// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/*
 * Copyright(c) 2020 Intel Corporation.
 *
 */

/*
 * This file contains HFI1 support for netdev RX functionality
 */

#include "sdma.h"
#include "verbs.h"
#include "netdev.h"
#include "hfi.h"

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <rdma/ib_verbs.h>

static int hfi1_netdev_setup_ctxt(struct hfi1_netdev_priv *priv,
                                  struct hfi1_ctxtdata *uctxt)
{
        unsigned int rcvctrl_ops;
        struct hfi1_devdata *dd = priv->dd;
        int ret;

        uctxt->rhf_rcv_function_map = netdev_rhf_rcv_functions;
        uctxt->do_interrupt = &handle_receive_interrupt_napi_sp;

        /* Now allocate the RcvHdr queue and eager buffers. */
        ret = hfi1_create_rcvhdrq(dd, uctxt);
        if (ret)
                goto done;

        ret = hfi1_setup_eagerbufs(uctxt);
        if (ret)
                goto done;

        clear_rcvhdrtail(uctxt);

        rcvctrl_ops = HFI1_RCVCTRL_CTXT_DIS;
        rcvctrl_ops |= HFI1_RCVCTRL_INTRAVAIL_DIS;

        if (!HFI1_CAP_KGET_MASK(uctxt->flags, MULTI_PKT_EGR))
                rcvctrl_ops |= HFI1_RCVCTRL_ONE_PKT_EGR_ENB;
        if (HFI1_CAP_KGET_MASK(uctxt->flags, NODROP_EGR_FULL))
                rcvctrl_ops |= HFI1_RCVCTRL_NO_EGR_DROP_ENB;
        if (HFI1_CAP_KGET_MASK(uctxt->flags, NODROP_RHQ_FULL))
                rcvctrl_ops |= HFI1_RCVCTRL_NO_RHQ_DROP_ENB;
        if (HFI1_CAP_KGET_MASK(uctxt->flags, DMA_RTAIL))
                rcvctrl_ops |= HFI1_RCVCTRL_TAILUPD_ENB;

        hfi1_rcvctrl(uctxt->dd, rcvctrl_ops, uctxt);
done:
        return ret;
}

static int hfi1_netdev_allocate_ctxt(struct hfi1_devdata *dd,
                                     struct hfi1_ctxtdata **ctxt)
{
        struct hfi1_ctxtdata *uctxt;
        int ret;

        if (dd->flags & HFI1_FROZEN)
                return -EIO;

        ret = hfi1_create_ctxtdata(dd->pport, dd->node, &uctxt);
        if (ret < 0) {
                dd_dev_err(dd, "Unable to create ctxtdata, failing open\n");
                return -ENOMEM;
        }

        uctxt->flags = HFI1_CAP_KGET(MULTI_PKT_EGR) |
                HFI1_CAP_KGET(NODROP_RHQ_FULL) |
                HFI1_CAP_KGET(NODROP_EGR_FULL) |
                HFI1_CAP_KGET(DMA_RTAIL);
        /* Netdev contexts are always NO_RDMA_RTAIL */
        uctxt->fast_handler = handle_receive_interrupt_napi_fp;
        uctxt->slow_handler = handle_receive_interrupt_napi_sp;
        hfi1_set_seq_cnt(uctxt, 1);
        uctxt->is_vnic = true;

        hfi1_stats.sps_ctxts++;

        dd_dev_info(dd, "created netdev context %d\n", uctxt->ctxt);
        *ctxt = uctxt;

        return 0;
}

static void hfi1_netdev_deallocate_ctxt(struct hfi1_devdata *dd,
                                        struct hfi1_ctxtdata *uctxt)
{
        flush_wc();

        /*
         * Disable receive context and interrupt available, reset all
         * RcvCtxtCtrl bits to default values.
         */
        hfi1_rcvctrl(dd, HFI1_RCVCTRL_CTXT_DIS |
                     HFI1_RCVCTRL_TIDFLOW_DIS |
                     HFI1_RCVCTRL_INTRAVAIL_DIS |
                     HFI1_RCVCTRL_ONE_PKT_EGR_DIS |
                     HFI1_RCVCTRL_NO_RHQ_DROP_DIS |
                     HFI1_RCVCTRL_NO_EGR_DROP_DIS, uctxt);

        if (uctxt->msix_intr != CCE_NUM_MSIX_VECTORS)
                msix_free_irq(dd, uctxt->msix_intr);

        uctxt->msix_intr = CCE_NUM_MSIX_VECTORS;
        uctxt->event_flags = 0;

        hfi1_clear_tids(uctxt);
        hfi1_clear_ctxt_pkey(dd, uctxt);

        hfi1_stats.sps_ctxts--;

        hfi1_free_ctxt(uctxt);
}

static int hfi1_netdev_allot_ctxt(struct hfi1_netdev_priv *priv,
                                  struct hfi1_ctxtdata **ctxt)
{
        int rc;
        struct hfi1_devdata *dd = priv->dd;

        rc = hfi1_netdev_allocate_ctxt(dd, ctxt);
        if (rc) {
                dd_dev_err(dd, "netdev ctxt alloc failed %d\n", rc);
                return rc;
        }

        rc = hfi1_netdev_setup_ctxt(priv, *ctxt);
        if (rc) {
                dd_dev_err(dd, "netdev ctxt setup failed %d\n", rc);
                hfi1_netdev_deallocate_ctxt(dd, *ctxt);
                *ctxt = NULL;
        }

        return rc;
}

/**
 * hfi1_num_netdev_contexts - Count of netdev recv contexts to use.
 * @dd: device on which to allocate netdev contexts
 * @available_contexts: count of available receive contexts
 * @cpu_mask: mask of possible cpus to include for contexts
 *
 * Return: count of physical cores on a node or the remaining available recv
 * contexts for netdev recv context usage up to the maximum of
 * HFI1_MAX_NETDEV_CTXTS.
 * A value of 0 can be returned when acceleration is explicitly turned off,
 * a memory allocation error occurs or when there are no available contexts.
 *
 */
u32 hfi1_num_netdev_contexts(struct hfi1_devdata *dd, u32 available_contexts,
                             struct cpumask *cpu_mask)
{
        cpumask_var_t node_cpu_mask;
        unsigned int available_cpus;

        if (!HFI1_CAP_IS_KSET(AIP))
                return 0;

        /* Always give user contexts priority over netdev contexts */
        if (available_contexts == 0) {
                dd_dev_info(dd, "No receive contexts available for netdevs.\n");
                return 0;
        }

        if (!zalloc_cpumask_var(&node_cpu_mask, GFP_KERNEL)) {
                dd_dev_err(dd, "Unable to allocate cpu_mask for netdevs.\n");
                return 0;
        }

        cpumask_and(node_cpu_mask, cpu_mask,
                    cpumask_of_node(pcibus_to_node(dd->pcidev->bus)));

        available_cpus = cpumask_weight(node_cpu_mask);

        free_cpumask_var(node_cpu_mask);

        return min3(available_cpus, available_contexts,
                    (u32)HFI1_MAX_NETDEV_CTXTS);
}

static int hfi1_netdev_rxq_init(struct net_device *dev)
{
        int i;
        int rc;
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dev);
        struct hfi1_devdata *dd = priv->dd;

        priv->num_rx_q = dd->num_netdev_contexts;
        priv->rxq = kcalloc_node(priv->num_rx_q, sizeof(struct hfi1_netdev_rxq),
                                 GFP_KERNEL, dd->node);

        if (!priv->rxq) {
                dd_dev_err(dd, "Unable to allocate netdev queue data\n");
                return (-ENOMEM);
        }

        for (i = 0; i < priv->num_rx_q; i++) {
                struct hfi1_netdev_rxq *rxq = &priv->rxq[i];

                rc = hfi1_netdev_allot_ctxt(priv, &rxq->rcd);
                if (rc)
                        goto bail_context_irq_failure;

                hfi1_rcd_get(rxq->rcd);
                rxq->priv = priv;
                rxq->rcd->napi = &rxq->napi;
                dd_dev_info(dd, "Setting rcv queue %d napi to context %d\n",
                            i, rxq->rcd->ctxt);
                /*
                 * Disable BUSY_POLL on this NAPI as this is not supported
                 * right now.
                 */
                set_bit(NAPI_STATE_NO_BUSY_POLL, &rxq->napi.state);
                netif_napi_add(dev, &rxq->napi, hfi1_netdev_rx_napi, 64);
                rc = msix_netdev_request_rcd_irq(rxq->rcd);
                if (rc)
                        goto bail_context_irq_failure;
        }

        return 0;

bail_context_irq_failure:
        dd_dev_err(dd, "Unable to allot receive context\n");
        for (; i >= 0; i--) {
                struct hfi1_netdev_rxq *rxq = &priv->rxq[i];

                if (rxq->rcd) {
                        hfi1_netdev_deallocate_ctxt(dd, rxq->rcd);
                        hfi1_rcd_put(rxq->rcd);
                        rxq->rcd = NULL;
                }
        }
        kfree(priv->rxq);
        priv->rxq = NULL;

        return rc;
}

static void hfi1_netdev_rxq_deinit(struct net_device *dev)
{
        int i;
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dev);
        struct hfi1_devdata *dd = priv->dd;

        for (i = 0; i < priv->num_rx_q; i++) {
                struct hfi1_netdev_rxq *rxq = &priv->rxq[i];

                netif_napi_del(&rxq->napi);
                hfi1_netdev_deallocate_ctxt(dd, rxq->rcd);
                hfi1_rcd_put(rxq->rcd);
                rxq->rcd = NULL;
        }

        kfree(priv->rxq);
        priv->rxq = NULL;
        priv->num_rx_q = 0;
}

static void enable_queues(struct hfi1_netdev_priv *priv)
{
        int i;

        for (i = 0; i < priv->num_rx_q; i++) {
                struct hfi1_netdev_rxq *rxq = &priv->rxq[i];

                dd_dev_info(priv->dd, "enabling queue %d on context %d\n", i,
                            rxq->rcd->ctxt);
                napi_enable(&rxq->napi);
                hfi1_rcvctrl(priv->dd,
                             HFI1_RCVCTRL_CTXT_ENB | HFI1_RCVCTRL_INTRAVAIL_ENB,
                             rxq->rcd);
        }
}

static void disable_queues(struct hfi1_netdev_priv *priv)
{
        int i;

        msix_netdev_synchronize_irq(priv->dd);

        for (i = 0; i < priv->num_rx_q; i++) {
                struct hfi1_netdev_rxq *rxq = &priv->rxq[i];

                dd_dev_info(priv->dd, "disabling queue %d on context %d\n", i,
                            rxq->rcd->ctxt);

                /* wait for napi if it was scheduled */
                hfi1_rcvctrl(priv->dd,
                             HFI1_RCVCTRL_CTXT_DIS | HFI1_RCVCTRL_INTRAVAIL_DIS,
                             rxq->rcd);
                napi_synchronize(&rxq->napi);
                napi_disable(&rxq->napi);
        }
}

/**
 * hfi1_netdev_rx_init - Incrememnts netdevs counter. When called first time,
 * it allocates receive queue data and calls netif_napi_add
 * for each queue.
 *
 * @dd: hfi1 dev data
 */
int hfi1_netdev_rx_init(struct hfi1_devdata *dd)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);
        int res;

        if (atomic_fetch_inc(&priv->netdevs))
                return 0;

        mutex_lock(&hfi1_mutex);
        init_dummy_netdev(dd->dummy_netdev);
        res = hfi1_netdev_rxq_init(dd->dummy_netdev);
        mutex_unlock(&hfi1_mutex);
        return res;
}

/**
 * hfi1_netdev_rx_destroy - Decrements netdevs counter, when it reaches 0
 * napi is deleted and receive queses memory is freed.
 *
 * @dd: hfi1 dev data
 */
int hfi1_netdev_rx_destroy(struct hfi1_devdata *dd)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);

        /* destroy the RX queues only if it is the last netdev going away */
        if (atomic_fetch_add_unless(&priv->netdevs, -1, 0) == 1) {
                mutex_lock(&hfi1_mutex);
                hfi1_netdev_rxq_deinit(dd->dummy_netdev);
                mutex_unlock(&hfi1_mutex);
        }

        return 0;
}

/**
 * hfi1_netdev_alloc - Allocates netdev and private data. It is required
 * because RMT index and MSI-X interrupt can be set only
 * during driver initialization.
 *
 * @dd: hfi1 dev data
 */
int hfi1_netdev_alloc(struct hfi1_devdata *dd)
{
        struct hfi1_netdev_priv *priv;
        const int netdev_size = sizeof(*dd->dummy_netdev) +
                sizeof(struct hfi1_netdev_priv);

        dd_dev_info(dd, "allocating netdev size %d\n", netdev_size);
        dd->dummy_netdev = kcalloc_node(1, netdev_size, GFP_KERNEL, dd->node);

        if (!dd->dummy_netdev)
                return -ENOMEM;

        priv = hfi1_netdev_priv(dd->dummy_netdev);
        priv->dd = dd;
        xa_init(&priv->dev_tbl);
        atomic_set(&priv->enabled, 0);
        atomic_set(&priv->netdevs, 0);

        return 0;
}

void hfi1_netdev_free(struct hfi1_devdata *dd)
{
        if (dd->dummy_netdev) {
                dd_dev_info(dd, "hfi1 netdev freed\n");
                kfree(dd->dummy_netdev);
                dd->dummy_netdev = NULL;
        }
}

/**
 * hfi1_netdev_enable_queues - This is napi enable function.
 * It enables napi objects associated with queues.
 * When at least one device has called it it increments atomic counter.
 * Disable function decrements counter and when it is 0,
 * calls napi_disable for every queue.
 *
 * @dd: hfi1 dev data
 */
void hfi1_netdev_enable_queues(struct hfi1_devdata *dd)
{
        struct hfi1_netdev_priv *priv;

        if (!dd->dummy_netdev)
                return;

        priv = hfi1_netdev_priv(dd->dummy_netdev);
        if (atomic_fetch_inc(&priv->enabled))
                return;

        mutex_lock(&hfi1_mutex);
        enable_queues(priv);
        mutex_unlock(&hfi1_mutex);
}

void hfi1_netdev_disable_queues(struct hfi1_devdata *dd)
{
        struct hfi1_netdev_priv *priv;

        if (!dd->dummy_netdev)
                return;

        priv = hfi1_netdev_priv(dd->dummy_netdev);
        if (atomic_dec_if_positive(&priv->enabled))
                return;

        mutex_lock(&hfi1_mutex);
        disable_queues(priv);
        mutex_unlock(&hfi1_mutex);
}

/**
 * hfi1_netdev_add_data - Registers data with unique identifier
 * to be requested later this is needed for VNIC and IPoIB VLANs
 * implementations.
 * This call is protected by mutex idr_lock.
 *
 * @dd: hfi1 dev data
 * @id: requested integer id up to INT_MAX
 * @data: data to be associated with index
 */
int hfi1_netdev_add_data(struct hfi1_devdata *dd, int id, void *data)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);

        return xa_insert(&priv->dev_tbl, id, data, GFP_NOWAIT);
}

/**
 * hfi1_netdev_remove_data - Removes data with previously given id.
 * Returns the reference to removed entry.
 *
 * @dd: hfi1 dev data
 * @id: requested integer id up to INT_MAX
 */
void *hfi1_netdev_remove_data(struct hfi1_devdata *dd, int id)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);

        return xa_erase(&priv->dev_tbl, id);
}

/**
 * hfi1_netdev_get_data - Gets data with given id
 *
 * @dd: hfi1 dev data
 * @id: requested integer id up to INT_MAX
 */
void *hfi1_netdev_get_data(struct hfi1_devdata *dd, int id)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);

        return xa_load(&priv->dev_tbl, id);
}

/**
 * hfi1_netdev_get_first_dat - Gets first entry with greater or equal id.
 *
 * @dd: hfi1 dev data
 * @id: requested integer id up to INT_MAX
 */
void *hfi1_netdev_get_first_data(struct hfi1_devdata *dd, int *start_id)
{
        struct hfi1_netdev_priv *priv = hfi1_netdev_priv(dd->dummy_netdev);
        unsigned long index = *start_id;
        void *ret;

        ret = xa_find(&priv->dev_tbl, &index, UINT_MAX, XA_PRESENT);
        *start_id = (int)index;
        return ret;
}