Commit 5b2ad270 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Martin Schwidefsky
Browse files

s390/qdio: limit direct access to first_to_check cursor 



Refactor all the low-level helpers to take the first_to_check cursor as
parameter, rather than accessing it directly.

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 913140e2

drivers/s390/cio/qdio_main.c

+29 −27
Original line number Diff line number Diff line
@@ -415,7 +415,8 @@ static inline void account_sbals(struct qdio_q *q, unsigned int count) 
	q->q_stats.nr_sbals[pos]++;

}



static void process_buffer_error(struct qdio_q *q, int count)

static void process_buffer_error(struct qdio_q *q, unsigned int start,

				 int count)

{

	unsigned char state = (q->is_input_q) ? SLSB_P_INPUT_NOT_INIT :

					SLSB_P_OUTPUT_NOT_INIT;
@@ -424,29 +425,29 @@ static void process_buffer_error(struct qdio_q *q, int count) 


	/* special handling for no target buffer empty */

	if (queue_type(q) == QDIO_IQDIO_QFMT && !q->is_input_q &&

	    q->sbal[q->first_to_check]->element[15].sflags == 0x10) {

	    q->sbal[start]->element[15].sflags == 0x10) {

		qperf_inc(q, target_full);

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%02x",

			      q->first_to_check);

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%02x", start);

		goto set;

	}



	DBF_ERROR("%4x BUF ERROR", SCH_NO(q));

	DBF_ERROR((q->is_input_q) ? "IN:%2d" : "OUT:%2d", q->nr);

	DBF_ERROR("FTC:%3d C:%3d", q->first_to_check, count);

	DBF_ERROR("FTC:%3d C:%3d", start, count);

	DBF_ERROR("F14:%2x F15:%2x",

		  q->sbal[q->first_to_check]->element[14].sflags,

		  q->sbal[q->first_to_check]->element[15].sflags);

		  q->sbal[start]->element[14].sflags,

		  q->sbal[start]->element[15].sflags);



set:

	/*

	 * Interrupts may be avoided as long as the error is present

	 * so change the buffer state immediately to avoid starvation.

	 */

	set_buf_states(q, q->first_to_check, state, count);

	set_buf_states(q, start, state, count);

}



static inline void inbound_primed(struct qdio_q *q, int count)

static inline void inbound_primed(struct qdio_q *q, unsigned int start,

				  int count)

{

	int new;
@@ -457,7 +458,7 @@ static inline void inbound_primed(struct qdio_q *q, int count) 
		if (!q->u.in.polling) {

			q->u.in.polling = 1;

			q->u.in.ack_count = count;

			q->u.in.ack_start = q->first_to_check;

			q->u.in.ack_start = start;

			return;

		}
@@ -465,7 +466,7 @@ static inline void inbound_primed(struct qdio_q *q, int count) 
		set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,

			       q->u.in.ack_count);

		q->u.in.ack_count = count;

		q->u.in.ack_start = q->first_to_check;

		q->u.in.ack_start = start;

		return;

	}
@@ -473,7 +474,7 @@ static inline void inbound_primed(struct qdio_q *q, int count) 
	 * ACK the newest buffer. The ACK will be removed in qdio_stop_polling

	 * or by the next inbound run.

	 */

	new = add_buf(q->first_to_check, count - 1);

	new = add_buf(start, count - 1);

	if (q->u.in.polling) {

		/* reset the previous ACK but first set the new one */

		set_buf_state(q, new, SLSB_P_INPUT_ACK);
@@ -488,11 +489,12 @@ static inline void inbound_primed(struct qdio_q *q, int count) 
	if (!count)

		return;

	/* need to change ALL buffers to get more interrupts */

	set_buf_states(q, q->first_to_check, SLSB_P_INPUT_NOT_INIT, count);

	set_buf_states(q, start, SLSB_P_INPUT_NOT_INIT, count);

}



static int get_inbound_buffer_frontier(struct qdio_q *q)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;

	int count;
@@ -510,22 +512,22 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
	 * No siga sync here, as a PCI or we after a thin interrupt

	 * already sync'ed the queues.

	 */

	count = get_buf_states(q, q->first_to_check, &state, count, 1, 0);

	count = get_buf_states(q, start, &state, count, 1, 0);

	if (!count)

		return 0;



	switch (state) {

	case SLSB_P_INPUT_PRIMED:

		inbound_primed(q, count);

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

		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)

			account_sbals(q, count);

		return count;

	case SLSB_P_INPUT_ERROR:

		process_buffer_error(q, count);

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

		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)
@@ -537,7 +539,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
		if (q->irq_ptr->perf_stat_enabled)

			q->q_stats.nr_sbal_nop++;

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in nop:%1d %#02x",

			q->nr, q->first_to_check);

			      q->nr, start);

		return 0;

	default:

		WARN_ON_ONCE(1);
@@ -559,6 +561,7 @@ static int qdio_inbound_q_moved(struct qdio_q *q) 


static inline int qdio_inbound_q_done(struct qdio_q *q)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;



	if (!atomic_read(&q->nr_buf_used))
@@ -566,7 +569,7 @@ static inline int qdio_inbound_q_done(struct qdio_q *q) 


	if (need_siga_sync(q))

		qdio_siga_sync_q(q);

	get_buf_state(q, q->first_to_check, &state, 0);

	get_buf_state(q, start, &state, 0);



	if (state == SLSB_P_INPUT_PRIMED || state == SLSB_P_INPUT_ERROR)

		/* more work coming */
@@ -584,8 +587,7 @@ static inline int qdio_inbound_q_done(struct qdio_q *q) 
	 * has (probably) not moved (see qdio_inbound_processing).

	 */

	if (get_tod_clock_fast() > q->u.in.timestamp + QDIO_INPUT_THRESHOLD) {

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in done:%02x",

			      q->first_to_check);

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in done:%02x", start);

		return 1;

	} else

		return 0;
@@ -706,6 +708,7 @@ void qdio_inbound_processing(unsigned long data) 


static int get_outbound_buffer_frontier(struct qdio_q *q)

{

	unsigned int start = q->first_to_check;

	unsigned char state = 0;

	int count;
@@ -726,8 +729,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) 
	if (!count)

		return 0;



	count = get_buf_states(q, q->first_to_check, &state, count, 0,

			       q->u.out.use_cq);

	count = get_buf_states(q, start, &state, count, 0, q->u.out.use_cq);

	if (!count)

		return 0;
@@ -738,13 +740,13 @@ 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(q->first_to_check, count);

		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, count);

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

		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);