From: Xiang Chen chenxiang66@hisilicon.com
[ Upstream commit 286ce4c65fbdf5eb9d4d5f4e4997c4e32bf1b073 ]
Add a file operation for "cnt" file under bist directory, so users can only read "cnt" or clear "cnt" to zero, but cannot randomly modify.
Link: https://lore.kernel.org/r/1645703489-87194-6-git-send-email-john.garry@huawe... Signed-off-by: Xiang Chen chenxiang66@hisilicon.com Signed-off-by: Qi Liu liuqi115@huawei.com Signed-off-by: John Garry john.garry@huawei.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 52 +++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c index 8392463d57de..20763f187886 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c @@ -3968,6 +3968,54 @@ static const struct file_operations debugfs_bist_phy_v3_hw_fops = { .owner = THIS_MODULE, };
+static ssize_t debugfs_bist_cnt_v3_hw_write(struct file *filp, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = filp->private_data; + struct hisi_hba *hisi_hba = m->private; + unsigned int cnt; + int val; + + if (hisi_hba->debugfs_bist_enable) + return -EPERM; + + val = kstrtouint_from_user(buf, count, 0, &cnt); + if (val) + return val; + + if (cnt) + return -EINVAL; + + hisi_hba->debugfs_bist_cnt = 0; + return count; +} + +static int debugfs_bist_cnt_v3_hw_show(struct seq_file *s, void *p) +{ + struct hisi_hba *hisi_hba = s->private; + + seq_printf(s, "%u\n", hisi_hba->debugfs_bist_cnt); + + return 0; +} + +static int debugfs_bist_cnt_v3_hw_open(struct inode *inode, + struct file *filp) +{ + return single_open(filp, debugfs_bist_cnt_v3_hw_show, + inode->i_private); +} + +static const struct file_operations debugfs_bist_cnt_v3_hw_ops = { + .open = debugfs_bist_cnt_v3_hw_open, + .read = seq_read, + .write = debugfs_bist_cnt_v3_hw_write, + .llseek = seq_lseek, + .release = single_release, + .owner = THIS_MODULE, +}; + static const struct { int value; char *name; @@ -4605,8 +4653,8 @@ static void debugfs_bist_init_v3_hw(struct hisi_hba *hisi_hba) debugfs_create_file("phy_id", 0600, hisi_hba->debugfs_bist_dentry, hisi_hba, &debugfs_bist_phy_v3_hw_fops);
- debugfs_create_u32("cnt", 0600, hisi_hba->debugfs_bist_dentry, - &hisi_hba->debugfs_bist_cnt); + debugfs_create_file("cnt", 0600, hisi_hba->debugfs_bist_dentry, + hisi_hba, &debugfs_bist_cnt_v3_hw_ops);
debugfs_create_file("loopback_mode", 0600, hisi_hba->debugfs_bist_dentry,