/* bnx2i.c: QLogic NetXtreme II iSCSI driver.
   *
   * Copyright (c) 2006 - 2013 Broadcom Corporation
   * Copyright (c) 2007, 2008 Red Hat, Inc.  All rights reserved.
   * Copyright (c) 2007, 2008 Mike Christie
   * Copyright (c) 2014, QLogic Corporation
   *
   * 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.
   *
   * Written by: Anil Veerabhadrappa (anilgv@broadcom.com)
   * Previously Maintained by: Eddie Wai (eddie.wai@broadcom.com)
   * Maintained by: QLogic-Storage-Upstream@qlogic.com
   */
  
  #include "bnx2i.h"
  
  static struct list_head adapter_list = LIST_HEAD_INIT(adapter_list);
  static u32 adapter_count;
  
  #define DRV_MODULE_NAME		"bnx2i"
  #define DRV_MODULE_VERSION	"2.7.10.1"
  #define DRV_MODULE_RELDATE	"Jul 16, 2014"
  
  static char version[] =
  		"QLogic NetXtreme II iSCSI Driver " DRV_MODULE_NAME \
  		" v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")
  ";
  
  
  MODULE_AUTHOR("Anil Veerabhadrappa <anilgv@broadcom.com> and "
  	      "Eddie Wai <eddie.wai@broadcom.com>");
  
  MODULE_DESCRIPTION("QLogic NetXtreme II BCM5706/5708/5709/57710/57711/57712"
  		   "/57800/57810/57840 iSCSI Driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_MODULE_VERSION);
  
  static DEFINE_MUTEX(bnx2i_dev_lock);
  
  unsigned int event_coal_min = 24;
  module_param(event_coal_min, int, 0664);
  MODULE_PARM_DESC(event_coal_min, "Event Coalescing Minimum Commands");
  
  unsigned int event_coal_div = 2;
  module_param(event_coal_div, int, 0664);
  MODULE_PARM_DESC(event_coal_div, "Event Coalescing Divide Factor");
  
  unsigned int en_tcp_dack = 1;
  module_param(en_tcp_dack, int, 0664);
  MODULE_PARM_DESC(en_tcp_dack, "Enable TCP Delayed ACK");
  
  unsigned int error_mask1 = 0x00;
  module_param(error_mask1, uint, 0664);
  MODULE_PARM_DESC(error_mask1, "Config FW iSCSI Error Mask #1");
  
  unsigned int error_mask2 = 0x00;
  module_param(error_mask2, uint, 0664);
  MODULE_PARM_DESC(error_mask2, "Config FW iSCSI Error Mask #2");
  
  unsigned int sq_size;
  module_param(sq_size, int, 0664);
  MODULE_PARM_DESC(sq_size, "Configure SQ size");
  
  unsigned int rq_size = BNX2I_RQ_WQES_DEFAULT;
  module_param(rq_size, int, 0664);
  MODULE_PARM_DESC(rq_size, "Configure RQ size");
  
  u64 iscsi_error_mask = 0x00;
  
  DEFINE_PER_CPU(struct bnx2i_percpu_s, bnx2i_percpu);
  
  static int bnx2i_cpu_callback(struct notifier_block *nfb,
  			      unsigned long action, void *hcpu);
  /* notification function for CPU hotplug events */
  static struct notifier_block bnx2i_cpu_notifier = {
  	.notifier_call = bnx2i_cpu_callback,
  };
  
  
  /**
   * bnx2i_identify_device - identifies NetXtreme II device type
   * @hba: 		Adapter structure pointer
   * @cnic:		Corresponding cnic device
   *
   * This function identifies the NX2 device type and sets appropriate
   *	queue mailbox register access method, 5709 requires driver to
   *	access MBOX regs using *bin* mode
   */
  void bnx2i_identify_device(struct bnx2i_hba *hba, struct cnic_dev *dev)
  {
  	hba->cnic_dev_type = 0;
  	if (test_bit(CNIC_F_BNX2_CLASS, &dev->flags)) {
  		if (hba->pci_did == PCI_DEVICE_ID_NX2_5706 ||
  		    hba->pci_did == PCI_DEVICE_ID_NX2_5706S) {
  			set_bit(BNX2I_NX2_DEV_5706, &hba->cnic_dev_type);
  		} else if (hba->pci_did == PCI_DEVICE_ID_NX2_5708 ||
  		    hba->pci_did == PCI_DEVICE_ID_NX2_5708S) {
  			set_bit(BNX2I_NX2_DEV_5708, &hba->cnic_dev_type);
  		} else if (hba->pci_did == PCI_DEVICE_ID_NX2_5709 ||
  		    hba->pci_did == PCI_DEVICE_ID_NX2_5709S) {
  			set_bit(BNX2I_NX2_DEV_5709, &hba->cnic_dev_type);
  			hba->mail_queue_access = BNX2I_MQ_BIN_MODE;
  		}
  	} else if (test_bit(CNIC_F_BNX2X_CLASS, &dev->flags)) {
  		set_bit(BNX2I_NX2_DEV_57710, &hba->cnic_dev_type);
  	} else {
  		printk(KERN_ALERT "bnx2i: unknown device, 0x%x
  ",
  				  hba->pci_did);
  	}
  }
  
  
  /**
   * get_adapter_list_head - returns head of adapter list
   */
  struct bnx2i_hba *get_adapter_list_head(void)
  {
  	struct bnx2i_hba *hba = NULL;
  	struct bnx2i_hba *tmp_hba;
  
  	if (!adapter_count)
  		goto hba_not_found;
  
  	mutex_lock(&bnx2i_dev_lock);
  	list_for_each_entry(tmp_hba, &adapter_list, link) {
  		if (tmp_hba->cnic && tmp_hba->cnic->cm_select_dev) {
  			hba = tmp_hba;
  			break;
  		}
  	}
  	mutex_unlock(&bnx2i_dev_lock);
  hba_not_found:
  	return hba;
  }
  
  
  /**
   * bnx2i_find_hba_for_cnic - maps cnic device instance to bnx2i adapter instance
   * @cnic:	pointer to cnic device instance
   *
   */
  struct bnx2i_hba *bnx2i_find_hba_for_cnic(struct cnic_dev *cnic)
  {
  	struct bnx2i_hba *hba, *temp;
  
  	mutex_lock(&bnx2i_dev_lock);
  	list_for_each_entry_safe(hba, temp, &adapter_list, link) {
  		if (hba->cnic == cnic) {
  			mutex_unlock(&bnx2i_dev_lock);
  			return hba;
  		}
  	}
  	mutex_unlock(&bnx2i_dev_lock);
  	return NULL;
  }
  
  
  /**
   * bnx2i_start - cnic callback to initialize & start adapter instance
   * @handle:	transparent handle pointing to adapter structure
   *
   * This function maps adapter structure to pcidev structure and initiates
   *	firmware handshake to enable/initialize on chip iscsi components
   * 	This bnx2i - cnic interface api callback is issued after following
   *	2 conditions are met -
   *	  a) underlying network interface is up (marked by event 'NETDEV_UP'
   *		from netdev
   *	  b) bnx2i adapter instance is registered
   */
  void bnx2i_start(void *handle)
  {
  #define BNX2I_INIT_POLL_TIME	(1000 / HZ)
  	struct bnx2i_hba *hba = handle;
  	int i = HZ;
  
  	/* On some bnx2x devices, it is possible that iSCSI is no
  	 * longer supported after firmware is downloaded.  In that
  	 * case, the iscsi_init_msg will return failure.
  	 */
  
  	bnx2i_send_fw_iscsi_init_msg(hba);
  	while (!test_bit(ADAPTER_STATE_UP, &hba->adapter_state) &&
  	       !test_bit(ADAPTER_STATE_INIT_FAILED, &hba->adapter_state) && i--)
  		msleep(BNX2I_INIT_POLL_TIME);
  }
  
  
  /**
   * bnx2i_chip_cleanup - local routine to handle chip cleanup
   * @hba:	Adapter instance to register
   *
   * Driver checks if adapter still has any active connections before
   *	executing the cleanup process
   */
  static void bnx2i_chip_cleanup(struct bnx2i_hba *hba)
  {
  	struct bnx2i_endpoint *bnx2i_ep;
  	struct list_head *pos, *tmp;
  
  	if (hba->ofld_conns_active) {
  		/* Stage to force the disconnection
  		 * This is the case where the daemon is either slow or
  		 * not present
  		 */
  		printk(KERN_ALERT "bnx2i: (%s) chip cleanup for %d active "
  			"connections
  ", hba->netdev->name,
  			hba->ofld_conns_active);
  		mutex_lock(&hba->net_dev_lock);
  		list_for_each_safe(pos, tmp, &hba->ep_active_list) {
  			bnx2i_ep = list_entry(pos, struct bnx2i_endpoint, link);
  			/* Clean up the chip only */
  			bnx2i_hw_ep_disconnect(bnx2i_ep);
  			bnx2i_ep->cm_sk = NULL;
  		}
  		mutex_unlock(&hba->net_dev_lock);
  	}
  }
  
  
  /**
   * bnx2i_stop - cnic callback to shutdown adapter instance
   * @handle:	transparent handle pointing to adapter structure
   *
   * driver checks if adapter is already in shutdown mode, if not start
   *	the shutdown process
   */
  void bnx2i_stop(void *handle)
  {
  	struct bnx2i_hba *hba = handle;
  	int conns_active;
  	int wait_delay = 1 * HZ;
  
  	/* check if cleanup happened in GOING_DOWN context */
  	if (!test_and_set_bit(ADAPTER_STATE_GOING_DOWN,
  			      &hba->adapter_state)) {
  		iscsi_host_for_each_session(hba->shost,
  					    bnx2i_drop_session);
  		wait_delay = hba->hba_shutdown_tmo;
  	}
  	/* Wait for inflight offload connection tasks to complete before
  	 * proceeding. Forcefully terminate all connection recovery in
  	 * progress at the earliest, either in bind(), send_pdu(LOGIN),
  	 * or conn_start()
  	 */
  	wait_event_interruptible_timeout(hba->eh_wait,
  					 (list_empty(&hba->ep_ofld_list) &&
  					 list_empty(&hba->ep_destroy_list)),
  					 2 * HZ);
  	/* Wait for all endpoints to be torn down, Chip will be reset once
  	 *  control returns to network driver. So it is required to cleanup and
  	 * release all connection resources before returning from this routine.
  	 */
  	while (hba->ofld_conns_active) {
  		conns_active = hba->ofld_conns_active;
  		wait_event_interruptible_timeout(hba->eh_wait,
  				(hba->ofld_conns_active != conns_active),
  				wait_delay);
  		if (hba->ofld_conns_active == conns_active)
  			break;
  	}
  	bnx2i_chip_cleanup(hba);
  
  	/* This flag should be cleared last so that ep_disconnect() gracefully
  	 * cleans up connection context
  	 */
  	clear_bit(ADAPTER_STATE_GOING_DOWN, &hba->adapter_state);
  	clear_bit(ADAPTER_STATE_UP, &hba->adapter_state);
  }
  
  
  /**
   * bnx2i_init_one - initialize an adapter instance and allocate memory resources
   * @hba:	bnx2i adapter instance
   * @cnic:	cnic device handle
   *
   * Global resource lock is held during critical sections below. This routine is
   *	called from either cnic_register_driver() or device hot plug context and
   *	and does majority of device specific initialization
   */
  static int bnx2i_init_one(struct bnx2i_hba *hba, struct cnic_dev *cnic)
  {
  	int rc;
  
  	mutex_lock(&bnx2i_dev_lock);
  	if (!cnic->max_iscsi_conn) {
  		printk(KERN_ALERT "bnx2i: dev %s does not support "
  			"iSCSI
  ", hba->netdev->name);
  		rc = -EOPNOTSUPP;
  		goto out;
  	}
  
  	hba->cnic = cnic;
  	rc = cnic->register_device(cnic, CNIC_ULP_ISCSI, hba);
  	if (!rc) {
  		hba->age++;
  		set_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic);
  		list_add_tail(&hba->link, &adapter_list);
  		adapter_count++;
  	} else if (rc == -EBUSY) 	/* duplicate registration */
  		printk(KERN_ALERT "bnx2i, duplicate registration"
  				  "hba=%p, cnic=%p
  ", hba, cnic);
  	else if (rc == -EAGAIN)
  		printk(KERN_ERR "bnx2i, driver not registered
  ");
  	else if (rc == -EINVAL)
  		printk(KERN_ERR "bnx2i, invalid type %d
  ", CNIC_ULP_ISCSI);
  	else
  		printk(KERN_ERR "bnx2i dev reg, unknown error, %d
  ", rc);
  
  out:
  	mutex_unlock(&bnx2i_dev_lock);
  
  	return rc;
  }
  
  
  /**
   * bnx2i_ulp_init - initialize an adapter instance
   * @dev:	cnic device handle
   *
   * Called from cnic_register_driver() context to initialize all enumerated
   *	cnic devices. This routine allocate adapter structure and other
   *	device specific resources.
   */
  void bnx2i_ulp_init(struct cnic_dev *dev)
  {
  	struct bnx2i_hba *hba;
  
  	/* Allocate a HBA structure for this device */
  	hba = bnx2i_alloc_hba(dev);
  	if (!hba) {
  		printk(KERN_ERR "bnx2i init: hba initialization failed
  ");
  		return;
  	}
  
  	/* Get PCI related information and update hba struct members */
  	clear_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic);
  	if (bnx2i_init_one(hba, dev)) {
  		printk(KERN_ERR "bnx2i - hba %p init failed
  ", hba);
  		bnx2i_free_hba(hba);
  	}
  }
  
  
  /**
   * bnx2i_ulp_exit - shuts down adapter instance and frees all resources
   * @dev:	cnic device handle
   *
   */
  void bnx2i_ulp_exit(struct cnic_dev *dev)
  {
  	struct bnx2i_hba *hba;
  
  	hba = bnx2i_find_hba_for_cnic(dev);
  	if (!hba) {
  		printk(KERN_INFO "bnx2i_ulp_exit: hba not "
  				 "found, dev 0x%p
  ", dev);
  		return;
  	}
  	mutex_lock(&bnx2i_dev_lock);
  	list_del_init(&hba->link);
  	adapter_count--;
  
  	if (test_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic)) {
  		hba->cnic->unregister_device(hba->cnic, CNIC_ULP_ISCSI);
  		clear_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic);
  	}
  	mutex_unlock(&bnx2i_dev_lock);
  
  	bnx2i_free_hba(hba);
  }
  
  
  /**
   * bnx2i_get_stats - Retrieve various statistic from iSCSI offload
   * @handle:	bnx2i_hba
   *
   * function callback exported via bnx2i - cnic driver interface to
   *      retrieve various iSCSI offload related statistics.
   */
  int bnx2i_get_stats(void *handle)
  {
  	struct bnx2i_hba *hba = handle;
  	struct iscsi_stats_info *stats;
  
  	if (!hba)
  		return -EINVAL;
  
  	stats = (struct iscsi_stats_info *)hba->cnic->stats_addr;
  
  	if (!stats)
  		return -ENOMEM;
  
  	strlcpy(stats->version, DRV_MODULE_VERSION, sizeof(stats->version));
  	memcpy(stats->mac_add1 + 2, hba->cnic->mac_addr, ETH_ALEN);
  
  	stats->max_frame_size = hba->netdev->mtu;
  	stats->txq_size = hba->max_sqes;
  	stats->rxq_size = hba->max_cqes;
  
  	stats->txq_avg_depth = 0;
  	stats->rxq_avg_depth = 0;
  
  	GET_STATS_64(hba, stats, rx_pdus);
  	GET_STATS_64(hba, stats, rx_bytes);
  
  	GET_STATS_64(hba, stats, tx_pdus);
  	GET_STATS_64(hba, stats, tx_bytes);
  
  	return 0;
  }
  
  
  /**
   * bnx2i_percpu_thread_create - Create a receive thread for an
   *				online CPU
   *
   * @cpu:	cpu index for the online cpu
   */
  static void bnx2i_percpu_thread_create(unsigned int cpu)
  {
  	struct bnx2i_percpu_s *p;
  	struct task_struct *thread;
  
  	p = &per_cpu(bnx2i_percpu, cpu);
  
  	thread = kthread_create_on_node(bnx2i_percpu_io_thread, (void *)p,
  					cpu_to_node(cpu),
  					"bnx2i_thread/%d", cpu);
  	/* bind thread to the cpu */
  	if (likely(!IS_ERR(thread))) {
  		kthread_bind(thread, cpu);
  		p->iothread = thread;
  		wake_up_process(thread);
  	}
  }
  
  
  static void bnx2i_percpu_thread_destroy(unsigned int cpu)
  {
  	struct bnx2i_percpu_s *p;
  	struct task_struct *thread;
  	struct bnx2i_work *work, *tmp;
  
  	/* Prevent any new work from being queued for this CPU */
  	p = &per_cpu(bnx2i_percpu, cpu);
  	spin_lock_bh(&p->p_work_lock);
  	thread = p->iothread;
  	p->iothread = NULL;
  
  	/* Free all work in the list */
  	list_for_each_entry_safe(work, tmp, &p->work_list, list) {
  		list_del_init(&work->list);
  		bnx2i_process_scsi_cmd_resp(work->session,
  					    work->bnx2i_conn, &work->cqe);
  		kfree(work);
  	}
  
  	spin_unlock_bh(&p->p_work_lock);
  	if (thread)
  		kthread_stop(thread);
  }
  
  
  /**
   * bnx2i_cpu_callback - Handler for CPU hotplug events
   *
   * @nfb:	The callback data block
   * @action:	The event triggering the callback
   * @hcpu:	The index of the CPU that the event is for
   *
   * This creates or destroys per-CPU data for iSCSI
   *
   * Returns NOTIFY_OK always.
   */
  static int bnx2i_cpu_callback(struct notifier_block *nfb,
  			      unsigned long action, void *hcpu)
  {
  	unsigned cpu = (unsigned long)hcpu;
  
  	switch (action) {
  	case CPU_ONLINE:
  	case CPU_ONLINE_FROZEN:
  		printk(KERN_INFO "bnx2i: CPU %x online: Create Rx thread
  ",
  			cpu);
  		bnx2i_percpu_thread_create(cpu);
  		break;
  	case CPU_DEAD:
  	case CPU_DEAD_FROZEN:
  		printk(KERN_INFO "CPU %x offline: Remove Rx thread
  ", cpu);
  		bnx2i_percpu_thread_destroy(cpu);
  		break;
  	default:
  		break;
  	}
  	return NOTIFY_OK;
  }
  
  
  /**
   * bnx2i_mod_init - module init entry point
   *
   * initialize any driver wide global data structures such as endpoint pool,
   *	tcp port manager/queue, sysfs. finally driver will register itself
   *	with the cnic module
   */
  static int __init bnx2i_mod_init(void)
  {
  	int err;
  	unsigned cpu = 0;
  	struct bnx2i_percpu_s *p;
  
  	printk(KERN_INFO "%s", version);
  
  	if (sq_size && !is_power_of_2(sq_size))
  		sq_size = roundup_pow_of_two(sq_size);
  
  	mutex_init(&bnx2i_dev_lock);
  
  	bnx2i_scsi_xport_template =
  			iscsi_register_transport(&bnx2i_iscsi_transport);
  	if (!bnx2i_scsi_xport_template) {
  		printk(KERN_ERR "Could not register bnx2i transport.
  ");
  		err = -ENOMEM;
  		goto out;
  	}
  
  	err = cnic_register_driver(CNIC_ULP_ISCSI, &bnx2i_cnic_cb);
  	if (err) {
  		printk(KERN_ERR "Could not register bnx2i cnic driver.
  ");
  		goto unreg_xport;
  	}
  
  	/* Create percpu kernel threads to handle iSCSI I/O completions */
  	for_each_possible_cpu(cpu) {
  		p = &per_cpu(bnx2i_percpu, cpu);
  		INIT_LIST_HEAD(&p->work_list);
  		spin_lock_init(&p->p_work_lock);
  		p->iothread = NULL;
  	}
  
  	cpu_notifier_register_begin();
  
  	for_each_online_cpu(cpu)
  		bnx2i_percpu_thread_create(cpu);
  
  	/* Initialize per CPU interrupt thread */
  	__register_hotcpu_notifier(&bnx2i_cpu_notifier);
  
  	cpu_notifier_register_done();
  
  	return 0;
  
  unreg_xport:
  	iscsi_unregister_transport(&bnx2i_iscsi_transport);
  out:
  	return err;
  }
  
  
  /**
   * bnx2i_mod_exit - module cleanup/exit entry point
   *
   * Global resource lock and host adapter lock is held during critical sections
   *	in this function. Driver will browse through the adapter list, cleans-up
   *	each instance, unregisters iscsi transport name and finally driver will
   *	unregister itself with the cnic module
   */
  static void __exit bnx2i_mod_exit(void)
  {
  	struct bnx2i_hba *hba;
  	unsigned cpu = 0;
  
  	mutex_lock(&bnx2i_dev_lock);
  	while (!list_empty(&adapter_list)) {
  		hba = list_entry(adapter_list.next, struct bnx2i_hba, link);
  		list_del(&hba->link);
  		adapter_count--;
  
  		if (test_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic)) {
  			bnx2i_chip_cleanup(hba);
  			hba->cnic->unregister_device(hba->cnic, CNIC_ULP_ISCSI);
  			clear_bit(BNX2I_CNIC_REGISTERED, &hba->reg_with_cnic);
  		}
  
  		bnx2i_free_hba(hba);
  	}
  	mutex_unlock(&bnx2i_dev_lock);
  
  	cpu_notifier_register_begin();
  
  	for_each_online_cpu(cpu)
  		bnx2i_percpu_thread_destroy(cpu);
  
  	__unregister_hotcpu_notifier(&bnx2i_cpu_notifier);
  
  	cpu_notifier_register_done();
  
  	iscsi_unregister_transport(&bnx2i_iscsi_transport);
  	cnic_unregister_driver(CNIC_ULP_ISCSI);
  }
  
  module_init(bnx2i_mod_init);
  module_exit(bnx2i_mod_exit);