// SPDX-License-Identifier: GPL-2.0
/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
/* Copyright 2019 Collabora ltd. */
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/dma-resv.h>
#include <drm/gpu_scheduler.h>
#include <drm/panfrost_drm.h>

#include "panfrost_device.h"
#include "panfrost_devfreq.h"
#include "panfrost_job.h"
#include "panfrost_features.h"
#include "panfrost_issues.h"
#include "panfrost_gem.h"
#include "panfrost_regs.h"
#include "panfrost_gpu.h"
#include "panfrost_mmu.h"
#include "panfrost_dump.h"

#define MAX_JM_CTX_PER_FILE 64
#define JOB_TIMEOUT_MS 500

#define job_write(dev, reg, data) writel(data, dev->iomem + (reg))
#define job_read(dev, reg) readl(dev->iomem + (reg))

const char * const panfrost_engine_names[] = {
        "fragment", "vertex-tiler", "compute-only"
};

struct panfrost_queue_state {
        struct drm_gpu_scheduler sched;
        u64 fence_context;
        u64 emit_seqno;
};

struct panfrost_job_slot {
        struct panfrost_queue_state queue[NUM_JOB_SLOTS];
        spinlock_t job_lock;
        int irq;
};

static struct panfrost_job *
to_panfrost_job(struct drm_sched_job *sched_job)
{
        return container_of(sched_job, struct panfrost_job, base);
}

struct panfrost_fence {
        struct dma_fence base;
        struct drm_device *dev;
        /* panfrost seqno for signaled() test */
        u64 seqno;
        int queue;
};

static inline struct panfrost_fence *
to_panfrost_fence(struct dma_fence *fence)
{
        return (struct panfrost_fence *)fence;
}

static const char *panfrost_fence_get_driver_name(struct dma_fence *fence)
{
        return "panfrost";
}

static const char *panfrost_fence_get_timeline_name(struct dma_fence *fence)
{
        struct panfrost_fence *f = to_panfrost_fence(fence);

        switch (f->queue) {
        case 0:
                return "panfrost-js-0";
        case 1:
                return "panfrost-js-1";
        case 2:
                return "panfrost-js-2";
        default:
                return NULL;
        }
}

static const struct dma_fence_ops panfrost_fence_ops = {
        .get_driver_name = panfrost_fence_get_driver_name,
        .get_timeline_name = panfrost_fence_get_timeline_name,
};

static struct dma_fence *panfrost_fence_create(struct panfrost_device *pfdev, int js_num)
{
        struct panfrost_fence *fence;
        struct panfrost_job_slot *js = pfdev->js;

        fence = kzalloc_obj(*fence);
        if (!fence)
                return ERR_PTR(-ENOMEM);

        fence->dev = &pfdev->base;
        fence->queue = js_num;
        fence->seqno = ++js->queue[js_num].emit_seqno;
        dma_fence_init(&fence->base, &panfrost_fence_ops, &js->job_lock,
                       js->queue[js_num].fence_context, fence->seqno);

        return &fence->base;
}

int panfrost_job_get_slot(struct panfrost_job *job)
{
        /* JS0: fragment jobs.
         * JS1: vertex/tiler jobs
         * JS2: compute jobs
         */
        if (job->requirements & PANFROST_JD_REQ_FS)
                return 0;

/* Not exposed to userspace yet */
#if 0
        if (job->requirements & PANFROST_JD_REQ_ONLY_COMPUTE) {
                if ((job->requirements & PANFROST_JD_REQ_CORE_GRP_MASK) &&
                    (job->pfdev->features.nr_core_groups == 2))
                        return 2;
                if (panfrost_has_hw_issue(job->pfdev, HW_ISSUE_8987))
                        return 2;
        }
#endif
        return 1;
}

static void panfrost_job_write_affinity(struct panfrost_device *pfdev,
                                        u32 requirements,
                                        int js)
{
        u64 affinity;

        /*
         * Use all cores for now.
         * Eventually we may need to support tiler only jobs and h/w with
         * multiple (2) coherent core groups
         */
        affinity = pfdev->features.shader_present;

        job_write(pfdev, JS_AFFINITY_NEXT_LO(js), lower_32_bits(affinity));
        job_write(pfdev, JS_AFFINITY_NEXT_HI(js), upper_32_bits(affinity));
}

static u32
panfrost_get_job_chain_flag(const struct panfrost_job *job)
{
        struct panfrost_fence *f = to_panfrost_fence(job->done_fence);

        if (!panfrost_has_hw_feature(job->pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION))
                return 0;

        return (f->seqno & 1) ? JS_CONFIG_JOB_CHAIN_FLAG : 0;
}

static struct panfrost_job *
panfrost_dequeue_job(struct panfrost_device *pfdev, int slot)
{
        struct panfrost_job *job = pfdev->jobs[slot][0];

        WARN_ON(!job);

        if (job->is_profiled && job->engine_usage) {
                job->engine_usage->elapsed_ns[slot] +=
                        ktime_to_ns(ktime_sub(ktime_get(), job->start_time));
                job->engine_usage->cycles[slot] +=
                        panfrost_cycle_counter_read(pfdev) - job->start_cycles;
        }

        if (job->requirements & PANFROST_JD_REQ_CYCLE_COUNT || job->is_profiled)
                panfrost_cycle_counter_put(pfdev);

        pfdev->jobs[slot][0] = pfdev->jobs[slot][1];
        pfdev->jobs[slot][1] = NULL;

        return job;
}

static unsigned int
panfrost_enqueue_job(struct panfrost_device *pfdev, int slot,
                     struct panfrost_job *job)
{
        if (WARN_ON(!job))
                return 0;

        if (!pfdev->jobs[slot][0]) {
                pfdev->jobs[slot][0] = job;
                return 0;
        }

        WARN_ON(pfdev->jobs[slot][1]);
        pfdev->jobs[slot][1] = job;
        WARN_ON(panfrost_get_job_chain_flag(job) ==
                panfrost_get_job_chain_flag(pfdev->jobs[slot][0]));
        return 1;
}

static int panfrost_job_hw_submit(struct panfrost_job *job, int js)
{
        struct panfrost_device *pfdev = job->pfdev;
        unsigned int subslot;
        u32 cfg;
        u64 jc_head = job->jc;
        int ret;

        ret = pm_runtime_get_sync(pfdev->base.dev);
        if (ret < 0)
                goto err_hwsubmit;

        if (WARN_ON(job_read(pfdev, JS_COMMAND_NEXT(js)))) {
                ret = -EINVAL;
                goto err_hwsubmit;
        }

        ret = panfrost_mmu_as_get(pfdev, job->mmu);
        if (ret < 0)
                goto err_hwsubmit;

        cfg = ret;

        panfrost_devfreq_record_busy(&pfdev->pfdevfreq);

        job_write(pfdev, JS_HEAD_NEXT_LO(js), lower_32_bits(jc_head));
        job_write(pfdev, JS_HEAD_NEXT_HI(js), upper_32_bits(jc_head));

        panfrost_job_write_affinity(pfdev, job->requirements, js);

        /* start MMU, medium priority, cache clean/flush on end, clean/flush on
         * start */
        cfg |= JS_CONFIG_THREAD_PRI(8) |
                JS_CONFIG_START_FLUSH_CLEAN_INVALIDATE |
                JS_CONFIG_END_FLUSH_CLEAN_INVALIDATE |
                panfrost_get_job_chain_flag(job);

        if (panfrost_has_hw_feature(pfdev, HW_FEATURE_FLUSH_REDUCTION))
                cfg |= JS_CONFIG_ENABLE_FLUSH_REDUCTION;

        if (panfrost_has_hw_issue(pfdev, HW_ISSUE_10649))
                cfg |= JS_CONFIG_START_MMU;

        job_write(pfdev, JS_CONFIG_NEXT(js), cfg);

        if (panfrost_has_hw_feature(pfdev, HW_FEATURE_FLUSH_REDUCTION))
                job_write(pfdev, JS_FLUSH_ID_NEXT(js), job->flush_id);

        /* GO ! */

        spin_lock(&pfdev->js->job_lock);
        subslot = panfrost_enqueue_job(pfdev, js, job);
        /* Don't queue the job if a reset is in progress */
        if (!atomic_read(&pfdev->reset.pending)) {
                job->is_profiled = pfdev->profile_mode;

                if (job->requirements & PANFROST_JD_REQ_CYCLE_COUNT ||
                    job->is_profiled)
                        panfrost_cycle_counter_get(pfdev);

                if (job->is_profiled) {
                        job->start_time = ktime_get();
                        job->start_cycles = panfrost_cycle_counter_read(pfdev);
                }

                job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
                dev_dbg(pfdev->base.dev,
                        "JS: Submitting atom %p to js[%d][%d] with head=0x%llx AS %d",
                        job, js, subslot, jc_head, cfg & 0xf);
        }
        spin_unlock(&pfdev->js->job_lock);

        return 0;

err_hwsubmit:
        pm_runtime_put_autosuspend(pfdev->base.dev);
        return ret;
}

static int panfrost_acquire_object_fences(struct drm_gem_object **bos,
                                          int bo_count,
                                          struct drm_sched_job *job)
{
        int i, ret;

        for (i = 0; i < bo_count; i++) {
                ret = dma_resv_reserve_fences(bos[i]->resv, 1);
                if (ret)
                        return ret;

                /* panfrost always uses write mode in its current uapi */
                ret = drm_sched_job_add_implicit_dependencies(job, bos[i],
                                                              true);
                if (ret)
                        return ret;
        }

        return 0;
}

static void panfrost_attach_object_fences(struct drm_gem_object **bos,
                                          int bo_count,
                                          struct dma_fence *fence)
{
        int i;

        for (i = 0; i < bo_count; i++)
                dma_resv_add_fence(bos[i]->resv, fence, DMA_RESV_USAGE_WRITE);
}

int panfrost_job_push(struct panfrost_job *job)
{
        struct panfrost_device *pfdev = job->pfdev;
        struct ww_acquire_ctx acquire_ctx;
        int ret = 0;

        ret = drm_gem_lock_reservations(job->bos, job->bo_count,
                                            &acquire_ctx);
        if (ret)
                return ret;

        mutex_lock(&pfdev->sched_lock);
        drm_sched_job_arm(&job->base);

        job->render_done_fence = dma_fence_get(&job->base.s_fence->finished);

        ret = panfrost_acquire_object_fences(job->bos, job->bo_count,
                                             &job->base);
        if (ret) {
                mutex_unlock(&pfdev->sched_lock);
                goto unlock;
        }

        kref_get(&job->refcount); /* put by scheduler job completion */

        drm_sched_entity_push_job(&job->base);

        mutex_unlock(&pfdev->sched_lock);

        panfrost_attach_object_fences(job->bos, job->bo_count,
                                      job->render_done_fence);

unlock:
        drm_gem_unlock_reservations(job->bos, job->bo_count, &acquire_ctx);

        return ret;
}

static void panfrost_job_cleanup(struct kref *ref)
{
        struct panfrost_job *job = container_of(ref, struct panfrost_job,
                                                refcount);
        unsigned int i;

        dma_fence_put(job->done_fence);
        dma_fence_put(job->render_done_fence);

        if (job->mappings) {
                for (i = 0; i < job->bo_count; i++) {
                        if (!job->mappings[i])
                                break;

                        atomic_dec(&job->mappings[i]->obj->gpu_usecount);
                        panfrost_gem_mapping_put(job->mappings[i]);
                }
                kvfree(job->mappings);
        }

        if (job->bos) {
                for (i = 0; i < job->bo_count; i++)
                        drm_gem_object_put(job->bos[i]);

                kvfree(job->bos);
        }

        panfrost_jm_ctx_put(job->ctx);
        kfree(job);
}

void panfrost_job_put(struct panfrost_job *job)
{
        kref_put(&job->refcount, panfrost_job_cleanup);
}

static void panfrost_job_free(struct drm_sched_job *sched_job)
{
        struct panfrost_job *job = to_panfrost_job(sched_job);

        drm_sched_job_cleanup(sched_job);

        panfrost_job_put(job);
}

static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
{
        struct panfrost_job *job = to_panfrost_job(sched_job);
        struct panfrost_device *pfdev = job->pfdev;
        int slot = panfrost_job_get_slot(job);
        struct dma_fence *fence = NULL;
        int ret;

        if (job->ctx->destroyed)
                return ERR_PTR(-ECANCELED);

        if (unlikely(job->base.s_fence->finished.error))
                return NULL;

        /* Nothing to execute: can happen if the job has finished while
         * we were resetting the GPU.
         */
        if (!job->jc)
                return NULL;

        fence = panfrost_fence_create(pfdev, slot);
        if (IS_ERR(fence))
                return fence;

        if (job->done_fence)
                dma_fence_put(job->done_fence);
        job->done_fence = dma_fence_get(fence);

        ret = panfrost_job_hw_submit(job, slot);
        if (ret) {
                dma_fence_put(fence);
                return ERR_PTR(ret);
        }

        return fence;
}

void panfrost_jm_reset_interrupts(struct panfrost_device *pfdev)
{
        job_write(pfdev, JOB_INT_CLEAR, ALL_JS_INT_MASK);
}

void panfrost_jm_enable_interrupts(struct panfrost_device *pfdev)
{
        clear_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended);
        job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
}

void panfrost_jm_suspend_irq(struct panfrost_device *pfdev)
{
        set_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended);

        job_write(pfdev, JOB_INT_MASK, 0);
        synchronize_irq(pfdev->js->irq);
}

static void panfrost_job_handle_err(struct panfrost_device *pfdev,
                                    struct panfrost_job *job,
                                    unsigned int js)
{
        u32 js_status = job_read(pfdev, JS_STATUS(js));
        const char *exception_name = panfrost_exception_name(js_status);
        bool signal_fence = true;

        if (!panfrost_exception_is_fault(js_status)) {
                dev_dbg(pfdev->base.dev, "js event, js=%d, status=%s, head=0x%x, tail=0x%x",
                        js, exception_name,
                        job_read(pfdev, JS_HEAD_LO(js)),
                        job_read(pfdev, JS_TAIL_LO(js)));
        } else {
                dev_err(pfdev->base.dev, "js fault, js=%d, status=%s, head=0x%x, tail=0x%x",
                        js, exception_name,
                        job_read(pfdev, JS_HEAD_LO(js)),
                        job_read(pfdev, JS_TAIL_LO(js)));
        }

        if (js_status == DRM_PANFROST_EXCEPTION_STOPPED) {
                /* Update the job head so we can resume */
                job->jc = job_read(pfdev, JS_TAIL_LO(js)) |
                          ((u64)job_read(pfdev, JS_TAIL_HI(js)) << 32);

                /* The job will be resumed, don't signal the fence */
                signal_fence = false;
        } else if (js_status == DRM_PANFROST_EXCEPTION_TERMINATED) {
                /* Job has been hard-stopped, flag it as canceled */
                dma_fence_set_error(job->done_fence, -ECANCELED);
                job->jc = 0;
        } else if (panfrost_exception_is_fault(js_status)) {
                /* We might want to provide finer-grained error code based on
                 * the exception type, but unconditionally setting to EINVAL
                 * is good enough for now.
                 */
                dma_fence_set_error(job->done_fence, -EINVAL);
                job->jc = 0;
        }

        panfrost_mmu_as_put(pfdev, job->mmu);
        panfrost_devfreq_record_idle(&pfdev->pfdevfreq);

        if (signal_fence)
                dma_fence_signal_locked(job->done_fence);

        pm_runtime_put_autosuspend(pfdev->base.dev);

        if (panfrost_exception_needs_reset(pfdev, js_status)) {
                atomic_set(&pfdev->reset.pending, 1);
                drm_sched_fault(&pfdev->js->queue[js].sched);
        }
}

static void panfrost_jm_handle_done(struct panfrost_device *pfdev,
                                    struct panfrost_job *job)
{
        /* Set ->jc to 0 to avoid re-submitting an already finished job (can
         * happen when we receive the DONE interrupt while doing a GPU reset).
         */
        job->jc = 0;
        panfrost_mmu_as_put(pfdev, job->mmu);
        panfrost_devfreq_record_idle(&pfdev->pfdevfreq);

        dma_fence_signal_locked(job->done_fence);
        pm_runtime_put_autosuspend(pfdev->base.dev);
}

static void panfrost_jm_handle_irq(struct panfrost_device *pfdev, u32 status)
{
        struct panfrost_job *done[NUM_JOB_SLOTS][2] = {};
        struct panfrost_job *failed[NUM_JOB_SLOTS] = {};
        u32 js_state = 0, js_events = 0;
        unsigned int i, j;

        /* First we collect all failed/done jobs. */
        while (status) {
                u32 js_state_mask = 0;

                for (j = 0; j < NUM_JOB_SLOTS; j++) {
                        if (status & MK_JS_MASK(j))
                                js_state_mask |= MK_JS_MASK(j);

                        if (status & JOB_INT_MASK_DONE(j)) {
                                if (done[j][0])
                                        done[j][1] = panfrost_dequeue_job(pfdev, j);
                                else
                                        done[j][0] = panfrost_dequeue_job(pfdev, j);
                        }

                        if (status & JOB_INT_MASK_ERR(j)) {
                                /* Cancel the next submission. Will be submitted
                                 * after we're done handling this failure if
                                 * there's no reset pending.
                                 */
                                job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP);
                                failed[j] = panfrost_dequeue_job(pfdev, j);
                        }
                }

                /* JS_STATE is sampled when JOB_INT_CLEAR is written.
                 * For each BIT(slot) or BIT(slot + 16) bit written to
                 * JOB_INT_CLEAR, the corresponding bits in JS_STATE
                 * (BIT(slot) and BIT(slot + 16)) are updated, but this
                 * is racy. If we only have one job done at the time we
                 * read JOB_INT_RAWSTAT but the second job fails before we
                 * clear the status, we end up with a status containing
                 * only the DONE bit and consider both jobs as DONE since
                 * JS_STATE reports both NEXT and CURRENT as inactive.
                 * To prevent that, let's repeat this clear+read steps
                 * until status is 0.
                 */
                job_write(pfdev, JOB_INT_CLEAR, status);
                js_state &= ~js_state_mask;
                js_state |= job_read(pfdev, JOB_INT_JS_STATE) & js_state_mask;
                js_events |= status;
                status = job_read(pfdev, JOB_INT_RAWSTAT);
        }

        /* Then we handle the dequeued jobs. */
        for (j = 0; j < NUM_JOB_SLOTS; j++) {
                if (!(js_events & MK_JS_MASK(j)))
                        continue;

                if (failed[j]) {
                        panfrost_job_handle_err(pfdev, failed[j], j);
                } else if (pfdev->jobs[j][0] && !(js_state & MK_JS_MASK(j))) {
                        /* When the current job doesn't fail, the JM dequeues
                         * the next job without waiting for an ACK, this means
                         * we can have 2 jobs dequeued and only catch the
                         * interrupt when the second one is done. If both slots
                         * are inactive, but one job remains in pfdev->jobs[j],
                         * consider it done. Of course that doesn't apply if a
                         * failure happened since we cancelled execution of the
                         * job in _NEXT (see above).
                         */
                        if (WARN_ON(!done[j][0]))
                                done[j][0] = panfrost_dequeue_job(pfdev, j);
                        else
                                done[j][1] = panfrost_dequeue_job(pfdev, j);
                }

                for (i = 0; i < ARRAY_SIZE(done[0]) && done[j][i]; i++)
                        panfrost_jm_handle_done(pfdev, done[j][i]);
        }

        /* And finally we requeue jobs that were waiting in the second slot
         * and have been stopped if we detected a failure on the first slot.
         */
        for (j = 0; j < NUM_JOB_SLOTS; j++) {
                if (!(js_events & MK_JS_MASK(j)))
                        continue;

                if (!failed[j] || !pfdev->jobs[j][0])
                        continue;

                if (pfdev->jobs[j][0]->jc == 0) {
                        /* The job was cancelled, signal the fence now */
                        struct panfrost_job *canceled = panfrost_dequeue_job(pfdev, j);

                        dma_fence_set_error(canceled->done_fence, -ECANCELED);
                        panfrost_jm_handle_done(pfdev, canceled);
                } else if (!atomic_read(&pfdev->reset.pending)) {
                        /* Requeue the job we removed if no reset is pending */
                        job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_START);
                }
        }
}

static void panfrost_jm_handle_irqs(struct panfrost_device *pfdev)
{
        u32 status = job_read(pfdev, JOB_INT_RAWSTAT);

        while (status) {
                pm_runtime_mark_last_busy(pfdev->base.dev);

                spin_lock(&pfdev->js->job_lock);
                panfrost_jm_handle_irq(pfdev, status);
                spin_unlock(&pfdev->js->job_lock);
                status = job_read(pfdev, JOB_INT_RAWSTAT);
        }
}

static u32 panfrost_active_slots(struct panfrost_device *pfdev,
                                 u32 *js_state_mask, u32 js_state)
{
        u32 rawstat;

        if (!(js_state & *js_state_mask))
                return 0;

        rawstat = job_read(pfdev, JOB_INT_RAWSTAT);
        if (rawstat) {
                unsigned int i;

                for (i = 0; i < NUM_JOB_SLOTS; i++) {
                        if (rawstat & MK_JS_MASK(i))
                                *js_state_mask &= ~MK_JS_MASK(i);
                }
        }

        return js_state & *js_state_mask;
}

static void
panfrost_reset(struct panfrost_device *pfdev,
               struct drm_sched_job *bad)
{
        u32 js_state, js_state_mask = 0xffffffff;
        unsigned int i, j;
        bool cookie;
        int ret;

        if (!atomic_read(&pfdev->reset.pending))
                return;

        /* Stop the schedulers.
         *
         * FIXME: We temporarily get out of the dma_fence_signalling section
         * because the cleanup path generate lockdep splats when taking locks
         * to release job resources. We should rework the code to follow this
         * pattern:
         *
         *      try_lock
         *      if (locked)
         *              release
         *      else
         *              schedule_work_to_release_later
         */
        for (i = 0; i < NUM_JOB_SLOTS; i++)
                drm_sched_stop(&pfdev->js->queue[i].sched, bad);

        cookie = dma_fence_begin_signalling();

        if (bad)
                drm_sched_increase_karma(bad);

        /* Mask job interrupts and synchronize to make sure we won't be
         * interrupted during our reset.
         */
        job_write(pfdev, JOB_INT_MASK, 0);
        synchronize_irq(pfdev->js->irq);

        for (i = 0; i < NUM_JOB_SLOTS; i++) {
                /* Cancel the next job and soft-stop the running job. */
                job_write(pfdev, JS_COMMAND_NEXT(i), JS_COMMAND_NOP);
                job_write(pfdev, JS_COMMAND(i), JS_COMMAND_SOFT_STOP);
        }

        /* Wait at most 10ms for soft-stops to complete */
        ret = readl_poll_timeout(pfdev->iomem + JOB_INT_JS_STATE, js_state,
                                 !panfrost_active_slots(pfdev, &js_state_mask, js_state),
                                 10, 10000);

        if (ret)
                dev_err(pfdev->base.dev, "Soft-stop failed\n");

        /* Handle the remaining interrupts before we reset. */
        panfrost_jm_handle_irqs(pfdev);

        /* Remaining interrupts have been handled, but we might still have
         * stuck jobs. Let's make sure the PM counters stay balanced by
         * manually calling pm_runtime_put_noidle() and
         * panfrost_devfreq_record_idle() for each stuck job.
         * Let's also make sure the cycle counting register's refcnt is
         * kept balanced to prevent it from running forever
         */
        spin_lock(&pfdev->js->job_lock);
        for (i = 0; i < NUM_JOB_SLOTS; i++) {
                for (j = 0; j < ARRAY_SIZE(pfdev->jobs[0]) && pfdev->jobs[i][j]; j++) {
                        if (pfdev->jobs[i][j]->requirements & PANFROST_JD_REQ_CYCLE_COUNT ||
                            pfdev->jobs[i][j]->is_profiled)
                                panfrost_cycle_counter_put(pfdev->jobs[i][j]->pfdev);
                        pm_runtime_put_noidle(pfdev->base.dev);
                        panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
                }
        }
        memset(pfdev->jobs, 0, sizeof(pfdev->jobs));
        spin_unlock(&pfdev->js->job_lock);

        /* Proceed with reset now. */
        panfrost_device_reset(pfdev, false);

        /* GPU has been reset, we can clear the reset pending bit. */
        atomic_set(&pfdev->reset.pending, 0);

        /* Now resubmit jobs that were previously queued but didn't have a
         * chance to finish.
         * FIXME: We temporarily get out of the DMA fence signalling section
         * while resubmitting jobs because the job submission logic will
         * allocate memory with the GFP_KERNEL flag which can trigger memory
         * reclaim and exposes a lock ordering issue.
         */
        dma_fence_end_signalling(cookie);
        for (i = 0; i < NUM_JOB_SLOTS; i++)
                drm_sched_resubmit_jobs(&pfdev->js->queue[i].sched);
        cookie = dma_fence_begin_signalling();

        /* Restart the schedulers */
        for (i = 0; i < NUM_JOB_SLOTS; i++)
                drm_sched_start(&pfdev->js->queue[i].sched, 0);

        /* Re-enable job interrupts now that everything has been restarted. */
        panfrost_jm_enable_interrupts(pfdev);

        dma_fence_end_signalling(cookie);
}

static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
                                                     *sched_job)
{
        struct panfrost_job *job = to_panfrost_job(sched_job);
        struct panfrost_device *pfdev = job->pfdev;
        int js = panfrost_job_get_slot(job);

        /*
         * If the GPU managed to complete this jobs fence, the timeout has
         * fired before free-job worker. The timeout is spurious, so bail out.
         */
        if (dma_fence_is_signaled(job->done_fence))
                return DRM_GPU_SCHED_STAT_NO_HANG;

        /*
         * Panfrost IRQ handler may take a long time to process an interrupt
         * if there is another IRQ handler hogging the processing.
         * For example, the HDMI encoder driver might be stuck in the IRQ
         * handler for a significant time in a case of bad cable connection.
         * In order to catch such cases and not report spurious Panfrost
         * job timeouts, synchronize the IRQ handler and re-check the fence
         * status.
         */
        synchronize_irq(pfdev->js->irq);

        if (dma_fence_is_signaled(job->done_fence)) {
                dev_warn(pfdev->base.dev, "unexpectedly high interrupt latency\n");
                return DRM_GPU_SCHED_STAT_NO_HANG;
        }

        dev_err(pfdev->base.dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p",
                js,
                job_read(pfdev, JS_CONFIG(js)),
                job_read(pfdev, JS_STATUS(js)),
                job_read(pfdev, JS_HEAD_LO(js)),
                job_read(pfdev, JS_TAIL_LO(js)),
                sched_job);

        panfrost_core_dump(job);

        atomic_set(&pfdev->reset.pending, 1);
        panfrost_reset(pfdev, sched_job);

        return DRM_GPU_SCHED_STAT_RESET;
}

static void panfrost_reset_work(struct work_struct *work)
{
        struct panfrost_device *pfdev;

        pfdev = container_of(work, struct panfrost_device, reset.work);
        panfrost_reset(pfdev, NULL);
}

static const struct drm_sched_backend_ops panfrost_sched_ops = {
        .run_job = panfrost_job_run,
        .timedout_job = panfrost_job_timedout,
        .free_job = panfrost_job_free
};

static irqreturn_t panfrost_jm_irq_handler_thread(int irq, void *data)
{
        struct panfrost_device *pfdev = data;

        panfrost_jm_handle_irqs(pfdev);

        /* Enable interrupts only if we're not about to get suspended */
        if (!test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended))
                job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);

        return IRQ_HANDLED;
}

static irqreturn_t panfrost_jm_irq_handler(int irq, void *data)
{
        struct panfrost_device *pfdev = data;
        u32 status;

        if (test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended))
                return IRQ_NONE;

        status = job_read(pfdev, JOB_INT_STAT);
        if (!status)
                return IRQ_NONE;

        job_write(pfdev, JOB_INT_MASK, 0);
        return IRQ_WAKE_THREAD;
}

int panfrost_jm_init(struct panfrost_device *pfdev)
{
        struct drm_sched_init_args args = {
                .ops = &panfrost_sched_ops,
                .num_rqs = DRM_SCHED_PRIORITY_COUNT,
                .credit_limit = 2,
                .timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
                .dev = pfdev->base.dev,
        };
        struct panfrost_job_slot *js;
        int ret, j;

        BUILD_BUG_ON(ARRAY_SIZE(panfrost_engine_names) != NUM_JOB_SLOTS);

        /* All GPUs have two entries per queue, but without jobchain
         * disambiguation stopping the right job in the close path is tricky,
         * so let's just advertise one entry in that case.
         */
        if (!panfrost_has_hw_feature(pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION))
                args.credit_limit = 1;

        js = devm_kzalloc(pfdev->base.dev, sizeof(*js), GFP_KERNEL);
        if (!js)
                return -ENOMEM;
        pfdev->js = js;

        INIT_WORK(&pfdev->reset.work, panfrost_reset_work);
        spin_lock_init(&js->job_lock);

        js->irq = platform_get_irq_byname(to_platform_device(pfdev->base.dev), "job");
        if (js->irq < 0)
                return js->irq;

        ret = devm_request_threaded_irq(pfdev->base.dev, js->irq,
                                        panfrost_jm_irq_handler,
                                        panfrost_jm_irq_handler_thread,
                                        IRQF_SHARED, KBUILD_MODNAME "-job",
                                        pfdev);
        if (ret) {
                dev_err(pfdev->base.dev, "failed to request job irq");
                return ret;
        }

        pfdev->reset.wq = alloc_ordered_workqueue("panfrost-reset", 0);
        if (!pfdev->reset.wq)
                return -ENOMEM;
        args.timeout_wq = pfdev->reset.wq;

        for (j = 0; j < NUM_JOB_SLOTS; j++) {
                js->queue[j].fence_context = dma_fence_context_alloc(1);
                args.name = panfrost_engine_names[j];

                ret = drm_sched_init(&js->queue[j].sched, &args);
                if (ret) {
                        dev_err(pfdev->base.dev, "Failed to create scheduler: %d.", ret);
                        goto err_sched;
                }
        }

        panfrost_jm_reset_interrupts(pfdev);
        panfrost_jm_enable_interrupts(pfdev);

        return 0;

err_sched:
        for (j--; j >= 0; j--)
                drm_sched_fini(&js->queue[j].sched);

        destroy_workqueue(pfdev->reset.wq);
        return ret;
}

void panfrost_jm_fini(struct panfrost_device *pfdev)
{
        struct panfrost_job_slot *js = pfdev->js;
        int j;

        job_write(pfdev, JOB_INT_MASK, 0);

        for (j = 0; j < NUM_JOB_SLOTS; j++) {
                drm_sched_fini(&js->queue[j].sched);
        }

        cancel_work_sync(&pfdev->reset.work);
        destroy_workqueue(pfdev->reset.wq);
}

int panfrost_jm_open(struct drm_file *file)
{
        struct panfrost_file_priv *panfrost_priv = file->driver_priv;
        int ret;

        struct drm_panfrost_jm_ctx_create default_jm_ctx = {
                .priority = PANFROST_JM_CTX_PRIORITY_MEDIUM,
        };

        xa_init_flags(&panfrost_priv->jm_ctxs, XA_FLAGS_ALLOC);

        ret = panfrost_jm_ctx_create(file, &default_jm_ctx);
        if (ret)
                return ret;

        /* We expect the default context to be assigned handle 0. */
        if (WARN_ON(default_jm_ctx.handle))
                return -EINVAL;

        return 0;
}

void panfrost_jm_close(struct drm_file *file)
{
        struct panfrost_file_priv *panfrost_priv = file->driver_priv;
        struct panfrost_jm_ctx *jm_ctx;
        unsigned long i;

        xa_for_each(&panfrost_priv->jm_ctxs, i, jm_ctx)
                panfrost_jm_ctx_destroy(file, i);

        xa_destroy(&panfrost_priv->jm_ctxs);
}

int panfrost_jm_is_idle(struct panfrost_device *pfdev)
{
        struct panfrost_job_slot *js = pfdev->js;
        int i;

        for (i = 0; i < NUM_JOB_SLOTS; i++) {
                /* If there are any jobs in the HW queue, we're not idle */
                if (atomic_read(&js->queue[i].sched.credit_count))
                        return false;
        }

        return true;
}

static void panfrost_jm_ctx_release(struct kref *kref)
{
        struct panfrost_jm_ctx *jm_ctx = container_of(kref, struct panfrost_jm_ctx, refcnt);

        WARN_ON(!jm_ctx->destroyed);

        for (u32 i = 0; i < ARRAY_SIZE(jm_ctx->slot_entity); i++)
                drm_sched_entity_destroy(&jm_ctx->slot_entity[i]);

        kfree(jm_ctx);
}

void
panfrost_jm_ctx_put(struct panfrost_jm_ctx *jm_ctx)
{
        if (jm_ctx)
                kref_put(&jm_ctx->refcnt, panfrost_jm_ctx_release);
}

struct panfrost_jm_ctx *
panfrost_jm_ctx_get(struct panfrost_jm_ctx *jm_ctx)
{
        if (jm_ctx)
                kref_get(&jm_ctx->refcnt);

        return jm_ctx;
}

struct panfrost_jm_ctx *
panfrost_jm_ctx_from_handle(struct drm_file *file, u32 handle)
{
        struct panfrost_file_priv *priv = file->driver_priv;
        struct panfrost_jm_ctx *jm_ctx;

        xa_lock(&priv->jm_ctxs);
        jm_ctx = panfrost_jm_ctx_get(xa_load(&priv->jm_ctxs, handle));
        xa_unlock(&priv->jm_ctxs);

        return jm_ctx;
}

static int jm_ctx_prio_to_drm_sched_prio(struct drm_file *file,
                                         enum drm_panfrost_jm_ctx_priority in,
                                         enum drm_sched_priority *out)
{
        switch (in) {
        case PANFROST_JM_CTX_PRIORITY_LOW:
                *out = DRM_SCHED_PRIORITY_LOW;
                return 0;
        case PANFROST_JM_CTX_PRIORITY_MEDIUM:
                *out = DRM_SCHED_PRIORITY_NORMAL;
                return 0;
        case PANFROST_JM_CTX_PRIORITY_HIGH:
                if (!panfrost_high_prio_allowed(file))
                        return -EACCES;

                *out = DRM_SCHED_PRIORITY_HIGH;
                return 0;
        default:
                return -EINVAL;
        }
}

int panfrost_jm_ctx_create(struct drm_file *file,
                           struct drm_panfrost_jm_ctx_create *args)
{
        struct panfrost_file_priv *priv = file->driver_priv;
        struct panfrost_device *pfdev = priv->pfdev;
        enum drm_sched_priority sched_prio;
        struct panfrost_jm_ctx *jm_ctx;
        int ret;

        jm_ctx = kzalloc_obj(*jm_ctx);
        if (!jm_ctx)
                return -ENOMEM;

        kref_init(&jm_ctx->refcnt);

        ret = jm_ctx_prio_to_drm_sched_prio(file, args->priority, &sched_prio);
        if (ret)
                goto err_put_jm_ctx;

        for (u32 i = 0; i < NUM_JOB_SLOTS; i++) {
                struct drm_gpu_scheduler *sched = &pfdev->js->queue[i].sched;

                ret = drm_sched_entity_init(&jm_ctx->slot_entity[i], sched_prio,
                                            &sched, 1, NULL);
                if (ret)
                        goto err_put_jm_ctx;
        }

        ret = xa_alloc(&priv->jm_ctxs, &args->handle, jm_ctx,
                       XA_LIMIT(0, MAX_JM_CTX_PER_FILE), GFP_KERNEL);
        if (ret)
                goto err_put_jm_ctx;

        return 0;

err_put_jm_ctx:
        jm_ctx->destroyed = true;
        panfrost_jm_ctx_put(jm_ctx);
        return ret;
}

int panfrost_jm_ctx_destroy(struct drm_file *file, u32 handle)
{
        struct panfrost_file_priv *priv = file->driver_priv;
        struct panfrost_device *pfdev = priv->pfdev;
        struct panfrost_jm_ctx *jm_ctx;

        jm_ctx = xa_erase(&priv->jm_ctxs, handle);
        if (!jm_ctx)
                return -EINVAL;

        jm_ctx->destroyed = true;

        /* Kill in-flight jobs */
        spin_lock(&pfdev->js->job_lock);
        for (u32 i = 0; i < ARRAY_SIZE(jm_ctx->slot_entity); i++) {
                struct drm_sched_entity *entity = &jm_ctx->slot_entity[i];

                for (int j = ARRAY_SIZE(pfdev->jobs[0]) - 1; j >= 0; j--) {
                        struct panfrost_job *job = pfdev->jobs[i][j];
                        u32 cmd;

                        if (!job || job->base.entity != entity)
                                continue;

                        if (j == 1) {
                                /* Try to cancel the job before it starts */
                                job_write(pfdev, JS_COMMAND_NEXT(i), JS_COMMAND_NOP);
                                /* Reset the job head so it doesn't get restarted if
                                 * the job in the first slot failed.
                                 */
                                job->jc = 0;
                        }

                        if (panfrost_has_hw_feature(pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION)) {
                                cmd = panfrost_get_job_chain_flag(job) ?
                                      JS_COMMAND_HARD_STOP_1 :
                                      JS_COMMAND_HARD_STOP_0;
                        } else {
                                cmd = JS_COMMAND_HARD_STOP;
                        }

                        job_write(pfdev, JS_COMMAND(i), cmd);

                        /* Jobs can outlive their file context */
                        job->engine_usage = NULL;
                }
        }
        spin_unlock(&pfdev->js->job_lock);

        panfrost_jm_ctx_put(jm_ctx);
        return 0;
}