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authorJulian Wiedmann <jwi@linux.ibm.com>2019-08-23 11:48:47 +0200
committerDavid S. Miller <davem@davemloft.net>2019-08-24 16:39:18 -0700
commit7c47f5afdeef763599f1ae22d29b8c3904c58315 (patch)
tree0aa9265576bf9f2fb6fc67307a6200b0fd2809d0 /drivers/s390/cio/qdio_main.c
parentbnxt_en: Fix allocation of zero statistics block size regression. (diff)
downloadlinux-dev-7c47f5afdeef763599f1ae22d29b8c3904c58315.tar.xz
linux-dev-7c47f5afdeef763599f1ae22d29b8c3904c58315.zip
s390/qdio: enable drivers to poll for Output completions
While commit d36deae75011 ("qdio: extend API to allow polling") enhanced the qdio layer so that drivers can poll their Input Queues, we don't have the corresponding infrastructure for Output Queues yet. Factor out a helper that scans a single QDIO Queue, so that qeth can implement TX NAPI on top of it. While doing so, remove the duplicated tracking of the next-to-scan index (q->first_to_check vs q->first_to_kick) in this code path. qdio_handle_aobs() needs to move slightly upwards in the code hierarchy, so that it's still called from the polling path. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--drivers/s390/cio/qdio_main.c64
1 files changed, 43 insertions, 21 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 4142c85e77d8..5efba0d29190 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -647,8 +647,6 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int count)
qperf_inc(q, outbound_handler);
DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "koh: s:%02x c:%02x",
start, count);
- if (q->u.out.use_cq)
- qdio_handle_aobs(q, start, count);
}
q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count,
@@ -774,8 +772,11 @@ static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start)
count = get_outbound_buffer_frontier(q, start);
- if (count)
+ if (count) {
DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
+ if (q->u.out.use_cq)
+ qdio_handle_aobs(q, start, count);
+ }
return count;
}
@@ -1655,6 +1656,44 @@ rescan:
}
EXPORT_SYMBOL(qdio_start_irq);
+static int __qdio_inspect_queue(struct qdio_q *q, unsigned int *bufnr,
+ unsigned int *error)
+{
+ unsigned int start = q->first_to_check;
+ int count;
+
+ count = q->is_input_q ? qdio_inbound_q_moved(q, start) :
+ qdio_outbound_q_moved(q, start);
+ if (count == 0)
+ return 0;
+
+ *bufnr = start;
+ *error = q->qdio_error;
+
+ /* for the next time */
+ q->first_to_check = add_buf(start, count);
+ q->qdio_error = 0;
+
+ return count;
+}
+
+int qdio_inspect_queue(struct ccw_device *cdev, unsigned int nr, bool is_input,
+ unsigned int *bufnr, unsigned int *error)
+{
+ struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+ struct qdio_q *q;
+
+ if (!irq_ptr)
+ return -ENODEV;
+ q = is_input ? irq_ptr->input_qs[nr] : irq_ptr->output_qs[nr];
+
+ if (need_siga_sync(q))
+ qdio_siga_sync_q(q);
+
+ return __qdio_inspect_queue(q, bufnr, error);
+}
+EXPORT_SYMBOL_GPL(qdio_inspect_queue);
+
/**
* qdio_get_next_buffers - process input buffers
* @cdev: associated ccw_device for the qdio subchannel
@@ -1672,13 +1711,10 @@ 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
@@ -1689,25 +1725,11 @@ 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, 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;
- *bufnr = q->first_to_kick;
- *error = q->qdio_error;
-
- /* for the next time */
- q->first_to_kick = add_buf(q->first_to_kick, count);
- q->qdio_error = 0;
-
- return count;
+ return __qdio_inspect_queue(q, bufnr, error);
}
EXPORT_SYMBOL(qdio_get_next_buffers);