/*
 * Copyright (c) 2013-2015, 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/mlx5/driver.h>
#include "mlx5_core.h"

static LIST_HEAD(intf_list);
static LIST_HEAD(mlx5_dev_list);
/* intf dev list mutex */
static DEFINE_MUTEX(mlx5_intf_mutex);

struct mlx5_device_context {
        struct list_head        list;
        struct mlx5_interface  *intf;
        void                   *context;
        unsigned long           state;
};

struct mlx5_delayed_event {
        struct list_head        list;
        struct mlx5_core_dev    *dev;
        enum mlx5_dev_event     event;
        unsigned long           param;
};

enum {
        MLX5_INTERFACE_ADDED,
        MLX5_INTERFACE_ATTACHED,
};

static void add_delayed_event(struct mlx5_priv *priv,
                              struct mlx5_core_dev *dev,
                              enum mlx5_dev_event event,
                              unsigned long param)
{
        struct mlx5_delayed_event *delayed_event;

        delayed_event = kzalloc(sizeof(*delayed_event), GFP_ATOMIC);
        if (!delayed_event) {
                mlx5_core_err(dev, "event %d is missed\n", event);
                return;
        }

        mlx5_core_dbg(dev, "Accumulating event %d\n", event);
        delayed_event->dev = dev;
        delayed_event->event = event;
        delayed_event->param = param;
        list_add_tail(&delayed_event->list, &priv->waiting_events_list);
}

static void delayed_event_release(struct mlx5_device_context *dev_ctx,
                                  struct mlx5_priv *priv)
{
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev, priv);
        struct mlx5_delayed_event *de;
        struct mlx5_delayed_event *n;
        struct list_head temp;

        INIT_LIST_HEAD(&temp);

        spin_lock_irq(&priv->ctx_lock);

        priv->is_accum_events = false;
        list_splice_init(&priv->waiting_events_list, &temp);
        if (!dev_ctx->context)
                goto out;
        list_for_each_entry_safe(de, n, &temp, list)
                dev_ctx->intf->event(dev, dev_ctx->context, de->event, de->param);

out:
        spin_unlock_irq(&priv->ctx_lock);

        list_for_each_entry_safe(de, n, &temp, list) {
                list_del(&de->list);
                kfree(de);
        }
}

/* accumulating events that can come after mlx5_ib calls to
 * ib_register_device, till adding that interface to the events list.
 */
static void delayed_event_start(struct mlx5_priv *priv)
{
        spin_lock_irq(&priv->ctx_lock);
        priv->is_accum_events = true;
        spin_unlock_irq(&priv->ctx_lock);
}

void mlx5_add_device(struct mlx5_interface *intf, struct mlx5_priv *priv)
{
        struct mlx5_device_context *dev_ctx;
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev, priv);

        if (!mlx5_lag_intf_add(intf, priv))
                return;

        dev_ctx = kzalloc(sizeof(*dev_ctx), GFP_KERNEL);
        if (!dev_ctx)
                return;

        dev_ctx->intf = intf;

        delayed_event_start(priv);

        dev_ctx->context = intf->add(dev);
        set_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state);
        if (intf->attach)
                set_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state);

        if (dev_ctx->context) {
                spin_lock_irq(&priv->ctx_lock);
                list_add_tail(&dev_ctx->list, &priv->ctx_list);

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
                if (dev_ctx->intf->pfault) {
                        if (priv->pfault) {
                                mlx5_core_err(dev, "multiple page fault handlers not supported");
                        } else {
                                priv->pfault_ctx = dev_ctx->context;
                                priv->pfault = dev_ctx->intf->pfault;
                        }
                }
#endif
                spin_unlock_irq(&priv->ctx_lock);
        }

        delayed_event_release(dev_ctx, priv);

        if (!dev_ctx->context)
                kfree(dev_ctx);
}

static struct mlx5_device_context *mlx5_get_device(struct mlx5_interface *intf,
                                                   struct mlx5_priv *priv)
{
        struct mlx5_device_context *dev_ctx;

        list_for_each_entry(dev_ctx, &priv->ctx_list, list)
                if (dev_ctx->intf == intf)
                        return dev_ctx;
        return NULL;
}

void mlx5_remove_device(struct mlx5_interface *intf, struct mlx5_priv *priv)
{
        struct mlx5_device_context *dev_ctx;
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev, priv);

        dev_ctx = mlx5_get_device(intf, priv);
        if (!dev_ctx)
                return;

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        spin_lock_irq(&priv->ctx_lock);
        if (priv->pfault == dev_ctx->intf->pfault)
                priv->pfault = NULL;
        spin_unlock_irq(&priv->ctx_lock);

        synchronize_srcu(&priv->pfault_srcu);
#endif

        spin_lock_irq(&priv->ctx_lock);
        list_del(&dev_ctx->list);
        spin_unlock_irq(&priv->ctx_lock);

        if (test_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state))
                intf->remove(dev, dev_ctx->context);

        kfree(dev_ctx);
}

static void mlx5_attach_interface(struct mlx5_interface *intf, struct mlx5_priv *priv)
{
        struct mlx5_device_context *dev_ctx;
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev, priv);

        dev_ctx = mlx5_get_device(intf, priv);
        if (!dev_ctx)
                return;

        delayed_event_start(priv);
        if (intf->attach) {
                if (test_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state))
                        goto out;
                intf->attach(dev, dev_ctx->context);
                set_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state);
        } else {
                if (test_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state))
                        goto out;
                dev_ctx->context = intf->add(dev);
                set_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state);
        }

out:
        delayed_event_release(dev_ctx, priv);
}

void mlx5_attach_device(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        struct mlx5_interface *intf;

        mutex_lock(&mlx5_intf_mutex);
        list_for_each_entry(intf, &intf_list, list)
                mlx5_attach_interface(intf, priv);
        mutex_unlock(&mlx5_intf_mutex);
}

static void mlx5_detach_interface(struct mlx5_interface *intf, struct mlx5_priv *priv)
{
        struct mlx5_device_context *dev_ctx;
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev, priv);

        dev_ctx = mlx5_get_device(intf, priv);
        if (!dev_ctx)
                return;

        if (intf->detach) {
                if (!test_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state))
                        return;
                intf->detach(dev, dev_ctx->context);
                clear_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state);
        } else {
                if (!test_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state))
                        return;
                intf->remove(dev, dev_ctx->context);
                clear_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state);
        }
}

void mlx5_detach_device(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        struct mlx5_interface *intf;

        mutex_lock(&mlx5_intf_mutex);
        list_for_each_entry(intf, &intf_list, list)
                mlx5_detach_interface(intf, priv);
        mutex_unlock(&mlx5_intf_mutex);
}

bool mlx5_device_registered(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv;
        bool found = false;

        mutex_lock(&mlx5_intf_mutex);
        list_for_each_entry(priv, &mlx5_dev_list, dev_list)
                if (priv == &dev->priv)
                        found = true;
        mutex_unlock(&mlx5_intf_mutex);

        return found;
}

int mlx5_register_device(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        struct mlx5_interface *intf;

        mutex_lock(&mlx5_intf_mutex);
        list_add_tail(&priv->dev_list, &mlx5_dev_list);
        list_for_each_entry(intf, &intf_list, list)
                mlx5_add_device(intf, priv);
        mutex_unlock(&mlx5_intf_mutex);

        return 0;
}

void mlx5_unregister_device(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        struct mlx5_interface *intf;

        mutex_lock(&mlx5_intf_mutex);
        list_for_each_entry(intf, &intf_list, list)
                mlx5_remove_device(intf, priv);
        list_del(&priv->dev_list);
        mutex_unlock(&mlx5_intf_mutex);
}

int mlx5_register_interface(struct mlx5_interface *intf)
{
        struct mlx5_priv *priv;

        if (!intf->add || !intf->remove)
                return -EINVAL;

        mutex_lock(&mlx5_intf_mutex);
        list_add_tail(&intf->list, &intf_list);
        list_for_each_entry(priv, &mlx5_dev_list, dev_list)
                mlx5_add_device(intf, priv);
        mutex_unlock(&mlx5_intf_mutex);

        return 0;
}
EXPORT_SYMBOL(mlx5_register_interface);

void mlx5_unregister_interface(struct mlx5_interface *intf)
{
        struct mlx5_priv *priv;

        mutex_lock(&mlx5_intf_mutex);
        list_for_each_entry(priv, &mlx5_dev_list, dev_list)
                mlx5_remove_device(intf, priv);
        list_del(&intf->list);
        mutex_unlock(&mlx5_intf_mutex);
}
EXPORT_SYMBOL(mlx5_unregister_interface);

void mlx5_reload_interface(struct mlx5_core_dev *mdev, int protocol)
{
        mutex_lock(&mlx5_intf_mutex);
        mlx5_remove_dev_by_protocol(mdev, protocol);
        mlx5_add_dev_by_protocol(mdev, protocol);
        mutex_unlock(&mlx5_intf_mutex);
}

void *mlx5_get_protocol_dev(struct mlx5_core_dev *mdev, int protocol)
{
        struct mlx5_priv *priv = &mdev->priv;
        struct mlx5_device_context *dev_ctx;
        unsigned long flags;
        void *result = NULL;

        spin_lock_irqsave(&priv->ctx_lock, flags);

        list_for_each_entry(dev_ctx, &mdev->priv.ctx_list, list)
                if ((dev_ctx->intf->protocol == protocol) &&
                    dev_ctx->intf->get_dev) {
                        result = dev_ctx->intf->get_dev(dev_ctx->context);
                        break;
                }

        spin_unlock_irqrestore(&priv->ctx_lock, flags);

        return result;
}
EXPORT_SYMBOL(mlx5_get_protocol_dev);

/* Must be called with intf_mutex held */
void mlx5_add_dev_by_protocol(struct mlx5_core_dev *dev, int protocol)
{
        struct mlx5_interface *intf;

        list_for_each_entry(intf, &intf_list, list)
                if (intf->protocol == protocol) {
                        mlx5_add_device(intf, &dev->priv);
                        break;
                }
}

/* Must be called with intf_mutex held */
void mlx5_remove_dev_by_protocol(struct mlx5_core_dev *dev, int protocol)
{
        struct mlx5_interface *intf;

        list_for_each_entry(intf, &intf_list, list)
                if (intf->protocol == protocol) {
                        mlx5_remove_device(intf, &dev->priv);
                        break;
                }
}

static u16 mlx5_gen_pci_id(struct mlx5_core_dev *dev)
{
        return (u16)((dev->pdev->bus->number << 8) |
                     PCI_SLOT(dev->pdev->devfn));
}

/* Must be called with intf_mutex held */
struct mlx5_core_dev *mlx5_get_next_phys_dev(struct mlx5_core_dev *dev)
{
        u16 pci_id = mlx5_gen_pci_id(dev);
        struct mlx5_core_dev *res = NULL;
        struct mlx5_core_dev *tmp_dev;
        struct mlx5_priv *priv;

        list_for_each_entry(priv, &mlx5_dev_list, dev_list) {
                tmp_dev = container_of(priv, struct mlx5_core_dev, priv);
                if ((dev != tmp_dev) && (mlx5_gen_pci_id(tmp_dev) == pci_id)) {
                        res = tmp_dev;
                        break;
                }
        }

        return res;
}

void mlx5_core_event(struct mlx5_core_dev *dev, enum mlx5_dev_event event,
                     unsigned long param)
{
        struct mlx5_priv *priv = &dev->priv;
        struct mlx5_device_context *dev_ctx;
        unsigned long flags;

        spin_lock_irqsave(&priv->ctx_lock, flags);

        if (priv->is_accum_events)
                add_delayed_event(priv, dev, event, param);

        /* After mlx5_detach_device, the dev_ctx->intf is still set and dev_ctx is
         * still in priv->ctx_list. In this case, only notify the dev_ctx if its
         * ADDED or ATTACHED bit are set.
         */
        list_for_each_entry(dev_ctx, &priv->ctx_list, list)
                if (dev_ctx->intf->event &&
                    (test_bit(MLX5_INTERFACE_ADDED, &dev_ctx->state) ||
                     test_bit(MLX5_INTERFACE_ATTACHED, &dev_ctx->state)))
                        dev_ctx->intf->event(dev, dev_ctx->context, event, param);

        spin_unlock_irqrestore(&priv->ctx_lock, flags);
}

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
void mlx5_core_page_fault(struct mlx5_core_dev *dev,
                          struct mlx5_pagefault *pfault)
{
        struct mlx5_priv *priv = &dev->priv;
        int srcu_idx;

        srcu_idx = srcu_read_lock(&priv->pfault_srcu);
        if (priv->pfault)
                priv->pfault(dev, priv->pfault_ctx, pfault);
        srcu_read_unlock(&priv->pfault_srcu, srcu_idx);
}
#endif

void mlx5_dev_list_lock(void)
{
        mutex_lock(&mlx5_intf_mutex);
}

void mlx5_dev_list_unlock(void)
{
        mutex_unlock(&mlx5_intf_mutex);
}

int mlx5_dev_list_trylock(void)
{
        return mutex_trylock(&mlx5_intf_mutex);
}