Re: [PATCH] drm/panfrost: Queue jobs on the hardware

From: Rob Herring
Date: Mon Aug 19 2019 - 12:58:31 EST

On Fri, Aug 16, 2019 at 4:31 AM Steven Price <steven.price@xxxxxxx> wrote:
>
> The hardware has a set of '_NEXT' registers that can hold a second job
> while the first is executing. Make use of these registers to enqueue a
> second job per slot.
>
> Signed-off-by: Steven Price <steven.price@xxxxxxx>
> ---
> Note that this is based on top of Rob Herring's "per FD address space"
> patch[1].
>
> [1] https://marc.info/?i=20190813150115.30338-1-robh%20()%20kernel%20!%20org
>
> drivers/gpu/drm/panfrost/panfrost_device.h | 4 +-
> drivers/gpu/drm/panfrost/panfrost_job.c | 76 ++++++++++++++++++----
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +-
> 3 files changed, 67 insertions(+), 15 deletions(-)

LGTM, but I'll give Tomeu a chance to comment.

Rob

>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index f503c566e99f..0153defd6085 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -55,7 +55,7 @@ struct panfrost_devfreq_slot {
> ktime_t busy_time;
> ktime_t idle_time;
> ktime_t time_last_update;
> - bool busy;
> + int busy;
> };
>
> struct panfrost_device {
> @@ -80,7 +80,7 @@ struct panfrost_device {
>
> struct panfrost_job_slot *js;
>
> - struct panfrost_job *jobs[NUM_JOB_SLOTS];
> + struct panfrost_job *jobs[NUM_JOB_SLOTS][2];
> struct list_head scheduled_jobs;
>
> struct panfrost_perfcnt *perfcnt;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index 05c85f45a0de..b2b5027af976 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -138,6 +138,37 @@ static void panfrost_job_write_affinity(struct panfrost_device *pfdev,
> job_write(pfdev, JS_AFFINITY_NEXT_HI(js), affinity >> 32);
> }
>
> +static int panfrost_job_count(struct panfrost_device *pfdev, int slot)
> +{
> + if (pfdev->jobs[slot][0] == NULL)
> + return 0;
> + if (pfdev->jobs[slot][1] == NULL)
> + return 1;
> + return 2;
> +}
> +
> +static struct panfrost_job *panfrost_dequeue_job(
> + struct panfrost_device *pfdev, int slot)
> +{
> + struct panfrost_job *job = pfdev->jobs[slot][0];
> +
> + pfdev->jobs[slot][0] = pfdev->jobs[slot][1];
> + pfdev->jobs[slot][1] = NULL;
> +
> + return job;
> +}
> +
> +static void panfrost_enqueue_job(struct panfrost_device *pfdev, int slot,
> + struct panfrost_job *job)
> +{
> + if (pfdev->jobs[slot][0] == NULL) {
> + pfdev->jobs[slot][0] = job;
> + return;
> + }
> + WARN_ON(pfdev->jobs[slot][1] != NULL);
> + pfdev->jobs[slot][1] = job;
> +}
> +
> static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
> {
> struct panfrost_device *pfdev = job->pfdev;
> @@ -150,13 +181,16 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
> if (ret < 0)
> return;
>
> - if (WARN_ON(job_read(pfdev, JS_COMMAND_NEXT(js))))
> - goto end;
> -
> cfg = panfrost_mmu_as_get(pfdev, &job->file_priv->mmu);
>
> - panfrost_devfreq_record_transition(pfdev, js);
> spin_lock_irqsave(&pfdev->hwaccess_lock, flags);
> + panfrost_enqueue_job(pfdev, js, job);
> +
> + if (WARN_ON(job_read(pfdev, JS_COMMAND_NEXT(js))))
> + goto end;
> +
> + if (panfrost_job_count(pfdev, js) == 1)
> + panfrost_devfreq_record_transition(pfdev, js);
>
> job_write(pfdev, JS_HEAD_NEXT_LO(js), jc_head & 0xFFFFFFFF);
> job_write(pfdev, JS_HEAD_NEXT_HI(js), jc_head >> 32);
> @@ -186,9 +220,9 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
>
> job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
>
> +end:
> spin_unlock_irqrestore(&pfdev->hwaccess_lock, flags);
>
> -end:
> pm_runtime_mark_last_busy(pfdev->dev);
> pm_runtime_put_autosuspend(pfdev->dev);
> }
> @@ -336,8 +370,6 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
> if (unlikely(job->base.s_fence->finished.error))
> return NULL;
>
> - pfdev->jobs[slot] = job;
> -
> fence = panfrost_fence_create(pfdev, slot);
> if (IS_ERR(fence))
> return NULL;
> @@ -421,21 +453,36 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> struct panfrost_device *pfdev = data;
> u32 status = job_read(pfdev, JOB_INT_STAT);
> int j;
> + unsigned long flags;
>
> dev_dbg(pfdev->dev, "jobslot irq status=%x\n", status);
>
> if (!status)
> return IRQ_NONE;
>
> + spin_lock_irqsave(&pfdev->hwaccess_lock, flags);
> +
> pm_runtime_mark_last_busy(pfdev->dev);
>
> for (j = 0; status; j++) {
> u32 mask = MK_JS_MASK(j);
> + int jobs = panfrost_job_count(pfdev, j);
> + int active;
>
> if (!(status & mask))
> continue;
>
> job_write(pfdev, JOB_INT_CLEAR, mask);
> + active = (job_read(pfdev, JOB_INT_JS_STATE) &
> + JOB_INT_MASK_DONE(j)) ? 1 : 0;
> +
> + if (!(status & JOB_INT_MASK_ERR(j))) {
> + /* Recheck RAWSTAT to check if there's a newly
> + * failed job (since JOB_INT_STAT was read)
> + */
> + status |= job_read(pfdev, JOB_INT_RAWSTAT) &
> + JOB_INT_MASK_ERR(j);
> + }
>
> if (status & JOB_INT_MASK_ERR(j)) {
> job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP);
> @@ -447,20 +494,25 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> job_read(pfdev, JS_TAIL_LO(j)));
>
> drm_sched_fault(&pfdev->js->queue[j].sched);
> + jobs --;
> }
>
> - if (status & JOB_INT_MASK_DONE(j)) {
> - struct panfrost_job *job = pfdev->jobs[j];
> + while (jobs -- > active) {
> + struct panfrost_job *job =
> + panfrost_dequeue_job(pfdev, j);
>
> - pfdev->jobs[j] = NULL;
> panfrost_mmu_as_put(pfdev, &job->file_priv->mmu);
> - panfrost_devfreq_record_transition(pfdev, j);
> dma_fence_signal(job->done_fence);
> }
>
> + if (!active)
> + panfrost_devfreq_record_transition(pfdev, j);
> +
> status &= ~mask;
> }
>
> + spin_unlock_irqrestore(&pfdev->hwaccess_lock, flags);
> +
> return IRQ_HANDLED;
> }
>
> @@ -491,7 +543,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
>
> ret = drm_sched_init(&js->queue[j].sched,
> &panfrost_sched_ops,
> - 1, 0, msecs_to_jiffies(500),
> + 2, 0, msecs_to_jiffies(500),
> "pan_js");
> if (ret) {
> dev_err(pfdev->dev, "Failed to create scheduler: %d.", ret);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index f22d8f02568d..c25fd88ef437 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -147,7 +147,7 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
> as = mmu->as;
> if (as >= 0) {
> int en = atomic_inc_return(&mmu->as_count);
> - WARN_ON(en >= NUM_JOB_SLOTS);
> + WARN_ON(en >= NUM_JOB_SLOTS*2);
>
> list_move(&mmu->list, &pfdev->as_lru_list);
> goto out;
> --
> 2.20.1
>