1 files changed, 90 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
index dee98dc72d29..ced9ef4d7c78 100644
--- a/drivers/scsi/ufs/ufs-debugfs.c
+++ b/drivers/scsi/ufs/ufs-debugfs.c
@@ -44,13 +44,103 @@ static int ufs_debugfs_stats_show(struct seq_file *s, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(ufs_debugfs_stats);
 
+static int ee_usr_mask_get(void *data, u64 *val)
+{
+	struct ufs_hba *hba = data;
+
+	*val = hba->ee_usr_mask;
+	return 0;
+}
+
+static int ufs_debugfs_get_user_access(struct ufs_hba *hba)
+__acquires(&hba->host_sem)
+{
+	down(&hba->host_sem);
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		up(&hba->host_sem);
+		return -EBUSY;
+	}
+	pm_runtime_get_sync(hba->dev);
+	return 0;
+}
+
+static void ufs_debugfs_put_user_access(struct ufs_hba *hba)
+__releases(&hba->host_sem)
+{
+	pm_runtime_put_sync(hba->dev);
+	up(&hba->host_sem);
+}
+
+static int ee_usr_mask_set(void *data, u64 val)
+{
+	struct ufs_hba *hba = data;
+	int err;
+
+	if (val & ~(u64)MASK_EE_STATUS)
+		return -EINVAL;
+	err = ufs_debugfs_get_user_access(hba);
+	if (err)
+		return err;
+	err = ufshcd_update_ee_usr_mask(hba, val, MASK_EE_STATUS);
+	ufs_debugfs_put_user_access(hba);
+	return err;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ee_usr_mask_fops, ee_usr_mask_get, ee_usr_mask_set, "%#llx\n");
+
+void ufs_debugfs_exception_event(struct ufs_hba *hba, u16 status)
+{
+	bool chgd = false;
+	u16 ee_ctrl_mask;
+	int err = 0;
+
+	if (!hba->debugfs_ee_rate_limit_ms || !status)
+		return;
+
+	mutex_lock(&hba->ee_ctrl_mutex);
+	ee_ctrl_mask = hba->ee_drv_mask | (hba->ee_usr_mask & ~status);
+	chgd = ee_ctrl_mask != hba->ee_ctrl_mask;
+	if (chgd) {
+		err = __ufshcd_write_ee_control(hba, ee_ctrl_mask);
+		if (err)
+			dev_err(hba->dev, "%s: failed to write ee control %d\n",
+				__func__, err);
+	}
+	mutex_unlock(&hba->ee_ctrl_mutex);
+
+	if (chgd && !err) {
+		unsigned long delay = msecs_to_jiffies(hba->debugfs_ee_rate_limit_ms);
+
+		queue_delayed_work(system_freezable_wq, &hba->debugfs_ee_work, delay);
+	}
+}
+
+static void ufs_debugfs_restart_ee(struct work_struct *work)
+{
+	struct ufs_hba *hba = container_of(work, struct ufs_hba, debugfs_ee_work.work);
+
+	if (!hba->ee_usr_mask || pm_runtime_suspended(hba->dev) ||
+	    ufs_debugfs_get_user_access(hba))
+		return;
+	ufshcd_write_ee_control(hba);
+	ufs_debugfs_put_user_access(hba);
+}
+
 void ufs_debugfs_hba_init(struct ufs_hba *hba)
 {
+	/* Set default exception event rate limit period to 20ms */
+	hba->debugfs_ee_rate_limit_ms = 20;
+	INIT_DELAYED_WORK(&hba->debugfs_ee_work, ufs_debugfs_restart_ee);
 	hba->debugfs_root = debugfs_create_dir(dev_name(hba->dev), ufs_debugfs_root);
 	debugfs_create_file("stats", 0400, hba->debugfs_root, hba, &ufs_debugfs_stats_fops);
+	debugfs_create_file("exception_event_mask", 0600, hba->debugfs_root,
+			    hba, &ee_usr_mask_fops);
+	debugfs_create_u32("exception_event_rate_limit_ms", 0600, hba->debugfs_root,
+			   &hba->debugfs_ee_rate_limit_ms);
 }
 
 void ufs_debugfs_hba_exit(struct ufs_hba *hba)
 {
 	debugfs_remove_recursive(hba->debugfs_root);
+	cancel_delayed_work_sync(&hba->debugfs_ee_work);
 }