[S390] qdio: cleanup SIGA sync

Simplify the SIGA sync code and add unlikely annotations. In polling mode
SBALs may be accessed without interrupt, so call SIGA sync before every scan.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 44 insertions, 55 deletions

diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index 1b40a92..7bc643f 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -148,10 +148,9 @@ struct siga_flag {
 	u8 input:1;
 	u8 output:1;
 	u8 sync:1;
-	u8 no_sync_ti:1;
-	u8 no_sync_out_ti:1;
-	u8 no_sync_out_pci:1;
-	u8:2;
+	u8 sync_after_ai:1;
+	u8 sync_out_after_pci:1;
+	u8:3;
 } __attribute__ ((packed));
 
 struct chsc_ssqd_area {
@@ -390,12 +389,13 @@ static inline int multicast_outbound(struct qdio_q *q)
 	(q->irq_ptr->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED)
 #define is_qebsm(q)			(q->irq_ptr->sch_token != 0)
 
-#define need_siga_sync_thinint(q)	(!q->irq_ptr->siga_flag.no_sync_ti)
-#define need_siga_sync_out_thinint(q)	(!q->irq_ptr->siga_flag.no_sync_out_ti)
 #define need_siga_in(q)			(q->irq_ptr->siga_flag.input)
 #define need_siga_out(q)		(q->irq_ptr->siga_flag.output)
-#define need_siga_sync(q)		(q->irq_ptr->siga_flag.sync)
-#define siga_syncs_out_pci(q)		(q->irq_ptr->siga_flag.no_sync_out_pci)
+#define need_siga_sync(q)		(unlikely(q->irq_ptr->siga_flag.sync))
+#define need_siga_sync_after_ai(q)	\
+	(unlikely(q->irq_ptr->siga_flag.sync_after_ai))
+#define need_siga_sync_out_after_pci(q)	\
+	(unlikely(q->irq_ptr->siga_flag.sync_out_after_pci))
 
 #define for_each_input_queue(irq_ptr, q, i)	\
 	for (i = 0, q = irq_ptr->input_qs[0];	\
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 8a722f2..e9fff2b 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -286,9 +286,6 @@ static inline int qdio_siga_sync(struct qdio_q *q, unsigned int output,
 	unsigned int fc = QDIO_SIGA_SYNC;
 	int cc;
 
-	if (!need_siga_sync(q))
-		return 0;
-
 	DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-s:%1d", q->nr);
 	qperf_inc(q, siga_sync);
 
@@ -311,16 +308,6 @@ static inline int qdio_siga_sync_q(struct qdio_q *q)
 		return qdio_siga_sync(q, q->mask, 0);
 }
 
-static inline int qdio_siga_sync_out(struct qdio_q *q)
-{
-	return qdio_siga_sync(q, ~0U, 0);
-}
-
-static inline int qdio_siga_sync_all(struct qdio_q *q)
-{
-	return qdio_siga_sync(q, ~0U, ~0U);
-}
-
 static int qdio_siga_output(struct qdio_q *q, unsigned int *busy_bit)
 {
 	unsigned long schid = *((u32 *) &q->irq_ptr->schid);
@@ -369,21 +356,23 @@ static inline int qdio_siga_input(struct qdio_q *q)
 	return cc;
 }
 
-static inline void qdio_sync_after_thinint(struct qdio_q *q)
+#define qdio_siga_sync_out(q) qdio_siga_sync(q, ~0U, 0)
+#define qdio_siga_sync_all(q) qdio_siga_sync(q, ~0U, ~0U)
+
+static inline void qdio_sync_queues(struct qdio_q *q)
 {
-	if (pci_out_supported(q)) {
-		if (need_siga_sync_thinint(q))
-			qdio_siga_sync_all(q);
-		else if (need_siga_sync_out_thinint(q))
-			qdio_siga_sync_out(q);
-	} else
+	/* PCI capable outbound queues will also be scanned so sync them too */
+	if (pci_out_supported(q))
+		qdio_siga_sync_all(q);
+	else
 		qdio_siga_sync_q(q);
 }
 
 int debug_get_buf_state(struct qdio_q *q, unsigned int bufnr,
 			unsigned char *state)
 {
-	qdio_siga_sync_q(q);
+	if (need_siga_sync(q))
+		qdio_siga_sync_q(q);
 	return get_buf_states(q, bufnr, state, 1, 0);
 }
 
@@ -560,7 +549,8 @@ static inline int qdio_inbound_q_done(struct qdio_q *q)
 	if (!atomic_read(&q->nr_buf_used))
 		return 1;
 
-	qdio_siga_sync_q(q);
+	if (need_siga_sync(q))
+		qdio_siga_sync_q(q);
 	get_buf_state(q, q->first_to_check, &state, 0);
 
 	if (state == SLSB_P_INPUT_PRIMED || state == SLSB_P_INPUT_ERROR)
@@ -655,9 +645,12 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
 	int count, stop;
 	unsigned char state;
 
-	if (((queue_type(q) != QDIO_IQDIO_QFMT) && !pci_out_supported(q)) ||
-	    (queue_type(q) == QDIO_IQDIO_QFMT && multicast_outbound(q)))
-		qdio_siga_sync_q(q);
+	if (need_siga_sync(q))
+		if (((queue_type(q) != QDIO_IQDIO_QFMT) &&
+		    !pci_out_supported(q)) ||
+		    (queue_type(q) == QDIO_IQDIO_QFMT &&
+		    multicast_outbound(q)))
+			qdio_siga_sync_q(q);
 
 	/*
 	 * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
@@ -829,7 +822,8 @@ static inline void qdio_check_outbound_after_thinint(struct qdio_q *q)
 static void __tiqdio_inbound_processing(struct qdio_q *q)
 {
 	qperf_inc(q, tasklet_inbound);
-	qdio_sync_after_thinint(q);
+	if (need_siga_sync(q) && need_siga_sync_after_ai(q))
+		qdio_sync_queues(q);
 
 	/*
 	 * The interrupt could be caused by a PCI request. Check the
@@ -909,16 +903,14 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
 			tasklet_schedule(&q->tasklet);
 	}
 
-	if (!(irq_ptr->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED))
+	if (!pci_out_supported(q))
 		return;
 
 	for_each_output_queue(irq_ptr, q, i) {
 		if (qdio_outbound_q_done(q))
 			continue;
-
-		if (!siga_syncs_out_pci(q))
+		if (need_siga_sync(q) && need_siga_sync_out_after_pci(q))
 			qdio_siga_sync_q(q);
-
 		tasklet_schedule(&q->tasklet);
 	}
 }
@@ -1470,7 +1462,7 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags,
 		WARN_ON_ONCE(count > 1 && !multicast_outbound(q));
 
 		rc = qdio_kick_outbound_q(q);
-	} else if (unlikely(need_siga_sync(q))) {
+	} else if (need_siga_sync(q)) {
 		rc = qdio_siga_sync_q(q);
 	} else {
 		/* try to fast requeue buffers */
@@ -1597,12 +1589,14 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr,
 	q = irq_ptr->input_qs[nr];
 	WARN_ON(queue_irqs_enabled(q));
 
-	qdio_sync_after_thinint(q);
-
 	/*
-	 * The interrupt could be caused by a PCI request. Check the
-	 * PCI capable outbound queues.
+	 * Cannot rely on automatic sync after interrupt since queues may
+	 * also be examined without interrupt.
 	 */
+	if (need_siga_sync(q))
+		qdio_sync_queues(q);
+
+	/* check the PCI capable outbound queues. */
 	qdio_check_outbound_after_thinint(q);
 
 	if (!qdio_inbound_q_moved(q))
diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index 635f35d..89107d0 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -197,14 +197,10 @@ static void process_ac_flags(struct qdio_irq *irq_ptr, unsigned char qdioac)
 		irq_ptr->siga_flag.output = 1;
 	if (qdioac & AC1_SIGA_SYNC_NEEDED)
 		irq_ptr->siga_flag.sync = 1;
-	if (qdioac & AC1_AUTOMATIC_SYNC_ON_THININT)
-		irq_ptr->siga_flag.no_sync_ti = 1;
-	if (qdioac & AC1_AUTOMATIC_SYNC_ON_OUT_PCI)
-		irq_ptr->siga_flag.no_sync_out_pci = 1;
-
-	if (irq_ptr->siga_flag.no_sync_out_pci &&
-	    irq_ptr->siga_flag.no_sync_ti)
-		irq_ptr->siga_flag.no_sync_out_ti = 1;
+	if (!(qdioac & AC1_AUTOMATIC_SYNC_ON_THININT))
+		irq_ptr->siga_flag.sync_after_ai = 1;
+	if (!(qdioac & AC1_AUTOMATIC_SYNC_ON_OUT_PCI))
+		irq_ptr->siga_flag.sync_out_after_pci = 1;
 }
 
 static void check_and_setup_qebsm(struct qdio_irq *irq_ptr,
@@ -452,7 +448,7 @@ void qdio_print_subchannel_info(struct qdio_irq *irq_ptr,
 	char s[80];
 
 	snprintf(s, 80, "qdio: %s %s on SC %x using "
-		 "AI:%d QEBSM:%d PCI:%d TDD:%d SIGA:%s%s%s%s%s%s\n",
+		 "AI:%d QEBSM:%d PCI:%d TDD:%d SIGA:%s%s%s%s%s\n",
 		 dev_name(&cdev->dev),
 		 (irq_ptr->qib.qfmt == QDIO_QETH_QFMT) ? "OSA" :
 			((irq_ptr->qib.qfmt == QDIO_ZFCP_QFMT) ? "ZFCP" : "HS"),
@@ -464,9 +460,8 @@ void qdio_print_subchannel_info(struct qdio_irq *irq_ptr,
 		 (irq_ptr->siga_flag.input) ? "R" : " ",
 		 (irq_ptr->siga_flag.output) ? "W" : " ",
 		 (irq_ptr->siga_flag.sync) ? "S" : " ",
-		 (!irq_ptr->siga_flag.no_sync_ti) ? "A" : " ",
-		 (!irq_ptr->siga_flag.no_sync_out_ti) ? "O" : " ",
-		 (!irq_ptr->siga_flag.no_sync_out_pci) ? "P" : " ");
+		 (irq_ptr->siga_flag.sync_after_ai) ? "A" : " ",
+		 (irq_ptr->siga_flag.sync_out_after_pci) ? "P" : " ");
 	printk(KERN_INFO "%s", s);
 }