scsi: hisi_sas: Add DFX Feature: Create root directory and device directory

This patch create root directory at hisi_sas_init() and generate
device directory when we probe device driver.

And we remove the root directory at hisi_sas_exit(),
but recursively delete device directory when we remove device driver.
Signed-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -14,6 +14,7 @@
 
 #include <linux/acpi.h>
 #include <linux/clk.h>
+#include <linux/debugfs.h>
 #include <linux/dmapool.h>
 #include <linux/iopoll.h>
 #include <linux/lcm.h>
@@ -333,6 +334,8 @@ struct hisi_hba {
 	u32 intr_coal_ticks;	/* time of interrupt coalesce, unit:1us */
 	u32 intr_coal_count;	/* count of interrupt coalesce */
 	int enable_dix_dif;
+
+	struct dentry *debugfs_dir;
 };
 
 /* Generic HW DMA host memory structures */
@@ -471,6 +474,8 @@ struct hisi_sas_slot_dif_buf_table {
 	struct hisi_sas_sge_dif_page sge_dif_page;
 };
 
+extern bool hisi_sas_debugfs_enable;
+extern struct dentry *hisi_sas_dbg_dir;
 extern struct scsi_transport_template *hisi_sas_stt;
 extern void hisi_sas_stop_phys(struct hisi_hba *hisi_hba);
 extern int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost);
@@ -504,4 +509,6 @@ extern void hisi_sas_release_tasks(struct hisi_hba *hisi_hba);
 extern u8 hisi_sas_get_prog_phy_linkrate_mask(enum sas_linkrate max);
 extern void hisi_sas_controller_reset_prepare(struct hisi_hba *hisi_hba);
 extern void hisi_sas_controller_reset_done(struct hisi_hba *hisi_hba);
+extern void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba);
+extern void hisi_sas_debugfs_exit(struct hisi_hba *hisi_hba);
 #endif

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -2572,6 +2572,23 @@ int hisi_sas_probe(struct platform_device *pdev,
 }
 EXPORT_SYMBOL_GPL(hisi_sas_probe);
 
+struct dentry *hisi_sas_dbg_dir;
+
+void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
+{
+	struct device *dev = hisi_hba->dev;
+
+	hisi_hba->debugfs_dir = debugfs_create_dir(dev_name(dev),
+						hisi_sas_dbg_dir);
+}
+EXPORT_SYMBOL_GPL(hisi_sas_debugfs_init);
+
+void hisi_sas_debugfs_exit(struct hisi_hba *hisi_hba)
+{
+	debugfs_remove_recursive(hisi_hba->debugfs_dir);
+}
+EXPORT_SYMBOL_GPL(hisi_sas_debugfs_exit);
+
 int hisi_sas_remove(struct platform_device *pdev)
 {
 	struct sas_ha_struct *sha = platform_get_drvdata(pdev);
@@ -2590,18 +2607,29 @@ int hisi_sas_remove(struct platform_device *pdev)
 }
 EXPORT_SYMBOL_GPL(hisi_sas_remove);
 
+bool hisi_sas_debugfs_enable;
+EXPORT_SYMBOL_GPL(hisi_sas_debugfs_enable);
+module_param_named(debugfs_enable, hisi_sas_debugfs_enable, bool, 0444);
+MODULE_PARM_DESC(hisi_sas_debugfs_enable, "Enable debugfs services");
+
 static __init int hisi_sas_init(void)
 {
 	hisi_sas_stt = sas_domain_attach_transport(&hisi_sas_transport_ops);
 	if (!hisi_sas_stt)
 		return -ENOMEM;
 
+	if (hisi_sas_debugfs_enable)
+		hisi_sas_dbg_dir = debugfs_create_dir("hisi_sas", NULL);
+
 	return 0;
 }
 
 static __exit void hisi_sas_exit(void)
 {
 	sas_release_transport(hisi_sas_stt);
+
+	if (hisi_sas_debugfs_enable)
+		debugfs_remove(hisi_sas_dbg_dir);
 }
 
 module_init(hisi_sas_init);

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -2584,6 +2584,9 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		sha->sas_port[i] = &hisi_hba->port[i].sas_port;
 	}
 
+	if (hisi_sas_debugfs_enable)
+		hisi_sas_debugfs_init(hisi_hba);
+
 	rc = scsi_add_host(shost, dev);
 	if (rc)
 		goto err_out_ha;
@@ -2643,6 +2646,9 @@ static void hisi_sas_v3_remove(struct pci_dev *pdev)
 	struct hisi_hba *hisi_hba = sha->lldd_ha;
 	struct Scsi_Host *shost = sha->core.shost;
 
+	if (hisi_sas_debugfs_enable)
+		hisi_sas_debugfs_exit(hisi_hba);
+
 	if (timer_pending(&hisi_hba->timer))
 		del_timer(&hisi_hba->timer);