[SCSI] bfa: add debugfs support

- Add debugfs support to obtain firmware trace, driver trace
  and read/write to registers.

- debugfs hierarchy:
  /sys/kernel/debug/bfa/host#
   where the host number corresponds to the one under /sys/class/scsi_host/host#

- Following are the new debugfs entries added:
  drvtrc: collect current driver trace
  fwtrc: collect current firmware trace.
  fwsave: collect last saved fw trace as a result of firmware crash.
  regwr: write one word to chip register
  regrd: read one or more words from chip register.

Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/bfa/Makefile

@@ -1,7 +1,7 @@
 obj-$(CONFIG_SCSI_BFA_FC) := bfa.o
 
 bfa-y := bfad.o bfad_intr.o bfad_os.o bfad_im.o bfad_attr.o bfad_fwimg.o
-
+bfa-y += bfad_debugfs.o
 bfa-y += bfa_core.o bfa_ioc.o bfa_ioc_ct.o bfa_ioc_cb.o bfa_iocfc.o bfa_fcxp.o
 bfa-y += bfa_lps.o bfa_hw_cb.o bfa_hw_ct.o bfa_intr.o bfa_timer.o bfa_rport.o
 bfa-y += bfa_fcport.o bfa_port.o bfa_uf.o bfa_sgpg.o bfa_module.o bfa_ioim.o

drivers/scsi/bfa/bfad.c

@@ -57,6 +57,7 @@ static int      ipfc_enable = BFA_FALSE;
 static int	fdmi_enable = BFA_TRUE;
 int 		bfa_lun_queue_depth = BFAD_LUN_QUEUE_DEPTH;
 int      	bfa_linkup_delay = -1;
+int		bfa_debugfs_enable = 1;
 
 module_param(os_name, charp, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(os_name, "OS name of the hba host machine");
@@ -106,6 +107,9 @@ MODULE_PARM_DESC(bfa_linkup_delay, "Link up delay, default=30 secs for boot"
 module_param(fdmi_enable, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(fdmi_enable, "Enables fdmi registration, default=1,"
 		" Range[false:0|true:1]");
+module_param(bfa_debugfs_enable, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(bfa_debugfs_enable, "Enables debugfs feature, default=1,"
+		" Range[false:0|true:1]");
 
 /*
  * Stores the module parm num_sgpgs value;
@@ -903,6 +907,10 @@ bfad_cfg_pport(struct bfad_s *bfad, enum bfa_port_role role)
 		bfad->pport.roles |= BFA_PORT_ROLE_FCP_IM;
 	}
 
+	/* Setup the debugfs node for this scsi_host */
+	if (bfa_debugfs_enable)
+		bfad_debugfs_init(&bfad->pport);
+
 	bfad->bfad_flags |= BFAD_CFG_PPORT_DONE;
 
 out:
@@ -912,6 +920,10 @@ out:
 void
 bfad_uncfg_pport(struct bfad_s *bfad)
 {
+	 /* Remove the debugfs node for this scsi_host */
+	kfree(bfad->regdata);
+	bfad_debugfs_exit(&bfad->pport);
+
 	if ((bfad->pport.roles & BFA_PORT_ROLE_FCP_IPFC) && ipfc_enable) {
 		bfad_ipfc_port_delete(bfad, &bfad->pport);
 		bfad->pport.roles &= ~BFA_PORT_ROLE_FCP_IPFC;

drivers/scsi/bfa/bfad_drv.h

@@ -111,6 +111,9 @@ struct bfad_port_s {
 	struct bfad_im_port_s *im_port;	/* IM specific data */
 	struct bfad_tm_port_s *tm_port;	/* TM specific data */
 	struct bfad_ipfc_port_s *ipfc_port;	/* IPFC specific data */
+
+	/* port debugfs specific data */
+	struct dentry *port_debugfs_root;
 };
 
 /*
@@ -186,6 +189,10 @@ struct bfad_s {
 	struct fc_host_statistics link_stats;
 	struct list_head pbc_pcfg_list;
 	atomic_t wq_reqcnt;
+	/* debugfs specific data */
+	char *regdata;
+	u32 reglen;
+	struct dentry *bfad_dentry_files[5];
 };
 
 struct bfad_pcfg_s {
@@ -276,7 +283,9 @@ void		bfad_drv_uninit(struct bfad_s *bfad);
 void		bfad_drv_log_level_set(struct bfad_s *bfad);
 bfa_status_t	bfad_fc4_module_init(void);
 void		bfad_fc4_module_exit(void);
-int		bfad_worker (void *ptr);
+int		bfad_worker(void *ptr);
+void		bfad_debugfs_init(struct bfad_port_s *port);
+void		bfad_debugfs_exit(struct bfad_port_s *port);
 
 void bfad_pci_remove(struct pci_dev *pdev);
 int bfad_pci_probe(struct pci_dev *pdev, const struct pci_device_id *pid);
@@ -289,6 +298,7 @@ extern struct list_head bfad_list;
 extern int bfa_lun_queue_depth;
 extern int bfad_supported_fc4s;
 extern int bfa_linkup_delay;
+extern int bfa_debugfs_enable;
 extern struct mutex bfad_mutex;
 
 #endif /* __BFAD_DRV_H__ */