isci: Add suspension cases for RNC INVALIDATING, POSTING states.

The RNC can be any of the states in the loop from suspended to
ready when the API "suspend" or "resume" are called.  This change
adds destination states parameters that control the suspension /
resumption action of the RNC statemachine for those transition states.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 97 insertions, 48 deletions

diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c
index feeca17..75cf043 100644
--- a/drivers/scsi/isci/remote_node_context.c
+++ b/drivers/scsi/isci/remote_node_context.c
@@ -165,21 +165,24 @@ static void sci_remote_node_context_construct_buffer(struct sci_remote_node_cont
 static void sci_remote_node_context_setup_to_resume(
 	struct sci_remote_node_context *sci_rnc,
 	scics_sds_remote_node_context_callback callback,
-	void *callback_parameter)
+	void *callback_parameter,
+	enum sci_remote_node_context_destination_state dest_param)
 {
-	if (sci_rnc->destination_state != SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL) {
-		sci_rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY;
-		sci_rnc->user_callback     = callback;
-		sci_rnc->user_cookie       = callback_parameter;
+	if (sci_rnc->destination_state != RNC_DEST_FINAL) {
+		sci_rnc->destination_state = dest_param;
+		if (callback != NULL) {
+			sci_rnc->user_callback = callback;
+			sci_rnc->user_cookie   = callback_parameter;
+		}
 	}
 }
 
-static void sci_remote_node_context_setup_to_destory(
+static void sci_remote_node_context_setup_to_destroy(
 	struct sci_remote_node_context *sci_rnc,
 	scics_sds_remote_node_context_callback callback,
 	void *callback_parameter)
 {
-	sci_rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL;
+	sci_rnc->destination_state = RNC_DEST_FINAL;
 	sci_rnc->user_callback     = callback;
 	sci_rnc->user_cookie       = callback_parameter;
 }
@@ -203,9 +206,13 @@ static void sci_remote_node_context_notify_user(
 
 static void sci_remote_node_context_continue_state_transitions(struct sci_remote_node_context *rnc)
 {
-	if (rnc->destination_state == SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY)
+	if ((rnc->destination_state == RNC_DEST_READY) ||
+	    (rnc->destination_state == RNC_DEST_SUSPENDED_RESUME)) {
+		rnc->destination_state = RNC_DEST_READY;
 		sci_remote_node_context_resume(rnc, rnc->user_callback,
 						    rnc->user_cookie);
+	} else
+		rnc->destination_state = RNC_DEST_UNSPECIFIED;
 }
 
 static void sci_remote_node_context_validate_context_buffer(struct sci_remote_node_context *sci_rnc)
@@ -252,7 +259,7 @@ static void sci_remote_node_context_initial_state_enter(struct sci_base_state_ma
 	 * someone requested to destroy the remote node context object.
 	 */
 	if (sm->previous_state_id == SCI_RNC_INVALIDATING) {
-		rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
+		rnc->destination_state = RNC_DEST_UNSPECIFIED;
 		sci_remote_node_context_notify_user(rnc);
 	}
 }
@@ -297,10 +304,26 @@ static void sci_remote_node_context_resuming_state_enter(struct sci_base_state_m
 static void sci_remote_node_context_ready_state_enter(struct sci_base_state_machine *sm)
 {
 	struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
-
-	rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
-
-	if (rnc->user_callback)
+	enum sci_remote_node_context_destination_state dest_select;
+	scics_sds_remote_node_context_callback usr_cb = rnc->user_callback;
+	void *usr_param = rnc->user_cookie;
+	int tell_user = 1;
+
+	dest_select = rnc->destination_state;
+	rnc->destination_state = RNC_DEST_UNSPECIFIED;
+
+	if ((dest_select == RNC_DEST_SUSPENDED) ||
+	    (dest_select == RNC_DEST_SUSPENDED_RESUME)) {
+		sci_remote_node_context_suspend(
+			rnc, SCI_SOFTWARE_SUSPENSION,
+			SCI_SOFTWARE_SUSPEND_EXPECTED_EVENT, NULL, NULL);
+
+		if (dest_select == RNC_DEST_SUSPENDED_RESUME) {
+			sci_remote_node_context_resume(rnc, usr_cb, usr_param);
+			tell_user = 0;  /* Wait until ready again. */
+		}
+	}
+	if (tell_user && rnc->user_callback)
 		sci_remote_node_context_notify_user(rnc);
 }
 
@@ -366,7 +389,7 @@ void sci_remote_node_context_construct(struct sci_remote_node_context *rnc,
 	memset(rnc, 0, sizeof(struct sci_remote_node_context));
 
 	rnc->remote_node_index = remote_node_index;
-	rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
+	rnc->destination_state = RNC_DEST_UNSPECIFIED;
 
 	sci_init_sm(&rnc->sm, sci_remote_node_context_state_table, SCI_RNC_INITIAL);
 }
@@ -390,11 +413,11 @@ enum sci_status sci_remote_node_context_event_handler(struct sci_remote_node_con
 		break;
 	case SCI_RNC_INVALIDATING:
 		if (scu_get_event_code(event_code) == SCU_EVENT_POST_RNC_INVALIDATE_COMPLETE) {
-			if (sci_rnc->destination_state == SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL)
-				state = SCI_RNC_INITIAL;
+			if (sci_rnc->destination_state == RNC_DEST_FINAL)
+				next_state = SCI_RNC_INITIAL;
 			else
-				state = SCI_RNC_POSTING;
-			sci_change_state(&sci_rnc->sm, state);
+				next_state = SCI_RNC_POSTING;
+			sci_change_state(&sci_rnc->sm, next_state);
 		} else {
 			switch (scu_get_event_type(event_code)) {
 			case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
@@ -483,7 +506,7 @@ enum sci_status sci_remote_node_context_destruct(struct sci_remote_node_context
 	state = sci_rnc->sm.current_state_id;
 	switch (state) {
 	case SCI_RNC_INVALIDATING:
-		sci_remote_node_context_setup_to_destory(sci_rnc, cb_fn, cb_p);
+		sci_remote_node_context_setup_to_destroy(sci_rnc, cb_fn, cb_p);
 		return SCI_SUCCESS;
 	case SCI_RNC_POSTING:
 	case SCI_RNC_RESUMING:
@@ -491,7 +514,7 @@ enum sci_status sci_remote_node_context_destruct(struct sci_remote_node_context
 	case SCI_RNC_TX_SUSPENDED:
 	case SCI_RNC_TX_RX_SUSPENDED:
 	case SCI_RNC_AWAIT_SUSPENSION:
-		sci_remote_node_context_setup_to_destory(sci_rnc, cb_fn, cb_p);
+		sci_remote_node_context_setup_to_destroy(sci_rnc, cb_fn, cb_p);
 		sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
 		return SCI_SUCCESS;
 	case SCI_RNC_INITIAL:
@@ -522,6 +545,8 @@ enum sci_status sci_remote_node_context_suspend(
 		= sci_rnc->sm.current_state_id;
 	struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 	enum sci_status status = SCI_FAILURE_INVALID_STATE;
+	enum sci_remote_node_context_destination_state dest_param =
+		RNC_DEST_UNSPECIFIED;
 
 	dev_dbg(scirdev_to_dev(idev),
 		"%s: current state %d, current suspend_type %x dest state %d,"
@@ -531,12 +556,31 @@ enum sci_status sci_remote_node_context_suspend(
 		suspend_type);
 
 	/* Disable automatic state continuations if explicitly suspending. */
-	if (suspend_reason == SCI_SOFTWARE_SUSPENSION)
-		sci_rnc->destination_state
-			= SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
+	if ((suspend_reason != SCI_SOFTWARE_SUSPENSION) ||
+	    (sci_rnc->destination_state == RNC_DEST_FINAL))
+		dest_param = sci_rnc->destination_state;
+
 	switch (state) {
+	case SCI_RNC_RESUMING:
+		break;  /* The RNC has been posted, so start the suspend. */
 	case SCI_RNC_READY:
 		break;
+	case SCI_RNC_INVALIDATING:
+		if (sci_rnc->destination_state == RNC_DEST_FINAL) {
+			dev_warn(scirdev_to_dev(idev),
+				 "%s: already destroying %p\n",
+				 __func__, sci_rnc);
+			return SCI_FAILURE_INVALID_STATE;
+		}
+		/* Fall through and handle like SCI_RNC_POSTING */
+	case SCI_RNC_POSTING:
+		/* Set the destination state to AWAIT - this signals the
+		 * entry into the SCI_RNC_READY state that a suspension
+		 * needs to be done immediately.
+		 */
+		sci_rnc->destination_state = RNC_DEST_SUSPENDED;
+		return SCI_SUCCESS;
+
 	case SCI_RNC_TX_SUSPENDED:
 		if (suspend_type == SCU_EVENT_TL_RNC_SUSPEND_TX)
 			status = SCI_SUCCESS;
@@ -556,6 +600,7 @@ enum sci_status sci_remote_node_context_suspend(
 			 rnc_state_name(state));
 		return SCI_FAILURE_INVALID_STATE;
 	}
+	sci_rnc->destination_state = dest_param;
 	sci_rnc->user_callback = cb_fn;
 	sci_rnc->user_cookie   = cb_p;
 	sci_rnc->suspend_type  = suspend_type;
@@ -590,18 +635,31 @@ enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *s
 		if (sci_rnc->remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
 			return SCI_FAILURE_INVALID_STATE;
 
-		sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
+		sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p,
+							RNC_DEST_READY);
 		sci_remote_node_context_construct_buffer(sci_rnc);
 		sci_change_state(&sci_rnc->sm, SCI_RNC_POSTING);
 		return SCI_SUCCESS;
 	case SCI_RNC_POSTING:
 	case SCI_RNC_INVALIDATING:
 	case SCI_RNC_RESUMING:
-		if (sci_rnc->destination_state != SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY)
-			return SCI_FAILURE_INVALID_STATE;
-
-		sci_rnc->user_callback = cb_fn;
-		sci_rnc->user_cookie   = cb_p;
+		/* We are still waiting to post when a resume was requested. */
+		switch (sci_rnc->destination_state) {
+		case RNC_DEST_SUSPENDED:
+		case RNC_DEST_SUSPENDED_RESUME:
+			/* Previously waiting to suspend after posting.  Now
+			 * continue onto resumption.
+			 */
+			sci_remote_node_context_setup_to_resume(
+				sci_rnc, cb_fn, cb_p,
+				RNC_DEST_SUSPENDED_RESUME);
+			break;
+		default:
+			sci_remote_node_context_setup_to_resume(
+				sci_rnc, cb_fn, cb_p,
+				RNC_DEST_READY);
+			break;
+		}
 		return SCI_SUCCESS;
 	case SCI_RNC_TX_SUSPENDED:
 	case SCI_RNC_TX_RX_SUSPENDED: {
@@ -613,7 +671,8 @@ enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *s
 		 * to clear the TCi to NCQ tag mapping table for the RNi.
 		 * All other device types we can just resume.
 		 */
-		sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
+		sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p,
+							RNC_DEST_READY);
 
 		if (dev_is_sata(dev) && dev->parent)
 			sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
@@ -622,7 +681,9 @@ enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *s
 		return SCI_SUCCESS;
 	}
 	case SCI_RNC_AWAIT_SUSPENSION:
-		sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
+		sci_remote_node_context_setup_to_resume(
+			sci_rnc, cb_fn, cb_p,
+			RNC_DEST_SUSPENDED_RESUME);
 		return SCI_SUCCESS;
 	default:
 		dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
@@ -663,24 +724,12 @@ enum sci_status sci_remote_node_context_start_task(
 	scics_sds_remote_node_context_callback cb_fn,
 	void *cb_p)
 {
-	enum scis_sds_remote_node_context_states state;
-
-	state = sci_rnc->sm.current_state_id;
-	switch (state) {
-	case SCI_RNC_RESUMING:
-	case SCI_RNC_READY:
-	case SCI_RNC_AWAIT_SUSPENSION:
-		return SCI_SUCCESS;
-	case SCI_RNC_TX_SUSPENDED:
-	case SCI_RNC_TX_RX_SUSPENDED:
-		sci_remote_node_context_resume(sci_rnc, cb_fn, cb_p);
-		return SCI_SUCCESS;
-	default:
+	enum sci_status status = sci_remote_node_context_resume(sci_rnc,
+								cb_fn, cb_p);
+	if (status != SCI_SUCCESS)
 		dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
-			"%s: invalid state %s\n", __func__,
-			rnc_state_name(state));
-		return SCI_FAILURE_INVALID_STATE;
-	}
+			"%s: resume failed: %d\n", __func__, status);
+	return status;
 }
 
 int sci_remote_node_context_is_safe_to_abort(