scsi: hisi_sas: Add manual trigger for debugfs dump

Add an interface to manually trigger a debugfs dump.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 1a3d31d4258c9370de7b16a93bf5df73fb0a3ee0..35619bdad1d5a69a56ee91d005d208562c03a462 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -2977,6 +2977,36 @@ static void hisi_sas_debugfs_snapshot_regs(struct hisi_hba *hisi_hba)
        hisi_hba->hw->snapshot_restore(hisi_hba);
 }
 
+static ssize_t hisi_sas_debugfs_trigger_dump_write(struct file *file,
+                                                  const char __user *user_buf,
+                                                  size_t count, loff_t *ppos)
+{
+       struct hisi_hba *hisi_hba = file->f_inode->i_private;
+       char buf[8];
+
+       /* A bit racy, but don't care too much since it's only debugfs */
+       if (hisi_hba->debugfs_snapshot)
+               return -EFAULT;
+
+       if (count > 8)
+               return -EFAULT;
+
+       if (copy_from_user(buf, user_buf, count))
+               return -EFAULT;
+
+       if (buf[0] != '1')
+               return -EFAULT;
+
+       queue_work(hisi_hba->wq, &hisi_hba->debugfs_work);
+
+       return count;
+}
+
+static const struct file_operations hisi_sas_debugfs_trigger_dump_fops = {
+       .write = &hisi_sas_debugfs_trigger_dump_write,
+       .owner = THIS_MODULE,
+};
+
 void hisi_sas_debugfs_work_handler(struct work_struct *work)
 {
        struct hisi_hba *hisi_hba =
@@ -2999,6 +3029,10 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 
        hisi_hba->debugfs_dir = debugfs_create_dir(dev_name(dev),
                                                   hisi_sas_debugfs_dir);
+       debugfs_create_file("trigger_dump", 0600,
+                           hisi_hba->debugfs_dir,
+                           hisi_hba,
+                           &hisi_sas_debugfs_trigger_dump_fops);
 
        /* Alloc buffer for global */
        sz = hisi_hba->hw->debugfs_reg_global->count * 4;