path: root/drivers/s390
diff options
authorJulian Wiedmann <jwi@linux.ibm.com>2020-04-21 10:38:18 +0200
committerVasily Gorbik <gor@linux.ibm.com>2020-05-20 10:22:50 +0200
commitc70d82e96644bd660ea53209c19f75cd86c560d6 (patch)
treea36f9bbd30c61b5ef70ecd1b509b1c6dd43aa473 /drivers/s390
parent1db85d0e73f3b017c63afcdec1197d4d0736c362 (diff)
s390/qdio: add IRQ reduction for error SBALs
SBALs in PRIMED or ERROR state represent new work on the Input Queue. But while inbound_primed() does all sorts of ACK management for new PRIMED work, the same handling is currently missing for ERROR work. In particular the path for ERROR work doesn't clear up _old_ ACKs. Treat ERROR work the same as PRIMED work, but consider that the QEBSM auto-ACK feature doesn't apply here. So we need to set the ACK manually, as if it was a non-QEBSM device. Note that this doesn't aspire to actually improve performance, the main goal is to just unify the code paths and have consistent behaviour. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'drivers/s390')
1 files changed, 11 insertions, 12 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index eea3032e68c0..f5596265b053 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -438,15 +438,12 @@ static void process_buffer_error(struct qdio_q *q, unsigned int start,
-static inline void inbound_primed(struct qdio_q *q, unsigned int start,
- int count)
+static inline void inbound_handle_work(struct qdio_q *q, unsigned int start,
+ int count, bool auto_ack)
int new;
- DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim:%1d %02x", q->nr, count);
- /* for QEBSM the ACK was already set by EQBS */
- if (is_qebsm(q)) {
+ if (auto_ack) {
if (!q->u.in.ack_count) {
q->u.in.ack_count = count;
q->u.in.ack_start = start;
@@ -507,19 +504,21 @@ static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start)
switch (state) {
- inbound_primed(q, start, count);
+ DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim:%1d %02x", q->nr,
+ count);
+ inbound_handle_work(q, start, count, is_qebsm(q));
if (atomic_sub_return(count, &q->nr_buf_used) == 0)
qperf_inc(q, inbound_queue_full);
if (q->irq_ptr->perf_stat_enabled)
account_sbals(q, count);
return count;
+ DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in err:%1d %02x", q->nr,
+ count);
process_buffer_error(q, start, count);
- /*
- * Interrupts may be avoided as long as the error is present
- * so change the buffer state immediately to avoid starvation.
- */
- set_buf_states(q, start, SLSB_P_INPUT_NOT_INIT, count);
+ inbound_handle_work(q, start, count, false);
if (atomic_sub_return(count, &q->nr_buf_used) == 0)
qperf_inc(q, inbound_queue_full);
if (q->irq_ptr->perf_stat_enabled)

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