RDMA/cxgb4: Fix QP flush logic
This patch makes following fixes in QP flush logic:
- correctly flushes unsignaled WRs followed by a signaled WR
- supports for flushing a CQ bound to multiple QPs
- resets cidx_flush if a active queue starts getting HW CQEs again
- marks WQ in error when we leave RTS. This was only being done for
user queues, but we need it for kernel queues too so that
post_send/post_recv will start returning the appropriate error
synchronously
- eats unsignaled read resp CQEs. HW always inserts CQEs so we must
silently discard them if the read work request was unsignaled.
- handles QP flushes with pending SW CQEs. The flush and out of order
completion logic has a bug where if out of order completions are
flushed but not yet polled by the consumer and the qp is then
flushed then we end up inserting duplicate completions.
- c4iw_flush_sq() should only flush wrs that have not already been
flushed. Since we already track where in the SQ we've flushed via
sq.cidx_flush, just start at that point and flush any remaining.
This bug only caused a problem in the presence of unsignaled work
requests.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
[ Fixed sparse warning due to htonl/ntohl confusion. - Roland ]
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/cxgb4/cq.c b/drivers/infiniband/hw/cxgb4/cq.c
index 0f1607c..6657390 100644
--- a/drivers/infiniband/hw/cxgb4/cq.c
+++ b/drivers/infiniband/hw/cxgb4/cq.c
@@ -225,43 +225,186 @@
t4_swcq_produce(cq);
}
-int c4iw_flush_sq(struct t4_wq *wq, struct t4_cq *cq, int count)
+static void advance_oldest_read(struct t4_wq *wq);
+
+int c4iw_flush_sq(struct c4iw_qp *qhp)
{
int flushed = 0;
- struct t4_swsqe *swsqe = &wq->sq.sw_sq[wq->sq.cidx + count];
- int in_use = wq->sq.in_use - count;
+ struct t4_wq *wq = &qhp->wq;
+ struct c4iw_cq *chp = to_c4iw_cq(qhp->ibqp.send_cq);
+ struct t4_cq *cq = &chp->cq;
+ int idx;
+ struct t4_swsqe *swsqe;
+ int error = (qhp->attr.state != C4IW_QP_STATE_CLOSING &&
+ qhp->attr.state != C4IW_QP_STATE_IDLE);
- BUG_ON(in_use < 0);
- while (in_use--) {
- swsqe->signaled = 0;
- insert_sq_cqe(wq, cq, swsqe);
- swsqe++;
- if (swsqe == (wq->sq.sw_sq + wq->sq.size))
- swsqe = wq->sq.sw_sq;
- flushed++;
+ if (wq->sq.flush_cidx == -1)
+ wq->sq.flush_cidx = wq->sq.cidx;
+ idx = wq->sq.flush_cidx;
+ BUG_ON(idx >= wq->sq.size);
+ while (idx != wq->sq.pidx) {
+ if (error) {
+ swsqe = &wq->sq.sw_sq[idx];
+ BUG_ON(swsqe->flushed);
+ swsqe->flushed = 1;
+ insert_sq_cqe(wq, cq, swsqe);
+ if (wq->sq.oldest_read == swsqe) {
+ BUG_ON(swsqe->opcode != FW_RI_READ_REQ);
+ advance_oldest_read(wq);
+ }
+ flushed++;
+ } else {
+ t4_sq_consume(wq);
+ }
+ if (++idx == wq->sq.size)
+ idx = 0;
}
+ wq->sq.flush_cidx += flushed;
+ if (wq->sq.flush_cidx >= wq->sq.size)
+ wq->sq.flush_cidx -= wq->sq.size;
return flushed;
}
+static void flush_completed_wrs(struct t4_wq *wq, struct t4_cq *cq)
+{
+ struct t4_swsqe *swsqe;
+ int cidx;
+
+ if (wq->sq.flush_cidx == -1)
+ wq->sq.flush_cidx = wq->sq.cidx;
+ cidx = wq->sq.flush_cidx;
+ BUG_ON(cidx > wq->sq.size);
+
+ while (cidx != wq->sq.pidx) {
+ swsqe = &wq->sq.sw_sq[cidx];
+ if (!swsqe->signaled) {
+ if (++cidx == wq->sq.size)
+ cidx = 0;
+ } else if (swsqe->complete) {
+
+ BUG_ON(swsqe->flushed);
+
+ /*
+ * Insert this completed cqe into the swcq.
+ */
+ PDBG("%s moving cqe into swcq sq idx %u cq idx %u\n",
+ __func__, cidx, cq->sw_pidx);
+ swsqe->cqe.header |= htonl(V_CQE_SWCQE(1));
+ cq->sw_queue[cq->sw_pidx] = swsqe->cqe;
+ t4_swcq_produce(cq);
+ swsqe->flushed = 1;
+ if (++cidx == wq->sq.size)
+ cidx = 0;
+ wq->sq.flush_cidx = cidx;
+ } else
+ break;
+ }
+}
+
+static void create_read_req_cqe(struct t4_wq *wq, struct t4_cqe *hw_cqe,
+ struct t4_cqe *read_cqe)
+{
+ read_cqe->u.scqe.cidx = wq->sq.oldest_read->idx;
+ read_cqe->len = htonl(wq->sq.oldest_read->read_len);
+ read_cqe->header = htonl(V_CQE_QPID(CQE_QPID(hw_cqe)) |
+ V_CQE_SWCQE(SW_CQE(hw_cqe)) |
+ V_CQE_OPCODE(FW_RI_READ_REQ) |
+ V_CQE_TYPE(1));
+ read_cqe->bits_type_ts = hw_cqe->bits_type_ts;
+}
+
+static void advance_oldest_read(struct t4_wq *wq)
+{
+
+ u32 rptr = wq->sq.oldest_read - wq->sq.sw_sq + 1;
+
+ if (rptr == wq->sq.size)
+ rptr = 0;
+ while (rptr != wq->sq.pidx) {
+ wq->sq.oldest_read = &wq->sq.sw_sq[rptr];
+
+ if (wq->sq.oldest_read->opcode == FW_RI_READ_REQ)
+ return;
+ if (++rptr == wq->sq.size)
+ rptr = 0;
+ }
+ wq->sq.oldest_read = NULL;
+}
+
/*
* Move all CQEs from the HWCQ into the SWCQ.
+ * Deal with out-of-order and/or completions that complete
+ * prior unsignalled WRs.
*/
-void c4iw_flush_hw_cq(struct t4_cq *cq)
+void c4iw_flush_hw_cq(struct c4iw_cq *chp)
{
- struct t4_cqe *cqe = NULL, *swcqe;
+ struct t4_cqe *hw_cqe, *swcqe, read_cqe;
+ struct c4iw_qp *qhp;
+ struct t4_swsqe *swsqe;
int ret;
- PDBG("%s cq %p cqid 0x%x\n", __func__, cq, cq->cqid);
- ret = t4_next_hw_cqe(cq, &cqe);
+ PDBG("%s cqid 0x%x\n", __func__, chp->cq.cqid);
+ ret = t4_next_hw_cqe(&chp->cq, &hw_cqe);
+
+ /*
+ * This logic is similar to poll_cq(), but not quite the same
+ * unfortunately. Need to move pertinent HW CQEs to the SW CQ but
+ * also do any translation magic that poll_cq() normally does.
+ */
while (!ret) {
- PDBG("%s flushing hwcq cidx 0x%x swcq pidx 0x%x\n",
- __func__, cq->cidx, cq->sw_pidx);
- swcqe = &cq->sw_queue[cq->sw_pidx];
- *swcqe = *cqe;
- swcqe->header |= cpu_to_be32(V_CQE_SWCQE(1));
- t4_swcq_produce(cq);
- t4_hwcq_consume(cq);
- ret = t4_next_hw_cqe(cq, &cqe);
+ qhp = get_qhp(chp->rhp, CQE_QPID(hw_cqe));
+
+ /*
+ * drop CQEs with no associated QP
+ */
+ if (qhp == NULL)
+ goto next_cqe;
+
+ if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE)
+ goto next_cqe;
+
+ if (CQE_OPCODE(hw_cqe) == FW_RI_READ_RESP) {
+
+ /*
+ * drop peer2peer RTR reads.
+ */
+ if (CQE_WRID_STAG(hw_cqe) == 1)
+ goto next_cqe;
+
+ /*
+ * Eat completions for unsignaled read WRs.
+ */
+ if (!qhp->wq.sq.oldest_read->signaled) {
+ advance_oldest_read(&qhp->wq);
+ goto next_cqe;
+ }
+
+ /*
+ * Don't write to the HWCQ, create a new read req CQE
+ * in local memory and move it into the swcq.
+ */
+ create_read_req_cqe(&qhp->wq, hw_cqe, &read_cqe);
+ hw_cqe = &read_cqe;
+ advance_oldest_read(&qhp->wq);
+ }
+
+ /* if its a SQ completion, then do the magic to move all the
+ * unsignaled and now in-order completions into the swcq.
+ */
+ if (SQ_TYPE(hw_cqe)) {
+ swsqe = &qhp->wq.sq.sw_sq[CQE_WRID_SQ_IDX(hw_cqe)];
+ swsqe->cqe = *hw_cqe;
+ swsqe->complete = 1;
+ flush_completed_wrs(&qhp->wq, &chp->cq);
+ } else {
+ swcqe = &chp->cq.sw_queue[chp->cq.sw_pidx];
+ *swcqe = *hw_cqe;
+ swcqe->header |= cpu_to_be32(V_CQE_SWCQE(1));
+ t4_swcq_produce(&chp->cq);
+ }
+next_cqe:
+ t4_hwcq_consume(&chp->cq);
+ ret = t4_next_hw_cqe(&chp->cq, &hw_cqe);
}
}
@@ -281,25 +424,6 @@
return 1;
}
-void c4iw_count_scqes(struct t4_cq *cq, struct t4_wq *wq, int *count)
-{
- struct t4_cqe *cqe;
- u32 ptr;
-
- *count = 0;
- ptr = cq->sw_cidx;
- while (ptr != cq->sw_pidx) {
- cqe = &cq->sw_queue[ptr];
- if ((SQ_TYPE(cqe) || ((CQE_OPCODE(cqe) == FW_RI_READ_RESP) &&
- wq->sq.oldest_read)) &&
- (CQE_QPID(cqe) == wq->sq.qid))
- (*count)++;
- if (++ptr == cq->size)
- ptr = 0;
- }
- PDBG("%s cq %p count %d\n", __func__, cq, *count);
-}
-
void c4iw_count_rcqes(struct t4_cq *cq, struct t4_wq *wq, int *count)
{
struct t4_cqe *cqe;
@@ -319,70 +443,6 @@
PDBG("%s cq %p count %d\n", __func__, cq, *count);
}
-static void flush_completed_wrs(struct t4_wq *wq, struct t4_cq *cq)
-{
- struct t4_swsqe *swsqe;
- u16 ptr = wq->sq.cidx;
- int count = wq->sq.in_use;
- int unsignaled = 0;
-
- swsqe = &wq->sq.sw_sq[ptr];
- while (count--)
- if (!swsqe->signaled) {
- if (++ptr == wq->sq.size)
- ptr = 0;
- swsqe = &wq->sq.sw_sq[ptr];
- unsignaled++;
- } else if (swsqe->complete) {
-
- /*
- * Insert this completed cqe into the swcq.
- */
- PDBG("%s moving cqe into swcq sq idx %u cq idx %u\n",
- __func__, ptr, cq->sw_pidx);
- swsqe->cqe.header |= htonl(V_CQE_SWCQE(1));
- cq->sw_queue[cq->sw_pidx] = swsqe->cqe;
- t4_swcq_produce(cq);
- swsqe->signaled = 0;
- wq->sq.in_use -= unsignaled;
- break;
- } else
- break;
-}
-
-static void create_read_req_cqe(struct t4_wq *wq, struct t4_cqe *hw_cqe,
- struct t4_cqe *read_cqe)
-{
- read_cqe->u.scqe.cidx = wq->sq.oldest_read->idx;
- read_cqe->len = cpu_to_be32(wq->sq.oldest_read->read_len);
- read_cqe->header = htonl(V_CQE_QPID(CQE_QPID(hw_cqe)) |
- V_CQE_SWCQE(SW_CQE(hw_cqe)) |
- V_CQE_OPCODE(FW_RI_READ_REQ) |
- V_CQE_TYPE(1));
- read_cqe->bits_type_ts = hw_cqe->bits_type_ts;
-}
-
-/*
- * Return a ptr to the next read wr in the SWSQ or NULL.
- */
-static void advance_oldest_read(struct t4_wq *wq)
-{
-
- u32 rptr = wq->sq.oldest_read - wq->sq.sw_sq + 1;
-
- if (rptr == wq->sq.size)
- rptr = 0;
- while (rptr != wq->sq.pidx) {
- wq->sq.oldest_read = &wq->sq.sw_sq[rptr];
-
- if (wq->sq.oldest_read->opcode == FW_RI_READ_REQ)
- return;
- if (++rptr == wq->sq.size)
- rptr = 0;
- }
- wq->sq.oldest_read = NULL;
-}
-
/*
* poll_cq
*
@@ -427,6 +487,22 @@
}
/*
+ * skip hw cqe's if the wq is flushed.
+ */
+ if (wq->flushed && !SW_CQE(hw_cqe)) {
+ ret = -EAGAIN;
+ goto skip_cqe;
+ }
+
+ /*
+ * skip TERMINATE cqes...
+ */
+ if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE) {
+ ret = -EAGAIN;
+ goto skip_cqe;
+ }
+
+ /*
* Gotta tweak READ completions:
* 1) the cqe doesn't contain the sq_wptr from the wr.
* 2) opcode not reflected from the wr.
@@ -440,7 +516,7 @@
* was generated by the kernel driver as part of peer-2-peer
* connection setup. So ignore the completion.
*/
- if (!wq->sq.oldest_read) {
+ if (CQE_WRID_STAG(hw_cqe) == 1) {
if (CQE_STATUS(hw_cqe))
t4_set_wq_in_error(wq);
ret = -EAGAIN;
@@ -448,6 +524,15 @@
}
/*
+ * Eat completions for unsignaled read WRs.
+ */
+ if (!wq->sq.oldest_read->signaled) {
+ advance_oldest_read(wq);
+ ret = -EAGAIN;
+ goto skip_cqe;
+ }
+
+ /*
* Don't write to the HWCQ, so create a new read req CQE
* in local memory.
*/
@@ -457,14 +542,8 @@
}
if (CQE_STATUS(hw_cqe) || t4_wq_in_error(wq)) {
- *cqe_flushed = t4_wq_in_error(wq);
+ *cqe_flushed = (CQE_STATUS(hw_cqe) == T4_ERR_SWFLUSH);
t4_set_wq_in_error(wq);
- goto proc_cqe;
- }
-
- if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE) {
- ret = -EAGAIN;
- goto skip_cqe;
}
/*
@@ -523,7 +602,21 @@
* completion.
*/
if (SQ_TYPE(hw_cqe)) {
- wq->sq.cidx = CQE_WRID_SQ_IDX(hw_cqe);
+ int idx = CQE_WRID_SQ_IDX(hw_cqe);
+ BUG_ON(idx > wq->sq.size);
+
+ /*
+ * Account for any unsignaled completions completed by
+ * this signaled completion. In this case, cidx points
+ * to the first unsignaled one, and idx points to the
+ * signaled one. So adjust in_use based on this delta.
+ * if this is not completing any unsigned wrs, then the
+ * delta will be 0.
+ */
+ wq->sq.in_use -= idx - wq->sq.cidx;
+ BUG_ON(wq->sq.in_use < 0 && wq->sq.in_use < wq->sq.size);
+
+ wq->sq.cidx = (uint16_t)idx;
PDBG("%s completing sq idx %u\n", __func__, wq->sq.cidx);
*cookie = wq->sq.sw_sq[wq->sq.cidx].wr_id;
t4_sq_consume(wq);
@@ -532,6 +625,7 @@
*cookie = wq->rq.sw_rq[wq->rq.cidx].wr_id;
BUG_ON(t4_rq_empty(wq));
t4_rq_consume(wq);
+ goto skip_cqe;
}
flush_wq: