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Commit 88bf319f authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Martin Schwidefsky
Browse files

s390/qdio: split up CCQ handling for EQBS / SQBS 



Get rid of the confusing two-stage translation in a hot path, and only
handle CCQs that we anticipate for the respective command. Any
unexpected value (such as CCQ 97 (rc == 1) for SQBS) should be
considered a severe HW/driver bug, and traced as such.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: default avatarBenjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent dae55b6f

drivers/s390/cio/qdio_main.c

+33 −44
Original line number Diff line number Diff line
@@ -98,22 +98,6 @@ static inline int do_siga_output(unsigned long schid, unsigned long mask, 
	return cc;

}



static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)

{

	/* all done or next buffer state different */

	if (ccq == 0 || ccq == 32)

		return 0;

	/* no buffer processed */

	if (ccq == 97)

		return 1;

	/* not all buffers processed */

	if (ccq == 96)

		return 2;

	/* notify devices immediately */

	DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);

	return -EIO;

}



/**

 * qdio_do_eqbs - extract buffer states for QEBSM

 * @q: queue to manipulate
@@ -128,7 +112,7 @@ static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq) 
static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,

			int start, int count, int auto_ack)

{

	int rc, tmp_count = count, tmp_start = start, nr = q->nr;

	int tmp_count = count, tmp_start = start, nr = q->nr;

	unsigned int ccq = 0;



	qperf_inc(q, eqbs);
@@ -138,28 +122,31 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state, 
again:

	ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,

		      auto_ack);

	rc = qdio_check_ccq(q, ccq);

	if (!rc)

		return count - tmp_count;



	if (rc == 1) {

		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);

		goto again;

	}



	if (rc == 2) {

	switch (ccq) {

	case 0:

	case 32:

		/* all done, or next buffer state different */

		return count - tmp_count;

	case 96:

		/* not all buffers processed */

		qperf_inc(q, eqbs_partial);

		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS part:%02x",

			tmp_count);

		return count - tmp_count;

	}



	case 97:

		/* no buffer processed */

		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);

		goto again;

	default:

		DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);

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

		DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);

	q->handler(q->irq_ptr->cdev, QDIO_ERROR_GET_BUF_STATE,

		   q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);

		q->handler(q->irq_ptr->cdev, QDIO_ERROR_GET_BUF_STATE, q->nr,

			   q->first_to_kick, count, q->irq_ptr->int_parm);

		return 0;

	}

}



/**

 * qdio_do_sqbs - set buffer states for QEBSM
@@ -178,7 +165,6 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start, 
	unsigned int ccq = 0;

	int tmp_count = count, tmp_start = start;

	int nr = q->nr;

	int rc;



	if (!count)

		return 0;
@@ -188,24 +174,27 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start, 
		nr += q->irq_ptr->nr_input_qs;

again:

	ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);

	rc = qdio_check_ccq(q, ccq);

	if (!rc) {



	switch (ccq) {

	case 0:

	case 32:

		/* all done, or active buffer adapter-owned */

		WARN_ON_ONCE(tmp_count);

		return count - tmp_count;

	}



	if (rc == 1 || rc == 2) {

	case 96:

		/* not all buffers processed */

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "SQBS again:%2d", ccq);

		qperf_inc(q, sqbs_partial);

		goto again;

	}



	default:

		DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);

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

		DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);

	q->handler(q->irq_ptr->cdev, QDIO_ERROR_SET_BUF_STATE,

		   q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);

		q->handler(q->irq_ptr->cdev, QDIO_ERROR_SET_BUF_STATE, q->nr,

			   q->first_to_kick, count, q->irq_ptr->int_parm);

		return 0;

	}

}



/*

 * Returns number of examined buffers and their common state in *state.