From 6bcf74e2d15c8339f0e4a0f0613638873098e85f Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Mon, 8 Apr 2019 13:32:12 +0200 Subject: [PATCH] s390/qdio: consolidate index tracking for queue scan qdio.ko offers a small number of high-level functions to drive the scanning of a QDIO queue for ready-to-process SBALs: qdio_get_next_buffers(), __[ti]qdio_inbound_processing() and __qdio_outbound_processing(). Let each of those functions maintain the 'start' index for their current scan, and pass it to lower-level helpers as needed. This improves the code's overall layering, and allows us to eliminate the additional first_to_kick cursor with a follow-on patch. Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_main.c | 55 +++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 24 deletions(-) diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 045f2aa..cfce255 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -492,9 +492,8 @@ static inline void inbound_primed(struct qdio_q *q, unsigned int start, set_buf_states(q, start, SLSB_P_INPUT_NOT_INIT, count); } -static int get_inbound_buffer_frontier(struct qdio_q *q) +static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start) { - unsigned int start = q->first_to_check; unsigned char state = 0; int count; @@ -519,7 +518,6 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) switch (state) { case SLSB_P_INPUT_PRIMED: inbound_primed(q, start, count); - q->first_to_check = add_buf(start, count); if (atomic_sub_return(count, &q->nr_buf_used) == 0) qperf_inc(q, inbound_queue_full); if (q->irq_ptr->perf_stat_enabled) @@ -527,7 +525,6 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) return count; case SLSB_P_INPUT_ERROR: process_buffer_error(q, start, count); - q->first_to_check = add_buf(start, count); if (atomic_sub_return(count, &q->nr_buf_used) == 0) qperf_inc(q, inbound_queue_full); if (q->irq_ptr->perf_stat_enabled) @@ -547,11 +544,11 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) } } -static int qdio_inbound_q_moved(struct qdio_q *q) +static int qdio_inbound_q_moved(struct qdio_q *q, unsigned int start) { int count; - count = get_inbound_buffer_frontier(q); + count = get_inbound_buffer_frontier(q, start); if (count && !is_thinint_irq(q->irq_ptr) && MACHINE_IS_LPAR) q->u.in.timestamp = get_tod_clock(); @@ -559,9 +556,8 @@ static int qdio_inbound_q_moved(struct qdio_q *q) return count; } -static inline int qdio_inbound_q_done(struct qdio_q *q) +static inline int qdio_inbound_q_done(struct qdio_q *q, unsigned int start) { - unsigned int start = q->first_to_check; unsigned char state = 0; if (!atomic_read(&q->nr_buf_used)) @@ -672,17 +668,20 @@ static inline int qdio_tasklet_schedule(struct qdio_q *q) static void __qdio_inbound_processing(struct qdio_q *q) { + unsigned int start = q->first_to_check; int count; qperf_inc(q, tasklet_inbound); - count = qdio_inbound_q_moved(q); + count = qdio_inbound_q_moved(q, start); if (count == 0) return; + start = add_buf(start, count); + q->first_to_check = start; qdio_kick_handler(q, count); - if (!qdio_inbound_q_done(q)) { + if (!qdio_inbound_q_done(q, start)) { /* means poll time is not yet over */ qperf_inc(q, tasklet_inbound_resched); if (!qdio_tasklet_schedule(q)) @@ -694,7 +693,7 @@ static void __qdio_inbound_processing(struct qdio_q *q) * We need to check again to not lose initiative after * resetting the ACK state. */ - if (!qdio_inbound_q_done(q)) { + if (!qdio_inbound_q_done(q, start)) { qperf_inc(q, tasklet_inbound_resched2); qdio_tasklet_schedule(q); } @@ -706,9 +705,8 @@ void qdio_inbound_processing(unsigned long data) __qdio_inbound_processing(q); } -static int get_outbound_buffer_frontier(struct qdio_q *q) +static int get_outbound_buffer_frontier(struct qdio_q *q, unsigned int start) { - unsigned int start = q->first_to_check; unsigned char state = 0; int count; @@ -740,13 +738,11 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) "out empty:%1d %02x", q->nr, count); atomic_sub(count, &q->nr_buf_used); - q->first_to_check = add_buf(start, count); if (q->irq_ptr->perf_stat_enabled) account_sbals(q, count); return count; case SLSB_P_OUTPUT_ERROR: process_buffer_error(q, start, count); - q->first_to_check = add_buf(start, count); atomic_sub(count, &q->nr_buf_used); if (q->irq_ptr->perf_stat_enabled) account_sbals_error(q, count); @@ -773,11 +769,11 @@ static inline int qdio_outbound_q_done(struct qdio_q *q) return atomic_read(&q->nr_buf_used) == 0; } -static inline int qdio_outbound_q_moved(struct qdio_q *q) +static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start) { int count; - count = get_outbound_buffer_frontier(q); + count = get_outbound_buffer_frontier(q, start); if (count) DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr); @@ -829,14 +825,17 @@ retry: static void __qdio_outbound_processing(struct qdio_q *q) { + unsigned int start = q->first_to_check; int count; qperf_inc(q, tasklet_outbound); WARN_ON_ONCE(atomic_read(&q->nr_buf_used) < 0); - count = qdio_outbound_q_moved(q); - if (count) + count = qdio_outbound_q_moved(q, start); + if (count) { + q->first_to_check = add_buf(start, count); qdio_kick_handler(q, count); + } if (queue_type(q) == QDIO_ZFCP_QFMT && !pci_out_supported(q->irq_ptr) && !qdio_outbound_q_done(q)) @@ -891,6 +890,7 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq) static void __tiqdio_inbound_processing(struct qdio_q *q) { + unsigned int start = q->first_to_check; int count; qperf_inc(q, tasklet_inbound); @@ -900,13 +900,15 @@ static void __tiqdio_inbound_processing(struct qdio_q *q) /* The interrupt could be caused by a PCI request: */ qdio_check_outbound_pci_queues(q->irq_ptr); - count = qdio_inbound_q_moved(q); + count = qdio_inbound_q_moved(q, start); if (count == 0) return; + start = add_buf(start, count); + q->first_to_check = start; qdio_kick_handler(q, count); - if (!qdio_inbound_q_done(q)) { + if (!qdio_inbound_q_done(q, start)) { qperf_inc(q, tasklet_inbound_resched); if (!qdio_tasklet_schedule(q)) return; @@ -917,7 +919,7 @@ static void __tiqdio_inbound_processing(struct qdio_q *q) * We need to check again to not lose initiative after * resetting the ACK state. */ - if (!qdio_inbound_q_done(q)) { + if (!qdio_inbound_q_done(q, start)) { qperf_inc(q, tasklet_inbound_resched2); qdio_tasklet_schedule(q); } @@ -1637,7 +1639,7 @@ int qdio_start_irq(struct ccw_device *cdev, int nr) */ if (test_nonshared_ind(irq_ptr)) goto rescan; - if (!qdio_inbound_q_done(q)) + if (!qdio_inbound_q_done(q, q->first_to_check)) goto rescan; return 0; @@ -1668,11 +1670,13 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, { struct qdio_q *q; struct qdio_irq *irq_ptr = cdev->private->qdio_data; + unsigned int start; int count; if (!irq_ptr) return -ENODEV; q = irq_ptr->input_qs[nr]; + start = q->first_to_check; /* * Cannot rely on automatic sync after interrupt since queues may @@ -1683,10 +1687,13 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, qdio_check_outbound_pci_queues(irq_ptr); - count = qdio_inbound_q_moved(q); + count = qdio_inbound_q_moved(q, start); if (count == 0) return 0; + start = add_buf(start, count); + q->first_to_check = start; + /* Note: upper-layer MUST stop processing immediately here ... */ if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)) return -EIO; -- 2.7.4