[PATCH v2 2/2] drm/panfrost: Queue jobs on the hardware
Boris Brezillon
boris.brezillon at collabora.com
Mon Jun 21 14:02:26 UTC 2021
From: Steven Price <steven.price at arm.com>
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.
v2:
* Make sure non-faulty jobs get properly paused/resumed on GPU reset
Signed-off-by: Steven Price <steven.price at arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
---
drivers/gpu/drm/panfrost/panfrost_device.h | 2 +-
drivers/gpu/drm/panfrost/panfrost_job.c | 311 ++++++++++++++++-----
2 files changed, 242 insertions(+), 71 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
index 95e6044008d2..a87917b9e714 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.h
+++ b/drivers/gpu/drm/panfrost/panfrost_device.h
@@ -101,7 +101,7 @@ 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 1b5c636794a1..888eceed227f 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -4,6 +4,7 @@
#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>
@@ -41,6 +42,7 @@ struct panfrost_queue_state {
};
struct panfrost_job_slot {
+ int irq;
struct panfrost_queue_state queue[NUM_JOB_SLOTS];
spinlock_t job_lock;
};
@@ -148,9 +150,43 @@ static void panfrost_job_write_affinity(struct panfrost_device *pfdev,
job_write(pfdev, JS_AFFINITY_NEXT_HI(js), affinity >> 32);
}
+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 unsigned int
+panfrost_enqueue_job(struct panfrost_device *pfdev, int slot,
+ struct panfrost_job *job)
+{
+ if (!pfdev->jobs[slot][0]) {
+ pfdev->jobs[slot][0] = job;
+ return 0;
+ }
+
+ WARN_ON(pfdev->jobs[slot][1]);
+ pfdev->jobs[slot][1] = job;
+ return 1;
+}
+
+static u32
+panfrost_get_job_chain_flag(const struct panfrost_job *job)
+{
+ struct panfrost_fence *f = to_panfrost_fence(job->done_fence);
+
+ return (f->seqno & 1) ? JS_CONFIG_JOB_CHAIN_FLAG : 0;
+}
+
static void 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;
@@ -176,7 +212,8 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
* start */
cfg |= JS_CONFIG_THREAD_PRI(8) |
JS_CONFIG_START_FLUSH_CLEAN_INVALIDATE |
- JS_CONFIG_END_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;
@@ -190,10 +227,17 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
job_write(pfdev, JS_FLUSH_ID_NEXT(js), job->flush_id);
/* GO ! */
- dev_dbg(pfdev->dev, "JS: Submitting atom %p to js[%d] with head=0x%llx",
- job, js, jc_head);
- job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
+ 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_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
+ dev_dbg(pfdev->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);
}
static void panfrost_acquire_object_fences(struct drm_gem_object **bos,
@@ -351,7 +395,11 @@ 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;
+ /* 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))
@@ -475,25 +523,67 @@ static const struct drm_sched_backend_ops panfrost_sched_ops = {
static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status)
{
- int j;
+ struct panfrost_job *done[NUM_JOB_SLOTS][2] = {};
+ struct panfrost_job *failed[NUM_JOB_SLOTS] = {};
+ u32 js_state, js_events = 0;
+ unsigned int i, j;
- dev_dbg(pfdev->dev, "jobslot irq status=%x\n", status);
+ while (status) {
+ for (j = 0; j < NUM_JOB_SLOTS; j++) {
+ if (status & JOB_INT_MASK_DONE(j)) {
+ if (done[j][0]) {
+ done[j][1] = panfrost_dequeue_job(pfdev, j);
+ WARN_ON(!done[j][1]);
+ } else {
+ done[j][0] = panfrost_dequeue_job(pfdev, j);
+ WARN_ON(!done[j][0]);
+ }
+ }
- for (j = 0; status; j++) {
- u32 mask = MK_JS_MASK(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);
+ }
+ }
- if (!(status & mask))
+ /* 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 = job_read(pfdev, JOB_INT_JS_STATE);
+ js_events |= status;
+ status = job_read(pfdev, JOB_INT_RAWSTAT);
+ }
+
+ for (j = 0; j < NUM_JOB_SLOTS; j++) {
+ if (!(js_events & MK_JS_MASK(j)))
continue;
- job_write(pfdev, JOB_INT_CLEAR, mask);
-
- if (status & JOB_INT_MASK_ERR(j)) {
- enum panfrost_queue_status old_status;
+ if (failed[j]) {
u32 js_status = job_read(pfdev, JS_STATUS(j));
int error = panfrost_exception_to_error(js_status);
const char *exception_name = panfrost_exception_name(js_status);
- job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP);
+ if (js_status == DRM_PANFROST_EXCEPTION_STOPPED) {
+ /* Update the job head so we can resume */
+ failed[j]->jc = job_read(pfdev, JS_TAIL_LO(j)) |
+ ((u64)job_read(pfdev, JS_TAIL_HI(j)) << 32);
+ } else {
+ failed[j]->jc = 0;
+ }
if (!error) {
dev_dbg(pfdev->dev, "js interrupt, js=%d, status=%s, head=0x%x, tail=0x%x",
@@ -505,51 +595,68 @@ static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status)
j, exception_name,
job_read(pfdev, JS_HEAD_LO(j)),
job_read(pfdev, JS_TAIL_LO(j)));
+ dma_fence_set_error(failed[j]->done_fence, error);
}
- /* If we need a reset, signal it to the reset handler,
- * otherwise, update the fence error field and signal
- * the job fence.
+ panfrost_mmu_as_put(pfdev, failed[j]->file_priv->mmu);
+ panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
+
+ dma_fence_signal_locked(failed[j]->done_fence);
+ pm_runtime_put_autosuspend(pfdev->dev);
+
+ if (panfrost_exception_needs_reset(pfdev, js_status))
+ panfrost_device_schedule_reset(pfdev);
+ } 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 (panfrost_exception_needs_reset(pfdev, js_status)) {
- /*
- * When the queue is being restarted we don't report
- * faults directly to avoid races between the timeout
- * and reset handlers. panfrost_scheduler_start() will
- * call drm_sched_fault() after the queue has been
- * started if status == FAULT_PENDING.
- */
- old_status = atomic_cmpxchg(&pfdev->js->queue[j].status,
- PANFROST_QUEUE_STATUS_STARTING,
- PANFROST_QUEUE_STATUS_FAULT_PENDING);
- if (old_status == PANFROST_QUEUE_STATUS_ACTIVE)
- drm_sched_fault(&pfdev->js->queue[j].sched);
- } else {
- dma_fence_set_error(pfdev->jobs[j]->done_fence,
- panfrost_exception_to_error(js_status));
- status |= JOB_INT_MASK_DONE(j);
- }
+ if (WARN_ON(!done[j][0]))
+ done[j][0] = panfrost_dequeue_job(pfdev, j);
+ else
+ done[j][1] = panfrost_dequeue_job(pfdev, j);
}
- if (status & JOB_INT_MASK_DONE(j)) {
- struct panfrost_job *job;
+ for (i = 0; i < ARRAY_SIZE(done[0]) && done[j][i]; i++) {
+ /* 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).
+ */
+ done[j][i]->jc = 0;
+ panfrost_mmu_as_put(pfdev, done[j][i]->file_priv->mmu);
+ panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
- spin_lock(&pfdev->js->job_lock);
- job = pfdev->jobs[j];
- /* Only NULL if job timeout occurred */
- if (job) {
- pfdev->jobs[j] = NULL;
-
- panfrost_mmu_as_put(pfdev, job->file_priv->mmu);
- panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
-
- dma_fence_signal_locked(job->done_fence);
- pm_runtime_put_autosuspend(pfdev->dev);
- }
- spin_unlock(&pfdev->js->job_lock);
+ dma_fence_signal_locked(done[j][i]->done_fence);
+ pm_runtime_put_autosuspend(pfdev->dev);
}
+ }
- status &= ~mask;
+ 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);
+
+ panfrost_mmu_as_put(pfdev, canceled->file_priv->mmu);
+ panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
+
+ dma_fence_set_error(canceled->done_fence, -ECANCELED);
+ dma_fence_signal_locked(canceled->done_fence);
+ pm_runtime_put_autosuspend(pfdev->dev);
+ } else if (!atomic_read(&pfdev->reset.pending)) {
+ /* Resume the job we stopped if no reset is pending */
+ job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_START);
+ }
}
}
@@ -583,12 +690,36 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
return IRQ_WAKE_THREAD;
}
+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 work_struct *work)
{
struct panfrost_device *pfdev = container_of(work,
struct panfrost_device,
reset.work);
+ u32 js_state, js_state_mask = 0xffffffff;
unsigned int i;
+ bool cookie;
+ int ret;
for (i = 0; i < NUM_JOB_SLOTS; i++) {
/*
@@ -612,21 +743,43 @@ static void panfrost_reset(struct work_struct *work)
panfrost_scheduler_stop(&pfdev->js->queue[i], NULL);
}
- /* All timers have been stopped, we can safely reset the pending state. */
- atomic_set(&pfdev->reset.pending, 0);
+ /* Mask job interrupts and make sure all interrupt handlers have
+ * returned. We'll call the job interrupt handler manually, after
+ * issuing soft-stops.
+ */
+ job_write(pfdev, JOB_INT_MASK, 0);
+ synchronize_irq(pfdev->js->irq);
- spin_lock(&pfdev->js->job_lock);
for (i = 0; i < NUM_JOB_SLOTS; i++) {
- if (pfdev->jobs[i]) {
- pm_runtime_put_noidle(pfdev->dev);
- panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
- pfdev->jobs[i] = NULL;
- }
+ /* 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);
}
- spin_unlock(&pfdev->js->job_lock);
+ /* Wait at most 10ms for soft-stops to complete */
+ job_write(pfdev, JOB_INT_MASK, 0);
+ 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->dev, "Soft-stop failed (active_mask=%x)\n", js_state);
+
+ /* Handle the remaining interrupts before we reset. */
+ cookie = dma_fence_begin_signalling();
+ panfrost_job_irq_handler_thread(pfdev->js->irq, pfdev);
+ dma_fence_end_signalling(cookie);
+
+ /* Proceed with reset now. */
panfrost_device_reset(pfdev);
+ /* Reset is done, we can clear the pending flag. */
+ atomic_set(&pfdev->reset.pending, 0);
+
+ /* Now resubmit jobs that were previously queued but didn't have a
+ * chance to finish.
+ */
+ memset(pfdev->jobs, 0, sizeof(pfdev->jobs));
for (i = 0; i < NUM_JOB_SLOTS; i++)
panfrost_scheduler_start(&pfdev->js->queue[i]);
}
@@ -634,7 +787,7 @@ static void panfrost_reset(struct work_struct *work)
int panfrost_job_init(struct panfrost_device *pfdev)
{
struct panfrost_job_slot *js;
- int ret, j, irq;
+ int ret, j;
INIT_WORK(&pfdev->reset.work, panfrost_reset);
@@ -644,11 +797,11 @@ int panfrost_job_init(struct panfrost_device *pfdev)
spin_lock_init(&js->job_lock);
- irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "job");
- if (irq <= 0)
+ js->irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "job");
+ if (js->irq <= 0)
return -ENODEV;
- ret = devm_request_threaded_irq(pfdev->dev, irq,
+ ret = devm_request_threaded_irq(pfdev->dev, js->irq,
panfrost_job_irq_handler,
panfrost_job_irq_handler_thread,
IRQF_SHARED, KBUILD_MODNAME "-job",
@@ -665,7 +818,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
ret = drm_sched_init(&js->queue[j].sched,
&panfrost_sched_ops,
- 1, 0, msecs_to_jiffies(JOB_TIMEOUT_MS),
+ 2, 0, msecs_to_jiffies(JOB_TIMEOUT_MS),
NULL, "pan_js");
if (ret) {
dev_err(pfdev->dev, "Failed to create scheduler: %d.", ret);
@@ -728,12 +881,30 @@ void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
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];
+ int j;
- if (!job || job->base.entity != entity)
- continue;
+ for (j = ARRAY_SIZE(pfdev->jobs[0]) - 1; j >= 0; j--) {
+ struct panfrost_job *job = pfdev->jobs[i][j];
+ u32 cmd;
- job_write(pfdev, JS_COMMAND(i), JS_COMMAND_HARD_STOP);
+ 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;
+ }
+
+ cmd = panfrost_get_job_chain_flag(job) ?
+ JS_COMMAND_HARD_STOP_1 :
+ JS_COMMAND_HARD_STOP_0;
+
+ job_write(pfdev, JS_COMMAND(i), cmd);
+ }
}
spin_unlock(&pfdev->js->job_lock);
}
--
2.31.1
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