[PATCH 16/36] scsi: fnic: Prepare for enabling lock context analysis

[Bart Van Assche <bvanassche@acm.org>]

Document locking requirements with __must_hold(). Suppress complaints
about conditional locking in fnic_device_reset() with __acquire() and
__release().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/fnic/fdls_disc.c | 52 +++++++++++++++++++++++++++++++++--
 drivers/scsi/fnic/fip.c       |  2 ++
 drivers/scsi/fnic/fnic_fcs.c  |  6 ++++
 drivers/scsi/fnic/fnic_scsi.c |  4 +++
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/fnic/fdls_disc.c b/drivers/scsi/fnic/fdls_disc.c
index 554dea767885..0ac12edb7df1 100644
--- a/drivers/scsi/fnic/fdls_disc.c
+++ b/drivers/scsi/fnic/fdls_disc.c
@@ -391,6 +391,7 @@ static void fdls_reset_oxid_pool(struct fnic_iport_s *iport)
 }
 
 void fnic_del_fabric_timer_sync(struct fnic *fnic)
+	__must_hold(&fnic->fnic_lock)
 {
 	fnic->iport.fabric.del_timer_inprogress = 1;
 	spin_unlock_irqrestore(&fnic->fnic_lock, fnic->lock_flags);
@@ -399,8 +400,8 @@ void fnic_del_fabric_timer_sync(struct fnic *fnic)
 	fnic->iport.fabric.del_timer_inprogress = 0;
 }
 
-void fnic_del_tport_timer_sync(struct fnic *fnic,
-						struct fnic_tport_s *tport)
+void fnic_del_tport_timer_sync(struct fnic *fnic, struct fnic_tport_s *tport)
+	__must_hold(&fnic->fnic_lock)
 {
 	tport->del_timer_inprogress = 1;
 	spin_unlock_irqrestore(&fnic->fnic_lock, fnic->lock_flags);
@@ -411,6 +412,7 @@ void fnic_del_tport_timer_sync(struct fnic *fnic,
 
 static void
 fdls_start_fabric_timer(struct fnic_iport_s *iport, int timeout)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	u64 fabric_tov;
 	struct fnic *fnic = iport->fnic;
@@ -436,6 +438,7 @@ fdls_start_fabric_timer(struct fnic_iport_s *iport, int timeout)
 static void
 fdls_start_tport_timer(struct fnic_iport_s *iport,
 					   struct fnic_tport_s *tport, int timeout)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	u64 fabric_tov;
 	struct fnic *fnic = iport->fnic;
@@ -631,6 +634,7 @@ fdls_send_logo_resp(struct fnic_iport_s *iport,
 void
 fdls_send_tport_abts(struct fnic_iport_s *iport,
 					 struct fnic_tport_s *tport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	uint8_t s_id[3];
@@ -674,7 +678,9 @@ fdls_send_tport_abts(struct fnic_iport_s *iport,
 	/* Even if fnic_send_fcoe_frame() fails we want to retry after timeout */
 	fdls_start_tport_timer(iport, tport, 2 * iport->e_d_tov);
 }
+
 static void fdls_send_fabric_abts(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	uint8_t s_id[3];
@@ -846,6 +852,7 @@ static void fdls_send_fdmi_abts(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_fabric_flogi(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_flogi *pflogi;
@@ -906,6 +913,7 @@ static void fdls_send_fabric_flogi(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_fabric_plogi(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_flogi *pplogi;
@@ -998,6 +1006,7 @@ static void fdls_send_fdmi_plogi(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_rpn_id(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_rpn_id *prpn_id;
@@ -1057,6 +1066,7 @@ static void fdls_send_rpn_id(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_scr(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_scr *pscr;
@@ -1112,6 +1122,7 @@ static void fdls_send_scr(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_gpn_ft(struct fnic_iport_s *iport, int fdls_state)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_gpn_ft *pgpn_ft;
@@ -1171,6 +1182,7 @@ static void fdls_send_gpn_ft(struct fnic_iport_s *iport, int fdls_state)
 
 static void
 fdls_send_tgt_adisc(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_els_adisc *padisc;
@@ -1236,6 +1248,7 @@ fdls_send_tgt_adisc(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
 }
 
 bool fdls_delete_tport(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_tport_event_s *tport_del_evt;
 	struct fnic *fnic = iport->fnic;
@@ -1293,6 +1306,7 @@ bool fdls_delete_tport(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
 
 static void
 fdls_send_tgt_plogi(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_flogi *pplogi;
@@ -1361,6 +1375,7 @@ fnic_fc_plogi_rsp_rdf(struct fnic_iport_s *iport,
 }
 
 static void fdls_send_register_fc4_types(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_rft_id *prft_id;
@@ -1421,6 +1436,7 @@ static void fdls_send_register_fc4_types(struct fnic_iport_s *iport)
 }
 
 static void fdls_send_register_fc4_features(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_rff_id *prff_id;
@@ -1480,6 +1496,7 @@ static void fdls_send_register_fc4_features(struct fnic_iport_s *iport)
 
 static void
 fdls_send_tgt_prli(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_els_prli *pprli;
@@ -1553,6 +1570,7 @@ fdls_send_tgt_prli(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
  * Currently this assumes to be called with fnic lock held.
  */
 void fdls_send_fabric_logo(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint8_t *frame;
 	struct fc_std_logo *plogo;
@@ -1652,6 +1670,7 @@ void fdls_tgt_logout(struct fnic_iport_s *iport, struct fnic_tport_s *tport)
 }
 
 static void fdls_tgt_discovery_start(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_tport_s *tport, *next;
 	u32 old_link_down_cnt = iport->fnic->link_down_cnt;
@@ -1702,6 +1721,7 @@ static void fdls_tgt_discovery_start(struct fnic_iport_s *iport)
  * pointing to it will be freed later
  */
 static void fdls_target_restart_nexus(struct fnic_tport_s *tport)
+	__must_hold(&((struct fnic_iport_s *)tport->iport)->fnic->fnic_lock)
 {
 	struct fnic_iport_s *iport = tport->iport;
 	struct fnic_tport_s *new_tport = NULL;
@@ -2482,6 +2502,7 @@ static void fdls_tport_timer_callback(struct timer_list *t)
 }
 
 static void fnic_fdls_start_flogi(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	iport->fabric.retry_counter = 0;
 	fdls_send_fabric_flogi(iport);
@@ -2490,6 +2511,7 @@ static void fnic_fdls_start_flogi(struct fnic_iport_s *iport)
 }
 
 static void fnic_fdls_start_plogi(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	iport->fabric.retry_counter = 0;
 	fdls_send_fabric_plogi(iport);
@@ -2508,6 +2530,7 @@ static void fnic_fdls_start_plogi(struct fnic_iport_s *iport)
 static void
 fdls_process_tgt_adisc_rsp(struct fnic_iport_s *iport,
 			   struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint32_t tgt_fcid;
 	struct fnic_tport_s *tport;
@@ -2598,6 +2621,7 @@ fdls_process_tgt_adisc_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_tgt_plogi_rsp(struct fnic_iport_s *iport,
 			   struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint32_t tgt_fcid;
 	struct fnic_tport_s *tport;
@@ -2632,6 +2656,8 @@ fdls_process_tgt_plogi_rsp(struct fnic_iport_s *iport,
 	if (tport->state != FDLS_TGT_STATE_PLOGI) {
 		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 			     "PLOGI rsp recvd in wrong state. Drop the frame and restart nexus");
+		/* Tell the compiler that tport->iport == iport. */
+		__assume_ctx_lock(&((struct fnic_iport_s *)tport->iport)->fnic->fnic_lock);
 		fdls_target_restart_nexus(tport);
 		return;
 	}
@@ -2719,9 +2745,11 @@ fdls_process_tgt_plogi_rsp(struct fnic_iport_s *iport,
 	fdls_set_tport_state(tport, FDLS_TGT_STATE_PRLI);
 	fdls_send_tgt_prli(iport, tport);
 }
+
 static void
 fdls_process_tgt_prli_rsp(struct fnic_iport_s *iport,
 			  struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint32_t tgt_fcid;
 	struct fnic_tport_s *tport;
@@ -2758,6 +2786,8 @@ fdls_process_tgt_prli_rsp(struct fnic_iport_s *iport,
 	if (tport->state != FDLS_TGT_STATE_PRLI) {
 		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 			     "PRLI rsp recvd in wrong state. Drop frame. Restarting nexus");
+		/* Tell the compiler that tport->iport == iport. */
+		__assume_ctx_lock(&((struct fnic_iport_s *)tport->iport)->fnic->fnic_lock);
 		fdls_target_restart_nexus(tport);
 		return;
 	}
@@ -2872,6 +2902,7 @@ fdls_process_tgt_prli_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_rff_id_rsp(struct fnic_iport_s *iport,
 			struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic *fnic = iport->fnic;
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
@@ -2945,6 +2976,7 @@ fdls_process_rff_id_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_rft_id_rsp(struct fnic_iport_s *iport,
 			struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
 	struct fc_std_rft_id *rft_rsp = (struct fc_std_rft_id *) fchdr;
@@ -3020,6 +3052,7 @@ fdls_process_rft_id_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_rpn_id_rsp(struct fnic_iport_s *iport,
 			struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
 	struct fc_std_rpn_id *rpn_rsp = (struct fc_std_rpn_id *) fchdr;
@@ -3090,6 +3123,7 @@ fdls_process_rpn_id_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_scr_rsp(struct fnic_iport_s *iport,
 		     struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
 	struct fc_std_scr *scr_rsp = (struct fc_std_scr *) fchdr;
@@ -3162,6 +3196,7 @@ fdls_process_scr_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_gpn_ft_tgt_list(struct fnic_iport_s *iport,
 			     struct fc_frame_header *fchdr, int len)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_gpn_ft_rsp_iu *gpn_ft_tgt;
 	struct fnic_tport_s *tport, *next;
@@ -3260,6 +3295,7 @@ fdls_process_gpn_ft_tgt_list(struct fnic_iport_s *iport,
 static void
 fdls_process_gpn_ft_rsp(struct fnic_iport_s *iport,
 			struct fc_frame_header *fchdr, int len)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
 	struct fc_std_gpn_ft *gpn_ft_rsp = (struct fc_std_gpn_ft *) fchdr;
@@ -3396,6 +3432,7 @@ fdls_process_gpn_ft_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_fabric_logo_rsp(struct fnic_iport_s *iport,
 			     struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_std_flogi *flogo_rsp = (struct fc_std_flogi *) fchdr;
 	struct fnic_fdls_fabric_s *fdls = &iport->fabric;
@@ -3449,6 +3486,7 @@ fdls_process_fabric_logo_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_flogi_rsp(struct fnic_iport_s *iport,
 		       struct fc_frame_header *fchdr, void *rx_frame)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_fdls_fabric_s *fabric = &iport->fabric;
 	struct fc_std_flogi *flogi_rsp = (struct fc_std_flogi *) fchdr;
@@ -3586,6 +3624,7 @@ fdls_process_flogi_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_fabric_plogi_rsp(struct fnic_iport_s *iport,
 			      struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_std_flogi *plogi_rsp = (struct fc_std_flogi *) fchdr;
 	struct fc_std_els_rjt_rsp *els_rjt = (struct fc_std_els_rjt_rsp *) fchdr;
@@ -3847,6 +3886,7 @@ static void fdls_process_fdmi_abts_rsp(struct fnic_iport_s *iport,
 static void
 fdls_process_fabric_abts_rsp(struct fnic_iport_s *iport,
 			     struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint32_t s_id;
 	struct fc_std_abts_ba_acc *ba_acc = (struct fc_std_abts_ba_acc *)fchdr;
@@ -4204,6 +4244,7 @@ fdls_process_els_req(struct fnic_iport_s *iport, struct fc_frame_header *fchdr,
 static void
 fdls_process_tgt_abts_rsp(struct fnic_iport_s *iport,
 			  struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	uint32_t s_id;
 	struct fnic_tport_s *tport;
@@ -4393,6 +4434,7 @@ fdls_process_plogi_req(struct fnic_iport_s *iport,
 
 static void
 fdls_process_logo_req(struct fnic_iport_s *iport, struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_std_logo *logo = (struct fc_std_logo *)fchdr;
 	uint32_t nport_id;
@@ -4433,6 +4475,8 @@ fdls_process_logo_req(struct fnic_iport_s *iport, struct fc_frame_header *fchdr)
 		FNIC_FCS_DBG(KERN_ERR, fnic->host, fnic->fnic_num,
 					 "tport fcid 0x%x: Canceling disc timer\n",
 					 tport->fcid);
+		/* Tell the compiler that tport->iport == iport. */
+		__assume_ctx_lock(&((struct fnic_iport_s *)tport->iport)->fnic->fnic_lock);
 		fnic_del_tport_timer_sync(fnic, tport);
 		tport->timer_pending = 0;
 	}
@@ -4470,6 +4514,7 @@ fdls_process_logo_req(struct fnic_iport_s *iport, struct fc_frame_header *fchdr)
 
 static void
 fdls_process_rscn(struct fnic_iport_s *iport, struct fc_frame_header *fchdr)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_std_rscn *rscn;
 	struct fc_els_rscn_page *rscn_port = NULL;
@@ -4603,6 +4648,7 @@ fdls_process_rscn(struct fnic_iport_s *iport, struct fc_frame_header *fchdr)
 }
 
 void fnic_fdls_disc_start(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic *fnic = iport->fnic;
 
@@ -4943,6 +4989,7 @@ fnic_fdls_validate_and_get_frame_type(struct fnic_iport_s *iport,
 
 void fnic_fdls_recv_frame(struct fnic_iport_s *iport, void *rx_frame,
 						  int len, int fchdr_offset)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fc_frame_header *fchdr;
 	uint32_t s_id = 0;
@@ -5061,6 +5108,7 @@ void fnic_fdls_disc_init(struct fnic_iport_s *iport)
 }
 
 void fnic_fdls_link_down(struct fnic_iport_s *iport)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic_tport_s *tport, *next;
 	struct fnic *fnic = iport->fnic;
diff --git a/drivers/scsi/fnic/fip.c b/drivers/scsi/fnic/fip.c
index 132f00512ee1..da8a8e9ffea4 100644
--- a/drivers/scsi/fnic/fip.c
+++ b/drivers/scsi/fnic/fip.c
@@ -610,6 +610,7 @@ void fnic_common_fip_cleanup(struct fnic *fnic)
  * and clean up and restart the vlan discovery.
  */
 void fnic_fcoe_process_cvl(struct fnic *fnic, struct fip_header *fiph)
+	__must_hold(&fnic->fnic_lock)
 {
 	struct fnic_iport_s *iport = &fnic->iport;
 	struct fip_cvl *cvl_msg = (struct fip_cvl *)fiph;
@@ -687,6 +688,7 @@ void fnic_fcoe_process_cvl(struct fnic *fnic, struct fip_header *fiph)
  * @frame: Received ethernet frame
  */
 int fdls_fip_recv_frame(struct fnic *fnic, void *frame)
+	__must_hold(&fnic->fnic_lock)
 {
 	struct ethhdr *eth = (struct ethhdr *)frame;
 	struct fip_header *fiph;
diff --git a/drivers/scsi/fnic/fnic_fcs.c b/drivers/scsi/fnic/fnic_fcs.c
index 063eb864a5cd..99f9fe13dfe4 100644
--- a/drivers/scsi/fnic/fnic_fcs.c
+++ b/drivers/scsi/fnic/fnic_fcs.c
@@ -925,6 +925,7 @@ void fnic_free_wq_buf(struct vnic_wq *wq, struct vnic_wq_buf *buf)
 void
 fnic_fdls_add_tport(struct fnic_iport_s *iport, struct fnic_tport_s *tport,
 					unsigned long flags)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic *fnic = iport->fnic;
 	struct fc_rport *rport;
@@ -964,6 +965,7 @@ fnic_fdls_add_tport(struct fnic_iport_s *iport, struct fnic_tport_s *tport,
 void
 fnic_fdls_remove_tport(struct fnic_iport_s *iport,
 					   struct fnic_tport_s *tport, unsigned long flags)
+	__must_hold(&iport->fnic->fnic_lock)
 {
 	struct fnic *fnic = iport->fnic;
 	struct rport_dd_data_s *rdd_data;
@@ -1013,6 +1015,8 @@ void fnic_delete_fcp_tports(struct fnic *fnic)
 	unsigned long flags;
 
 	spin_lock_irqsave(&fnic->fnic_lock, flags);
+	/* Tell the compiler that fnic->iport.fnic == fnic. */
+	__assume_ctx_lock(&fnic->iport.fnic->fnic_lock);
 	list_for_each_entry_safe(tport, next, &fnic->iport.tport_list, links) {
 		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 					 "removing fcp rport fcid: 0x%x", tport->fcid);
@@ -1037,6 +1041,8 @@ void fnic_tport_event_handler(struct work_struct *work)
 	struct fnic_tport_s *tport;
 
 	spin_lock_irqsave(&fnic->fnic_lock, flags);
+	/* Tell the compiler that fnic->iport.fnic == fnic. */
+	__assume_ctx_lock(&fnic->iport.fnic->fnic_lock);
 	list_for_each_entry_safe(cur_evt, next, &fnic->tport_event_list, links) {
 		tport = cur_evt->arg1;
 		switch (cur_evt->event) {
diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 6ee3c559e129..a757b20756ad 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -2617,6 +2617,8 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 		 * allocated by mid layer.
 		 */
 		mutex_lock(&fnic->sgreset_mutex);
+		/* Fake __release() to keep the lock context analyzer happy. */
+		__release(&fnic->sgreset_mutex);
 		mqtag = fnic->fnic_max_tag_id;
 		new_sc = 1;
 	}  else {
@@ -2803,6 +2805,8 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 
 	if (new_sc) {
 		fnic->sgreset_sc = NULL;
+		/* Fake __acquire() to keep the lock context analyzer happy. */
+		__acquire(&fnic->sgreset_mutex);
 		mutex_unlock(&fnic->sgreset_mutex);
 	}