IB/hfi1: Add the capability for reserved operations
This fix allows for support of in-kernel reserved operations
without impacting the ULP user.
The low level driver can register a non-zero value which
will be transparently added to the send queue size and hidden
from the ULP in every respect.
ULP post sends will never see a full queue due to a reserved
post send and reserved operations will never exceed that
registered value.
The s_avail will continue to track the ULP swqe availability
and the difference between the reserved value and the reserved
in use will track reserved availabity.
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index f79b809..218494c 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -584,6 +584,7 @@
qp->r_rq.wq->tail = 0;
}
qp->r_sge.num_sge = 0;
+ atomic_set(&qp->s_reserved_used, 0);
}
/**
@@ -645,7 +646,8 @@
return ERR_PTR(-EINVAL);
}
sqsize =
- init_attr->cap.max_send_wr + 1;
+ init_attr->cap.max_send_wr + 1 +
+ rdi->dparms.reserved_operations;
switch (init_attr->qp_type) {
case IB_QPT_SMI:
case IB_QPT_GSI:
@@ -1335,7 +1337,8 @@
attr->sq_psn = qp->s_next_psn & rdi->dparms.psn_mask;
attr->dest_qp_num = qp->remote_qpn;
attr->qp_access_flags = qp->qp_access_flags;
- attr->cap.max_send_wr = qp->s_size - 1;
+ attr->cap.max_send_wr = qp->s_size - 1 -
+ rdi->dparms.reserved_operations;
attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
attr->cap.max_send_sge = qp->s_max_sge;
attr->cap.max_recv_sge = qp->r_rq.max_sge;
@@ -1494,27 +1497,65 @@
}
/**
- * qp_get_savail - return number of avail send entries
+ * rvt_qp_is_avail - determine queue capacity
* @qp - the qp
+ * @rdi - the rdmavt device
+ * @reserved_op - is reserved operation
*
* This assumes the s_hlock is held but the s_last
* qp variable is uncontrolled.
*
- * The return is adjusted to not count device specific
- * reserved operations.
+ * For non reserved operations, the qp->s_avail
+ * may be changed.
+ *
+ * The return value is zero or a -ENOMEM.
*/
-static inline u32 qp_get_savail(struct rvt_qp *qp)
+static inline int rvt_qp_is_avail(
+ struct rvt_qp *qp,
+ struct rvt_dev_info *rdi,
+ bool reserved_op)
{
u32 slast;
- u32 ret;
+ u32 avail;
+ u32 reserved_used;
+ /* see rvt_qp_wqe_unreserve() */
+ smp_mb__before_atomic();
+ reserved_used = atomic_read(&qp->s_reserved_used);
+ if (unlikely(reserved_op)) {
+ /* see rvt_qp_wqe_unreserve() */
+ smp_mb__before_atomic();
+ if (reserved_used >= rdi->dparms.reserved_operations)
+ return -ENOMEM;
+ return 0;
+ }
+ /* non-reserved operations */
+ if (likely(qp->s_avail))
+ return 0;
smp_read_barrier_depends(); /* see rc.c */
slast = ACCESS_ONCE(qp->s_last);
if (qp->s_head >= slast)
- ret = qp->s_size - (qp->s_head - slast);
+ avail = qp->s_size - (qp->s_head - slast);
else
- ret = slast - qp->s_head;
- return ret - 1;
+ avail = slast - qp->s_head;
+
+ /* see rvt_qp_wqe_unreserve() */
+ smp_mb__before_atomic();
+ reserved_used = atomic_read(&qp->s_reserved_used);
+ avail = avail - 1 -
+ (rdi->dparms.reserved_operations - reserved_used);
+ /* insure we don't assign a negative s_avail */
+ if ((s32)avail <= 0)
+ return -ENOMEM;
+ qp->s_avail = avail;
+ if (WARN_ON(qp->s_avail >
+ (qp->s_size - 1 - rdi->dparms.reserved_operations)))
+ rvt_pr_err(rdi,
+ "More avail entries than QP RB size.\nQP: %u, size: %u, avail: %u\nhead: %u, tail: %u, cur: %u, acked: %u, last: %u",
+ qp->ibqp.qp_num, qp->s_size, qp->s_avail,
+ qp->s_head, qp->s_tail, qp->s_cur,
+ qp->s_acked, qp->s_last);
+ return 0;
}
/**
@@ -1537,6 +1578,7 @@
u8 log_pmtu;
int ret;
size_t cplen;
+ bool reserved_op;
BUILD_BUG_ON(IB_QPT_MAX >= (sizeof(u32) * BITS_PER_BYTE));
@@ -1574,18 +1616,12 @@
}
}
+ reserved_op = rdi->post_parms[wr->opcode].flags &
+ RVT_OPERATION_USE_RESERVE;
/* check for avail */
- if (unlikely(!qp->s_avail)) {
- qp->s_avail = qp_get_savail(qp);
- if (WARN_ON(qp->s_avail > (qp->s_size - 1)))
- rvt_pr_err(rdi,
- "More avail entries than QP RB size.\nQP: %u, size: %u, avail: %u\nhead: %u, tail: %u, cur: %u, acked: %u, last: %u",
- qp->ibqp.qp_num, qp->s_size, qp->s_avail,
- qp->s_head, qp->s_tail, qp->s_cur,
- qp->s_acked, qp->s_last);
- if (!qp->s_avail)
- return -ENOMEM;
- }
+ ret = rvt_qp_is_avail(qp, rdi, reserved_op);
+ if (ret)
+ return ret;
next = qp->s_head + 1;
if (next >= qp->s_size)
next = 0;
@@ -1653,8 +1689,11 @@
qp->s_next_psn = wqe->lpsn + 1;
}
trace_rvt_post_one_wr(qp, wqe);
+ if (unlikely(reserved_op))
+ rvt_qp_wqe_reserve(qp, wqe);
+ else
+ qp->s_avail--;
smp_wmb(); /* see request builders */
- qp->s_avail--;
qp->s_head = next;
return 0;
diff --git a/include/rdma/rdma_vt.h b/include/rdma/rdma_vt.h
index 7fdba92..e315021 100644
--- a/include/rdma/rdma_vt.h
+++ b/include/rdma/rdma_vt.h
@@ -158,6 +158,7 @@
u32 max_mad_size;
u8 qos_shift;
u8 max_rdma_atomic;
+ u8 reserved_operations;
};
/* Protection domain */
diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h
index b0ab12b..56adcfca 100644
--- a/include/rdma/rdmavt_qp.h
+++ b/include/rdma/rdmavt_qp.h
@@ -145,6 +145,11 @@
(RVT_PROCESS_SEND_OK | RVT_FLUSH_SEND)
/*
+ * Internal send flags
+ */
+#define RVT_SEND_RESERVE_USED IB_SEND_RESERVED_START
+
+/*
* Send work request queue entry.
* The size of the sg_list is determined when the QP is created and stored
* in qp->s_max_sge.
@@ -232,6 +237,7 @@
#define RVT_OPERATION_ATOMIC 0x00000002
#define RVT_OPERATION_ATOMIC_SGE 0x00000004
#define RVT_OPERATION_LOCAL 0x00000008
+#define RVT_OPERATION_USE_RESERVE 0x00000010
#define RVT_OPERATION_MAX (IB_WR_RESERVED10 + 1)
@@ -328,6 +334,7 @@
u32 s_next_psn; /* PSN for next request */
u32 s_avail; /* number of entries avail */
u32 s_ssn; /* SSN of tail entry */
+ atomic_t s_reserved_used; /* reserved entries in use */
spinlock_t s_lock ____cacheline_aligned_in_smp;
u32 s_flags;
@@ -459,6 +466,49 @@
rq->max_sge * sizeof(struct ib_sge)) * n);
}
+/**
+ * rvt_qp_wqe_reserve - reserve operation
+ * @qp - the rvt qp
+ * @wqe - the send wqe
+ *
+ * This routine used in post send to record
+ * a wqe relative reserved operation use.
+ */
+static inline void rvt_qp_wqe_reserve(
+ struct rvt_qp *qp,
+ struct rvt_swqe *wqe)
+{
+ wqe->wr.send_flags |= RVT_SEND_RESERVE_USED;
+ atomic_inc(&qp->s_reserved_used);
+}
+
+/**
+ * rvt_qp_wqe_unreserve - clean reserved operation
+ * @qp - the rvt qp
+ * @wqe - the send wqe
+ *
+ * This decrements the reserve use count.
+ *
+ * This call MUST precede the change to
+ * s_last to insure that post send sees a stable
+ * s_avail.
+ *
+ * An smp_mp__after_atomic() is used to insure
+ * the compiler does not juggle the order of the s_last
+ * ring index and the decrementing of s_reserved_used.
+ */
+static inline void rvt_qp_wqe_unreserve(
+ struct rvt_qp *qp,
+ struct rvt_swqe *wqe)
+{
+ if (unlikely(wqe->wr.send_flags & RVT_SEND_RESERVE_USED)) {
+ wqe->wr.send_flags &= ~RVT_SEND_RESERVE_USED;
+ atomic_dec(&qp->s_reserved_used);
+ /* insure no compiler re-order up to s_last change */
+ smp_mb__after_atomic();
+ }
+}
+
extern const int ib_rvt_state_ops[];
struct rvt_dev_info;