/*
   * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
   * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer in the documentation and/or other materials
   *        provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <linux/workqueue.h>
  #include <linux/module.h>
  
  #include "mlx4.h"
  
  enum {
  	MLX4_CATAS_POLL_INTERVAL	= 5 * HZ,
  };
  
  
  
  int mlx4_internal_err_reset = 1;
  module_param_named(internal_err_reset, mlx4_internal_err_reset,  int, 0644);
  MODULE_PARM_DESC(internal_err_reset,
  		 "Reset device on internal errors if non-zero (default 1)");
  
  static int read_vendor_id(struct mlx4_dev *dev)
  {
  	u16 vendor_id = 0;
  	int ret;
  
  	ret = pci_read_config_word(dev->persist->pdev, 0, &vendor_id);
  	if (ret) {
  		mlx4_err(dev, "Failed to read vendor ID, ret=%d
  ", ret);
  		return ret;
  	}
  
  	if (vendor_id == 0xffff) {
  		mlx4_err(dev, "PCI can't be accessed to read vendor id
  ");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int mlx4_reset_master(struct mlx4_dev *dev)
  {
  	int err = 0;
  
  	if (mlx4_is_master(dev))
  		mlx4_report_internal_err_comm_event(dev);
  
  	if (!pci_channel_offline(dev->persist->pdev)) {
  		err = read_vendor_id(dev);
  		/* If PCI can't be accessed to read vendor ID we assume that its
  		 * link was disabled and chip was already reset.
  		 */
  		if (err)
  			return 0;
  
  		err = mlx4_reset(dev);
  		if (err)
  			mlx4_err(dev, "Fail to reset HCA
  ");
  	}
  
  	return err;
  }
  
  static int mlx4_reset_slave(struct mlx4_dev *dev)
  {
  #define COM_CHAN_RST_REQ_OFFSET 0x10
  #define COM_CHAN_RST_ACK_OFFSET 0x08
  
  	u32 comm_flags;
  	u32 rst_req;
  	u32 rst_ack;
  	unsigned long end;
  	struct mlx4_priv *priv = mlx4_priv(dev);
  
  	if (pci_channel_offline(dev->persist->pdev))
  		return 0;
  
  	comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
  				  MLX4_COMM_CHAN_FLAGS));
  	if (comm_flags == 0xffffffff) {
  		mlx4_err(dev, "VF reset is not needed
  ");
  		return 0;
  	}
  
  	if (!(dev->caps.vf_caps & MLX4_VF_CAP_FLAG_RESET)) {
  		mlx4_err(dev, "VF reset is not supported
  ");
  		return -EOPNOTSUPP;
  	}
  
  	rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
  		COM_CHAN_RST_REQ_OFFSET;
  	rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
  		COM_CHAN_RST_ACK_OFFSET;
  	if (rst_req != rst_ack) {
  		mlx4_err(dev, "Communication channel isn't sync, fail to send reset
  ");
  		return -EIO;
  	}
  
  	rst_req ^= 1;
  	mlx4_warn(dev, "VF is sending reset request to Firmware
  ");
  	comm_flags = rst_req << COM_CHAN_RST_REQ_OFFSET;
  	__raw_writel((__force u32)cpu_to_be32(comm_flags),
  		     (__iomem char *)priv->mfunc.comm + MLX4_COMM_CHAN_FLAGS);
  	/* Make sure that our comm channel write doesn't
  	 * get mixed in with writes from another CPU.
  	 */
  	mmiowb();
  
  	end = msecs_to_jiffies(MLX4_COMM_TIME) + jiffies;
  	while (time_before(jiffies, end)) {
  		comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
  					  MLX4_COMM_CHAN_FLAGS));
  		rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
  			COM_CHAN_RST_ACK_OFFSET;
  
  		/* Reading rst_req again since the communication channel can
  		 * be reset at any time by the PF and all its bits will be
  		 * set to zero.
  		 */
  		rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
  			COM_CHAN_RST_REQ_OFFSET;
  
  		if (rst_ack == rst_req) {
  			mlx4_warn(dev, "VF Reset succeed
  ");
  			return 0;
  		}
  		cond_resched();
  	}
  	mlx4_err(dev, "Fail to send reset over the communication channel
  ");
  	return -ETIMEDOUT;
  }
  
  static int mlx4_comm_internal_err(u32 slave_read)
  {
  	return (u32)COMM_CHAN_EVENT_INTERNAL_ERR ==
  		(slave_read & (u32)COMM_CHAN_EVENT_INTERNAL_ERR) ? 1 : 0;
  }
  
  void mlx4_enter_error_state(struct mlx4_dev_persistent *persist)
  {
  	int err;
  	struct mlx4_dev *dev;
  
  	if (!mlx4_internal_err_reset)
  		return;
  
  	mutex_lock(&persist->device_state_mutex);
  	if (persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR)
  		goto out;
  
  	dev = persist->dev;
  	mlx4_err(dev, "device is going to be reset
  ");
  	if (mlx4_is_slave(dev))
  		err = mlx4_reset_slave(dev);
  	else
  		err = mlx4_reset_master(dev);
  	BUG_ON(err != 0);
  
  	dev->persist->state |= MLX4_DEVICE_STATE_INTERNAL_ERROR;
  	mlx4_err(dev, "device was reset successfully
  ");
  	mutex_unlock(&persist->device_state_mutex);
  
  	/* At that step HW was already reset, now notify clients */
  	mlx4_dispatch_event(dev, MLX4_DEV_EVENT_CATASTROPHIC_ERROR, 0);
  	mlx4_cmd_wake_completions(dev);
  	return;
  
  out:
  	mutex_unlock(&persist->device_state_mutex);
  }
  
  static void mlx4_handle_error_state(struct mlx4_dev_persistent *persist)
  {
  	int err = 0;
  
  	mlx4_enter_error_state(persist);
  	mutex_lock(&persist->interface_state_mutex);
  	if (persist->interface_state & MLX4_INTERFACE_STATE_UP &&
  	    !(persist->interface_state & MLX4_INTERFACE_STATE_DELETION)) {
  		err = mlx4_restart_one(persist->pdev);
  		mlx4_info(persist->dev, "mlx4_restart_one was ended, ret=%d
  ",
  			  err);
  	}
  	mutex_unlock(&persist->interface_state_mutex);
  }
  
  static void dump_err_buf(struct mlx4_dev *dev)
  {
  	struct mlx4_priv *priv = mlx4_priv(dev);
  
  	int i;
  
  	mlx4_err(dev, "Internal error detected:
  ");
  	for (i = 0; i < priv->fw.catas_size; ++i)
  		mlx4_err(dev, "  buf[%02x]: %08x
  ",
  			 i, swab32(readl(priv->catas_err.map + i)));
  }
  
  static void poll_catas(unsigned long dev_ptr)
  {
  	struct mlx4_dev *dev = (struct mlx4_dev *) dev_ptr;
  	struct mlx4_priv *priv = mlx4_priv(dev);
  	u32 slave_read;
  
  	if (mlx4_is_slave(dev)) {
  		slave_read = swab32(readl(&priv->mfunc.comm->slave_read));
  		if (mlx4_comm_internal_err(slave_read)) {
  			mlx4_warn(dev, "Internal error detected on the communication channel
  ");
  			goto internal_err;
  		}
  	} else if (readl(priv->catas_err.map)) {
  		dump_err_buf(dev);
  		goto internal_err;
  	}
  
  	if (dev->persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR) {
  		mlx4_warn(dev, "Internal error mark was detected on device
  ");
  		goto internal_err;
  	}
  
  	mod_timer(&priv->catas_err.timer,
  		  round_jiffies(jiffies + MLX4_CATAS_POLL_INTERVAL));
  	return;
  
  internal_err:
  	if (mlx4_internal_err_reset)
  		queue_work(dev->persist->catas_wq, &dev->persist->catas_work);
  }
  
  static void catas_reset(struct work_struct *work)
  {
  	struct mlx4_dev_persistent *persist =
  		container_of(work, struct mlx4_dev_persistent,
  			     catas_work);
  
  	mlx4_handle_error_state(persist);
  }
  
  void mlx4_start_catas_poll(struct mlx4_dev *dev)
  {
  	struct mlx4_priv *priv = mlx4_priv(dev);
  	phys_addr_t addr;
  
  	INIT_LIST_HEAD(&priv->catas_err.list);
  	init_timer(&priv->catas_err.timer);
  	priv->catas_err.map = NULL;
  
  	if (!mlx4_is_slave(dev)) {
  		addr = pci_resource_start(dev->persist->pdev,
  					  priv->fw.catas_bar) +
  					  priv->fw.catas_offset;
  
  		priv->catas_err.map = ioremap(addr, priv->fw.catas_size * 4);
  		if (!priv->catas_err.map) {
  			mlx4_warn(dev, "Failed to map internal error buffer at 0x%llx
  ",
  				  (unsigned long long)addr);
  			return;
  		}
  	}
  
  	priv->catas_err.timer.data     = (unsigned long) dev;
  	priv->catas_err.timer.function = poll_catas;
  	priv->catas_err.timer.expires  =
  		round_jiffies(jiffies + MLX4_CATAS_POLL_INTERVAL);
  	add_timer(&priv->catas_err.timer);
  }
  
  void mlx4_stop_catas_poll(struct mlx4_dev *dev)
  {
  	struct mlx4_priv *priv = mlx4_priv(dev);
  
  	del_timer_sync(&priv->catas_err.timer);
  
  	if (priv->catas_err.map) {
  		iounmap(priv->catas_err.map);
  		priv->catas_err.map = NULL;
  	}
  
  	if (dev->persist->interface_state & MLX4_INTERFACE_STATE_DELETION)
  		flush_workqueue(dev->persist->catas_wq);
  }
  
  int  mlx4_catas_init(struct mlx4_dev *dev)
  {
  	INIT_WORK(&dev->persist->catas_work, catas_reset);
  	dev->persist->catas_wq = create_singlethread_workqueue("mlx4_health");
  	if (!dev->persist->catas_wq)
  		return -ENOMEM;
  
  	return 0;
  }
  
  void mlx4_catas_end(struct mlx4_dev *dev)
  {
  	if (dev->persist->catas_wq) {
  		destroy_workqueue(dev->persist->catas_wq);
  		dev->persist->catas_wq = NULL;
  	}
  }