s390/qdio: remove Input tasklet code

Both qeth and zfcp have fully moved to the polling-driven flow for
Input Queues with commit 0a6e6345 ("s390/qdio: extend polling
support to multiple queues") and commit 0b524abc ("scsi: zfcp: Lift
Input Queue tasklet from qdio").

So remove the tasklet code for Input Queues, streamline the IRQ handlers
and push the tasklet struct into struct qdio_output_q.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/include/asm/qdio.h

@@ -336,7 +336,7 @@ typedef void qdio_handler_t(struct ccw_device *, unsigned int, int,
  * @no_output_qs: number of output queues
  * @input_handler: handler to be called for input queues
  * @output_handler: handler to be called for output queues
- * @irq_poll: Data IRQ polling handler (NULL when not supported)
+ * @irq_poll: Data IRQ polling handler
  * @scan_threshold: # of in-use buffers that triggers scan on output queue
  * @int_parm: interruption parameter
  * @input_sbal_addr_array:  per-queue array, each element points to 128 SBALs

drivers/s390/cio/qdio.h

@@ -139,9 +139,6 @@ struct qdio_dev_perf_stat {
 	unsigned int qdio_int;
 	unsigned int pci_request_int;
 
-	unsigned int tasklet_inbound;
-	unsigned int tasklet_inbound_resched;
-	unsigned int tasklet_inbound_resched2;
 	unsigned int tasklet_outbound;
 
 	unsigned int siga_read;
@@ -193,6 +190,8 @@ struct qdio_output_q {
 	struct qdio_outbuf_state *sbal_state;
 	/* timer to check for more outbound work */
 	struct timer_list timer;
+	/* tasklet to check for completions */
+	struct tasklet_struct tasklet;
 };
 
 /*
@@ -222,7 +221,6 @@ struct qdio_q {
 	/* last scan of the queue */
 	u64 timestamp;
 
-	struct tasklet_struct tasklet;
 	struct qdio_queue_perf_stat q_stats;
 
 	struct qdio_buffer *sbal[QDIO_MAX_BUFFERS_PER_Q] ____cacheline_aligned;
@@ -324,6 +322,14 @@ static inline int multicast_outbound(struct qdio_q *q)
 	       (q->nr == q->irq_ptr->nr_output_qs - 1);
 }
 
+static inline void qdio_deliver_irq(struct qdio_irq *irq)
+{
+	if (!test_and_set_bit(QDIO_IRQ_DISABLED, &irq->poll_state))
+		irq->irq_poll(irq->cdev, irq->int_parm);
+	else
+		QDIO_PERF_STAT_INC(irq, int_discarded);
+}
+
 #define pci_out_supported(irq) ((irq)->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED)
 #define is_qebsm(q)			(q->irq_ptr->sch_token != 0)
 
@@ -359,13 +365,11 @@ int qdio_establish_thinint(struct qdio_irq *irq_ptr);
 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr);
 void tiqdio_add_device(struct qdio_irq *irq_ptr);
 void tiqdio_remove_device(struct qdio_irq *irq_ptr);
-void tiqdio_inbound_processing(unsigned long q);
 int qdio_thinint_init(void);
 void qdio_thinint_exit(void);
 int test_nonshared_ind(struct qdio_irq *);
 
 /* prototypes for setup */
-void qdio_inbound_processing(unsigned long data);
 void qdio_outbound_processing(unsigned long data);
 void qdio_outbound_timer(struct timer_list *t);
 void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm,

drivers/s390/cio/qdio_debug.c

@@ -197,9 +197,6 @@ static char *qperf_names[] = {
 	"Assumed adapter interrupts",
 	"QDIO interrupts",
 	"Requested PCIs",
-	"Inbound tasklet runs",
-	"Inbound tasklet resched",
-	"Inbound tasklet resched2",
 	"Outbound tasklet runs",
 	"SIGA read",
 	"SIGA write",

drivers/s390/cio/qdio_main.c

@@ -575,51 +575,12 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int start,
 static inline int qdio_tasklet_schedule(struct qdio_q *q)
 {
 	if (likely(q->irq_ptr->state == QDIO_IRQ_STATE_ACTIVE)) {
-		tasklet_schedule(&q->tasklet);
+		tasklet_schedule(&q->u.out.tasklet);
 		return 0;
 	}
 	return -EPERM;
 }
 
-static void __qdio_inbound_processing(struct qdio_q *q)
-{
-	unsigned int start = q->first_to_check;
-	int count;
-
-	qperf_inc(q, tasklet_inbound);
-
-	count = qdio_inbound_q_moved(q, start);
-	if (count == 0)
-		return;
-
-	qdio_kick_handler(q, start, count);
-	start = add_buf(start, count);
-	q->first_to_check = start;
-
-	if (!qdio_inbound_q_done(q, start)) {
-		/* means poll time is not yet over */
-		qperf_inc(q, tasklet_inbound_resched);
-		if (!qdio_tasklet_schedule(q))
-			return;
-	}
-
-	qdio_stop_polling(q);
-	/*
-	 * We need to check again to not lose initiative after
-	 * resetting the ACK state.
-	 */
-	if (!qdio_inbound_q_done(q, start)) {
-		qperf_inc(q, tasklet_inbound_resched2);
-		qdio_tasklet_schedule(q);
-	}
-}
-
-void qdio_inbound_processing(unsigned long data)
-{
-	struct qdio_q *q = (struct qdio_q *)data;
-	__qdio_inbound_processing(q);
-}
-
 static void qdio_check_pending(struct qdio_q *q, unsigned int index)
 {
 	unsigned char state;
@@ -825,19 +786,6 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq)
 			qdio_tasklet_schedule(out);
 }
 
-void tiqdio_inbound_processing(unsigned long data)
-{
-	struct qdio_q *q = (struct qdio_q *)data;
-
-	if (need_siga_sync(q) && need_siga_sync_after_ai(q))
-		qdio_sync_queues(q);
-
-	/* The interrupt could be caused by a PCI request: */
-	qdio_check_outbound_pci_queues(q->irq_ptr);
-
-	__qdio_inbound_processing(q);
-}
-
 static inline void qdio_set_state(struct qdio_irq *irq_ptr,
 				  enum qdio_irq_states state)
 {
@@ -865,15 +813,7 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
 	if (unlikely(irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
 		return;
 
-	if (irq_ptr->irq_poll) {
-		if (!test_and_set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state))
-			irq_ptr->irq_poll(irq_ptr->cdev, irq_ptr->int_parm);
-		else
-			QDIO_PERF_STAT_INC(irq_ptr, int_discarded);
-	} else {
-		for_each_input_queue(irq_ptr, q, i)
-			tasklet_schedule(&q->tasklet);
-	}
+	qdio_deliver_irq(irq_ptr);
 
 	if (!pci_out_supported(irq_ptr) || !irq_ptr->scan_threshold)
 		return;
@@ -1016,12 +956,9 @@ static void qdio_shutdown_queues(struct qdio_irq *irq_ptr)
 	struct qdio_q *q;
 	int i;
 
-	for_each_input_queue(irq_ptr, q, i)
-		tasklet_kill(&q->tasklet);
-
 	for_each_output_queue(irq_ptr, q, i) {
 		del_timer_sync(&q->u.out.timer);
-		tasklet_kill(&q->tasklet);
+		tasklet_kill(&q->u.out.tasklet);
 	}
 }
 
@@ -1263,6 +1200,9 @@ int qdio_establish(struct ccw_device *cdev,
 	    !init_data->output_sbal_addr_array)
 		return -EINVAL;
 
+	if (!init_data->irq_poll)
+		return -EINVAL;
+
 	mutex_lock(&irq_ptr->setup_mutex);
 	qdio_trace_init_data(irq_ptr, init_data);
 	qdio_setup_irq(irq_ptr, init_data);

drivers/s390/cio/qdio_setup.c

@@ -259,14 +259,6 @@ static void setup_queues(struct qdio_irq *irq_ptr,
 
 		setup_storage_lists(q, irq_ptr,
 				    qdio_init->input_sbal_addr_array[i], i);
-
-		if (is_thinint_irq(irq_ptr)) {
-			tasklet_init(&q->tasklet, tiqdio_inbound_processing,
-				     (unsigned long) q);
-		} else {
-			tasklet_init(&q->tasklet, qdio_inbound_processing,
-				     (unsigned long) q);
-		}
 	}
 
 	for_each_output_queue(irq_ptr, q, i) {
@@ -280,7 +272,7 @@ static void setup_queues(struct qdio_irq *irq_ptr,
 		setup_storage_lists(q, irq_ptr,
 				    qdio_init->output_sbal_addr_array[i], i);
 
-		tasklet_init(&q->tasklet, qdio_outbound_processing,
+		tasklet_init(&q->u.out.tasklet, qdio_outbound_processing,
 			     (unsigned long) q);
 		timer_setup(&q->u.out.timer, qdio_outbound_timer, 0);
 	}
@@ -483,12 +475,8 @@ int qdio_setup_irq(struct qdio_irq *irq_ptr, struct qdio_initialize *init_data)
 	ccw_device_get_schid(cdev, &irq_ptr->schid);
 	setup_queues(irq_ptr, init_data);
 
-	if (init_data->irq_poll) {
-		irq_ptr->irq_poll = init_data->irq_poll;
-		set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state);
-	} else {
-		irq_ptr->irq_poll = NULL;
-	}
+	irq_ptr->irq_poll = init_data->irq_poll;
+	set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state);
 
 	setup_qib(irq_ptr, init_data);
 	set_impl_params(irq_ptr, init_data->qib_param_field_format,

drivers/s390/cio/qdio_thinint.c

@@ -106,32 +106,6 @@ static inline u32 clear_shared_ind(void)
 	return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
 }
 
-static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
-{
-	struct qdio_q *q;
-	int i;
-
-	if (!references_shared_dsci(irq))
-		xchg(irq->dsci, 0);
-
-	if (irq->irq_poll) {
-		if (!test_and_set_bit(QDIO_IRQ_DISABLED, &irq->poll_state))
-			irq->irq_poll(irq->cdev, irq->int_parm);
-		else
-			QDIO_PERF_STAT_INC(irq, int_discarded);
-
-		return;
-	}
-
-	for_each_input_queue(irq, q, i) {
-		/*
-		 * Call inbound processing but not directly
-		 * since that could starve other thinint queues.
-		 */
-		tasklet_schedule(&q->tasklet);
-	}
-}
-
 /**
  * tiqdio_thinint_handler - thin interrupt handler for qdio
  * @airq: pointer to adapter interrupt descriptor
@@ -153,10 +127,14 @@ static void tiqdio_thinint_handler(struct airq_struct *airq, bool floating)
 		if (unlikely(references_shared_dsci(irq))) {
 			if (!si_used)
 				continue;
-		} else if (!*irq->dsci)
-			continue;
+		} else {
+			if (!*irq->dsci)
+				continue;
+
+			xchg(irq->dsci, 0);
+		}
 
-		tiqdio_call_inq_handlers(irq);
+		qdio_deliver_irq(irq);
 
 		QDIO_PERF_STAT_INC(irq, adapter_int);
 	}