Commit cafebf86 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Vasily Gorbik
Browse files

s390/qdio: remove q->first_to_kick 



q->first_to_kick is obsolete, and can be replaced by q->first_to_check.

Both cursors start off at 0. Out of the three code paths that update
first_to_check, the qdio_inspect_queue() path is irrelevant as it
doesn't even touch first_to_kick anymore.
This leaves us with the two tasklet-driven code paths. Here any update
to first_to_check is followed by a call to qdio_kick_handler(), which
advances first_to_kick by the same amount.

So the two cursors will differ only for a tiny moment. Drivers have no
way of deterministically observing this difference, and thus it doesn't
matter which of the cursors we use for reporting an error to q->handler.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 0623b7dd

drivers/s390/cio/qdio.h

+0 −3
Original line number Diff line number Diff line
@@ -221,9 +221,6 @@ struct qdio_q { 
	 */

	int first_to_check;



	/* beginning position for calling the program */

	int first_to_kick;



	/* number of buffers in use by the adapter */

	atomic_t nr_buf_used;

drivers/s390/cio/qdio_main.c

+7 −11
Original line number Diff line number Diff line
@@ -143,7 +143,7 @@ again: 
		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->first_to_check, count, q->irq_ptr->int_parm);

		return 0;

	}

}
@@ -191,7 +191,7 @@ again: 
		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->first_to_check, count, q->irq_ptr->int_parm);

		return 0;

	}

}
@@ -622,10 +622,9 @@ static inline unsigned long qdio_aob_for_buffer(struct qdio_output_q *q, 
	return phys_aob;

}



static void qdio_kick_handler(struct qdio_q *q, unsigned int count)

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

			      unsigned int count)

{

	int start = q->first_to_kick;



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

		return;
@@ -642,7 +641,6 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int count) 
		   q->irq_ptr->int_parm);



	/* for the next time */

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

	q->qdio_error = 0;

}
@@ -666,9 +664,9 @@ static void __qdio_inbound_processing(struct qdio_q *q) 
	if (count == 0)

		return;



	qdio_kick_handler(q, start, count);

	start = add_buf(start, count);

	q->first_to_check = start;

	qdio_kick_handler(q, count);



	if (!qdio_inbound_q_done(q, start)) {

		/* means poll time is not yet over */
@@ -824,7 +822,7 @@ static void __qdio_outbound_processing(struct qdio_q *q) 
	count = qdio_outbound_q_moved(q, start);

	if (count) {

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

		qdio_kick_handler(q, count);

		qdio_kick_handler(q, start, count);

	}



	if (queue_type(q) == QDIO_ZFCP_QFMT && !pci_out_supported(q->irq_ptr) &&
@@ -945,7 +943,6 @@ static void qdio_handle_activate_check(struct ccw_device *cdev, 
{

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

	struct qdio_q *q;

	int count;



	DBF_ERROR("%4x ACT CHECK", irq_ptr->schid.sch_no);

	DBF_ERROR("intp :%lx", intparm);
@@ -960,9 +957,8 @@ static void qdio_handle_activate_check(struct ccw_device *cdev, 
		goto no_handler;

	}



	count = sub_buf(q->first_to_check, q->first_to_kick);

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

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

		   q->nr, q->first_to_check, 0, irq_ptr->int_parm);

no_handler:

	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);

	/*

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