// SPDX-License-Identifier: (BSD-3-Clause OR GPL-2.0-only)
/* Copyright(c) 2014 - 2020 Intel Corporation */
#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 u32 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;
}

/**
 * adf_clean_vf_map() - Cleans VF id mappings
 * @vf: flag indicating whether mappings is cleaned
 *      for vfs only or for vfs and pfs
 *
 * Function cleans internal ids for virtual functions.
 */
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 - optimized to remove redundant is_vf */
        if (!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_obj(*map);
                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_obj(*map);
                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);
        }
        mutex_init(&accel_dev->state_lock);
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);
        /* PF on host or VF on guest - optimized to remove redundant is_vf */
        if (!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:
        mutex_destroy(&accel_dev->state_lock);
        list_del(&accel_dev->list);
        mutex_unlock(&table_lock);
}
EXPORT_SYMBOL_GPL(adf_devmgr_rm_dev);

/**
 * adf_devmgr_pci_to_accel_dev() - Get accel_dev associated with the pci_dev.
 * @pci_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);

/**
 * 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);