// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2023 Advanced Micro Devices, Inc */

#include <linux/pci.h>
#include <linux/vmalloc.h>

#include "core.h"

static BLOCKING_NOTIFIER_HEAD(pds_notify_chain);

int pdsc_register_notify(struct notifier_block *nb)
{
        return blocking_notifier_chain_register(&pds_notify_chain, nb);
}
EXPORT_SYMBOL_GPL(pdsc_register_notify);

void pdsc_unregister_notify(struct notifier_block *nb)
{
        blocking_notifier_chain_unregister(&pds_notify_chain, nb);
}
EXPORT_SYMBOL_GPL(pdsc_unregister_notify);

void pdsc_notify(unsigned long event, void *data)
{
        blocking_notifier_call_chain(&pds_notify_chain, event, data);
}

void pdsc_intr_free(struct pdsc *pdsc, int index)
{
        struct pdsc_intr_info *intr_info;

        if (index >= pdsc->nintrs || index < 0) {
                WARN(true, "bad intr index %d\n", index);
                return;
        }

        intr_info = &pdsc->intr_info[index];
        if (!intr_info->vector)
                return;
        dev_dbg(pdsc->dev, "%s: idx %d vec %d name %s\n",
                __func__, index, intr_info->vector, intr_info->name);

        pds_core_intr_mask(&pdsc->intr_ctrl[index], PDS_CORE_INTR_MASK_SET);
        pds_core_intr_clean(&pdsc->intr_ctrl[index]);

        free_irq(intr_info->vector, intr_info->data);

        memset(intr_info, 0, sizeof(*intr_info));
}

int pdsc_intr_alloc(struct pdsc *pdsc, char *name,
                    irq_handler_t handler, void *data)
{
        struct pdsc_intr_info *intr_info;
        unsigned int index;
        int err;

        /* Find the first available interrupt */
        for (index = 0; index < pdsc->nintrs; index++)
                if (!pdsc->intr_info[index].vector)
                        break;
        if (index >= pdsc->nintrs) {
                dev_warn(pdsc->dev, "%s: no intr, index=%d nintrs=%d\n",
                         __func__, index, pdsc->nintrs);
                return -ENOSPC;
        }

        pds_core_intr_clean_flags(&pdsc->intr_ctrl[index],
                                  PDS_CORE_INTR_CRED_RESET_COALESCE);

        intr_info = &pdsc->intr_info[index];

        intr_info->index = index;
        intr_info->data = data;
        strscpy(intr_info->name, name, sizeof(intr_info->name));

        /* Get the OS vector number for the interrupt */
        err = pci_irq_vector(pdsc->pdev, index);
        if (err < 0) {
                dev_err(pdsc->dev, "failed to get intr vector index %d: %pe\n",
                        index, ERR_PTR(err));
                goto err_out_free_intr;
        }
        intr_info->vector = err;

        /* Init the device's intr mask */
        pds_core_intr_clean(&pdsc->intr_ctrl[index]);
        pds_core_intr_mask_assert(&pdsc->intr_ctrl[index], 1);
        pds_core_intr_mask(&pdsc->intr_ctrl[index], PDS_CORE_INTR_MASK_SET);

        /* Register the isr with a name */
        err = request_irq(intr_info->vector, handler, 0, intr_info->name, data);
        if (err) {
                dev_err(pdsc->dev, "failed to get intr irq vector %d: %pe\n",
                        intr_info->vector, ERR_PTR(err));
                goto err_out_free_intr;
        }

        return index;

err_out_free_intr:
        pdsc_intr_free(pdsc, index);
        return err;
}

static void pdsc_qcq_intr_free(struct pdsc *pdsc, struct pdsc_qcq *qcq)
{
        if (!(qcq->flags & PDS_CORE_QCQ_F_INTR) ||
            qcq->intx == PDS_CORE_INTR_INDEX_NOT_ASSIGNED)
                return;

        pdsc_intr_free(pdsc, qcq->intx);
        qcq->intx = PDS_CORE_INTR_INDEX_NOT_ASSIGNED;
}

static int pdsc_qcq_intr_alloc(struct pdsc *pdsc, struct pdsc_qcq *qcq)
{
        char name[PDSC_INTR_NAME_MAX_SZ];
        int index;

        if (!(qcq->flags & PDS_CORE_QCQ_F_INTR)) {
                qcq->intx = PDS_CORE_INTR_INDEX_NOT_ASSIGNED;
                return 0;
        }

        snprintf(name, sizeof(name), "%s-%d-%s",
                 PDS_CORE_DRV_NAME, pdsc->pdev->bus->number, qcq->q.name);
        index = pdsc_intr_alloc(pdsc, name, pdsc_adminq_isr, pdsc);
        if (index < 0)
                return index;
        qcq->intx = index;
        qcq->cq.bound_intr = &pdsc->intr_info[index];

        return 0;
}

void pdsc_qcq_free(struct pdsc *pdsc, struct pdsc_qcq *qcq)
{
        struct device *dev = pdsc->dev;

        if (!(qcq && qcq->pdsc))
                return;

        pdsc_debugfs_del_qcq(qcq);

        pdsc_qcq_intr_free(pdsc, qcq);

        if (qcq->q_base)
                dma_free_coherent(dev, qcq->q_size,
                                  qcq->q_base, qcq->q_base_pa);

        if (qcq->cq_base)
                dma_free_coherent(dev, qcq->cq_size,
                                  qcq->cq_base, qcq->cq_base_pa);

        vfree(qcq->cq.info);
        vfree(qcq->q.info);

        memset(qcq, 0, sizeof(*qcq));
}

static void pdsc_q_map(struct pdsc_queue *q, void *base, dma_addr_t base_pa)
{
        struct pdsc_q_info *cur;
        unsigned int i;

        q->base = base;
        q->base_pa = base_pa;

        for (i = 0, cur = q->info; i < q->num_descs; i++, cur++) {
                cur->desc = base + (i * q->desc_size);
                init_completion(&cur->completion);
        }
}

static void pdsc_cq_map(struct pdsc_cq *cq, void *base, dma_addr_t base_pa)
{
        struct pdsc_cq_info *cur;
        unsigned int i;

        cq->base = base;
        cq->base_pa = base_pa;

        for (i = 0, cur = cq->info; i < cq->num_descs; i++, cur++)
                cur->comp = base + (i * cq->desc_size);
}

int pdsc_qcq_alloc(struct pdsc *pdsc, unsigned int type, unsigned int index,
                   const char *name, unsigned int flags, unsigned int num_descs,
                   unsigned int desc_size, unsigned int cq_desc_size,
                   unsigned int pid, struct pdsc_qcq *qcq)
{
        struct device *dev = pdsc->dev;
        void *q_base, *cq_base;
        dma_addr_t cq_base_pa;
        dma_addr_t q_base_pa;
        int err;

        qcq->q.info = vcalloc(num_descs, sizeof(*qcq->q.info));
        if (!qcq->q.info) {
                err = -ENOMEM;
                goto err_out;
        }

        qcq->pdsc = pdsc;
        qcq->flags = flags;
        INIT_WORK(&qcq->work, pdsc_work_thread);

        qcq->q.type = type;
        qcq->q.index = index;
        qcq->q.num_descs = num_descs;
        qcq->q.desc_size = desc_size;
        qcq->q.tail_idx = 0;
        qcq->q.head_idx = 0;
        qcq->q.pid = pid;
        snprintf(qcq->q.name, sizeof(qcq->q.name), "%s%u", name, index);

        err = pdsc_qcq_intr_alloc(pdsc, qcq);
        if (err)
                goto err_out_free_q_info;

        qcq->cq.info = vcalloc(num_descs, sizeof(*qcq->cq.info));
        if (!qcq->cq.info) {
                err = -ENOMEM;
                goto err_out_free_irq;
        }

        qcq->cq.num_descs = num_descs;
        qcq->cq.desc_size = cq_desc_size;
        qcq->cq.tail_idx = 0;
        qcq->cq.done_color = 1;

        if (flags & PDS_CORE_QCQ_F_NOTIFYQ) {
                /* q & cq need to be contiguous in case of notifyq */
                qcq->q_size = PDS_PAGE_SIZE +
                              ALIGN(num_descs * desc_size, PDS_PAGE_SIZE) +
                              ALIGN(num_descs * cq_desc_size, PDS_PAGE_SIZE);
                qcq->q_base = dma_alloc_coherent(dev,
                                                 qcq->q_size + qcq->cq_size,
                                                 &qcq->q_base_pa,
                                                 GFP_KERNEL);
                if (!qcq->q_base) {
                        err = -ENOMEM;
                        goto err_out_free_cq_info;
                }
                q_base = PTR_ALIGN(qcq->q_base, PDS_PAGE_SIZE);
                q_base_pa = ALIGN(qcq->q_base_pa, PDS_PAGE_SIZE);
                pdsc_q_map(&qcq->q, q_base, q_base_pa);

                cq_base = PTR_ALIGN(q_base +
                                    ALIGN(num_descs * desc_size, PDS_PAGE_SIZE),
                                    PDS_PAGE_SIZE);
                cq_base_pa = ALIGN(qcq->q_base_pa +
                                   ALIGN(num_descs * desc_size, PDS_PAGE_SIZE),
                                   PDS_PAGE_SIZE);

        } else {
                /* q DMA descriptors */
                qcq->q_size = PDS_PAGE_SIZE + (num_descs * desc_size);
                qcq->q_base = dma_alloc_coherent(dev, qcq->q_size,
                                                 &qcq->q_base_pa,
                                                 GFP_KERNEL);
                if (!qcq->q_base) {
                        err = -ENOMEM;
                        goto err_out_free_cq_info;
                }
                q_base = PTR_ALIGN(qcq->q_base, PDS_PAGE_SIZE);
                q_base_pa = ALIGN(qcq->q_base_pa, PDS_PAGE_SIZE);
                pdsc_q_map(&qcq->q, q_base, q_base_pa);

                /* cq DMA descriptors */
                qcq->cq_size = PDS_PAGE_SIZE + (num_descs * cq_desc_size);
                qcq->cq_base = dma_alloc_coherent(dev, qcq->cq_size,
                                                  &qcq->cq_base_pa,
                                                  GFP_KERNEL);
                if (!qcq->cq_base) {
                        err = -ENOMEM;
                        goto err_out_free_q;
                }
                cq_base = PTR_ALIGN(qcq->cq_base, PDS_PAGE_SIZE);
                cq_base_pa = ALIGN(qcq->cq_base_pa, PDS_PAGE_SIZE);
        }

        pdsc_cq_map(&qcq->cq, cq_base, cq_base_pa);
        qcq->cq.bound_q = &qcq->q;

        pdsc_debugfs_add_qcq(pdsc, qcq);

        return 0;

err_out_free_q:
        dma_free_coherent(dev, qcq->q_size, qcq->q_base, qcq->q_base_pa);
err_out_free_cq_info:
        vfree(qcq->cq.info);
err_out_free_irq:
        pdsc_qcq_intr_free(pdsc, qcq);
err_out_free_q_info:
        vfree(qcq->q.info);
        memset(qcq, 0, sizeof(*qcq));
err_out:
        dev_err(dev, "qcq alloc of %s%d failed %d\n", name, index, err);
        return err;
}

static void pdsc_core_uninit(struct pdsc *pdsc)
{
        pdsc_qcq_free(pdsc, &pdsc->notifyqcq);
        pdsc_qcq_free(pdsc, &pdsc->adminqcq);

        if (pdsc->kern_dbpage) {
                iounmap(pdsc->kern_dbpage);
                pdsc->kern_dbpage = NULL;
        }
}

static int pdsc_core_init(struct pdsc *pdsc)
{
        union pds_core_dev_comp comp = {};
        union pds_core_dev_cmd cmd = {
                .init.opcode = PDS_CORE_CMD_INIT,
        };
        struct pds_core_dev_init_data_out cido;
        struct pds_core_dev_init_data_in cidi;
        u32 dbid_count;
        u32 dbpage_num;
        int numdescs;
        size_t sz;
        int err;

        numdescs = PDSC_ADMINQ_MAX_LENGTH;
        err = pdsc_qcq_alloc(pdsc, PDS_CORE_QTYPE_ADMINQ, 0, "adminq",
                             PDS_CORE_QCQ_F_CORE | PDS_CORE_QCQ_F_INTR,
                             numdescs,
                             sizeof(union pds_core_adminq_cmd),
                             sizeof(union pds_core_adminq_comp),
                             0, &pdsc->adminqcq);
        if (err)
                return err;

        err = pdsc_qcq_alloc(pdsc, PDS_CORE_QTYPE_NOTIFYQ, 0, "notifyq",
                             PDS_CORE_QCQ_F_NOTIFYQ,
                             PDSC_NOTIFYQ_LENGTH,
                             sizeof(struct pds_core_notifyq_cmd),
                             sizeof(union pds_core_notifyq_comp),
                             0, &pdsc->notifyqcq);
        if (err)
                goto err_out_uninit;

        cidi.adminq_q_base = cpu_to_le64(pdsc->adminqcq.q_base_pa);
        cidi.adminq_cq_base = cpu_to_le64(pdsc->adminqcq.cq_base_pa);
        cidi.notifyq_cq_base = cpu_to_le64(pdsc->notifyqcq.cq.base_pa);
        cidi.flags = cpu_to_le32(PDS_CORE_QINIT_F_IRQ | PDS_CORE_QINIT_F_ENA);
        cidi.intr_index = cpu_to_le16(pdsc->adminqcq.intx);
        cidi.adminq_ring_size = ilog2(pdsc->adminqcq.q.num_descs);
        cidi.notifyq_ring_size = ilog2(pdsc->notifyqcq.q.num_descs);

        mutex_lock(&pdsc->devcmd_lock);

        sz = min_t(size_t, sizeof(cidi), sizeof(pdsc->cmd_regs->data));
        memcpy_toio(&pdsc->cmd_regs->data, &cidi, sz);

        err = pdsc_devcmd_locked(pdsc, &cmd, &comp, pdsc->devcmd_timeout);
        if (!err) {
                sz = min_t(size_t, sizeof(cido), sizeof(pdsc->cmd_regs->data));
                memcpy_fromio(&cido, &pdsc->cmd_regs->data, sz);
        }

        mutex_unlock(&pdsc->devcmd_lock);
        if (err) {
                dev_err(pdsc->dev, "Device init command failed: %pe\n",
                        ERR_PTR(err));
                goto err_out_uninit;
        }

        pdsc->hw_index = le32_to_cpu(cido.core_hw_index);

        dbid_count = le32_to_cpu(pdsc->dev_ident.ndbpgs_per_lif);
        dbpage_num = pdsc->hw_index * dbid_count;
        pdsc->kern_dbpage = pdsc_map_dbpage(pdsc, dbpage_num);
        if (!pdsc->kern_dbpage) {
                dev_err(pdsc->dev, "Cannot map dbpage, aborting\n");
                err = -ENOMEM;
                goto err_out_uninit;
        }

        pdsc->adminqcq.q.hw_type = cido.adminq_hw_type;
        pdsc->adminqcq.q.hw_index = le32_to_cpu(cido.adminq_hw_index);
        pdsc->adminqcq.q.dbval = PDS_CORE_DBELL_QID(pdsc->adminqcq.q.hw_index);

        pdsc->notifyqcq.q.hw_type = cido.notifyq_hw_type;
        pdsc->notifyqcq.q.hw_index = le32_to_cpu(cido.notifyq_hw_index);
        pdsc->notifyqcq.q.dbval = PDS_CORE_DBELL_QID(pdsc->notifyqcq.q.hw_index);

        pdsc->last_eid = 0;

        return 0;

err_out_uninit:
        pdsc_core_uninit(pdsc);
        return err;
}

static struct pdsc_viftype pdsc_viftype_defaults[] = {
        [PDS_DEV_TYPE_FWCTL] = { .name = PDS_DEV_TYPE_FWCTL_STR,
                                 .enabled = true,
                                 .vif_id = PDS_DEV_TYPE_FWCTL,
                                 .dl_id = -1 },
        [PDS_DEV_TYPE_VDPA] = { .name = PDS_DEV_TYPE_VDPA_STR,
                                .vif_id = PDS_DEV_TYPE_VDPA,
                                .dl_id = DEVLINK_PARAM_GENERIC_ID_ENABLE_VNET },
        [PDS_DEV_TYPE_MAX] = {}
};

static int pdsc_viftypes_init(struct pdsc *pdsc)
{
        enum pds_core_vif_types vt;

        pdsc->viftype_status = kzalloc_objs(*pdsc->viftype_status,
                                            ARRAY_SIZE(pdsc_viftype_defaults));
        if (!pdsc->viftype_status)
                return -ENOMEM;

        for (vt = 0; vt < PDS_DEV_TYPE_MAX; vt++) {
                bool vt_support;

                if (!pdsc_viftype_defaults[vt].name)
                        continue;

                /* Grab the defaults */
                pdsc->viftype_status[vt] = pdsc_viftype_defaults[vt];

                /* See what the Core device has for support */
                vt_support = !!le16_to_cpu(pdsc->dev_ident.vif_types[vt]);

                dev_dbg(pdsc->dev, "VIF %s is %ssupported\n",
                        pdsc->viftype_status[vt].name,
                        vt_support ? "" : "not ");

                pdsc->viftype_status[vt].supported = vt_support;
        }

        return 0;
}

int pdsc_setup(struct pdsc *pdsc, bool init)
{
        int err;

        err = pdsc_dev_init(pdsc);
        if (err)
                return err;

        /* Set up the Core with the AdminQ and NotifyQ info */
        err = pdsc_core_init(pdsc);
        if (err)
                goto err_out_teardown;

        /* Set up the VIFs */
        if (init) {
                err = pdsc_viftypes_init(pdsc);
                if (err)
                        goto err_out_teardown;

                pdsc_debugfs_add_viftype(pdsc);
        }

        refcount_set(&pdsc->adminq_refcnt, 1);
        clear_bit(PDSC_S_FW_DEAD, &pdsc->state);
        return 0;

err_out_teardown:
        pdsc_teardown(pdsc, init);
        return err;
}

void pdsc_teardown(struct pdsc *pdsc, bool removing)
{
        if (!pdsc->pdev->is_virtfn)
                pdsc_devcmd_reset(pdsc);
        if (pdsc->adminqcq.work.func)
                cancel_work_sync(&pdsc->adminqcq.work);

        pdsc_core_uninit(pdsc);

        if (removing) {
                kfree(pdsc->viftype_status);
                pdsc->viftype_status = NULL;
        }

        pdsc_dev_uninit(pdsc);

        set_bit(PDSC_S_FW_DEAD, &pdsc->state);
}

int pdsc_start(struct pdsc *pdsc)
{
        pds_core_intr_mask(&pdsc->intr_ctrl[pdsc->adminqcq.intx],
                           PDS_CORE_INTR_MASK_CLEAR);

        return 0;
}

void pdsc_stop(struct pdsc *pdsc)
{
        int i;

        if (!pdsc->intr_info)
                return;

        /* Mask interrupts that are in use */
        for (i = 0; i < pdsc->nintrs; i++)
                if (pdsc->intr_info[i].vector)
                        pds_core_intr_mask(&pdsc->intr_ctrl[i],
                                           PDS_CORE_INTR_MASK_SET);
}

static void pdsc_adminq_wait_and_dec_once_unused(struct pdsc *pdsc)
{
        /* The driver initializes the adminq_refcnt to 1 when the adminq is
         * allocated and ready for use. Other users/requesters will increment
         * the refcnt while in use. If the refcnt is down to 1 then the adminq
         * is not in use and the refcnt can be cleared and adminq freed. Before
         * calling this function the driver will set PDSC_S_FW_DEAD, which
         * prevent subsequent attempts to use the adminq and increment the
         * refcnt to fail. This guarantees that this function will eventually
         * exit.
         */
        while (!refcount_dec_if_one(&pdsc->adminq_refcnt)) {
                dev_dbg_ratelimited(pdsc->dev, "%s: adminq in use\n",
                                    __func__);
                cpu_relax();
        }
}

void pdsc_fw_down(struct pdsc *pdsc)
{
        union pds_core_notifyq_comp reset_event = {
                .reset.ecode = cpu_to_le16(PDS_EVENT_RESET),
                .reset.state = 0,
        };

        if (test_and_set_bit(PDSC_S_FW_DEAD, &pdsc->state)) {
                dev_warn(pdsc->dev, "%s: already happening\n", __func__);
                return;
        }

        if (pdsc->pdev->is_virtfn)
                return;

        pdsc_adminq_wait_and_dec_once_unused(pdsc);

        /* Notify clients of fw_down */
        if (pdsc->fw_reporter)
                devlink_health_report(pdsc->fw_reporter, "FW down reported", pdsc);
        pdsc_notify(PDS_EVENT_RESET, &reset_event);

        pdsc_stop(pdsc);
        pdsc_teardown(pdsc, PDSC_TEARDOWN_RECOVERY);
}

void pdsc_fw_up(struct pdsc *pdsc)
{
        union pds_core_notifyq_comp reset_event = {
                .reset.ecode = cpu_to_le16(PDS_EVENT_RESET),
                .reset.state = 1,
        };
        int err;

        if (!test_bit(PDSC_S_FW_DEAD, &pdsc->state)) {
                dev_err(pdsc->dev, "%s: fw not dead\n", __func__);
                return;
        }

        if (pdsc->pdev->is_virtfn) {
                clear_bit(PDSC_S_FW_DEAD, &pdsc->state);
                return;
        }

        err = pdsc_setup(pdsc, PDSC_SETUP_RECOVERY);
        if (err)
                goto err_out;

        err = pdsc_start(pdsc);
        if (err)
                goto err_out;

        /* Notify clients of fw_up */
        pdsc->fw_recoveries++;
        if (pdsc->fw_reporter)
                devlink_health_reporter_state_update(pdsc->fw_reporter,
                                                     DEVLINK_HEALTH_REPORTER_STATE_HEALTHY);
        pdsc_notify(PDS_EVENT_RESET, &reset_event);

        return;

err_out:
        pdsc_teardown(pdsc, PDSC_TEARDOWN_RECOVERY);
}

void pdsc_pci_reset_thread(struct work_struct *work)
{
        struct pdsc *pdsc = container_of(work, struct pdsc, pci_reset_work);
        struct pci_dev *pdev = pdsc->pdev;

        pci_dev_get(pdev);
        pci_reset_function(pdev);
        pci_dev_put(pdev);
}

static void pdsc_check_pci_health(struct pdsc *pdsc)
{
        u8 fw_status;

        /* some sort of teardown already in progress */
        if (!pdsc->info_regs)
                return;

        fw_status = ioread8(&pdsc->info_regs->fw_status);

        /* is PCI broken? */
        if (fw_status != PDS_RC_BAD_PCI)
                return;

        /* prevent deadlock between pdsc_reset_prepare and pdsc_health_thread */
        queue_work(pdsc->wq, &pdsc->pci_reset_work);
}

void pdsc_health_thread(struct work_struct *work)
{
        struct pdsc *pdsc = container_of(work, struct pdsc, health_work);
        unsigned long mask;
        bool healthy;

        mutex_lock(&pdsc->config_lock);

        /* Don't do a check when in a transition state */
        mask = BIT_ULL(PDSC_S_INITING_DRIVER) |
               BIT_ULL(PDSC_S_STOPPING_DRIVER);
        if (pdsc->state & mask)
                goto out_unlock;

        healthy = pdsc_is_fw_good(pdsc);
        dev_dbg(pdsc->dev, "%s: health %d fw_status %#02x fw_heartbeat %d\n",
                __func__, healthy, pdsc->fw_status, pdsc->last_hb);

        if (test_bit(PDSC_S_FW_DEAD, &pdsc->state)) {
                if (healthy)
                        pdsc_fw_up(pdsc);
        } else {
                if (!healthy)
                        pdsc_fw_down(pdsc);
        }

        pdsc_check_pci_health(pdsc);

        pdsc->fw_generation = pdsc->fw_status & PDS_CORE_FW_STS_F_GENERATION;

out_unlock:
        mutex_unlock(&pdsc->config_lock);
}