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authorJulian Wiedmann <jwi@linux.ibm.com>2019-11-25 14:18:29 +0100
committerVasily Gorbik <gor@linux.ibm.com>2020-02-10 12:49:35 +0100
commit0b6f499022b6a87d04f56edd2bf863ea76923206 (patch)
treeedae4fea767436a891a55f09442fb2e2fbcb0681 /drivers
parentfcd98d4002539f1e381916fc1b6648938c1eac76 (diff)
downloadlinux-0b6f499022b6a87d04f56edd2bf863ea76923206.tar.bz2
s390/qdio: simplify ACK tracking
Current code uses a 'polling' flag to keep track of whether an Input Queue has any ACKed SBALs. QEBSM devices might have multiple ACKed SBALs, and those are tracked separately with 'ack_count'. By also setting ack_count for non-QEBSM devices (to a fixed value of 1), we can use 'ack_count != 0' as replacement for the polling flag. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/s390/cio/qdio.h4
-rw-r--r--drivers/s390/cio/qdio_debug.c5
-rw-r--r--drivers/s390/cio/qdio_main.c29
3 files changed, 14 insertions, 24 deletions
diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index 4b0798472643..ff74eb5fce50 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -182,11 +182,9 @@ enum qdio_queue_irq_states {
};
struct qdio_input_q {
- /* input buffer acknowledgement flag */
- int polling;
/* first ACK'ed buffer */
int ack_start;
- /* how much sbals are acknowledged with qebsm */
+ /* how many SBALs are acknowledged */
int ack_count;
/* last time of noticing incoming data */
u64 timestamp;
diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 35410e6eda2e..9c0370b27426 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -124,9 +124,8 @@ static int qstat_show(struct seq_file *m, void *v)
seq_printf(m, "nr_used: %d ftc: %d\n",
atomic_read(&q->nr_buf_used), q->first_to_check);
if (q->is_input_q) {
- seq_printf(m, "polling: %d ack start: %d ack count: %d\n",
- q->u.in.polling, q->u.in.ack_start,
- q->u.in.ack_count);
+ seq_printf(m, "ack start: %d ack count: %d\n",
+ q->u.in.ack_start, q->u.in.ack_count);
seq_printf(m, "DSCI: %x IRQs disabled: %u\n",
*(u8 *)q->irq_ptr->dsci,
test_bit(QDIO_QUEUE_IRQS_DISABLED,
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index f8b897b7e78b..3475317c42e5 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -393,19 +393,15 @@ int debug_get_buf_state(struct qdio_q *q, unsigned int bufnr,
static inline void qdio_stop_polling(struct qdio_q *q)
{
- if (!q->u.in.polling)
+ if (!q->u.in.ack_count)
return;
- q->u.in.polling = 0;
qperf_inc(q, stop_polling);
/* show the card that we are not polling anymore */
- if (is_qebsm(q)) {
- set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
- q->u.in.ack_count);
- q->u.in.ack_count = 0;
- } else
- set_buf_state(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT);
+ set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
+ q->u.in.ack_count);
+ q->u.in.ack_count = 0;
}
static inline void account_sbals(struct qdio_q *q, unsigned int count)
@@ -451,8 +447,7 @@ static inline void inbound_primed(struct qdio_q *q, unsigned int start,
/* for QEBSM the ACK was already set by EQBS */
if (is_qebsm(q)) {
- if (!q->u.in.polling) {
- q->u.in.polling = 1;
+ if (!q->u.in.ack_count) {
q->u.in.ack_count = count;
q->u.in.ack_start = start;
return;
@@ -471,12 +466,12 @@ static inline void inbound_primed(struct qdio_q *q, unsigned int start,
* or by the next inbound run.
*/
new = add_buf(start, count - 1);
- if (q->u.in.polling) {
+ if (q->u.in.ack_count) {
/* reset the previous ACK but first set the new one */
set_buf_state(q, new, SLSB_P_INPUT_ACK);
set_buf_state(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT);
} else {
- q->u.in.polling = 1;
+ q->u.in.ack_count = 1;
set_buf_state(q, new, SLSB_P_INPUT_ACK);
}
@@ -1479,13 +1474,12 @@ static int handle_inbound(struct qdio_q *q, unsigned int callflags,
qperf_inc(q, inbound_call);
- if (!q->u.in.polling)
+ if (!q->u.in.ack_count)
goto set;
/* protect against stop polling setting an ACK for an emptied slsb */
if (count == QDIO_MAX_BUFFERS_PER_Q) {
/* overwriting everything, just delete polling status */
- q->u.in.polling = 0;
q->u.in.ack_count = 0;
goto set;
} else if (buf_in_between(q->u.in.ack_start, bufnr, count)) {
@@ -1495,15 +1489,14 @@ static int handle_inbound(struct qdio_q *q, unsigned int callflags,
diff = sub_buf(diff, q->u.in.ack_start);
q->u.in.ack_count -= diff;
if (q->u.in.ack_count <= 0) {
- q->u.in.polling = 0;
q->u.in.ack_count = 0;
goto set;
}
q->u.in.ack_start = add_buf(q->u.in.ack_start, diff);
+ } else {
+ /* the only ACK will be deleted */
+ q->u.in.ack_count = 0;
}
- else
- /* the only ACK will be deleted, so stop polling */
- q->u.in.polling = 0;
}
set: