From: Steven Price steven.price@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.
v5: * Fix a comment in panfrost_job_init()
v3: * Fix the done/err job dequeuing logic to get a valid active state * Only enable the second slot on GPUs supporting jobchain disambiguation * Split interrupt handling in sub-functions
Signed-off-by: Steven Price steven.price@arm.com Signed-off-by: Boris Brezillon boris.brezillon@collabora.com --- drivers/gpu/drm/panfrost/panfrost_device.h | 2 +- drivers/gpu/drm/panfrost/panfrost_job.c | 468 +++++++++++++++------ 2 files changed, 351 insertions(+), 119 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h index d2ee6e5fe5d8..9f1f2a603208 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 d8e1bc227455..e89e6adef481 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> @@ -140,9 +141,52 @@ static void panfrost_job_write_affinity(struct panfrost_device *pfdev, job_write(pfdev, JS_AFFINITY_NEXT_HI(js), affinity >> 32); }
+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); + 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 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; @@ -168,7 +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; @@ -182,10 +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, @@ -343,7 +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)) @@ -371,11 +427,218 @@ void panfrost_job_enable_interrupts(struct panfrost_device *pfdev) job_write(pfdev, JOB_INT_MASK, irq_mask); }
-static void panfrost_reset(struct panfrost_device *pfdev, - struct drm_sched_job *bad) +static void panfrost_job_handle_err(struct panfrost_device *pfdev, + struct panfrost_job *job, + unsigned int js) { - unsigned int i; + 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->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->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->file_priv->mmu); + panfrost_devfreq_record_idle(&pfdev->pfdevfreq); + + if (signal_fence) + dma_fence_signal_locked(job->done_fence); + + pm_runtime_put_autosuspend(pfdev->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_job_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->file_priv->mmu); + panfrost_devfreq_record_idle(&pfdev->pfdevfreq); + + dma_fence_signal_locked(job->done_fence); + pm_runtime_put_autosuspend(pfdev->dev); +} + +static void panfrost_job_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_job_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_job_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_job_handle_irqs(struct panfrost_device *pfdev) +{ + 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); + } +} + +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; @@ -407,21 +670,46 @@ static void panfrost_reset(struct panfrost_device *pfdev, job_write(pfdev, JOB_INT_MASK, 0); synchronize_irq(pfdev->js->irq);
- /* Schedulers are stopped and interrupts are masked+flushed, we don't - * need to protect the 'evict unfinished jobs' lock with the job_lock. + 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->dev, "Soft-stop failed\n"); + + /* Handle the remaining interrupts before we reset. */ + panfrost_job_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. */ spin_lock(&pfdev->js->job_lock); for (i = 0; i < NUM_JOB_SLOTS; i++) { - if (pfdev->jobs[i]) { + for (j = 0; j < ARRAY_SIZE(pfdev->jobs[0]) && pfdev->jobs[i][j]; j++) { pm_runtime_put_noidle(pfdev->dev); panfrost_devfreq_record_idle(&pfdev->pfdevfreq); - pfdev->jobs[i] = NULL; } } + memset(pfdev->jobs, 0, sizeof(pfdev->jobs)); spin_unlock(&pfdev->js->job_lock);
+ /* Proceed with reset now. */ panfrost_device_reset(pfdev);
+ /* panfrost_device_reset() unmasks job interrupts, but we want to + * keep them masked a bit longer. + */ + job_write(pfdev, JOB_INT_MASK, 0); + /* GPU has been reset, we can cancel timeout/fault work that may have * been queued in the meantime and clear the reset pending bit. */ @@ -429,7 +717,6 @@ static void panfrost_reset(struct panfrost_device *pfdev, for (i = 0; i < NUM_JOB_SLOTS; i++) cancel_delayed_work(&pfdev->js->queue[i].sched.work_tdr);
- /* 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 @@ -442,9 +729,15 @@ static void panfrost_reset(struct panfrost_device *pfdev, 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, true);
+ /* Re-enable job interrupts now that everything has been restarted. */ + job_write(pfdev, JOB_INT_MASK, + GENMASK(16 + NUM_JOB_SLOTS - 1, 16) | + GENMASK(NUM_JOB_SLOTS - 1, 0)); + dma_fence_end_signalling(cookie); }
@@ -476,6 +769,14 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job return DRM_GPU_SCHED_STAT_NOMINAL; }
+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 = { .dependency = panfrost_job_dependency, .run_job = panfrost_job_run, @@ -483,100 +784,11 @@ static const struct drm_sched_backend_ops panfrost_sched_ops = { .free_job = panfrost_job_free };
-static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status) -{ - int j; - - dev_dbg(pfdev->dev, "jobslot irq status=%x\n", status); - - for (j = 0; status; j++) { - u32 mask = MK_JS_MASK(j); - - if (!(status & mask)) - continue; - - job_write(pfdev, JOB_INT_CLEAR, mask); - - if (status & JOB_INT_MASK_ERR(j)) { - u32 js_status = job_read(pfdev, JS_STATUS(j)); - const char *exception_name = panfrost_exception_name(js_status); - - job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP); - - if (!panfrost_exception_is_fault(js_status)) { - dev_dbg(pfdev->dev, "js interrupt, js=%d, status=%s, head=0x%x, tail=0x%x", - j, exception_name, - job_read(pfdev, JS_HEAD_LO(j)), - job_read(pfdev, JS_TAIL_LO(j))); - } else { - dev_err(pfdev->dev, "js fault, js=%d, status=%s, head=0x%x, tail=0x%x", - j, exception_name, - job_read(pfdev, JS_HEAD_LO(j)), - job_read(pfdev, JS_TAIL_LO(j))); - } - - /* If we need a reset, signal it to the timeout - * handler, otherwise, update the fence error field and - * signal the job fence. - */ - if (panfrost_exception_needs_reset(pfdev, js_status)) { - drm_sched_fault(&pfdev->js->queue[j].sched); - } else { - int error = 0; - - if (js_status == DRM_PANFROST_EXCEPTION_TERMINATED) - error = -ECANCELED; - else if (panfrost_exception_is_fault(js_status)) - error = -EINVAL; - - if (error) - dma_fence_set_error(pfdev->jobs[j]->done_fence, error); - - status |= JOB_INT_MASK_DONE(j); - } - } - - if (status & JOB_INT_MASK_DONE(j)) { - struct panfrost_job *job; - - job = pfdev->jobs[j]; - /* The only reason this job could be NULL is if the - * job IRQ handler is called just after the - * in-flight job eviction in the reset path, and - * this shouldn't happen because the job IRQ has - * been masked and synchronized when this eviction - * happens. - */ - WARN_ON(!job); - 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); - } - } - - 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); - }
+ panfrost_job_handle_irqs(pfdev); job_write(pfdev, JOB_INT_MASK, GENMASK(16 + NUM_JOB_SLOTS - 1, 16) | GENMASK(NUM_JOB_SLOTS - 1, 0)); @@ -595,26 +807,24 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data) return IRQ_WAKE_THREAD; }
-static void panfrost_reset_work(struct work_struct *work) -{ - struct panfrost_device *pfdev = container_of(work, - struct panfrost_device, - reset.work); - - panfrost_reset(pfdev, NULL); -} - int panfrost_job_init(struct panfrost_device *pfdev) { struct panfrost_job_slot *js; + unsigned int nentries = 2; int ret, j;
- INIT_WORK(&pfdev->reset.work, panfrost_reset_work); + /* 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)) + nentries = 1;
pfdev->js = js = devm_kzalloc(pfdev->dev, sizeof(*js), GFP_KERNEL); if (!js) return -ENOMEM;
+ INIT_WORK(&pfdev->reset.work, panfrost_reset_work); spin_lock_init(&js->job_lock);
js->irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "job"); @@ -640,7 +850,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
ret = drm_sched_init(&js->queue[j].sched, &panfrost_sched_ops, - 1, 0, + nentries, 0, msecs_to_jiffies(JOB_TIMEOUT_MS), pfdev->reset.wq, NULL, "pan_js"); @@ -707,12 +917,34 @@ 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; + } + + 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); + } } spin_unlock(&pfdev->js->job_lock); }