On 21/06/2021 15:02, Boris Brezillon wrote:
> This should avoid uneccessary interrupt-context switches when the GPU
> is passed a lot of short jobs.
LGTM:
Reviewed-by: Steven Price <steven.price@xxxxxxx>
>
> v2:
> * New patch
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_job.c | 54 +++++++++++++++++--------
> 1 file changed, 38 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index cf6abe0fdf47..1b5c636794a1 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -473,19 +473,12 @@ static const struct drm_sched_backend_ops panfrost_sched_ops = {
> .free_job = panfrost_job_free
> };
>
> -static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> +static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status)
> {
> - struct panfrost_device *pfdev = data;
> - u32 status = job_read(pfdev, JOB_INT_STAT);
> int j;
>
> dev_dbg(pfdev->dev, "jobslot irq status=%x\n", status);
>
> - if (!status)
> - return IRQ_NONE;
> -
> - pm_runtime_mark_last_busy(pfdev->dev);
> -
> for (j = 0; status; j++) {
> u32 mask = MK_JS_MASK(j);
>
> @@ -558,16 +551,43 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
>
> status &= ~mask;
> }
> +}
>
> +static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data)
> +{
> + struct panfrost_device *pfdev = data;
> + u32 status = job_read(pfdev, JOB_INT_RAWSTAT);
> +
> + while (status) {
> + pm_runtime_mark_last_busy(pfdev->dev);
> +
> + spin_lock(&pfdev->js->job_lock);
> + panfrost_job_handle_irq(pfdev, status);
> + spin_unlock(&pfdev->js->job_lock);
> + status = job_read(pfdev, JOB_INT_RAWSTAT);
> + }
> +
> + job_write(pfdev, JOB_INT_MASK, ~0);
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> +{
> + struct panfrost_device *pfdev = data;
> + u32 status = job_read(pfdev, JOB_INT_STAT);
> +
> + if (!status)
> + return IRQ_NONE;
> +
> + job_write(pfdev, JOB_INT_MASK, 0);
> + return IRQ_WAKE_THREAD;
> +}
> +
> static void panfrost_reset(struct work_struct *work)
> {
> struct panfrost_device *pfdev = container_of(work,
> struct panfrost_device,
> reset.work);
> - unsigned long flags;
> unsigned int i;
>
> for (i = 0; i < NUM_JOB_SLOTS; i++) {
> @@ -595,7 +615,7 @@ static void panfrost_reset(struct work_struct *work)
> /* All timers have been stopped, we can safely reset the pending state. */
> atomic_set(&pfdev->reset.pending, 0);
>
> - spin_lock_irqsave(&pfdev->js->job_lock, flags);
> + spin_lock(&pfdev->js->job_lock);
> for (i = 0; i < NUM_JOB_SLOTS; i++) {
> if (pfdev->jobs[i]) {
> pm_runtime_put_noidle(pfdev->dev);
> @@ -603,7 +623,7 @@ static void panfrost_reset(struct work_struct *work)
> pfdev->jobs[i] = NULL;
> }
> }
> - spin_unlock_irqrestore(&pfdev->js->job_lock, flags);
> + spin_unlock(&pfdev->js->job_lock);
>
> panfrost_device_reset(pfdev);
>
> @@ -628,8 +648,11 @@ int panfrost_job_init(struct panfrost_device *pfdev)
> if (irq <= 0)
> return -ENODEV;
>
> - ret = devm_request_irq(pfdev->dev, irq, panfrost_job_irq_handler,
> - IRQF_SHARED, KBUILD_MODNAME "-job", pfdev);
> + ret = devm_request_threaded_irq(pfdev->dev, irq,
> + panfrost_job_irq_handler,
> + panfrost_job_irq_handler_thread,
> + IRQF_SHARED, KBUILD_MODNAME "-job",
> + pfdev);
> if (ret) {
> dev_err(pfdev->dev, "failed to request job irq");
> return ret;
> @@ -696,14 +719,13 @@ int panfrost_job_open(struct panfrost_file_priv *panfrost_priv)
> void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
> {
> struct panfrost_device *pfdev = panfrost_priv->pfdev;
> - unsigned long flags;
> int i;
>
> for (i = 0; i < NUM_JOB_SLOTS; i++)
> drm_sched_entity_destroy(&panfrost_priv->sched_entity[i]);
>
> /* Kill in-flight jobs */
> - spin_lock_irqsave(&pfdev->js->job_lock, flags);
> + spin_lock(&pfdev->js->job_lock);
> for (i = 0; i < NUM_JOB_SLOTS; i++) {
> struct drm_sched_entity *entity = &panfrost_priv->sched_entity[i];
> struct panfrost_job *job = pfdev->jobs[i];
> @@ -713,7 +735,7 @@ void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
>
> job_write(pfdev, JS_COMMAND(i), JS_COMMAND_HARD_STOP);
> }
> - spin_unlock_irqrestore(&pfdev->js->job_lock, flags);
> + spin_unlock(&pfdev->js->job_lock);
> }
>
> int panfrost_job_is_idle(struct panfrost_device *pfdev)
>
