From 070ce7657bdfaab5913908c93d57281c639cdca4 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Wed, 30 Jun 2021 08:27:43 +0200 Subject: [PATCH] drm/panfrost: Use a threaded IRQ for job interrupts This should avoid switching to interrupt context when the GPU is under heavy use. v3: * Don't take the job_lock in panfrost_job_handle_irq() Signed-off-by: Boris Brezillon Acked-by: Alyssa Rosenzweig Reviewed-by: Steven Price Link: https://patchwork.freedesktop.org/patch/msgid/20210630062751.2832545-9-boris.brezillon@collabora.com --- drivers/gpu/drm/panfrost/panfrost_job.c | 53 +++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 12285a2..6149e4c 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -459,19 +459,12 @@ 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); @@ -508,7 +501,6 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data) if (status & JOB_INT_MASK_DONE(j)) { struct panfrost_job *job; - spin_lock(&pfdev->js->job_lock); job = pfdev->jobs[j]; /* Only NULL if job timeout occurred */ if (job) { @@ -520,21 +512,49 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data) dma_fence_signal_locked(job->done_fence); pm_runtime_put_autosuspend(pfdev->dev); } - spin_unlock(&pfdev->js->job_lock); } 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, + GENMASK(16 + NUM_JOB_SLOTS - 1, 16) | + GENMASK(NUM_JOB_SLOTS - 1, 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; bool cookie; @@ -564,7 +584,7 @@ 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); @@ -572,7 +592,7 @@ 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); @@ -599,8 +619,11 @@ 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; -- 2.7.4