Commit 6bcf74e2 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Martin Schwidefsky
Browse files

s390/qdio: consolidate index tracking for queue scan 



qdio.ko offers a small number of high-level functions to drive the
scanning of a QDIO queue for ready-to-process SBALs:
qdio_get_next_buffers(), __[ti]qdio_inbound_processing() and
__qdio_outbound_processing().

Let each of those functions maintain the 'start' index for their current
scan, and pass it to lower-level helpers as needed. This improves the
code's overall layering, and allows us to eliminate the additional
first_to_kick cursor with a follow-on patch.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: default avatarJens Remus <jremus@linux.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 5b2ad270

drivers/s390/cio/qdio_main.c

+31 −24
Original line number Diff line number Diff line
@@ -492,9 +492,8 @@ static inline void inbound_primed(struct qdio_q *q, unsigned int start, 
	set_buf_states(q, start, SLSB_P_INPUT_NOT_INIT, count);

}



static int get_inbound_buffer_frontier(struct qdio_q *q)

static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;

	int count;
@@ -519,7 +518,6 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
	switch (state) {

	case SLSB_P_INPUT_PRIMED:

		inbound_primed(q, start, count);

		q->first_to_check = add_buf(start, count);

		if (atomic_sub_return(count, &q->nr_buf_used) == 0)

			qperf_inc(q, inbound_queue_full);

		if (q->irq_ptr->perf_stat_enabled)
@@ -527,7 +525,6 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
		return count;

	case SLSB_P_INPUT_ERROR:

		process_buffer_error(q, start, count);

		q->first_to_check = add_buf(start, count);

		if (atomic_sub_return(count, &q->nr_buf_used) == 0)

			qperf_inc(q, inbound_queue_full);

		if (q->irq_ptr->perf_stat_enabled)
@@ -547,11 +544,11 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
	}

}



static int qdio_inbound_q_moved(struct qdio_q *q)

static int qdio_inbound_q_moved(struct qdio_q *q, unsigned int start)

{

	int count;



	count = get_inbound_buffer_frontier(q);

	count = get_inbound_buffer_frontier(q, start);



	if (count && !is_thinint_irq(q->irq_ptr) && MACHINE_IS_LPAR)

		q->u.in.timestamp = get_tod_clock();
@@ -559,9 +556,8 @@ static int qdio_inbound_q_moved(struct qdio_q *q) 
	return count;

}



static inline int qdio_inbound_q_done(struct qdio_q *q)

static inline int qdio_inbound_q_done(struct qdio_q *q, unsigned int start)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;



	if (!atomic_read(&q->nr_buf_used))
@@ -672,17 +668,20 @@ static inline int qdio_tasklet_schedule(struct qdio_q *q) 


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);

	count = qdio_inbound_q_moved(q, start);

	if (count == 0)

		return;



	start = add_buf(start, count);

	q->first_to_check = start;

	qdio_kick_handler(q, count);



	if (!qdio_inbound_q_done(q)) {

	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))
@@ -694,7 +693,7 @@ static void __qdio_inbound_processing(struct qdio_q *q) 
	 * We need to check again to not lose initiative after

	 * resetting the ACK state.

	 */

	if (!qdio_inbound_q_done(q)) {

	if (!qdio_inbound_q_done(q, start)) {

		qperf_inc(q, tasklet_inbound_resched2);

		qdio_tasklet_schedule(q);

	}
@@ -706,9 +705,8 @@ void qdio_inbound_processing(unsigned long data) 
	__qdio_inbound_processing(q);

}



static int get_outbound_buffer_frontier(struct qdio_q *q)

static int get_outbound_buffer_frontier(struct qdio_q *q, unsigned int start)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;

	int count;
@@ -740,13 +738,11 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) 
			"out empty:%1d %02x", q->nr, count);



		atomic_sub(count, &q->nr_buf_used);

		q->first_to_check = add_buf(start, count);

		if (q->irq_ptr->perf_stat_enabled)

			account_sbals(q, count);

		return count;

	case SLSB_P_OUTPUT_ERROR:

		process_buffer_error(q, start, count);

		q->first_to_check = add_buf(start, count);

		atomic_sub(count, &q->nr_buf_used);

		if (q->irq_ptr->perf_stat_enabled)

			account_sbals_error(q, count);
@@ -773,11 +769,11 @@ static inline int qdio_outbound_q_done(struct qdio_q *q) 
	return atomic_read(&q->nr_buf_used) == 0;

}



static inline int qdio_outbound_q_moved(struct qdio_q *q)

static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start)

{

	int count;



	count = get_outbound_buffer_frontier(q);

	count = get_outbound_buffer_frontier(q, start);



	if (count)

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
@@ -829,14 +825,17 @@ retry: 


static void __qdio_outbound_processing(struct qdio_q *q)

{

	unsigned int start = q->first_to_check;

	int count;



	qperf_inc(q, tasklet_outbound);

	WARN_ON_ONCE(atomic_read(&q->nr_buf_used) < 0);



	count = qdio_outbound_q_moved(q);

	if (count)

	count = qdio_outbound_q_moved(q, start);

	if (count) {

		q->first_to_check = add_buf(start, count);

		qdio_kick_handler(q, count);

	}



	if (queue_type(q) == QDIO_ZFCP_QFMT && !pci_out_supported(q->irq_ptr) &&

	    !qdio_outbound_q_done(q))
@@ -891,6 +890,7 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq) 


static void __tiqdio_inbound_processing(struct qdio_q *q)

{

	unsigned int start = q->first_to_check;

	int count;



	qperf_inc(q, tasklet_inbound);
@@ -900,13 +900,15 @@ static void __tiqdio_inbound_processing(struct qdio_q *q) 
	/* The interrupt could be caused by a PCI request: */

	qdio_check_outbound_pci_queues(q->irq_ptr);



	count = qdio_inbound_q_moved(q);

	count = qdio_inbound_q_moved(q, start);

	if (count == 0)

		return;



	start = add_buf(start, count);

	q->first_to_check = start;

	qdio_kick_handler(q, count);



	if (!qdio_inbound_q_done(q)) {

	if (!qdio_inbound_q_done(q, start)) {

		qperf_inc(q, tasklet_inbound_resched);

		if (!qdio_tasklet_schedule(q))

			return;
@@ -917,7 +919,7 @@ static void __tiqdio_inbound_processing(struct qdio_q *q) 
	 * We need to check again to not lose initiative after

	 * resetting the ACK state.

	 */

	if (!qdio_inbound_q_done(q)) {

	if (!qdio_inbound_q_done(q, start)) {

		qperf_inc(q, tasklet_inbound_resched2);

		qdio_tasklet_schedule(q);

	}
@@ -1637,7 +1639,7 @@ int qdio_start_irq(struct ccw_device *cdev, int nr) 
	 */

	if (test_nonshared_ind(irq_ptr))

		goto rescan;

	if (!qdio_inbound_q_done(q))

	if (!qdio_inbound_q_done(q, q->first_to_check))

		goto rescan;

	return 0;
@@ -1668,11 +1670,13 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, 
{

	struct qdio_q *q;

	struct qdio_irq *irq_ptr = cdev->private->qdio_data;

	unsigned int start;

	int count;



	if (!irq_ptr)

		return -ENODEV;

	q = irq_ptr->input_qs[nr];

	start = q->first_to_check;



	/*

	 * Cannot rely on automatic sync after interrupt since queues may
@@ -1683,10 +1687,13 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, 


	qdio_check_outbound_pci_queues(irq_ptr);



	count = qdio_inbound_q_moved(q);

	count = qdio_inbound_q_moved(q, start);

	if (count == 0)

		return 0;



	start = add_buf(start, count);

	q->first_to_check = start;



	/* Note: upper-layer MUST stop processing immediately here ... */

	if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))

		return -EIO;

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