drm/panthor: add DRM fdinfo support

Drawing from the FW-calculated values in a previous commit, we can increase
the numbers for an open file by collecting them from finished jobs when
updating their group synchronisation objects.

Display of fdinfo key-value pairs is governed by a bitmask that is by
default unset in the present commit, and supporting manual toggle of it
will be the matter of a later commit.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923230912.2207320-4-adrian.larumbe@collabora.com

drivers/gpu/drm/panthor/panthor_device.h

@@ -192,6 +192,11 @@ struct panthor_device {
 	unsigned long fast_rate;
 };
 
+struct panthor_gpu_usage {
+	u64 time;
+	u64 cycles;
+};
+
 /**
  * struct panthor_file - Panthor file
  */
@@ -204,6 +209,9 @@ struct panthor_file {
 
 	/** @groups: Scheduling group pool attached to this file. */
 	struct panthor_group_pool *groups;
+
+	/** @stats: cycle and timestamp measures for job execution. */
+	struct panthor_gpu_usage stats;
 };
 
 int panthor_device_init(struct panthor_device *ptdev);

drivers/gpu/drm/panthor/panthor_drv.c

@@ -13,6 +13,7 @@
 #include <linux/pagemap.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/time64.h>
 
 #include <drm/drm_auth.h>
 #include <drm/drm_debugfs.h>
@@ -1435,6 +1436,37 @@ static int panthor_mmap(struct file *filp, struct vm_area_struct *vma)
 	return ret;
 }
 
+static void panthor_gpu_show_fdinfo(struct panthor_device *ptdev,
+				    struct panthor_file *pfile,
+				    struct drm_printer *p)
+{
+	if (ptdev->profile_mask & PANTHOR_DEVICE_PROFILING_ALL)
+		panthor_fdinfo_gather_group_samples(pfile);
+
+	if (ptdev->profile_mask & PANTHOR_DEVICE_PROFILING_TIMESTAMP) {
+#ifdef CONFIG_ARM_ARCH_TIMER
+		drm_printf(p, "drm-engine-panthor:\t%llu ns\n",
+			   DIV_ROUND_UP_ULL((pfile->stats.time * NSEC_PER_SEC),
+					    arch_timer_get_cntfrq()));
+#endif
+	}
+	if (ptdev->profile_mask & PANTHOR_DEVICE_PROFILING_CYCLES)
+		drm_printf(p, "drm-cycles-panthor:\t%llu\n", pfile->stats.cycles);
+
+	drm_printf(p, "drm-maxfreq-panthor:\t%lu Hz\n", ptdev->fast_rate);
+	drm_printf(p, "drm-curfreq-panthor:\t%lu Hz\n", ptdev->current_frequency);
+}
+
+static void panthor_show_fdinfo(struct drm_printer *p, struct drm_file *file)
+{
+	struct drm_device *dev = file->minor->dev;
+	struct panthor_device *ptdev = container_of(dev, struct panthor_device, base);
+
+	panthor_gpu_show_fdinfo(ptdev, file->driver_priv, p);
+
+	drm_show_memory_stats(p, file);
+}
+
 static const struct file_operations panthor_drm_driver_fops = {
 	.open = drm_open,
 	.release = drm_release,
@@ -1444,6 +1476,7 @@ static const struct file_operations panthor_drm_driver_fops = {
 	.read = drm_read,
 	.llseek = noop_llseek,
 	.mmap = panthor_mmap,
+	.show_fdinfo = drm_show_fdinfo,
 };
 
 #ifdef CONFIG_DEBUG_FS
@@ -1465,6 +1498,7 @@ static const struct drm_driver panthor_drm_driver = {
 			   DRIVER_SYNCOBJ_TIMELINE | DRIVER_GEM_GPUVA,
 	.open = panthor_open,
 	.postclose = panthor_postclose,
+	.show_fdinfo = panthor_show_fdinfo,
 	.ioctls = panthor_drm_driver_ioctls,
 	.num_ioctls = ARRAY_SIZE(panthor_drm_driver_ioctls),
 	.fops = &panthor_drm_driver_fops,

drivers/gpu/drm/panthor/panthor_sched.c

@@ -617,6 +617,18 @@ struct panthor_group {
 	 */
 	struct panthor_kernel_bo *syncobjs;
 
+	/** @fdinfo: Per-file total cycle and timestamp values reference. */
+	struct {
+		/** @data: Total sampled values for jobs in queues from this group. */
+		struct panthor_gpu_usage data;
+
+		/**
+		 * @lock: Mutex to govern concurrent access from drm file's fdinfo callback
+		 * and job post-completion processing function
+		 */
+		struct mutex lock;
+	} fdinfo;
+
 	/** @state: Group state. */
 	enum panthor_group_state state;
 
@@ -887,6 +899,8 @@ static void group_release_work(struct work_struct *work)
 						   release_work);
 	u32 i;
 
+	mutex_destroy(&group->fdinfo.lock);
+
 	for (i = 0; i < group->queue_count; i++)
 		group_free_queue(group, group->queues[i]);
 
@@ -2809,6 +2823,41 @@ void panthor_sched_post_reset(struct panthor_device *ptdev, bool reset_failed)
 	}
 }
 
+static void update_fdinfo_stats(struct panthor_job *job)
+{
+	struct panthor_group *group = job->group;
+	struct panthor_queue *queue = group->queues[job->queue_idx];
+	struct panthor_gpu_usage *fdinfo = &group->fdinfo.data;
+	struct panthor_job_profiling_data *slots = queue->profiling.slots->kmap;
+	struct panthor_job_profiling_data *data = &slots[job->profiling.slot];
+
+	mutex_lock(&group->fdinfo.lock);
+	if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_CYCLES)
+		fdinfo->cycles += data->cycles.after - data->cycles.before;
+	if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_TIMESTAMP)
+		fdinfo->time += data->time.after - data->time.before;
+	mutex_unlock(&group->fdinfo.lock);
+}
+
+void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile)
+{
+	struct panthor_group_pool *gpool = pfile->groups;
+	struct panthor_group *group;
+	unsigned long i;
+
+	if (IS_ERR_OR_NULL(gpool))
+		return;
+
+	xa_for_each(&gpool->xa, i, group) {
+		mutex_lock(&group->fdinfo.lock);
+		pfile->stats.cycles += group->fdinfo.data.cycles;
+		pfile->stats.time += group->fdinfo.data.time;
+		group->fdinfo.data.cycles = 0;
+		group->fdinfo.data.time = 0;
+		mutex_unlock(&group->fdinfo.lock);
+	}
+}
+
 static void group_sync_upd_work(struct work_struct *work)
 {
 	struct panthor_group *group =
@@ -2841,6 +2890,8 @@ static void group_sync_upd_work(struct work_struct *work)
 	dma_fence_end_signalling(cookie);
 
 	list_for_each_entry_safe(job, job_tmp, &done_jobs, node) {
+		if (job->profiling.mask)
+			update_fdinfo_stats(job);
 		list_del_init(&job->node);
 		panthor_job_put(&job->base);
 	}
@@ -3424,6 +3475,8 @@ int panthor_group_create(struct panthor_file *pfile,
 	}
 	mutex_unlock(&sched->reset.lock);
 
+	mutex_init(&group->fdinfo.lock);
+
 	return gid;
 
 err_put_group:

drivers/gpu/drm/panthor/panthor_sched.h

@@ -47,4 +47,6 @@ void panthor_sched_resume(struct panthor_device *ptdev);
 void panthor_sched_report_mmu_fault(struct panthor_device *ptdev);
 void panthor_sched_report_fw_events(struct panthor_device *ptdev, u32 events);
 
+void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile);
+
 #endif