// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/*
 * Copyright(c) 2018 - 2020 Intel Corporation.
 */

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

/**
 * msix_initialize() - Calculate, request and configure MSIx IRQs
 * @dd: valid hfi1 devdata
 *
 */
int msix_initialize(struct hfi1_devdata *dd)
{
        u32 total;
        int ret;
        struct hfi1_msix_entry *entries;

        /*
         * MSIx interrupt count:
         *      one for the general, "slow path" interrupt
         *      one per used SDMA engine
         *      one per kernel receive context
         *      one for each VNIC context
         *      ...any new IRQs should be added here.
         */
        total = 1 + dd->num_sdma + dd->n_krcv_queues + dd->num_netdev_contexts;

        if (total >= CCE_NUM_MSIX_VECTORS)
                return -EINVAL;

        ret = pci_alloc_irq_vectors(dd->pcidev, total, total, PCI_IRQ_MSIX);
        if (ret < 0) {
                dd_dev_err(dd, "pci_alloc_irq_vectors() failed: %d\n", ret);
                return ret;
        }

        entries = kcalloc(total, sizeof(*dd->msix_info.msix_entries),
                          GFP_KERNEL);
        if (!entries) {
                pci_free_irq_vectors(dd->pcidev);
                return -ENOMEM;
        }

        dd->msix_info.msix_entries = entries;
        spin_lock_init(&dd->msix_info.msix_lock);
        bitmap_zero(dd->msix_info.in_use_msix, total);
        dd->msix_info.max_requested = total;
        dd_dev_info(dd, "%u MSI-X interrupts allocated\n", total);

        return 0;
}

/**
 * msix_request_irq() - Allocate a free MSIx IRQ
 * @dd: valid devdata
 * @arg: context information for the IRQ
 * @handler: IRQ handler
 * @thread: IRQ thread handler (could be NULL)
 * @type: affinty IRQ type
 * @name: IRQ name
 *
 * Allocated an MSIx vector if available, and then create the appropriate
 * meta data needed to keep track of the pci IRQ request.
 *
 * Return:
 *   < 0   Error
 *   >= 0  MSIx vector
 *
 */
static int msix_request_irq(struct hfi1_devdata *dd, void *arg,
                            irq_handler_t handler, irq_handler_t thread,
                            enum irq_type type, const char *name)
{
        unsigned long nr;
        int irq;
        int ret;
        struct hfi1_msix_entry *me;

        /* Allocate an MSIx vector */
        spin_lock(&dd->msix_info.msix_lock);
        nr = find_first_zero_bit(dd->msix_info.in_use_msix,
                                 dd->msix_info.max_requested);
        if (nr < dd->msix_info.max_requested)
                __set_bit(nr, dd->msix_info.in_use_msix);
        spin_unlock(&dd->msix_info.msix_lock);

        if (nr == dd->msix_info.max_requested)
                return -ENOSPC;

        if (type < IRQ_SDMA || type >= IRQ_OTHER)
                return -EINVAL;

        irq = pci_irq_vector(dd->pcidev, nr);
        ret = pci_request_irq(dd->pcidev, nr, handler, thread, arg, name);
        if (ret) {
                dd_dev_err(dd,
                           "%s: request for IRQ %d failed, MSIx %lx, err %d\n",
                           name, irq, nr, ret);
                spin_lock(&dd->msix_info.msix_lock);
                __clear_bit(nr, dd->msix_info.in_use_msix);
                spin_unlock(&dd->msix_info.msix_lock);
                return ret;
        }

        /*
         * assign arg after pci_request_irq call, so it will be
         * cleaned up
         */
        me = &dd->msix_info.msix_entries[nr];
        me->irq = irq;
        me->arg = arg;
        me->type = type;

        /* This is a request, so a failure is not fatal */
        ret = hfi1_get_irq_affinity(dd, me);
        if (ret)
                dd_dev_err(dd, "%s: unable to pin IRQ %d\n", name, ret);

        return nr;
}

static int msix_request_rcd_irq_common(struct hfi1_ctxtdata *rcd,
                                       irq_handler_t handler,
                                       irq_handler_t thread,
                                       const char *name)
{
        int nr = msix_request_irq(rcd->dd, rcd, handler, thread,
                                  rcd->is_vnic ? IRQ_NETDEVCTXT : IRQ_RCVCTXT,
                                  name);
        if (nr < 0)
                return nr;

        /*
         * Set the interrupt register and mask for this
         * context's interrupt.
         */
        rcd->ireg = (IS_RCVAVAIL_START + rcd->ctxt) / 64;
        rcd->imask = ((u64)1) << ((IS_RCVAVAIL_START + rcd->ctxt) % 64);
        rcd->msix_intr = nr;
        remap_intr(rcd->dd, IS_RCVAVAIL_START + rcd->ctxt, nr);

        return 0;
}

/**
 * msix_request_rcd_irq() - Helper function for RCVAVAIL IRQs
 * @rcd: valid rcd context
 *
 */
int msix_request_rcd_irq(struct hfi1_ctxtdata *rcd)
{
        char name[MAX_NAME_SIZE];

        snprintf(name, sizeof(name), DRIVER_NAME "_%d kctxt%d",
                 rcd->dd->unit, rcd->ctxt);

        return msix_request_rcd_irq_common(rcd, receive_context_interrupt,
                                           receive_context_thread, name);
}

/**
 * msix_netdev_request_rcd_irq  - Helper function for RCVAVAIL IRQs
 * for netdev context
 * @rcd: valid netdev contexti
 */
int msix_netdev_request_rcd_irq(struct hfi1_ctxtdata *rcd)
{
        char name[MAX_NAME_SIZE];

        snprintf(name, sizeof(name), DRIVER_NAME "_%d nd kctxt%d",
                 rcd->dd->unit, rcd->ctxt);
        return msix_request_rcd_irq_common(rcd, receive_context_interrupt_napi,
                                           NULL, name);
}

/**
 * msix_request_sdma_irq  - Helper for getting SDMA IRQ resources
 * @sde: valid sdma engine
 *
 */
int msix_request_sdma_irq(struct sdma_engine *sde)
{
        int nr;
        char name[MAX_NAME_SIZE];

        snprintf(name, sizeof(name), DRIVER_NAME "_%d sdma%d",
                 sde->dd->unit, sde->this_idx);
        nr = msix_request_irq(sde->dd, sde, sdma_interrupt, NULL,
                              IRQ_SDMA, name);
        if (nr < 0)
                return nr;
        sde->msix_intr = nr;
        remap_sdma_interrupts(sde->dd, sde->this_idx, nr);

        return 0;
}

/**
 * msix_request_general_irq - Helper for getting general IRQ
 * resources
 * @dd: valid device data
 */
int msix_request_general_irq(struct hfi1_devdata *dd)
{
        int nr;
        char name[MAX_NAME_SIZE];

        snprintf(name, sizeof(name), DRIVER_NAME "_%d", dd->unit);
        nr = msix_request_irq(dd, dd, general_interrupt, NULL, IRQ_GENERAL,
                              name);
        if (nr < 0)
                return nr;

        /* general interrupt must be MSIx vector 0 */
        if (nr) {
                msix_free_irq(dd, (u8)nr);
                dd_dev_err(dd, "Invalid index %d for GENERAL IRQ\n", nr);
                return -EINVAL;
        }

        return 0;
}

/**
 * enable_sdma_srcs - Helper to enable SDMA IRQ srcs
 * @dd: valid devdata structure
 * @i: index of SDMA engine
 */
static void enable_sdma_srcs(struct hfi1_devdata *dd, int i)
{
        set_intr_bits(dd, IS_SDMA_START + i, IS_SDMA_START + i, true);
        set_intr_bits(dd, IS_SDMA_PROGRESS_START + i,
                      IS_SDMA_PROGRESS_START + i, true);
        set_intr_bits(dd, IS_SDMA_IDLE_START + i, IS_SDMA_IDLE_START + i, true);
        set_intr_bits(dd, IS_SDMAENG_ERR_START + i, IS_SDMAENG_ERR_START + i,
                      true);
}

/**
 * msix_request_irqs() - Allocate all MSIx IRQs
 * @dd: valid devdata structure
 *
 * Helper function to request the used MSIx IRQs.
 *
 */
int msix_request_irqs(struct hfi1_devdata *dd)
{
        int i;
        int ret = msix_request_general_irq(dd);

        if (ret)
                return ret;

        for (i = 0; i < dd->num_sdma; i++) {
                struct sdma_engine *sde = &dd->per_sdma[i];

                ret = msix_request_sdma_irq(sde);
                if (ret)
                        return ret;
                enable_sdma_srcs(sde->dd, i);
        }

        for (i = 0; i < dd->n_krcv_queues; i++) {
                struct hfi1_ctxtdata *rcd = hfi1_rcd_get_by_index_safe(dd, i);

                if (rcd)
                        ret = msix_request_rcd_irq(rcd);
                hfi1_rcd_put(rcd);
                if (ret)
                        return ret;
        }

        return 0;
}

/**
 * msix_free_irq() - Free the specified MSIx resources and IRQ
 * @dd: valid devdata
 * @msix_intr: MSIx vector to free.
 *
 */
void msix_free_irq(struct hfi1_devdata *dd, u8 msix_intr)
{
        struct hfi1_msix_entry *me;

        if (msix_intr >= dd->msix_info.max_requested)
                return;

        me = &dd->msix_info.msix_entries[msix_intr];

        if (!me->arg) /* => no irq, no affinity */
                return;

        hfi1_put_irq_affinity(dd, me);
        pci_free_irq(dd->pcidev, msix_intr, me->arg);

        me->arg = NULL;

        spin_lock(&dd->msix_info.msix_lock);
        __clear_bit(msix_intr, dd->msix_info.in_use_msix);
        spin_unlock(&dd->msix_info.msix_lock);
}

/**
 * msix_clean_up_interrupts  - Free all MSIx IRQ resources
 * @dd: valid device data data structure
 *
 * Free the MSIx and associated PCI resources, if they have been allocated.
 */
void msix_clean_up_interrupts(struct hfi1_devdata *dd)
{
        int i;
        struct hfi1_msix_entry *me = dd->msix_info.msix_entries;

        /* remove irqs - must happen before disabling/turning off */
        for (i = 0; i < dd->msix_info.max_requested; i++, me++)
                msix_free_irq(dd, i);

        /* clean structures */
        kfree(dd->msix_info.msix_entries);
        dd->msix_info.msix_entries = NULL;
        dd->msix_info.max_requested = 0;

        pci_free_irq_vectors(dd->pcidev);
}

/**
 * msix_netdev_synchronize_irq - netdev IRQ synchronize
 * @dd: valid devdata
 */
void msix_netdev_synchronize_irq(struct hfi1_devdata *dd)
{
        int i;
        int ctxt_count = hfi1_netdev_ctxt_count(dd);

        for (i = 0; i < ctxt_count; i++) {
                struct hfi1_ctxtdata *rcd = hfi1_netdev_get_ctxt(dd, i);
                struct hfi1_msix_entry *me;

                me = &dd->msix_info.msix_entries[rcd->msix_intr];

                synchronize_irq(me->irq);
        }
}