/*
 * Copyright (c) 2014-2015 Hisilicon Limited.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include "hnae.h"

#define cls_to_ae_dev(dev) container_of(dev, struct hnae_ae_dev, cls_dev)

static struct class *hnae_class;

static void
hnae_list_add(spinlock_t *lock, struct list_head *node, struct list_head *head)
{
        unsigned long flags;

        spin_lock_irqsave(lock, flags);
        list_add_tail_rcu(node, head);
        spin_unlock_irqrestore(lock, flags);
}

static void hnae_list_del(spinlock_t *lock, struct list_head *node)
{
        unsigned long flags;

        spin_lock_irqsave(lock, flags);
        list_del_rcu(node);
        spin_unlock_irqrestore(lock, flags);
}

static int hnae_alloc_buffer(struct hnae_ring *ring, struct hnae_desc_cb *cb)
{
        unsigned int order = hnae_page_order(ring);
        struct page *p = dev_alloc_pages(order);

        if (!p)
                return -ENOMEM;

        cb->priv = p;
        cb->page_offset = 0;
        cb->reuse_flag = 0;
        cb->buf  = page_address(p);
        cb->length = hnae_page_size(ring);
        cb->type = DESC_TYPE_PAGE;

        return 0;
}

static void hnae_free_buffer(struct hnae_ring *ring, struct hnae_desc_cb *cb)
{
        if (unlikely(!cb->priv))
                return;

        if (cb->type == DESC_TYPE_SKB)
                dev_kfree_skb_any((struct sk_buff *)cb->priv);
        else if (unlikely(is_rx_ring(ring)))
                put_page((struct page *)cb->priv);

        cb->priv = NULL;
}

static int hnae_map_buffer(struct hnae_ring *ring, struct hnae_desc_cb *cb)
{
        cb->dma = dma_map_page(ring_to_dev(ring), cb->priv, 0,
                               cb->length, ring_to_dma_dir(ring));

        if (dma_mapping_error(ring_to_dev(ring), cb->dma))
                return -EIO;

        return 0;
}

static void hnae_unmap_buffer(struct hnae_ring *ring, struct hnae_desc_cb *cb)
{
        if (cb->type == DESC_TYPE_SKB)
                dma_unmap_single(ring_to_dev(ring), cb->dma, cb->length,
                                 ring_to_dma_dir(ring));
        else
                dma_unmap_page(ring_to_dev(ring), cb->dma, cb->length,
                               ring_to_dma_dir(ring));
}

static struct hnae_buf_ops hnae_bops = {
        .alloc_buffer = hnae_alloc_buffer,
        .free_buffer = hnae_free_buffer,
        .map_buffer = hnae_map_buffer,
        .unmap_buffer = hnae_unmap_buffer,
};

static int __ae_match(struct device *dev, const void *data)
{
        struct hnae_ae_dev *hdev = cls_to_ae_dev(dev);

        if (dev_of_node(hdev->dev))
                return (data == &hdev->dev->of_node->fwnode);
        else if (is_acpi_node(hdev->dev->fwnode))
                return (data == hdev->dev->fwnode);

        dev_err(dev, "__ae_match cannot read cfg data from OF or acpi\n");
        return 0;
}

static struct hnae_ae_dev *find_ae(const struct fwnode_handle *fwnode)
{
        struct device *dev;

        WARN_ON(!fwnode);

        dev = class_find_device(hnae_class, NULL, fwnode, __ae_match);

        return dev ? cls_to_ae_dev(dev) : NULL;
}

static void hnae_free_buffers(struct hnae_ring *ring)
{
        int i;

        for (i = 0; i < ring->desc_num; i++)
                hnae_free_buffer_detach(ring, i);
}

/* Allocate memory for raw pkg, and map with dma */
static int hnae_alloc_buffers(struct hnae_ring *ring)
{
        int i, j, ret;

        for (i = 0; i < ring->desc_num; i++) {
                ret = hnae_alloc_buffer_attach(ring, i);
                if (ret)
                        goto out_buffer_fail;
        }

        return 0;

out_buffer_fail:
        for (j = i - 1; j >= 0; j--)
                hnae_free_buffer_detach(ring, j);
        return ret;
}

/* free desc along with its attached buffer */
static void hnae_free_desc(struct hnae_ring *ring)
{
        hnae_free_buffers(ring);
        dma_unmap_single(ring_to_dev(ring), ring->desc_dma_addr,
                         ring->desc_num * sizeof(ring->desc[0]),
                         ring_to_dma_dir(ring));
        ring->desc_dma_addr = 0;
        kfree(ring->desc);
        ring->desc = NULL;
}

/* alloc desc, without buffer attached */
static int hnae_alloc_desc(struct hnae_ring *ring)
{
        int size = ring->desc_num * sizeof(ring->desc[0]);

        ring->desc = kzalloc(size, GFP_KERNEL);
        if (!ring->desc)
                return -ENOMEM;

        ring->desc_dma_addr = dma_map_single(ring_to_dev(ring),
                ring->desc, size, ring_to_dma_dir(ring));
        if (dma_mapping_error(ring_to_dev(ring), ring->desc_dma_addr)) {
                ring->desc_dma_addr = 0;
                kfree(ring->desc);
                ring->desc = NULL;
                return -ENOMEM;
        }

        return 0;
}

/* fini ring, also free the buffer for the ring */
static void hnae_fini_ring(struct hnae_ring *ring)
{
        hnae_free_desc(ring);
        kfree(ring->desc_cb);
        ring->desc_cb = NULL;
        ring->next_to_clean = 0;
        ring->next_to_use = 0;
}

/* init ring, and with buffer for rx ring */
static int
hnae_init_ring(struct hnae_queue *q, struct hnae_ring *ring, int flags)
{
        int ret;

        if (ring->desc_num <= 0 || ring->buf_size <= 0)
                return -EINVAL;

        ring->q = q;
        ring->flags = flags;
        spin_lock_init(&ring->lock);
        ring->coal_param = q->handle->coal_param;
        assert(!ring->desc && !ring->desc_cb && !ring->desc_dma_addr);

        /* not matter for tx or rx ring, the ntc and ntc start from 0 */
        assert(ring->next_to_use == 0);
        assert(ring->next_to_clean == 0);

        ring->desc_cb = kcalloc(ring->desc_num, sizeof(ring->desc_cb[0]),
                        GFP_KERNEL);
        if (!ring->desc_cb) {
                ret = -ENOMEM;
                goto out;
        }

        ret = hnae_alloc_desc(ring);
        if (ret)
                goto out_with_desc_cb;

        if (is_rx_ring(ring)) {
                ret = hnae_alloc_buffers(ring);
                if (ret)
                        goto out_with_desc;
        }

        return 0;

out_with_desc:
        hnae_free_desc(ring);
out_with_desc_cb:
        kfree(ring->desc_cb);
        ring->desc_cb = NULL;
out:
        return ret;
}

static int hnae_init_queue(struct hnae_handle *h, struct hnae_queue *q,
                           struct hnae_ae_dev *dev)
{
        int ret;

        q->dev = dev;
        q->handle = h;

        ret = hnae_init_ring(q, &q->tx_ring, q->tx_ring.flags | RINGF_DIR);
        if (ret)
                goto out;

        ret = hnae_init_ring(q, &q->rx_ring, q->rx_ring.flags & ~RINGF_DIR);
        if (ret)
                goto out_with_tx_ring;

        if (dev->ops->init_queue)
                dev->ops->init_queue(q);

        return 0;

out_with_tx_ring:
        hnae_fini_ring(&q->tx_ring);
out:
        return ret;
}

static void hnae_fini_queue(struct hnae_queue *q)
{
        if (q->dev->ops->fini_queue)
                q->dev->ops->fini_queue(q);

        hnae_fini_ring(&q->tx_ring);
        hnae_fini_ring(&q->rx_ring);
}

/**
 * ae_chain - define ae chain head
 */
static RAW_NOTIFIER_HEAD(ae_chain);

int hnae_register_notifier(struct notifier_block *nb)
{
        return raw_notifier_chain_register(&ae_chain, nb);
}
EXPORT_SYMBOL(hnae_register_notifier);

void hnae_unregister_notifier(struct notifier_block *nb)
{
        if (raw_notifier_chain_unregister(&ae_chain, nb))
                dev_err(NULL, "notifier chain unregister fail\n");
}
EXPORT_SYMBOL(hnae_unregister_notifier);

int hnae_reinit_handle(struct hnae_handle *handle)
{
        int i, j;
        int ret;

        for (i = 0; i < handle->q_num; i++) /* free ring*/
                hnae_fini_queue(handle->qs[i]);

        if (handle->dev->ops->reset)
                handle->dev->ops->reset(handle);

        for (i = 0; i < handle->q_num; i++) {/* reinit ring*/
                ret = hnae_init_queue(handle, handle->qs[i], handle->dev);
                if (ret)
                        goto out_when_init_queue;
        }
        return 0;
out_when_init_queue:
        for (j = i - 1; j >= 0; j--)
                hnae_fini_queue(handle->qs[j]);
        return ret;
}
EXPORT_SYMBOL(hnae_reinit_handle);

/* hnae_get_handle - get a handle from the AE
 * @owner_dev: the dev use this handle
 * @ae_id: the id of the ae to be used
 * @ae_opts: the options set for the handle
 * @bops: the callbacks for buffer management
 *
 * return handle ptr or ERR_PTR
 */
struct hnae_handle *hnae_get_handle(struct device *owner_dev,
                                    const struct fwnode_handle  *fwnode,
                                    u32 port_id,
                                    struct hnae_buf_ops *bops)
{
        struct hnae_ae_dev *dev;
        struct hnae_handle *handle;
        int i, j;
        int ret;

        dev = find_ae(fwnode);
        if (!dev)
                return ERR_PTR(-ENODEV);

        handle = dev->ops->get_handle(dev, port_id);
        if (IS_ERR(handle)) {
                put_device(&dev->cls_dev);
                return handle;
        }

        handle->dev = dev;
        handle->owner_dev = owner_dev;
        handle->bops = bops ? bops : &hnae_bops;
        handle->eport_id = port_id;

        for (i = 0; i < handle->q_num; i++) {
                ret = hnae_init_queue(handle, handle->qs[i], dev);
                if (ret)
                        goto out_when_init_queue;
        }

        __module_get(dev->owner);

        hnae_list_add(&dev->lock, &handle->node, &dev->handle_list);

        return handle;

out_when_init_queue:
        for (j = i - 1; j >= 0; j--)
                hnae_fini_queue(handle->qs[j]);

        put_device(&dev->cls_dev);

        return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(hnae_get_handle);

void hnae_put_handle(struct hnae_handle *h)
{
        struct hnae_ae_dev *dev = h->dev;
        int i;

        for (i = 0; i < h->q_num; i++)
                hnae_fini_queue(h->qs[i]);

        if (h->dev->ops->reset)
                h->dev->ops->reset(h);

        hnae_list_del(&dev->lock, &h->node);

        if (dev->ops->put_handle)
                dev->ops->put_handle(h);

        module_put(dev->owner);

        put_device(&dev->cls_dev);
}
EXPORT_SYMBOL(hnae_put_handle);

static void hnae_release(struct device *dev)
{
}

/**
 * hnae_ae_register - register a AE engine to hnae framework
 * @hdev: the hnae ae engine device
 * @owner:  the module who provides this dev
 * NOTE: the duplicated name will not be checked
 */
int hnae_ae_register(struct hnae_ae_dev *hdev, struct module *owner)
{
        static atomic_t id = ATOMIC_INIT(-1);
        int ret;

        if (!hdev->dev)
                return -ENODEV;

        if (!hdev->ops || !hdev->ops->get_handle ||
            !hdev->ops->toggle_ring_irq ||
            !hdev->ops->get_status || !hdev->ops->adjust_link)
                return -EINVAL;

        hdev->owner = owner;
        hdev->id = (int)atomic_inc_return(&id);
        hdev->cls_dev.parent = hdev->dev;
        hdev->cls_dev.class = hnae_class;
        hdev->cls_dev.release = hnae_release;
        (void)dev_set_name(&hdev->cls_dev, "hnae%d", hdev->id);
        ret = device_register(&hdev->cls_dev);
        if (ret)
                return ret;

        __module_get(THIS_MODULE);

        INIT_LIST_HEAD(&hdev->handle_list);
        spin_lock_init(&hdev->lock);

        ret = raw_notifier_call_chain(&ae_chain, HNAE_AE_REGISTER, NULL);
        if (ret)
                dev_dbg(hdev->dev,
                        "has not notifier for AE: %s\n", hdev->name);

        return 0;
}
EXPORT_SYMBOL(hnae_ae_register);

/**
 * hnae_ae_unregister - unregisters a HNAE AE engine
 * @cdev: the device to unregister
 */
void hnae_ae_unregister(struct hnae_ae_dev *hdev)
{
        device_unregister(&hdev->cls_dev);
        module_put(THIS_MODULE);
}
EXPORT_SYMBOL(hnae_ae_unregister);

static int __init hnae_init(void)
{
        hnae_class = class_create(THIS_MODULE, "hnae");
        return PTR_ERR_OR_ZERO(hnae_class);
}

static void __exit hnae_exit(void)
{
        class_destroy(hnae_class);
}

subsys_initcall(hnae_init);
module_exit(hnae_exit);

MODULE_AUTHOR("Hisilicon, Inc.");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Hisilicon Network Acceleration Engine Framework");

/* vi: set tw=78 noet: */