "RIO: failed to allocate new net
  ");
  			rc = -ENOMEM;
  			goto out;
  		}

  		/* reserve mport destID in new net */
  		rio_destid_reserve(net, mport->host_deviceid);

  		/* Enable Input Output Port (transmitter reviever) */
  		rio_enable_rx_tx_port(mport, 1, 0, 0, 0);

  		/* Set component tag for host */
  		rio_local_write_config_32(mport, RIO_COMPONENT_TAG_CSR,
  					  next_comptag++);

  		next_destid = rio_destid_alloc(net);

  		if (rio_enum_peer(net, mport, 0, NULL, 0) < 0) {

  			/* A higher priority host won enumeration, bail. */
  			printk(KERN_INFO
  			       "RIO: master port %d device has lost enumeration to a remote host
  ",
  			       mport->id);

  			rio_clear_locks(net);

  			rc = -EBUSY;
  			goto out;
  		}

  		/* free the last allocated destID (unused) */
  		rio_destid_free(net, next_destid);

  		rio_update_route_tables(net);
  		rio_clear_locks(net);

  		rio_pw_enable(mport, 1);

  	} else {
  		printk(KERN_INFO "RIO: master port %d link inactive
  ",
  		       mport->id);
  		rc = -EINVAL;
  	}
  
        out:
  	return rc;
  }
  
  /**
   * rio_build_route_tables- Generate route tables from switch route entries

   * @net: RIO network to run route tables scan on

   *
   * For each switch device, generate a route table by copying existing
   * route entries from the switch.
   */

  static void rio_build_route_tables(struct rio_net *net)

  {

  	struct rio_switch *rswitch;

  	struct rio_dev *rdev;
  	int i;
  	u8 sport;

  	list_for_each_entry(rswitch, &net->switches, node) {
  		rdev = sw_to_rio_dev(rswitch);

  		rio_lock_device(net->hport, rdev->destid,
  				rdev->hopcount, 1000);
  		for (i = 0;
  		     i < RIO_MAX_ROUTE_ENTRIES(net->hport->sys_size);
  		     i++) {
  			if (rio_route_get_entry(rdev, RIO_GLOBAL_TABLE,
  						i, &sport, 0) < 0)
  				continue;
  			rswitch->route_table[i] = sport;

  		}

  
  		rio_unlock_device(net->hport, rdev->destid, rdev->hopcount);
  	}

  }
  
  /**

   * rio_disc_mport- Start discovery through a master port
   * @mport: Master port to send transactions

   * @flags: discovery control flags

   *
   * Starts the discovery process. If we have an active link,

   * then wait for the signal that enumeration is complete (if wait
   * is allowed).

   * When enumeration completion is signaled, start recursive
   * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
   * on failure.
   */

  static int rio_disc_mport(struct rio_mport *mport, u32 flags)

  {
  	struct rio_net *net = NULL;

  	unsigned long to_end;

  
  	printk(KERN_INFO "RIO: discover master port %d, %s
  ", mport->id,
  	       mport->name);
  
  	/* If master port has an active link, allocate net and discover peers */
  	if (rio_mport_is_active(mport)) {

  		if (rio_enum_complete(mport))
  			goto enum_done;
  		else if (flags & RIO_SCAN_ENUM_NO_WAIT)
  			return -EAGAIN;

  		pr_debug("RIO: wait for enumeration to complete...
  ");

  		to_end = jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
  		while (time_before(jiffies, to_end)) {
  			if (rio_enum_complete(mport))
  				goto enum_done;

  			msleep(10);

  		}

  		pr_debug("RIO: discovery timeout on mport %d %s
  ",
  			 mport->id, mport->name);
  		goto bail;
  enum_done:
  		pr_debug("RIO: ... enumeration done
  ");

  		net = rio_alloc_net(mport, 0, 0);

  		if (!net) {
  			printk(KERN_ERR "RIO: Failed to allocate new net
  ");
  			goto bail;
  		}

  
  		/* Read DestID assigned by enumerator */
  		rio_local_read_config_32(mport, RIO_DID_CSR,
  					 &mport->host_deviceid);
  		mport->host_deviceid = RIO_GET_DID(mport->sys_size,
  						   mport->host_deviceid);

  		if (rio_disc_peer(net, mport, RIO_ANY_DESTID(mport->sys_size),

  					0, NULL, 0) < 0) {

  			printk(KERN_INFO
  			       "RIO: master port %d device has failed discovery
  ",
  			       mport->id);
  			goto bail;
  		}

  		rio_build_route_tables(net);

  	}
  
  	return 0;

  bail:

  	return -EBUSY;
  }

  
  static struct rio_scan rio_scan_ops = {

  	.owner = THIS_MODULE,

  	.enumerate = rio_enum_mport,
  	.discover = rio_disc_mport,
  };
  
  static bool scan;
  module_param(scan, bool, 0);
  MODULE_PARM_DESC(scan, "Start RapidIO network enumeration/discovery "
  			"(default = 0)");
  
  /**
   * rio_basic_attach:
   *
   * When this enumeration/discovery method is loaded as a module this function
   * registers its specific enumeration and discover routines for all available
   * RapidIO mport devices. The "scan" command line parameter controls ability of
   * the module to start RapidIO enumeration/discovery automatically.
   *
   * Returns 0 for success or -EIO if unable to register itself.
   *
   * This enumeration/discovery method cannot be unloaded and therefore does not
   * provide a matching cleanup_module routine.
   */
  
  static int __init rio_basic_attach(void)
  {
  	if (rio_register_scan(RIO_MPORT_ANY, &rio_scan_ops))
  		return -EIO;
  	if (scan)
  		rio_init_mports();
  	return 0;
  }
  
  late_initcall(rio_basic_attach);
  
  MODULE_DESCRIPTION("Basic RapidIO enumeration/discovery");
  MODULE_LICENSE("GPL");