diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c index 2ec359ed2def02..28b7ddce774770 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.c +++ b/drivers/gpu/drm/v3d/v3d_drv.c @@ -121,6 +121,7 @@ v3d_open(struct drm_device *dev, struct drm_file *file) 1, NULL); memset(&v3d_priv->stats[i], 0, sizeof(v3d_priv->stats[i])); + seqcount_init(&v3d_priv->stats[i].lock); } v3d_perfmon_open_file(v3d_priv); @@ -145,10 +146,15 @@ v3d_postclose(struct drm_device *dev, struct drm_file *file) void v3d_get_stats(const struct v3d_stats *stats, u64 timestamp, u64 *active_runtime, u64 *jobs_completed) { - *active_runtime = stats->enabled_ns; - if (stats->start_ns) - *active_runtime += timestamp - stats->start_ns; - *jobs_completed = stats->jobs_completed; + unsigned int seq; + + do { + seq = read_seqcount_begin(&stats->lock); + *active_runtime = stats->enabled_ns; + if (stats->start_ns) + *active_runtime += timestamp - stats->start_ns; + *jobs_completed = stats->jobs_completed; + } while (read_seqcount_retry(&stats->lock, seq)); } static void v3d_show_fdinfo(struct drm_printer *p, struct drm_file *file) diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index ff06dc1cc078a4..a2c516fe6d7969 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -40,6 +40,13 @@ struct v3d_stats { u64 start_ns; u64 enabled_ns; u64 jobs_completed; + + /* + * This seqcount is used to protect the access to the GPU stats + * variables. It must be used as, while we are reading the stats, + * IRQs can happen and the stats can be updated. + */ + seqcount_t lock; }; struct v3d_queue_state { diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 0086081a926185..da8faf3b901165 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -251,6 +251,7 @@ v3d_gem_init(struct drm_device *dev) queue->fence_context = dma_fence_context_alloc(1); memset(&queue->stats, 0, sizeof(queue->stats)); + seqcount_init(&queue->stats.lock); } spin_lock_init(&v3d->mm_lock); diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index b9614944931c81..7cd8c335cd9b7e 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -114,16 +114,23 @@ v3d_job_start_stats(struct v3d_job *job, enum v3d_queue queue) struct v3d_stats *local_stats = &file->stats[queue]; u64 now = local_clock(); + write_seqcount_begin(&local_stats->lock); local_stats->start_ns = now; + write_seqcount_end(&local_stats->lock); + + write_seqcount_begin(&global_stats->lock); global_stats->start_ns = now; + write_seqcount_end(&global_stats->lock); } static void v3d_stats_update(struct v3d_stats *stats, u64 now) { + write_seqcount_begin(&stats->lock); stats->enabled_ns += now - stats->start_ns; stats->jobs_completed++; stats->start_ns = 0; + write_seqcount_end(&stats->lock); } void