// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2016-2019 HabanaLabs, Ltd.
 * All Rights Reserved.
 */

#include <uapi/misc/habanalabs.h>
#include "habanalabs.h"

#include <linux/uaccess.h>
#include <linux/slab.h>

static void job_wq_completion(struct work_struct *work);
static long _hl_cs_wait_ioctl(struct hl_device *hdev,
                struct hl_ctx *ctx, u64 timeout_us, u64 seq);
static void cs_do_release(struct kref *ref);

static const char *hl_fence_get_driver_name(struct dma_fence *fence)
{
        return "HabanaLabs";
}

static const char *hl_fence_get_timeline_name(struct dma_fence *fence)
{
        struct hl_dma_fence *hl_fence =
                container_of(fence, struct hl_dma_fence, base_fence);

        return dev_name(hl_fence->hdev->dev);
}

static bool hl_fence_enable_signaling(struct dma_fence *fence)
{
        return true;
}

static void hl_fence_release(struct dma_fence *fence)
{
        struct hl_dma_fence *hl_fence =
                container_of(fence, struct hl_dma_fence, base_fence);

        kfree_rcu(hl_fence, base_fence.rcu);
}

static const struct dma_fence_ops hl_fence_ops = {
        .get_driver_name = hl_fence_get_driver_name,
        .get_timeline_name = hl_fence_get_timeline_name,
        .enable_signaling = hl_fence_enable_signaling,
        .wait = dma_fence_default_wait,
        .release = hl_fence_release
};

static void cs_get(struct hl_cs *cs)
{
        kref_get(&cs->refcount);
}

static int cs_get_unless_zero(struct hl_cs *cs)
{
        return kref_get_unless_zero(&cs->refcount);
}

static void cs_put(struct hl_cs *cs)
{
        kref_put(&cs->refcount, cs_do_release);
}

/*
 * cs_parser - parse the user command submission
 *
 * @hpriv       : pointer to the private data of the fd
 * @job        : pointer to the job that holds the command submission info
 *
 * The function parses the command submission of the user. It calls the
 * ASIC specific parser, which returns a list of memory blocks to send
 * to the device as different command buffers
 *
 */
static int cs_parser(struct hl_fpriv *hpriv, struct hl_cs_job *job)
{
        struct hl_device *hdev = hpriv->hdev;
        struct hl_cs_parser parser;
        int rc;

        parser.ctx_id = job->cs->ctx->asid;
        parser.cs_sequence = job->cs->sequence;
        parser.job_id = job->id;

        parser.hw_queue_id = job->hw_queue_id;
        parser.job_userptr_list = &job->userptr_list;
        parser.patched_cb = NULL;
        parser.user_cb = job->user_cb;
        parser.user_cb_size = job->user_cb_size;
        parser.ext_queue = job->ext_queue;
        job->patched_cb = NULL;

        rc = hdev->asic_funcs->cs_parser(hdev, &parser);
        if (job->ext_queue) {
                if (!rc) {
                        job->patched_cb = parser.patched_cb;
                        job->job_cb_size = parser.patched_cb_size;

                        spin_lock(&job->patched_cb->lock);
                        job->patched_cb->cs_cnt++;
                        spin_unlock(&job->patched_cb->lock);
                }

                /*
                 * Whether the parsing worked or not, we don't need the
                 * original CB anymore because it was already parsed and
                 * won't be accessed again for this CS
                 */
                spin_lock(&job->user_cb->lock);
                job->user_cb->cs_cnt--;
                spin_unlock(&job->user_cb->lock);
                hl_cb_put(job->user_cb);
                job->user_cb = NULL;
        }

        return rc;
}

static void free_job(struct hl_device *hdev, struct hl_cs_job *job)
{
        struct hl_cs *cs = job->cs;

        if (job->ext_queue) {
                hl_userptr_delete_list(hdev, &job->userptr_list);

                /*
                 * We might arrive here from rollback and patched CB wasn't
                 * created, so we need to check it's not NULL
                 */
                if (job->patched_cb) {
                        spin_lock(&job->patched_cb->lock);
                        job->patched_cb->cs_cnt--;
                        spin_unlock(&job->patched_cb->lock);

                        hl_cb_put(job->patched_cb);
                }
        }

        /*
         * This is the only place where there can be multiple threads
         * modifying the list at the same time
         */
        spin_lock(&cs->job_lock);
        list_del(&job->cs_node);
        spin_unlock(&cs->job_lock);

        hl_debugfs_remove_job(hdev, job);

        if (job->ext_queue)
                cs_put(cs);

        kfree(job);
}

static void cs_do_release(struct kref *ref)
{
        struct hl_cs *cs = container_of(ref, struct hl_cs,
                                                refcount);
        struct hl_device *hdev = cs->ctx->hdev;
        struct hl_cs_job *job, *tmp;

        cs->completed = true;

        /*
         * Although if we reached here it means that all external jobs have
         * finished, because each one of them took refcnt to CS, we still
         * need to go over the internal jobs and free them. Otherwise, we
         * will have leaked memory and what's worse, the CS object (and
         * potentially the CTX object) could be released, while the JOB
         * still holds a pointer to them (but no reference).
         */
        list_for_each_entry_safe(job, tmp, &cs->job_list, cs_node)
                free_job(hdev, job);

        /* We also need to update CI for internal queues */
        if (cs->submitted) {
                int cs_cnt = atomic_dec_return(&hdev->cs_active_cnt);

                WARN_ONCE((cs_cnt < 0),
                        "hl%d: error in CS active cnt %d\n",
                        hdev->id, cs_cnt);

                hl_int_hw_queue_update_ci(cs);

                spin_lock(&hdev->hw_queues_mirror_lock);
                /* remove CS from hw_queues mirror list */
                list_del_init(&cs->mirror_node);
                spin_unlock(&hdev->hw_queues_mirror_lock);

                /*
                 * Don't cancel TDR in case this CS was timedout because we
                 * might be running from the TDR context
                 */
                if ((!cs->timedout) &&
                        (hdev->timeout_jiffies != MAX_SCHEDULE_TIMEOUT)) {
                        struct hl_cs *next;

                        if (cs->tdr_active)
                                cancel_delayed_work_sync(&cs->work_tdr);

                        spin_lock(&hdev->hw_queues_mirror_lock);

                        /* queue TDR for next CS */
                        next = list_first_entry_or_null(
                                        &hdev->hw_queues_mirror_list,
                                        struct hl_cs, mirror_node);

                        if ((next) && (!next->tdr_active)) {
                                next->tdr_active = true;
                                schedule_delayed_work(&next->work_tdr,
                                                        hdev->timeout_jiffies);
                        }

                        spin_unlock(&hdev->hw_queues_mirror_lock);
                }
        }

        /*
         * Must be called before hl_ctx_put because inside we use ctx to get
         * the device
         */
        hl_debugfs_remove_cs(cs);

        hl_ctx_put(cs->ctx);

        if (cs->timedout)
                dma_fence_set_error(cs->fence, -ETIMEDOUT);
        else if (cs->aborted)
                dma_fence_set_error(cs->fence, -EIO);

        dma_fence_signal(cs->fence);
        dma_fence_put(cs->fence);

        kfree(cs);
}

static void cs_timedout(struct work_struct *work)
{
        struct hl_device *hdev;
        int ctx_asid, rc;
        struct hl_cs *cs = container_of(work, struct hl_cs,
                                                 work_tdr.work);
        rc = cs_get_unless_zero(cs);
        if (!rc)
                return;

        if ((!cs->submitted) || (cs->completed)) {
                cs_put(cs);
                return;
        }

        /* Mark the CS is timed out so we won't try to cancel its TDR */
        cs->timedout = true;

        hdev = cs->ctx->hdev;
        ctx_asid = cs->ctx->asid;

        /* TODO: add information about last signaled seq and last emitted seq */
        dev_err(hdev->dev, "User %d command submission %llu got stuck!\n",
                ctx_asid, cs->sequence);

        cs_put(cs);

        if (hdev->reset_on_lockup)
                hl_device_reset(hdev, false, false);
}

static int allocate_cs(struct hl_device *hdev, struct hl_ctx *ctx,
                        struct hl_cs **cs_new)
{
        struct hl_dma_fence *fence;
        struct dma_fence *other = NULL;
        struct hl_cs *cs;
        int rc;

        cs = kzalloc(sizeof(*cs), GFP_ATOMIC);
        if (!cs)
                return -ENOMEM;

        cs->ctx = ctx;
        cs->submitted = false;
        cs->completed = false;
        INIT_LIST_HEAD(&cs->job_list);
        INIT_DELAYED_WORK(&cs->work_tdr, cs_timedout);
        kref_init(&cs->refcount);
        spin_lock_init(&cs->job_lock);

        fence = kmalloc(sizeof(*fence), GFP_ATOMIC);
        if (!fence) {
                rc = -ENOMEM;
                goto free_cs;
        }

        fence->hdev = hdev;
        spin_lock_init(&fence->lock);
        cs->fence = &fence->base_fence;

        spin_lock(&ctx->cs_lock);

        fence->cs_seq = ctx->cs_sequence;
        other = ctx->cs_pending[fence->cs_seq & (HL_MAX_PENDING_CS - 1)];
        if ((other) && (!dma_fence_is_signaled(other))) {
                spin_unlock(&ctx->cs_lock);
                rc = -EAGAIN;
                goto free_fence;
        }

        dma_fence_init(&fence->base_fence, &hl_fence_ops, &fence->lock,
                        ctx->asid, ctx->cs_sequence);

        cs->sequence = fence->cs_seq;

        ctx->cs_pending[fence->cs_seq & (HL_MAX_PENDING_CS - 1)] =
                                                        &fence->base_fence;
        ctx->cs_sequence++;

        dma_fence_get(&fence->base_fence);

        dma_fence_put(other);

        spin_unlock(&ctx->cs_lock);

        *cs_new = cs;

        return 0;

free_fence:
        kfree(fence);
free_cs:
        kfree(cs);
        return rc;
}

static void cs_rollback(struct hl_device *hdev, struct hl_cs *cs)
{
        struct hl_cs_job *job, *tmp;

        list_for_each_entry_safe(job, tmp, &cs->job_list, cs_node)
                free_job(hdev, job);
}

void hl_cs_rollback_all(struct hl_device *hdev)
{
        struct hl_cs *cs, *tmp;

        /* flush all completions */
        flush_workqueue(hdev->cq_wq);

        /* Make sure we don't have leftovers in the H/W queues mirror list */
        list_for_each_entry_safe(cs, tmp, &hdev->hw_queues_mirror_list,
                                mirror_node) {
                cs_get(cs);
                cs->aborted = true;
                dev_warn_ratelimited(hdev->dev, "Killing CS %d.%llu\n",
                                        cs->ctx->asid, cs->sequence);
                cs_rollback(hdev, cs);
                cs_put(cs);
        }
}

static void job_wq_completion(struct work_struct *work)
{
        struct hl_cs_job *job = container_of(work, struct hl_cs_job,
                                                finish_work);
        struct hl_cs *cs = job->cs;
        struct hl_device *hdev = cs->ctx->hdev;

        /* job is no longer needed */
        free_job(hdev, job);
}

static struct hl_cb *validate_queue_index(struct hl_device *hdev,
                                        struct hl_cb_mgr *cb_mgr,
                                        struct hl_cs_chunk *chunk,
                                        bool *ext_queue)
{
        struct asic_fixed_properties *asic = &hdev->asic_prop;
        struct hw_queue_properties *hw_queue_prop;
        u32 cb_handle;
        struct hl_cb *cb;

        /* Assume external queue */
        *ext_queue = true;

        hw_queue_prop = &asic->hw_queues_props[chunk->queue_index];

        if ((chunk->queue_index >= HL_MAX_QUEUES) ||
                        (hw_queue_prop->type == QUEUE_TYPE_NA)) {
                dev_err(hdev->dev, "Queue index %d is invalid\n",
                        chunk->queue_index);
                return NULL;
        }

        if (hw_queue_prop->kmd_only) {
                dev_err(hdev->dev, "Queue index %d is restricted for KMD\n",
                        chunk->queue_index);
                return NULL;
        } else if (hw_queue_prop->type == QUEUE_TYPE_INT) {
                *ext_queue = false;
                return (struct hl_cb *) (uintptr_t) chunk->cb_handle;
        }

        /* Retrieve CB object */
        cb_handle = (u32) (chunk->cb_handle >> PAGE_SHIFT);

        cb = hl_cb_get(hdev, cb_mgr, cb_handle);
        if (!cb) {
                dev_err(hdev->dev, "CB handle 0x%x invalid\n", cb_handle);
                return NULL;
        }

        if ((chunk->cb_size < 8) || (chunk->cb_size > cb->size)) {
                dev_err(hdev->dev, "CB size %u invalid\n", chunk->cb_size);
                goto release_cb;
        }

        spin_lock(&cb->lock);
        cb->cs_cnt++;
        spin_unlock(&cb->lock);

        return cb;

release_cb:
        hl_cb_put(cb);
        return NULL;
}

struct hl_cs_job *hl_cs_allocate_job(struct hl_device *hdev, bool ext_queue)
{
        struct hl_cs_job *job;

        job = kzalloc(sizeof(*job), GFP_ATOMIC);
        if (!job)
                return NULL;

        job->ext_queue = ext_queue;

        if (job->ext_queue) {
                INIT_LIST_HEAD(&job->userptr_list);
                INIT_WORK(&job->finish_work, job_wq_completion);
        }

        return job;
}

static int _hl_cs_ioctl(struct hl_fpriv *hpriv, void __user *chunks,
                        u32 num_chunks, u64 *cs_seq)
{
        struct hl_device *hdev = hpriv->hdev;
        struct hl_cs_chunk *cs_chunk_array;
        struct hl_cs_job *job;
        struct hl_cs *cs;
        struct hl_cb *cb;
        bool ext_queue_present = false;
        u32 size_to_copy;
        int rc, i, parse_cnt;

        *cs_seq = ULLONG_MAX;

        if (num_chunks > HL_MAX_JOBS_PER_CS) {
                dev_err(hdev->dev,
                        "Number of chunks can NOT be larger than %d\n",
                        HL_MAX_JOBS_PER_CS);
                rc = -EINVAL;
                goto out;
        }

        cs_chunk_array = kmalloc_array(num_chunks, sizeof(*cs_chunk_array),
                                        GFP_ATOMIC);
        if (!cs_chunk_array) {
                rc = -ENOMEM;
                goto out;
        }

        size_to_copy = num_chunks * sizeof(struct hl_cs_chunk);
        if (copy_from_user(cs_chunk_array, chunks, size_to_copy)) {
                dev_err(hdev->dev, "Failed to copy cs chunk array from user\n");
                rc = -EFAULT;
                goto free_cs_chunk_array;
        }

        /* increment refcnt for context */
        hl_ctx_get(hdev, hpriv->ctx);

        rc = allocate_cs(hdev, hpriv->ctx, &cs);
        if (rc) {
                hl_ctx_put(hpriv->ctx);
                goto free_cs_chunk_array;
        }

        *cs_seq = cs->sequence;

        hl_debugfs_add_cs(cs);

        /* Validate ALL the CS chunks before submitting the CS */
        for (i = 0, parse_cnt = 0 ; i < num_chunks ; i++, parse_cnt++) {
                struct hl_cs_chunk *chunk = &cs_chunk_array[i];
                bool ext_queue;

                cb = validate_queue_index(hdev, &hpriv->cb_mgr, chunk,
                                        &ext_queue);
                if (ext_queue) {
                        ext_queue_present = true;
                        if (!cb) {
                                rc = -EINVAL;
                                goto free_cs_object;
                        }
                }

                job = hl_cs_allocate_job(hdev, ext_queue);
                if (!job) {
                        dev_err(hdev->dev, "Failed to allocate a new job\n");
                        rc = -ENOMEM;
                        if (ext_queue)
                                goto release_cb;
                        else
                                goto free_cs_object;
                }

                job->id = i + 1;
                job->cs = cs;
                job->user_cb = cb;
                job->user_cb_size = chunk->cb_size;
                if (job->ext_queue)
                        job->job_cb_size = cb->size;
                else
                        job->job_cb_size = chunk->cb_size;
                job->hw_queue_id = chunk->queue_index;

                cs->jobs_in_queue_cnt[job->hw_queue_id]++;

                list_add_tail(&job->cs_node, &cs->job_list);

                /*
                 * Increment CS reference. When CS reference is 0, CS is
                 * done and can be signaled to user and free all its resources
                 * Only increment for JOB on external queues, because only
                 * for those JOBs we get completion
                 */
                if (job->ext_queue)
                        cs_get(cs);

                hl_debugfs_add_job(hdev, job);

                rc = cs_parser(hpriv, job);
                if (rc) {
                        dev_err(hdev->dev,
                                "Failed to parse JOB %d.%llu.%d, err %d, rejecting the CS\n",
                                cs->ctx->asid, cs->sequence, job->id, rc);
                        goto free_cs_object;
                }
        }

        if (!ext_queue_present) {
                dev_err(hdev->dev,
                        "Reject CS %d.%llu because no external queues jobs\n",
                        cs->ctx->asid, cs->sequence);
                rc = -EINVAL;
                goto free_cs_object;
        }

        rc = hl_hw_queue_schedule_cs(cs);
        if (rc) {
                dev_err(hdev->dev,
                        "Failed to submit CS %d.%llu to H/W queues, error %d\n",
                        cs->ctx->asid, cs->sequence, rc);
                goto free_cs_object;
        }

        rc = HL_CS_STATUS_SUCCESS;
        goto put_cs;

release_cb:
        spin_lock(&cb->lock);
        cb->cs_cnt--;
        spin_unlock(&cb->lock);
        hl_cb_put(cb);
free_cs_object:
        cs_rollback(hdev, cs);
        *cs_seq = ULLONG_MAX;
        /* The path below is both for good and erroneous exits */
put_cs:
        /* We finished with the CS in this function, so put the ref */
        cs_put(cs);
free_cs_chunk_array:
        kfree(cs_chunk_array);
out:
        return rc;
}

int hl_cs_ioctl(struct hl_fpriv *hpriv, void *data)
{
        struct hl_device *hdev = hpriv->hdev;
        union hl_cs_args *args = data;
        struct hl_ctx *ctx = hpriv->ctx;
        void __user *chunks;
        u32 num_chunks;
        u64 cs_seq = ULONG_MAX;
        int rc, do_ctx_switch;
        bool need_soft_reset = false;

        if (hl_device_disabled_or_in_reset(hdev)) {
                dev_warn_ratelimited(hdev->dev,
                        "Device is %s. Can't submit new CS\n",
                        atomic_read(&hdev->in_reset) ? "in_reset" : "disabled");
                rc = -EBUSY;
                goto out;
        }

        do_ctx_switch = atomic_cmpxchg(&ctx->thread_ctx_switch_token, 1, 0);

        if (do_ctx_switch || (args->in.cs_flags & HL_CS_FLAGS_FORCE_RESTORE)) {
                long ret;

                chunks = (void __user *)(uintptr_t)args->in.chunks_restore;
                num_chunks = args->in.num_chunks_restore;

                mutex_lock(&hpriv->restore_phase_mutex);

                if (do_ctx_switch) {
                        rc = hdev->asic_funcs->context_switch(hdev, ctx->asid);
                        if (rc) {
                                dev_err_ratelimited(hdev->dev,
                                        "Failed to switch to context %d, rejecting CS! %d\n",
                                        ctx->asid, rc);
                                /*
                                 * If we timedout, or if the device is not IDLE
                                 * while we want to do context-switch (-EBUSY),
                                 * we need to soft-reset because QMAN is
                                 * probably stuck. However, we can't call to
                                 * reset here directly because of deadlock, so
                                 * need to do it at the very end of this
                                 * function
                                 */
                                if ((rc == -ETIMEDOUT) || (rc == -EBUSY))
                                        need_soft_reset = true;
                                mutex_unlock(&hpriv->restore_phase_mutex);
                                goto out;
                        }
                }

                hdev->asic_funcs->restore_phase_topology(hdev);

                if (num_chunks == 0) {
                        dev_dbg(hdev->dev,
                        "Need to run restore phase but restore CS is empty\n");
                        rc = 0;
                } else {
                        rc = _hl_cs_ioctl(hpriv, chunks, num_chunks,
                                                &cs_seq);
                }

                mutex_unlock(&hpriv->restore_phase_mutex);

                if (rc) {
                        dev_err(hdev->dev,
                                "Failed to submit restore CS for context %d (%d)\n",
                                ctx->asid, rc);
                        goto out;
                }

                /* Need to wait for restore completion before execution phase */
                if (num_chunks > 0) {
                        ret = _hl_cs_wait_ioctl(hdev, ctx,
                                        jiffies_to_usecs(hdev->timeout_jiffies),
                                        cs_seq);
                        if (ret <= 0) {
                                dev_err(hdev->dev,
                                        "Restore CS for context %d failed to complete %ld\n",
                                        ctx->asid, ret);
                                rc = -ENOEXEC;
                                goto out;
                        }
                }

                ctx->thread_ctx_switch_wait_token = 1;
        } else if (!ctx->thread_ctx_switch_wait_token) {
                u32 tmp;

                rc = hl_poll_timeout_memory(hdev,
                        &ctx->thread_ctx_switch_wait_token, tmp, (tmp == 1),
                        100, jiffies_to_usecs(hdev->timeout_jiffies), false);

                if (rc == -ETIMEDOUT) {
                        dev_err(hdev->dev,
                                "context switch phase timeout (%d)\n", tmp);
                        goto out;
                }
        }

        chunks = (void __user *)(uintptr_t)args->in.chunks_execute;
        num_chunks = args->in.num_chunks_execute;

        if (num_chunks == 0) {
                dev_err(hdev->dev,
                        "Got execute CS with 0 chunks, context %d\n",
                        ctx->asid);
                rc = -EINVAL;
                goto out;
        }

        rc = _hl_cs_ioctl(hpriv, chunks, num_chunks, &cs_seq);

out:
        if (rc != -EAGAIN) {
                memset(args, 0, sizeof(*args));
                args->out.status = rc;
                args->out.seq = cs_seq;
        }

        if (((rc == -ETIMEDOUT) || (rc == -EBUSY)) && (need_soft_reset))
                hl_device_reset(hdev, false, false);

        return rc;
}

static long _hl_cs_wait_ioctl(struct hl_device *hdev,
                struct hl_ctx *ctx, u64 timeout_us, u64 seq)
{
        struct dma_fence *fence;
        unsigned long timeout;
        long rc;

        if (timeout_us == MAX_SCHEDULE_TIMEOUT)
                timeout = timeout_us;
        else
                timeout = usecs_to_jiffies(timeout_us);

        hl_ctx_get(hdev, ctx);

        fence = hl_ctx_get_fence(ctx, seq);
        if (IS_ERR(fence)) {
                rc = PTR_ERR(fence);
        } else if (fence) {
                rc = dma_fence_wait_timeout(fence, true, timeout);
                if (fence->error == -ETIMEDOUT)
                        rc = -ETIMEDOUT;
                else if (fence->error == -EIO)
                        rc = -EIO;
                dma_fence_put(fence);
        } else
                rc = 1;

        hl_ctx_put(ctx);

        return rc;
}

int hl_cs_wait_ioctl(struct hl_fpriv *hpriv, void *data)
{
        struct hl_device *hdev = hpriv->hdev;
        union hl_wait_cs_args *args = data;
        u64 seq = args->in.seq;
        long rc;

        rc = _hl_cs_wait_ioctl(hdev, hpriv->ctx, args->in.timeout_us, seq);

        memset(args, 0, sizeof(*args));

        if (rc < 0) {
                dev_err(hdev->dev, "Error %ld on waiting for CS handle %llu\n",
                        rc, seq);
                if (rc == -ERESTARTSYS) {
                        args->out.status = HL_WAIT_CS_STATUS_INTERRUPTED;
                        rc = -EINTR;
                } else if (rc == -ETIMEDOUT) {
                        args->out.status = HL_WAIT_CS_STATUS_TIMEDOUT;
                } else if (rc == -EIO) {
                        args->out.status = HL_WAIT_CS_STATUS_ABORTED;
                }
                return rc;
        }

        if (rc == 0)
                args->out.status = HL_WAIT_CS_STATUS_BUSY;
        else
                args->out.status = HL_WAIT_CS_STATUS_COMPLETED;

        return 0;
}