/*
  This file is provided under a dual BSD/GPLv2 license.  When using or
  redistributing this file, you may do so under either license.

  GPL LICENSE SUMMARY
  Copyright(c) 2014 Intel Corporation.
  This program is free software; you can redistribute it and/or modify
  it under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  Contact Information:
  qat-linux@intel.com

  BSD LICENSE
  Copyright(c) 2014 Intel Corporation.
  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.
    * Neither the name of Intel Corporation nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/mutex.h>
#include <linux/list.h>
#include "adf_cfg.h"
#include "adf_common_drv.h"

static LIST_HEAD(accel_table);
static LIST_HEAD(vfs_table);
static DEFINE_MUTEX(table_lock);
static uint32_t num_devices;
static u8 id_map[ADF_MAX_DEVICES];

struct vf_id_map {
	u32 bdf;
	u32 id;
	u32 fake_id;
	bool attached;
	struct list_head list;
};

static int adf_get_vf_id(struct adf_accel_dev *vf)
{
	return ((7 * (PCI_SLOT(accel_to_pci_dev(vf)->devfn) - 1)) +
		PCI_FUNC(accel_to_pci_dev(vf)->devfn) +
		(PCI_SLOT(accel_to_pci_dev(vf)->devfn) - 1));
}

static int adf_get_vf_num(struct adf_accel_dev *vf)
{
	return (accel_to_pci_dev(vf)->bus->number << 8) | adf_get_vf_id(vf);
}

static struct vf_id_map *adf_find_vf(u32 bdf)
{
	struct list_head *itr;

	list_for_each(itr, &vfs_table) {
		struct vf_id_map *ptr =
			list_entry(itr, struct vf_id_map, list);

		if (ptr->bdf == bdf)
			return ptr;
	}
	return NULL;
}

static int adf_get_vf_real_id(u32 fake)
{
	struct list_head *itr;

	list_for_each(itr, &vfs_table) {
		struct vf_id_map *ptr =
			list_entry(itr, struct vf_id_map, list);
		if (ptr->fake_id == fake)
			return ptr->id;
	}
	return -1;
}

/**
 * adf_clean_vf_map() - Cleans VF id mapings
 *
 * Function cleans internal ids for virtual functions.
 * @vf: flag indicating whether mappings is cleaned
 *	for vfs only or for vfs and pfs
 */
void adf_clean_vf_map(bool vf)
{
	struct vf_id_map *map;
	struct list_head *ptr, *tmp;

	mutex_lock(&table_lock);
	list_for_each_safe(ptr, tmp, &vfs_table) {
		map = list_entry(ptr, struct vf_id_map, list);
		if (map->bdf != -1) {
			id_map[map->id] = 0;
			num_devices--;
		}

		if (vf && map->bdf == -1)
			continue;

		list_del(ptr);
		kfree(map);
	}
	mutex_unlock(&table_lock);
}
EXPORT_SYMBOL_GPL(adf_clean_vf_map);

/**
 * adf_devmgr_update_class_index() - Update internal index
 * @hw_data:  Pointer to internal device data.
 *
 * Function updates internal dev index for VFs
 */
void adf_devmgr_update_class_index(struct adf_hw_device_data *hw_data)
{
	struct adf_hw_device_class *class = hw_data->dev_class;
	struct list_head *itr;
	int i = 0;

	list_for_each(itr, &accel_table) {
		struct adf_accel_dev *ptr =
				list_entry(itr, struct adf_accel_dev, list);

		if (ptr->hw_device->dev_class == class)
			ptr->hw_device->instance_id = i++;

		if (i == class->instances)
			break;
	}
}
EXPORT_SYMBOL_GPL(adf_devmgr_update_class_index);

static unsigned int adf_find_free_id(void)
{
	unsigned int i;

	for (i = 0; i < ADF_MAX_DEVICES; i++) {
		if (!id_map[i]) {
			id_map[i] = 1;
			return i;
		}
	}
	return ADF_MAX_DEVICES + 1;
}

/**
 * adf_devmgr_add_dev() - Add accel_dev to the acceleration framework
 * @accel_dev:  Pointer to acceleration device.
 * @pf:		Corresponding PF if the accel_dev is a VF
 *
 * Function adds acceleration device to the acceleration framework.
 * To be used by QAT device specific drivers.
 *
 * Return: 0 on success, error code otherwise.
 */
int adf_devmgr_add_dev(struct adf_accel_dev *accel_dev,
		       struct adf_accel_dev *pf)
{
	struct list_head *itr;
	int ret = 0;

	if (num_devices == ADF_MAX_DEVICES) {
		dev_err(&GET_DEV(accel_dev), "Only support up to %d devices\n",
			ADF_MAX_DEVICES);
		return -EFAULT;
	}

	mutex_lock(&table_lock);
	atomic_set(&accel_dev->ref_count, 0);

	/* PF on host or VF on guest */
	if (!accel_dev->is_vf || (accel_dev->is_vf && !pf)) {
		struct vf_id_map *map;

		list_for_each(itr, &accel_table) {
			struct adf_accel_dev *ptr =
				list_entry(itr, struct adf_accel_dev, list);

			if (ptr == accel_dev) {
				ret = -EEXIST;
				goto unlock;
			}
		}

		list_add_tail(&accel_dev->list, &accel_table);
		accel_dev->accel_id = adf_find_free_id();
		if (accel_dev->accel_id > ADF_MAX_DEVICES) {
			ret = -EFAULT;
			goto unlock;
		}
		num_devices++;
		map = kzalloc(sizeof(*map), GFP_KERNEL);
		if (!map) {
			ret = -ENOMEM;
			goto unlock;
		}
		map->bdf = ~0;
		map->id = accel_dev->accel_id;
		map->fake_id = map->id;
		map->attached = true;
		list_add_tail(&map->list, &vfs_table);
	} else if (accel_dev->is_vf && pf) {
		/* VF on host */
		struct vf_id_map *map;

		map = adf_find_vf(adf_get_vf_num(accel_dev));
		if (map) {
			struct vf_id_map *next;

			accel_dev->accel_id = map->id;
			list_add_tail(&accel_dev->list, &accel_table);
			map->fake_id++;
			map->attached = true;
			next = list_next_entry(map, list);
			while (next && &next->list != &vfs_table) {
				next->fake_id++;
				next = list_next_entry(next, list);
			}

			ret = 0;
			goto unlock;
		}

		map = kzalloc(sizeof(*map), GFP_KERNEL);
		if (!map) {
			ret = -ENOMEM;
			goto unlock;
		}
		accel_dev->accel_id = adf_find_free_id();
		if (accel_dev->accel_id > ADF_MAX_DEVICES) {
			kfree(map);
			ret = -EFAULT;
			goto unlock;
		}
		num_devices++;
		list_add_tail(&accel_dev->list, &accel_table);
		map->bdf = adf_get_vf_num(accel_dev);
		map->id = accel_dev->accel_id;
		map->fake_id = map->id;
		map->attached = true;
		list_add_tail(&map->list, &vfs_table);
	}
unlock:
	mutex_unlock(&table_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(adf_devmgr_add_dev);

struct list_head *adf_devmgr_get_head(void)
{
	return &accel_table;
}

/**
 * adf_devmgr_rm_dev() - Remove accel_dev from the acceleration framework.
 * @accel_dev:  Pointer to acceleration device.
 * @pf:		Corresponding PF if the accel_dev is a VF
 *
 * Function removes acceleration device from the acceleration framework.
 * To be used by QAT device specific drivers.
 *
 * Return: void
 */
void adf_devmgr_rm_dev(struct adf_accel_dev *accel_dev,
		       struct adf_accel_dev *pf)
{
	mutex_lock(&table_lock);
	if (!accel_dev->is_vf || (accel_dev->is_vf && !pf)) {
		id_map[accel_dev->accel_id] = 0;
		num_devices--;
	} else if (accel_dev->is_vf && pf) {
		struct vf_id_map *map, *next;

		map = adf_find_vf(adf_get_vf_num(accel_dev));
		if (!map) {
			dev_err(&GET_DEV(accel_dev), "Failed to find VF map\n");
			goto unlock;
		}
		map->fake_id--;
		map->attached = false;
		next = list_next_entry(map, list);
		while (next && &next->list != &vfs_table) {
			next->fake_id--;
			next = list_next_entry(next, list);
		}
	}
unlock:
	list_del(&accel_dev->list);
	mutex_unlock(&table_lock);
}
EXPORT_SYMBOL_GPL(adf_devmgr_rm_dev);

struct adf_accel_dev *adf_devmgr_get_first(void)
{
	struct adf_accel_dev *dev = NULL;

	if (!list_empty(&accel_table))
		dev = list_first_entry(&accel_table, struct adf_accel_dev,
				       list);
	return dev;
}

/**
 * adf_devmgr_pci_to_accel_dev() - Get accel_dev associated with the pci_dev.
 * @accel_dev:  Pointer to pci device.
 *
 * Function returns acceleration device associated with the given pci device.
 * To be used by QAT device specific drivers.
 *
 * Return: pointer to accel_dev or NULL if not found.
 */
struct adf_accel_dev *adf_devmgr_pci_to_accel_dev(struct pci_dev *pci_dev)
{
	struct list_head *itr;

	mutex_lock(&table_lock);
	list_for_each(itr, &accel_table) {
		struct adf_accel_dev *ptr =
				list_entry(itr, struct adf_accel_dev, list);

		if (ptr->accel_pci_dev.pci_dev == pci_dev) {
			mutex_unlock(&table_lock);
			return ptr;
		}
	}
	mutex_unlock(&table_lock);
	return NULL;
}
EXPORT_SYMBOL_GPL(adf_devmgr_pci_to_accel_dev);

struct adf_accel_dev *adf_devmgr_get_dev_by_id(uint32_t id)
{
	struct list_head *itr;
	int real_id;

	mutex_lock(&table_lock);
	real_id = adf_get_vf_real_id(id);
	if (real_id < 0)
		goto unlock;

	id = real_id;

	list_for_each(itr, &accel_table) {
		struct adf_accel_dev *ptr =
				list_entry(itr, struct adf_accel_dev, list);
		if (ptr->accel_id == id) {
			mutex_unlock(&table_lock);
			return ptr;
		}
	}
unlock:
	mutex_unlock(&table_lock);
	return NULL;
}

int adf_devmgr_verify_id(uint32_t id)
{
	if (id == ADF_CFG_ALL_DEVICES)
		return 0;

	if (adf_devmgr_get_dev_by_id(id))
		return 0;

	return -ENODEV;
}

static int adf_get_num_dettached_vfs(void)
{
	struct list_head *itr;
	int vfs = 0;

	mutex_lock(&table_lock);
	list_for_each(itr, &vfs_table) {
		struct vf_id_map *ptr =
			list_entry(itr, struct vf_id_map, list);
		if (ptr->bdf != ~0 && !ptr->attached)
			vfs++;
	}
	mutex_unlock(&table_lock);
	return vfs;
}

void adf_devmgr_get_num_dev(uint32_t *num)
{
	*num = num_devices - adf_get_num_dettached_vfs();
}

/**
 * adf_dev_in_use() - Check whether accel_dev is currently in use
 * @accel_dev: Pointer to acceleration device.
 *
 * To be used by QAT device specific drivers.
 *
 * Return: 1 when device is in use, 0 otherwise.
 */
int adf_dev_in_use(struct adf_accel_dev *accel_dev)
{
	return atomic_read(&accel_dev->ref_count) != 0;
}
EXPORT_SYMBOL_GPL(adf_dev_in_use);

/**
 * adf_dev_get() - Increment accel_dev reference count
 * @accel_dev: Pointer to acceleration device.
 *
 * Increment the accel_dev refcount and if this is the first time
 * incrementing it during this period the accel_dev is in use,
 * increment the module refcount too.
 * To be used by QAT device specific drivers.
 *
 * Return: 0 when successful, EFAULT when fail to bump module refcount
 */
int adf_dev_get(struct adf_accel_dev *accel_dev)
{
	if (atomic_add_return(1, &accel_dev->ref_count) == 1)
		if (!try_module_get(accel_dev->owner))
			return -EFAULT;
	return 0;
}
EXPORT_SYMBOL_GPL(adf_dev_get);

/**
 * adf_dev_put() - Decrement accel_dev reference count
 * @accel_dev: Pointer to acceleration device.
 *
 * Decrement the accel_dev refcount and if this is the last time
 * decrementing it during this period the accel_dev is in use,
 * decrement the module refcount too.
 * To be used by QAT device specific drivers.
 *
 * Return: void
 */
void adf_dev_put(struct adf_accel_dev *accel_dev)
{
	if (atomic_sub_return(1, &accel_dev->ref_count) == 0)
		module_put(accel_dev->owner);
}
EXPORT_SYMBOL_GPL(adf_dev_put);

/**
 * adf_devmgr_in_reset() - Check whether device is in reset
 * @accel_dev: Pointer to acceleration device.
 *
 * To be used by QAT device specific drivers.
 *
 * Return: 1 when the device is being reset, 0 otherwise.
 */
int adf_devmgr_in_reset(struct adf_accel_dev *accel_dev)
{
	return test_bit(ADF_STATUS_RESTARTING, &accel_dev->status);
}
EXPORT_SYMBOL_GPL(adf_devmgr_in_reset);

/**
 * adf_dev_started() - Check whether device has started
 * @accel_dev: Pointer to acceleration device.
 *
 * To be used by QAT device specific drivers.
 *
 * Return: 1 when the device has started, 0 otherwise
 */
int adf_dev_started(struct adf_accel_dev *accel_dev)
{
	return test_bit(ADF_STATUS_STARTED, &accel_dev->status);
}
EXPORT_SYMBOL_GPL(adf_dev_started);