Skip to content

Commit

Permalink
s390/qdio: rework BUG's and WARN_ON's
Browse files Browse the repository at this point in the history 
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: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
  • Loading branch information
Jan Glauber authored and Martin Schwidefsky committed Nov 23, 2012
1 parent 773bab4 commit ce1d801
Show file tree
Hide file tree
Showing 3 changed files with 12 additions and 46 deletions.
52 changes: 11 additions & 41 deletions drivers/s390/cio/qdio_main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -147,7 +146,6 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
}

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);
Expand Down Expand Up @@ -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)
Expand All @@ -199,7 +195,7 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
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;
}

Expand All @@ -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);

Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -345,7 +335,6 @@ static int qdio_siga_output(struct qdio_q *q, unsigned int *busy_bit,

/* hipersocket busy condition */
if (unlikely(*busy_bit)) {
WARN_ON(queue_type(q) != QDIO_IQDIO_QFMT || cc != 2);
retries++;

if (!start_time) {
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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:
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -912,7 +896,7 @@ static int qdio_kick_outbound_q(struct qdio_q *q, unsigned long aob)
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);
Expand Down Expand Up @@ -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;
}
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;
}
qdio_irq_check_sense(irq_ptr, irb);
cstat = irb->scsw.cmd.cstat;
Expand All @@ -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);
}
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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))
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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
Expand Down
4 changes: 1 addition & 3 deletions drivers/s390/cio/qdio_setup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) {
Expand Down
2 changes: 0 additions & 2 deletions drivers/s390/cio/qdio_thinint.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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)
Expand Down

0 comments on commit ce1d801

Please sign in to comment.