Commit ce1d8014 authored by Jan Glauber's avatar Jan Glauber Committed by Martin Schwidefsky
Browse files

s390/qdio: rework BUG's and WARN_ON's 

Remove or replace BUG/BUG_ON where possible and convert WARN_ON
to WARN_ON_ONCE if they can occur freqeuently as pointed out by:
https://lkml.org/lkml/2012/9/27/461



Checks have been removed if:
- the error condition leads to a hardware error which gets logged
  and in most cases stops the device
- the error condition is a null pointer access
- the error condition is just pointless or already handled at
  another location

Signed-off-by: default avatarJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 773bab4a

drivers/s390/cio/qdio_main.c

+11 −41
Original line number Diff line number Diff line
@@ -129,7 +129,6 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state, 
	int rc, tmp_count = count, tmp_start = start, nr = q->nr, retried = 0;

	unsigned int ccq = 0;



	BUG_ON(!q->irq_ptr->sch_token);

	qperf_inc(q, eqbs);



	if (!q->is_input_q)
@@ -147,7 +146,6 @@ again: 
	}



	if (rc == 2) {

		BUG_ON(tmp_count == count);

		qperf_inc(q, eqbs_partial);

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

			tmp_count);
@@ -189,8 +187,6 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start, 


	if (!count)

		return 0;



	BUG_ON(!q->irq_ptr->sch_token);

	qperf_inc(q, sqbs);



	if (!q->is_input_q)
@@ -199,7 +195,7 @@ again: 
	ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);

	rc = qdio_check_ccq(q, ccq);

	if (!rc) {

		WARN_ON(tmp_count);

		WARN_ON_ONCE(tmp_count);

		return count - tmp_count;

	}
@@ -224,9 +220,6 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr, 
	unsigned char __state = 0;

	int i;



	BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);

	BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);



	if (is_qebsm(q))

		return qdio_do_eqbs(q, state, bufnr, count, auto_ack);
@@ -258,9 +251,6 @@ static inline int set_buf_states(struct qdio_q *q, int bufnr, 
{

	int i;



	BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);

	BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);



	if (is_qebsm(q))

		return qdio_do_sqbs(q, state, bufnr, count);
@@ -345,7 +335,6 @@ again: 


	/* hipersocket busy condition */

	if (unlikely(*busy_bit)) {

		WARN_ON(queue_type(q) != QDIO_IQDIO_QFMT || cc != 2);

		retries++;



		if (!start_time) {
@@ -559,7 +548,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) 
		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in nop");

		break;

	default:

		BUG();

		WARN_ON_ONCE(1);

	}

out:

	return q->first_to_check;
@@ -678,12 +667,10 @@ static inline void qdio_handle_aobs(struct qdio_q *q, int start, int count) 
			if (aob == NULL)

				continue;



			BUG_ON(q->u.out.sbal_state == NULL);

			q->u.out.sbal_state[b].flags |=

				QDIO_OUTBUF_STATE_FLAG_PENDING;

			q->u.out.aobs[b] = NULL;

		} else if (state == SLSB_P_OUTPUT_EMPTY) {

			BUG_ON(q->u.out.sbal_state == NULL);

			q->u.out.sbal_state[b].aob = NULL;

		}

		b = next_buf(b);
@@ -703,12 +690,11 @@ static inline unsigned long qdio_aob_for_buffer(struct qdio_output_q *q, 
		q->aobs[bufnr] = aob;

	}

	if (q->aobs[bufnr]) {

		BUG_ON(q->sbal_state == NULL);

		q->sbal_state[bufnr].flags = QDIO_OUTBUF_STATE_FLAG_NONE;

		q->sbal_state[bufnr].aob = q->aobs[bufnr];

		q->aobs[bufnr]->user1 = (u64) q->sbal_state[bufnr].user;

		phys_aob = virt_to_phys(q->aobs[bufnr]);

		BUG_ON(phys_aob & 0xFF);

		WARN_ON_ONCE(phys_aob & 0xFF);

	}



out:
@@ -809,8 +795,6 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) 
		goto out;



	switch (state) {

	case SLSB_P_OUTPUT_PENDING:

		BUG();

	case SLSB_P_OUTPUT_EMPTY:

		/* the adapter got it */

		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr,
@@ -840,7 +824,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) 
	case SLSB_P_OUTPUT_HALTED:

		break;

	default:

		BUG();

		WARN_ON_ONCE(1);

	}



out:
@@ -912,7 +896,7 @@ retry: 
static void __qdio_outbound_processing(struct qdio_q *q)

{

	qperf_inc(q, tasklet_outbound);

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

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



	if (qdio_outbound_q_moved(q))

		qdio_kick_handler(q);
@@ -1138,16 +1122,10 @@ void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm, 
		irq_ptr->perf_stat.qdio_int++;



	if (IS_ERR(irb)) {

		switch (PTR_ERR(irb)) {

		case -EIO:

		DBF_ERROR("%4x IO error", irq_ptr->schid.sch_no);

		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);

		wake_up(&cdev->private->wait_q);

		return;

		default:

			WARN_ON(1);

			return;

		}

	}

	qdio_irq_check_sense(irq_ptr, irb);

	cstat = irb->scsw.cmd.cstat;
@@ -1173,7 +1151,7 @@ void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm, 
	case QDIO_IRQ_STATE_STOPPED:

		break;

	default:

		WARN_ON(1);

		WARN_ON_ONCE(1);

	}

	wake_up(&cdev->private->wait_q);

}
@@ -1227,7 +1205,7 @@ int qdio_shutdown(struct ccw_device *cdev, int how) 
	if (!irq_ptr)

		return -ENODEV;



	BUG_ON(irqs_disabled());

	WARN_ON_ONCE(irqs_disabled());

	DBF_EVENT("qshutdown:%4x", cdev->private->schid.sch_no);



	mutex_lock(&irq_ptr->setup_mutex);
@@ -1358,7 +1336,6 @@ int qdio_allocate(struct qdio_initialize *init_data) 
	irq_ptr->qdr = (struct qdr *) get_zeroed_page(GFP_KERNEL | GFP_DMA);

	if (!irq_ptr->qdr)

		goto out_rel;

	WARN_ON((unsigned long)irq_ptr->qdr & 0xfff);



	if (qdio_allocate_qs(irq_ptr, init_data->no_input_qs,

			     init_data->no_output_qs))
@@ -1597,9 +1574,7 @@ static int handle_inbound(struct qdio_q *q, unsigned int callflags, 


set:

	count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);



	used = atomic_add_return(count, &q->nr_buf_used) - count;

	BUG_ON(used + count > QDIO_MAX_BUFFERS_PER_Q);



	if (need_siga_in(q))

		return qdio_siga_input(q);
@@ -1624,7 +1599,6 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags, 


	count = set_buf_states(q, bufnr, SLSB_CU_OUTPUT_PRIMED, count);

	used = atomic_add_return(count, &q->nr_buf_used);

	BUG_ON(used > QDIO_MAX_BUFFERS_PER_Q);



	if (used == QDIO_MAX_BUFFERS_PER_Q)

		qperf_inc(q, outbound_queue_full);
@@ -1678,7 +1652,6 @@ int do_QDIO(struct ccw_device *cdev, unsigned int callflags, 
{

	struct qdio_irq *irq_ptr;





	if (bufnr >= QDIO_MAX_BUFFERS_PER_Q || count > QDIO_MAX_BUFFERS_PER_Q)

		return -EINVAL;
@@ -1721,8 +1694,6 @@ int qdio_start_irq(struct ccw_device *cdev, int nr) 
		return -ENODEV;

	q = irq_ptr->input_qs[nr];



	WARN_ON(queue_irqs_enabled(q));



	clear_nonshared_ind(irq_ptr);

	qdio_stop_polling(q);

	clear_bit(QDIO_QUEUE_IRQS_DISABLED, &q->u.in.queue_irq_state);
@@ -1769,7 +1740,6 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, 
	if (!irq_ptr)

		return -ENODEV;

	q = irq_ptr->input_qs[nr];

	WARN_ON(queue_irqs_enabled(q));



	/*

	 * Cannot rely on automatic sync after interrupt since queues may

drivers/s390/cio/qdio_setup.c

+1 −3
Original line number Diff line number Diff line
@@ -140,10 +140,8 @@ static void setup_storage_lists(struct qdio_q *q, struct qdio_irq *irq_ptr, 
	q->sl = (struct sl *)((char *)q->slib + PAGE_SIZE / 2);



	/* fill in sbal */

	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; j++) {

	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; j++)

		q->sbal[j] = *sbals_array++;

		BUG_ON((unsigned long)q->sbal[j] & 0xff);

	}



	/* fill in slib */

	if (i > 0) {

drivers/s390/cio/qdio_thinint.c

+0 −2
Original line number Diff line number Diff line
@@ -73,7 +73,6 @@ static void put_indicator(u32 *addr) 
void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)

{

	mutex_lock(&tiq_list_lock);

	BUG_ON(irq_ptr->nr_input_qs < 1);

	list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);

	mutex_unlock(&tiq_list_lock);

	xchg(irq_ptr->dsci, 1 << 7);
@@ -83,7 +82,6 @@ void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) 
{

	struct qdio_q *q;



	BUG_ON(irq_ptr->nr_input_qs < 1);

	q = irq_ptr->input_qs[0];

	/* if establish triggered an error */

	if (!q || !q->entry.prev || !q->entry.next)

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