1 files changed, 95 insertions, 3 deletions

diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
index 4e1ff209b933..4a0bbcf1757a 100644
--- a/drivers/scsi/ufs/ufs-debugfs.c
+++ b/drivers/scsi/ufs/ufs-debugfs.c
@@ -8,6 +8,18 @@
 
 static struct dentry *ufs_debugfs_root;
 
+struct ufs_debugfs_attr {
+	const char			*name;
+	mode_t				mode;
+	const struct file_operations	*fops;
+};
+
+/* @file corresponds to a debugfs attribute in directory hba->debugfs_root. */
+static inline struct ufs_hba *hba_from_file(const struct file *file)
+{
+	return d_inode(file->f_path.dentry->d_parent)->i_private;
+}
+
 void __init ufs_debugfs_init(void)
 {
 	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
@@ -20,7 +32,7 @@ void ufs_debugfs_exit(void)
 
 static int ufs_debugfs_stats_show(struct seq_file *s, void *data)
 {
-	struct ufs_hba *hba = s->private;
+	struct ufs_hba *hba = hba_from_file(s->file);
 	struct ufs_event_hist *e = hba->ufs_stats.event;
 
 #define PRT(fmt, typ) \
@@ -126,13 +138,93 @@ static void ufs_debugfs_restart_ee(struct work_struct *work)
 	ufs_debugfs_put_user_access(hba);
 }
 
+static int ufs_saved_err_show(struct seq_file *s, void *data)
+{
+	struct ufs_debugfs_attr *attr = s->private;
+	struct ufs_hba *hba = hba_from_file(s->file);
+	const int *p;
+
+	if (strcmp(attr->name, "saved_err") == 0) {
+		p = &hba->saved_err;
+	} else if (strcmp(attr->name, "saved_uic_err") == 0) {
+		p = &hba->saved_uic_err;
+	} else {
+		return -ENOENT;
+	}
+
+	seq_printf(s, "%d\n", *p);
+	return 0;
+}
+
+static ssize_t ufs_saved_err_write(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	struct ufs_debugfs_attr *attr = file->f_inode->i_private;
+	struct ufs_hba *hba = hba_from_file(file);
+	char val_str[16] = { };
+	int val, ret;
+
+	if (count > sizeof(val_str))
+		return -EINVAL;
+	if (copy_from_user(val_str, buf, count))
+		return -EFAULT;
+	ret = kstrtoint(val_str, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_irq(hba->host->host_lock);
+	if (strcmp(attr->name, "saved_err") == 0) {
+		hba->saved_err = val;
+	} else if (strcmp(attr->name, "saved_uic_err") == 0) {
+		hba->saved_uic_err = val;
+	} else {
+		ret = -ENOENT;
+	}
+	if (ret == 0)
+		ufshcd_schedule_eh_work(hba);
+	spin_unlock_irq(hba->host->host_lock);
+
+	return ret < 0 ? ret : count;
+}
+
+static int ufs_saved_err_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ufs_saved_err_show, inode->i_private);
+}
+
+static const struct file_operations ufs_saved_err_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ufs_saved_err_open,
+	.read		= seq_read,
+	.write		= ufs_saved_err_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static const struct ufs_debugfs_attr ufs_attrs[] = {
+	{ "stats", 0400, &ufs_debugfs_stats_fops },
+	{ "saved_err", 0600, &ufs_saved_err_fops },
+	{ "saved_uic_err", 0600, &ufs_saved_err_fops },
+	{ }
+};
+
 void ufs_debugfs_hba_init(struct ufs_hba *hba)
 {
+	const struct ufs_debugfs_attr *attr;
+	struct dentry *root;
+
 	/* 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);
+
+	root = debugfs_create_dir(dev_name(hba->dev), ufs_debugfs_root);
+	if (IS_ERR_OR_NULL(root))
+		return;
+	hba->debugfs_root = root;
+	d_inode(root)->i_private = hba;
+	for (attr = ufs_attrs; attr->name; attr++)
+		debugfs_create_file(attr->name, attr->mode, root, (void *)attr,
+				    attr->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,