1 files changed, 354 insertions, 134 deletions

diff --git a/drivers/misc/habanalabs/device.c b/drivers/misc/habanalabs/device.c
index 7a8f9d0b71b5..459fee70a597 100644
--- a/drivers/misc/habanalabs/device.c
+++ b/drivers/misc/habanalabs/device.c
@@ -42,10 +42,12 @@ static void hpriv_release(struct kref *ref)
 {
 	struct hl_fpriv *hpriv;
 	struct hl_device *hdev;
+	struct hl_ctx *ctx;
 
 	hpriv = container_of(ref, struct hl_fpriv, refcount);
 
 	hdev = hpriv->hdev;
+	ctx = hpriv->ctx;
 
 	put_pid(hpriv->taskpid);
 
@@ -53,13 +55,12 @@ static void hpriv_release(struct kref *ref)
 
 	mutex_destroy(&hpriv->restore_phase_mutex);
 
-	kfree(hpriv);
-
-	/* Now the FD is really closed */
-	atomic_dec(&hdev->fd_open_cnt);
+	mutex_lock(&hdev->fpriv_list_lock);
+	list_del(&hpriv->dev_node);
+	hdev->compute_ctx = NULL;
+	mutex_unlock(&hdev->fpriv_list_lock);
 
-	/* This allows a new user context to open the device */
-	hdev->user_ctx = NULL;
+	kfree(hpriv);
 }
 
 void hl_hpriv_get(struct hl_fpriv *hpriv)
@@ -94,6 +95,24 @@ static int hl_device_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static int hl_device_release_ctrl(struct inode *inode, struct file *filp)
+{
+	struct hl_fpriv *hpriv = filp->private_data;
+	struct hl_device *hdev;
+
+	filp->private_data = NULL;
+
+	hdev = hpriv->hdev;
+
+	mutex_lock(&hdev->fpriv_list_lock);
+	list_del(&hpriv->dev_node);
+	mutex_unlock(&hdev->fpriv_list_lock);
+
+	kfree(hpriv);
+
+	return 0;
+}
+
 /*
  * hl_mmap - mmap function for habanalabs device
  *
@@ -124,55 +143,102 @@ static const struct file_operations hl_ops = {
 	.compat_ioctl = hl_ioctl
 };
 
+static const struct file_operations hl_ctrl_ops = {
+	.owner = THIS_MODULE,
+	.open = hl_device_open_ctrl,
+	.release = hl_device_release_ctrl,
+	.unlocked_ioctl = hl_ioctl_control,
+	.compat_ioctl = hl_ioctl_control
+};
+
+static void device_release_func(struct device *dev)
+{
+	kfree(dev);
+}
+
 /*
- * device_setup_cdev - setup cdev and device for habanalabs device
+ * device_init_cdev - Initialize cdev and device for habanalabs device
  *
  * @hdev: pointer to habanalabs device structure
  * @hclass: pointer to the class object of the device
  * @minor: minor number of the specific device
- * @fpos : file operations to install for this device
+ * @fpos: file operations to install for this device
+ * @name: name of the device as it will appear in the filesystem
+ * @cdev: pointer to the char device object that will be initialized
+ * @dev: pointer to the device object that will be initialized
  *
- * Create a cdev and a Linux device for habanalabs's device. Need to be
- * called at the end of the habanalabs device initialization process,
- * because this function exposes the device to the user
+ * Initialize a cdev and a Linux device for habanalabs's device.
  */
-static int device_setup_cdev(struct hl_device *hdev, struct class *hclass,
-				int minor, const struct file_operations *fops)
+static int device_init_cdev(struct hl_device *hdev, struct class *hclass,
+				int minor, const struct file_operations *fops,
+				char *name, struct cdev *cdev,
+				struct device **dev)
 {
-	int err, devno = MKDEV(hdev->major, minor);
-	struct cdev *hdev_cdev = &hdev->cdev;
-	char *name;
+	cdev_init(cdev, fops);
+	cdev->owner = THIS_MODULE;
 
-	name = kasprintf(GFP_KERNEL, "hl%d", hdev->id);
-	if (!name)
+	*dev = kzalloc(sizeof(**dev), GFP_KERNEL);
+	if (!*dev)
 		return -ENOMEM;
 
-	cdev_init(hdev_cdev, fops);
-	hdev_cdev->owner = THIS_MODULE;
-	err = cdev_add(hdev_cdev, devno, 1);
-	if (err) {
-		pr_err("Failed to add char device %s\n", name);
-		goto err_cdev_add;
+	device_initialize(*dev);
+	(*dev)->devt = MKDEV(hdev->major, minor);
+	(*dev)->class = hclass;
+	(*dev)->release = device_release_func;
+	dev_set_drvdata(*dev, hdev);
+	dev_set_name(*dev, "%s", name);
+
+	return 0;
+}
+
+static int device_cdev_sysfs_add(struct hl_device *hdev)
+{
+	int rc;
+
+	rc = cdev_device_add(&hdev->cdev, hdev->dev);
+	if (rc) {
+		dev_err(hdev->dev,
+			"failed to add a char device to the system\n");
+		return rc;
 	}
 
-	hdev->dev = device_create(hclass, NULL, devno, NULL, "%s", name);
-	if (IS_ERR(hdev->dev)) {
-		pr_err("Failed to create device %s\n", name);
-		err = PTR_ERR(hdev->dev);
-		goto err_device_create;
+	rc = cdev_device_add(&hdev->cdev_ctrl, hdev->dev_ctrl);
+	if (rc) {
+		dev_err(hdev->dev,
+			"failed to add a control char device to the system\n");
+		goto delete_cdev_device;
 	}
 
-	dev_set_drvdata(hdev->dev, hdev);
+	/* hl_sysfs_init() must be done after adding the device to the system */
+	rc = hl_sysfs_init(hdev);
+	if (rc) {
+		dev_err(hdev->dev, "failed to initialize sysfs\n");
+		goto delete_ctrl_cdev_device;
+	}
 
-	kfree(name);
+	hdev->cdev_sysfs_created = true;
 
 	return 0;
 
-err_device_create:
-	cdev_del(hdev_cdev);
-err_cdev_add:
-	kfree(name);
-	return err;
+delete_ctrl_cdev_device:
+	cdev_device_del(&hdev->cdev_ctrl, hdev->dev_ctrl);
+delete_cdev_device:
+	cdev_device_del(&hdev->cdev, hdev->dev);
+	return rc;
+}
+
+static void device_cdev_sysfs_del(struct hl_device *hdev)
+{
+	/* device_release() won't be called so must free devices explicitly */
+	if (!hdev->cdev_sysfs_created) {
+		kfree(hdev->dev_ctrl);
+		kfree(hdev->dev);
+		return;
+	}
+
+	hl_sysfs_fini(hdev);
+	cdev_device_del(&hdev->cdev_ctrl, hdev->dev_ctrl);
+	cdev_device_del(&hdev->cdev, hdev->dev);
 }
 
 /*
@@ -227,20 +293,29 @@ static int device_early_init(struct hl_device *hdev)
 		goto free_eq_wq;
 	}
 
+	hdev->idle_busy_ts_arr = kmalloc_array(HL_IDLE_BUSY_TS_ARR_SIZE,
+					sizeof(struct hl_device_idle_busy_ts),
+					(GFP_KERNEL | __GFP_ZERO));
+	if (!hdev->idle_busy_ts_arr) {
+		rc = -ENOMEM;
+		goto free_chip_info;
+	}
+
 	hl_cb_mgr_init(&hdev->kernel_cb_mgr);
 
-	mutex_init(&hdev->fd_open_cnt_lock);
 	mutex_init(&hdev->send_cpu_message_lock);
 	mutex_init(&hdev->debug_lock);
 	mutex_init(&hdev->mmu_cache_lock);
 	INIT_LIST_HEAD(&hdev->hw_queues_mirror_list);
 	spin_lock_init(&hdev->hw_queues_mirror_lock);
+	INIT_LIST_HEAD(&hdev->fpriv_list);
+	mutex_init(&hdev->fpriv_list_lock);
 	atomic_set(&hdev->in_reset, 0);
-	atomic_set(&hdev->fd_open_cnt, 0);
-	atomic_set(&hdev->cs_active_cnt, 0);
 
 	return 0;
 
+free_chip_info:
+	kfree(hdev->hl_chip_info);
 free_eq_wq:
 	destroy_workqueue(hdev->eq_wq);
 free_cq_wq:
@@ -266,8 +341,11 @@ static void device_early_fini(struct hl_device *hdev)
 	mutex_destroy(&hdev->debug_lock);
 	mutex_destroy(&hdev->send_cpu_message_lock);
 
+	mutex_destroy(&hdev->fpriv_list_lock);
+
 	hl_cb_mgr_fini(hdev, &hdev->kernel_cb_mgr);
 
+	kfree(hdev->idle_busy_ts_arr);
 	kfree(hdev->hl_chip_info);
 
 	destroy_workqueue(hdev->eq_wq);
@@ -277,8 +355,6 @@ static void device_early_fini(struct hl_device *hdev)
 
 	if (hdev->asic_funcs->early_fini)
 		hdev->asic_funcs->early_fini(hdev);
-
-	mutex_destroy(&hdev->fd_open_cnt_lock);
 }
 
 static void set_freq_to_low_job(struct work_struct *work)
@@ -286,9 +362,13 @@ static void set_freq_to_low_job(struct work_struct *work)
 	struct hl_device *hdev = container_of(work, struct hl_device,
 						work_freq.work);
 
-	if (atomic_read(&hdev->fd_open_cnt) == 0)
+	mutex_lock(&hdev->fpriv_list_lock);
+
+	if (!hdev->compute_ctx)
 		hl_device_set_frequency(hdev, PLL_LOW);
 
+	mutex_unlock(&hdev->fpriv_list_lock);
+
 	schedule_delayed_work(&hdev->work_freq,
 			usecs_to_jiffies(HL_PLL_LOW_JOB_FREQ_USEC));
 }
@@ -338,7 +418,7 @@ static int device_late_init(struct hl_device *hdev)
 	hdev->high_pll = hdev->asic_prop.high_pll;
 
 	/* force setting to low frequency */
-	atomic_set(&hdev->curr_pll_profile, PLL_LOW);
+	hdev->curr_pll_profile = PLL_LOW;
 
 	if (hdev->pm_mng_profile == PM_AUTO)
 		hdev->asic_funcs->set_pll_profile(hdev, PLL_LOW);
@@ -381,44 +461,128 @@ static void device_late_fini(struct hl_device *hdev)
 	hdev->late_init_done = false;
 }
 
+uint32_t hl_device_utilization(struct hl_device *hdev, uint32_t period_ms)
+{
+	struct hl_device_idle_busy_ts *ts;
+	ktime_t zero_ktime, curr = ktime_get();
+	u32 overlap_cnt = 0, last_index = hdev->idle_busy_ts_idx;
+	s64 period_us, last_start_us, last_end_us, last_busy_time_us,
+		total_busy_time_us = 0, total_busy_time_ms;
+
+	zero_ktime = ktime_set(0, 0);
+	period_us = period_ms * USEC_PER_MSEC;
+	ts = &hdev->idle_busy_ts_arr[last_index];
+
+	/* check case that device is currently in idle */
+	if (!ktime_compare(ts->busy_to_idle_ts, zero_ktime) &&
+			!ktime_compare(ts->idle_to_busy_ts, zero_ktime)) {
+
+		last_index--;
+		/* Handle case idle_busy_ts_idx was 0 */
+		if (last_index > HL_IDLE_BUSY_TS_ARR_SIZE)
+			last_index = HL_IDLE_BUSY_TS_ARR_SIZE - 1;
+
+		ts = &hdev->idle_busy_ts_arr[last_index];
+	}
+
+	while (overlap_cnt < HL_IDLE_BUSY_TS_ARR_SIZE) {
+		/* Check if we are in last sample case. i.e. if the sample
+		 * begun before the sampling period. This could be a real
+		 * sample or 0 so need to handle both cases
+		 */
+		last_start_us = ktime_to_us(
+				ktime_sub(curr, ts->idle_to_busy_ts));
+
+		if (last_start_us > period_us) {
+
+			/* First check two cases:
+			 * 1. If the device is currently busy
+			 * 2. If the device was idle during the whole sampling
+			 *    period
+			 */
+
+			if (!ktime_compare(ts->busy_to_idle_ts, zero_ktime)) {
+				/* Check if the device is currently busy */
+				if (ktime_compare(ts->idle_to_busy_ts,
+						zero_ktime))
+					return 100;
+
+				/* We either didn't have any activity or we
+				 * reached an entry which is 0. Either way,
+				 * exit and return what was accumulated so far
+				 */
+				break;
+			}
+
+			/* If sample has finished, check it is relevant */
+			last_end_us = ktime_to_us(
+					ktime_sub(curr, ts->busy_to_idle_ts));
+
+			if (last_end_us > period_us)
+				break;
+
+			/* It is relevant so add it but with adjustment */
+			last_busy_time_us = ktime_to_us(
+						ktime_sub(ts->busy_to_idle_ts,
+						ts->idle_to_busy_ts));
+			total_busy_time_us += last_busy_time_us -
+					(last_start_us - period_us);
+			break;
+		}
+
+		/* Check if the sample is finished or still open */
+		if (ktime_compare(ts->busy_to_idle_ts, zero_ktime))
+			last_busy_time_us = ktime_to_us(
+						ktime_sub(ts->busy_to_idle_ts,
+						ts->idle_to_busy_ts));
+		else
+			last_busy_time_us = ktime_to_us(
+					ktime_sub(curr, ts->idle_to_busy_ts));
+
+		total_busy_time_us += last_busy_time_us;
+
+		last_index--;
+		/* Handle case idle_busy_ts_idx was 0 */
+		if (last_index > HL_IDLE_BUSY_TS_ARR_SIZE)
+			last_index = HL_IDLE_BUSY_TS_ARR_SIZE - 1;
+
+		ts = &hdev->idle_busy_ts_arr[last_index];
+
+		overlap_cnt++;
+	}
+
+	total_busy_time_ms = DIV_ROUND_UP_ULL(total_busy_time_us,
+						USEC_PER_MSEC);
+
+	return DIV_ROUND_UP_ULL(total_busy_time_ms * 100, period_ms);
+}
+
 /*
  * hl_device_set_frequency - set the frequency of the device
  *
  * @hdev: pointer to habanalabs device structure
  * @freq: the new frequency value
  *
- * Change the frequency if needed.
- * We allose to set PLL to low only if there is no user process
- * Returns 0 if no change was done, otherwise returns 1;
+ * Change the frequency if needed. This function has no protection against
+ * concurrency, therefore it is assumed that the calling function has protected
+ * itself against the case of calling this function from multiple threads with
+ * different values
+ *
+ * Returns 0 if no change was done, otherwise returns 1
  */
 int hl_device_set_frequency(struct hl_device *hdev, enum hl_pll_frequency freq)
 {
-	enum hl_pll_frequency old_freq =
-			(freq == PLL_HIGH) ? PLL_LOW : PLL_HIGH;
-	int ret;
-
-	if (hdev->pm_mng_profile == PM_MANUAL)
-		return 0;
-
-	ret = atomic_cmpxchg(&hdev->curr_pll_profile, old_freq, freq);
-	if (ret == freq)
+	if ((hdev->pm_mng_profile == PM_MANUAL) ||
+			(hdev->curr_pll_profile == freq))
 		return 0;
 
-	/*
-	 * in case we want to lower frequency, check if device is not
-	 * opened. We must have a check here to workaround race condition with
-	 * hl_device_open
-	 */
-	if ((freq == PLL_LOW) && (atomic_read(&hdev->fd_open_cnt) > 0)) {
-		atomic_set(&hdev->curr_pll_profile, PLL_HIGH);
-		return 0;
-	}
-
 	dev_dbg(hdev->dev, "Changing device frequency to %s\n",
 		freq == PLL_HIGH ? "high" : "low");
 
 	hdev->asic_funcs->set_pll_profile(hdev, freq);
 
+	hdev->curr_pll_profile = freq;
+
 	return 1;
 }
 
@@ -449,19 +613,8 @@ int hl_device_set_debug_mode(struct hl_device *hdev, bool enable)
 		goto out;
 	}
 
-	mutex_lock(&hdev->fd_open_cnt_lock);
-
-	if (atomic_read(&hdev->fd_open_cnt) > 1) {
-		dev_err(hdev->dev,
-			"Failed to enable debug mode. More then a single user is using the device\n");
-		rc = -EPERM;
-		goto unlock_fd_open_lock;
-	}
-
 	hdev->in_debug = 1;
 
-unlock_fd_open_lock:
-	mutex_unlock(&hdev->fd_open_cnt_lock);
 out:
 	mutex_unlock(&hdev->debug_lock);
 
@@ -568,6 +721,7 @@ disable_device:
 static void device_kill_open_processes(struct hl_device *hdev)
 {
 	u16 pending_total, pending_cnt;
+	struct hl_fpriv	*hpriv;
 	struct task_struct *task = NULL;
 
 	if (hdev->pldm)
@@ -575,32 +729,31 @@ static void device_kill_open_processes(struct hl_device *hdev)
 	else
 		pending_total = HL_PENDING_RESET_PER_SEC;
 
-	pending_cnt = pending_total;
-
-	/* Flush all processes that are inside hl_open */
-	mutex_lock(&hdev->fd_open_cnt_lock);
-
-	while ((atomic_read(&hdev->fd_open_cnt)) && (pending_cnt)) {
-
-		pending_cnt--;
-
-		dev_info(hdev->dev,
-			"Can't HARD reset, waiting for user to close FD\n");
+	/* Giving time for user to close FD, and for processes that are inside
+	 * hl_device_open to finish
+	 */
+	if (!list_empty(&hdev->fpriv_list))
 		ssleep(1);
-	}
 
-	if (atomic_read(&hdev->fd_open_cnt)) {
-		task = get_pid_task(hdev->user_ctx->hpriv->taskpid,
-					PIDTYPE_PID);
+	mutex_lock(&hdev->fpriv_list_lock);
+
+	/* This section must be protected because we are dereferencing
+	 * pointers that are freed if the process exits
+	 */
+	list_for_each_entry(hpriv, &hdev->fpriv_list, dev_node) {
+		task = get_pid_task(hpriv->taskpid, PIDTYPE_PID);
 		if (task) {
-			dev_info(hdev->dev, "Killing user processes\n");
+			dev_info(hdev->dev, "Killing user process pid=%d\n",
+				task_pid_nr(task));
 			send_sig(SIGKILL, task, 1);
-			msleep(100);
+			usleep_range(1000, 10000);
 
 			put_task_struct(task);
 		}
 	}
 
+	mutex_unlock(&hdev->fpriv_list_lock);
+
 	/* We killed the open users, but because the driver cleans up after the
 	 * user contexts are closed (e.g. mmu mappings), we need to wait again
 	 * to make sure the cleaning phase is finished before continuing with
@@ -609,19 +762,18 @@ static void device_kill_open_processes(struct hl_device *hdev)
 
 	pending_cnt = pending_total;
 
-	while ((atomic_read(&hdev->fd_open_cnt)) && (pending_cnt)) {
+	while ((!list_empty(&hdev->fpriv_list)) && (pending_cnt)) {
+		dev_info(hdev->dev,
+			"Waiting for all unmap operations to finish before hard reset\n");
 
 		pending_cnt--;
 
 		ssleep(1);
 	}
 
-	if (atomic_read(&hdev->fd_open_cnt))
+	if (!list_empty(&hdev->fpriv_list))
 		dev_crit(hdev->dev,
 			"Going to hard reset with open user contexts\n");
-
-	mutex_unlock(&hdev->fd_open_cnt_lock);
-
 }
 
 static void device_hard_reset_pending(struct work_struct *work)
@@ -630,8 +782,6 @@ static void device_hard_reset_pending(struct work_struct *work)
 		container_of(work, struct hl_device_reset_work, reset_work);
 	struct hl_device *hdev = device_reset_work->hdev;
 
-	device_kill_open_processes(hdev);
-
 	hl_device_reset(hdev, true, true);
 
 	kfree(device_reset_work);
@@ -679,13 +829,16 @@ int hl_device_reset(struct hl_device *hdev, bool hard_reset,
 		/* This also blocks future CS/VM/JOB completion operations */
 		hdev->disabled = true;
 
-		/*
-		 * Flush anyone that is inside the critical section of enqueue
+		/* Flush anyone that is inside the critical section of enqueue
 		 * jobs to the H/W
 		 */
 		hdev->asic_funcs->hw_queues_lock(hdev);
 		hdev->asic_funcs->hw_queues_unlock(hdev);
 
+		/* Flush anyone that is inside device open */
+		mutex_lock(&hdev->fpriv_list_lock);
+		mutex_unlock(&hdev->fpriv_list_lock);
+
 		dev_err(hdev->dev, "Going to RESET device!\n");
 	}
 
@@ -736,6 +889,13 @@ again:
 	/* Go over all the queues, release all CS and their jobs */
 	hl_cs_rollback_all(hdev);
 
+	/* Kill processes here after CS rollback. This is because the process
+	 * can't really exit until all its CSs are done, which is what we
+	 * do in cs rollback
+	 */
+	if (from_hard_reset_thread)
+		device_kill_open_processes(hdev);
+
 	/* Release kernel context */
 	if ((hard_reset) && (hl_ctx_put(hdev->kernel_ctx) == 1))
 		hdev->kernel_ctx = NULL;
@@ -754,12 +914,24 @@ again:
 	for (i = 0 ; i < hdev->asic_prop.completion_queues_count ; i++)
 		hl_cq_reset(hdev, &hdev->completion_queue[i]);
 
+	hdev->idle_busy_ts_idx = 0;
+	hdev->idle_busy_ts_arr[0].busy_to_idle_ts = ktime_set(0, 0);
+	hdev->idle_busy_ts_arr[0].idle_to_busy_ts = ktime_set(0, 0);
+
+	if (hdev->cs_active_cnt)
+		dev_crit(hdev->dev, "CS active cnt %d is not 0 during reset\n",
+			hdev->cs_active_cnt);
+
+	mutex_lock(&hdev->fpriv_list_lock);
+
 	/* Make sure the context switch phase will run again */
-	if (hdev->user_ctx) {
-		atomic_set(&hdev->user_ctx->thread_ctx_switch_token, 1);
-		hdev->user_ctx->thread_ctx_switch_wait_token = 0;
+	if (hdev->compute_ctx) {
+		atomic_set(&hdev->compute_ctx->thread_ctx_switch_token, 1);
+		hdev->compute_ctx->thread_ctx_switch_wait_token = 0;
 	}
 
+	mutex_unlock(&hdev->fpriv_list_lock);
+
 	/* Finished tear-down, starting to re-initialize */
 
 	if (hard_reset) {
@@ -788,7 +960,7 @@ again:
 			goto out_err;
 		}
 
-		hdev->user_ctx = NULL;
+		hdev->compute_ctx = NULL;
 
 		rc = hl_ctx_init(hdev, hdev->kernel_ctx, true);
 		if (rc) {
@@ -849,6 +1021,8 @@ again:
 	else
 		hdev->soft_reset_cnt++;
 
+	dev_warn(hdev->dev, "Successfully finished resetting the device\n");
+
 	return 0;
 
 out_err:
@@ -883,17 +1057,43 @@ out_err:
 int hl_device_init(struct hl_device *hdev, struct class *hclass)
 {
 	int i, rc, cq_ready_cnt;
+	char *name;
+	bool add_cdev_sysfs_on_err = false;
 
-	/* Create device */
-	rc = device_setup_cdev(hdev, hclass, hdev->id, &hl_ops);
+	name = kasprintf(GFP_KERNEL, "hl%d", hdev->id / 2);
+	if (!name) {
+		rc = -ENOMEM;
+		goto out_disabled;
+	}
+
+	/* Initialize cdev and device structures */
+	rc = device_init_cdev(hdev, hclass, hdev->id, &hl_ops, name,
+				&hdev->cdev, &hdev->dev);
+
+	kfree(name);
 
 	if (rc)
 		goto out_disabled;
 
+	name = kasprintf(GFP_KERNEL, "hl_controlD%d", hdev->id / 2);
+	if (!name) {
+		rc = -ENOMEM;
+		goto free_dev;
+	}
+
+	/* Initialize cdev and device structures for control device */
+	rc = device_init_cdev(hdev, hclass, hdev->id_control, &hl_ctrl_ops,
+				name, &hdev->cdev_ctrl, &hdev->dev_ctrl);
+
+	kfree(name);
+
+	if (rc)
+		goto free_dev;
+
 	/* Initialize ASIC function pointers and perform early init */
 	rc = device_early_init(hdev);
 	if (rc)
-		goto release_device;
+		goto free_dev_ctrl;
 
 	/*
 	 * Start calling ASIC initialization. First S/W then H/W and finally
@@ -965,7 +1165,7 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 		goto mmu_fini;
 	}
 
-	hdev->user_ctx = NULL;
+	hdev->compute_ctx = NULL;
 
 	rc = hl_ctx_init(hdev, hdev->kernel_ctx, true);
 	if (rc) {
@@ -980,12 +1180,6 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 		goto release_ctx;
 	}
 
-	rc = hl_sysfs_init(hdev);
-	if (rc) {
-		dev_err(hdev->dev, "failed to initialize sysfs\n");
-		goto free_cb_pool;
-	}
-
 	hl_debugfs_add_device(hdev);
 
 	if (hdev->asic_funcs->get_hw_state(hdev) == HL_DEVICE_HW_STATE_DIRTY) {
@@ -994,6 +1188,12 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 		hdev->asic_funcs->hw_fini(hdev, true);
 	}
 
+	/*
+	 * From this point, in case of an error, add char devices and create
+	 * sysfs nodes as part of the error flow, to allow debugging.
+	 */
+	add_cdev_sysfs_on_err = true;
+
 	rc = hdev->asic_funcs->hw_init(hdev);
 	if (rc) {
 		dev_err(hdev->dev, "failed to initialize the H/W\n");
@@ -1030,9 +1230,24 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 	}
 
 	/*
-	 * hl_hwmon_init must be called after device_late_init, because only
+	 * Expose devices and sysfs nodes to user.
+	 * From here there is no need to add char devices and create sysfs nodes
+	 * in case of an error.
+	 */
+	add_cdev_sysfs_on_err = false;
+	rc = device_cdev_sysfs_add(hdev);
+	if (rc) {
+		dev_err(hdev->dev,
+			"Failed to add char devices and sysfs nodes\n");
+		rc = 0;
+		goto out_disabled;
+	}
+
+	/*
+	 * hl_hwmon_init() must be called after device_late_init(), because only
 	 * there we get the information from the device about which
-	 * hwmon-related sensors the device supports
+	 * hwmon-related sensors the device supports.
+	 * Furthermore, it must be done after adding the device to the system.
 	 */
 	rc = hl_hwmon_init(hdev);
 	if (rc) {
@@ -1048,8 +1263,6 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
 
 	return 0;
 
-free_cb_pool:
-	hl_cb_pool_fini(hdev);
 release_ctx:
 	if (hl_ctx_put(hdev->kernel_ctx) != 1)
 		dev_err(hdev->dev,
@@ -1068,18 +1281,21 @@ sw_fini:
 	hdev->asic_funcs->sw_fini(hdev);
 early_fini:
 	device_early_fini(hdev);
-release_device:
-	device_destroy(hclass, hdev->dev->devt);
-	cdev_del(&hdev->cdev);
+free_dev_ctrl:
+	kfree(hdev->dev_ctrl);
+free_dev:
+	kfree(hdev->dev);
 out_disabled:
 	hdev->disabled = true;
+	if (add_cdev_sysfs_on_err)
+		device_cdev_sysfs_add(hdev);
 	if (hdev->pdev)
 		dev_err(&hdev->pdev->dev,
 			"Failed to initialize hl%d. Device is NOT usable !\n",
-			hdev->id);
+			hdev->id / 2);
 	else
 		pr_err("Failed to initialize hl%d. Device is NOT usable !\n",
-			hdev->id);
+			hdev->id / 2);
 
 	return rc;
 }
@@ -1120,16 +1336,17 @@ void hl_device_fini(struct hl_device *hdev)
 	/* Mark device as disabled */
 	hdev->disabled = true;
 
-	/*
-	 * Flush anyone that is inside the critical section of enqueue
+	/* Flush anyone that is inside the critical section of enqueue
 	 * jobs to the H/W
 	 */
 	hdev->asic_funcs->hw_queues_lock(hdev);
 	hdev->asic_funcs->hw_queues_unlock(hdev);
 
-	hdev->hard_reset_pending = true;
+	/* Flush anyone that is inside device open */
+	mutex_lock(&hdev->fpriv_list_lock);
+	mutex_unlock(&hdev->fpriv_list_lock);
 
-	device_kill_open_processes(hdev);
+	hdev->hard_reset_pending = true;
 
 	hl_hwmon_fini(hdev);
 
@@ -1137,8 +1354,6 @@ void hl_device_fini(struct hl_device *hdev)
 
 	hl_debugfs_remove_device(hdev);
 
-	hl_sysfs_fini(hdev);
-
 	/*
 	 * Halt the engines and disable interrupts so we won't get any more
 	 * completions from H/W and we won't have any accesses from the
@@ -1149,6 +1364,12 @@ void hl_device_fini(struct hl_device *hdev)
 	/* Go over all the queues, release all CS and their jobs */
 	hl_cs_rollback_all(hdev);
 
+	/* Kill processes here after CS rollback. This is because the process
+	 * can't really exit until all its CSs are done, which is what we
+	 * do in cs rollback
+	 */
+	device_kill_open_processes(hdev);
+
 	hl_cb_pool_fini(hdev);
 
 	/* Release kernel context */
@@ -1175,9 +1396,8 @@ void hl_device_fini(struct hl_device *hdev)
 
 	device_early_fini(hdev);
 
-	/* Hide device from user */
-	device_destroy(hdev->dev->class, hdev->dev->devt);
-	cdev_del(&hdev->cdev);
+	/* Hide devices and sysfs nodes from user */
+	device_cdev_sysfs_del(hdev);
 
 	pr_info("removed device successfully\n");
 }