Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rdmavt/rc.c b/drivers/infiniband/sw/rdmavt/rc.c
new file mode 100644
index 000000000..4e5d4a276
--- /dev/null
+++ b/drivers/infiniband/sw/rdmavt/rc.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Copyright(c) 2016 Intel Corporation.
+ */
+
+#include <rdma/rdmavt_qp.h>
+#include <rdma/ib_hdrs.h>
+
+/*
+ * Convert the AETH credit code into the number of credits.
+ */
+static const u16 credit_table[31] = {
+	0,                      /* 0 */
+	1,                      /* 1 */
+	2,                      /* 2 */
+	3,                      /* 3 */
+	4,                      /* 4 */
+	6,                      /* 5 */
+	8,                      /* 6 */
+	12,                     /* 7 */
+	16,                     /* 8 */
+	24,                     /* 9 */
+	32,                     /* A */
+	48,                     /* B */
+	64,                     /* C */
+	96,                     /* D */
+	128,                    /* E */
+	192,                    /* F */
+	256,                    /* 10 */
+	384,                    /* 11 */
+	512,                    /* 12 */
+	768,                    /* 13 */
+	1024,                   /* 14 */
+	1536,                   /* 15 */
+	2048,                   /* 16 */
+	3072,                   /* 17 */
+	4096,                   /* 18 */
+	6144,                   /* 19 */
+	8192,                   /* 1A */
+	12288,                  /* 1B */
+	16384,                  /* 1C */
+	24576,                  /* 1D */
+	32768                   /* 1E */
+};
+
+/**
+ * rvt_compute_aeth - compute the AETH (syndrome + MSN)
+ * @qp: the queue pair to compute the AETH for
+ *
+ * Returns the AETH.
+ */
+__be32 rvt_compute_aeth(struct rvt_qp *qp)
+{
+	u32 aeth = qp->r_msn & IB_MSN_MASK;
+
+	if (qp->ibqp.srq) {
+		/*
+		 * Shared receive queues don't generate credits.
+		 * Set the credit field to the invalid value.
+		 */
+		aeth |= IB_AETH_CREDIT_INVAL << IB_AETH_CREDIT_SHIFT;
+	} else {
+		u32 min, max, x;
+		u32 credits;
+		u32 head;
+		u32 tail;
+
+		credits = READ_ONCE(qp->r_rq.kwq->count);
+		if (credits == 0) {
+			/* sanity check pointers before trusting them */
+			if (qp->ip) {
+				head = RDMA_READ_UAPI_ATOMIC(qp->r_rq.wq->head);
+				tail = RDMA_READ_UAPI_ATOMIC(qp->r_rq.wq->tail);
+			} else {
+				head = READ_ONCE(qp->r_rq.kwq->head);
+				tail = READ_ONCE(qp->r_rq.kwq->tail);
+			}
+			if (head >= qp->r_rq.size)
+				head = 0;
+			if (tail >= qp->r_rq.size)
+				tail = 0;
+			/*
+			 * Compute the number of credits available (RWQEs).
+			 * There is a small chance that the pair of reads are
+			 * not atomic, which is OK, since the fuzziness is
+			 * resolved as further ACKs go out.
+			 */
+			credits = rvt_get_rq_count(&qp->r_rq, head, tail);
+		}
+		/*
+		 * Binary search the credit table to find the code to
+		 * use.
+		 */
+		min = 0;
+		max = 31;
+		for (;;) {
+			x = (min + max) / 2;
+			if (credit_table[x] == credits)
+				break;
+			if (credit_table[x] > credits) {
+				max = x;
+			} else {
+				if (min == x)
+					break;
+				min = x;
+			}
+		}
+		aeth |= x << IB_AETH_CREDIT_SHIFT;
+	}
+	return cpu_to_be32(aeth);
+}
+EXPORT_SYMBOL(rvt_compute_aeth);
+
+/**
+ * rvt_get_credit - flush the send work queue of a QP
+ * @qp: the qp who's send work queue to flush
+ * @aeth: the Acknowledge Extended Transport Header
+ *
+ * The QP s_lock should be held.
+ */
+void rvt_get_credit(struct rvt_qp *qp, u32 aeth)
+{
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	u32 credit = (aeth >> IB_AETH_CREDIT_SHIFT) & IB_AETH_CREDIT_MASK;
+
+	lockdep_assert_held(&qp->s_lock);
+	/*
+	 * If the credit is invalid, we can send
+	 * as many packets as we like.  Otherwise, we have to
+	 * honor the credit field.
+	 */
+	if (credit == IB_AETH_CREDIT_INVAL) {
+		if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
+			qp->s_flags |= RVT_S_UNLIMITED_CREDIT;
+			if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
+				qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
+				rdi->driver_f.schedule_send(qp);
+			}
+		}
+	} else if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
+		/* Compute new LSN (i.e., MSN + credit) */
+		credit = (aeth + credit_table[credit]) & IB_MSN_MASK;
+		if (rvt_cmp_msn(credit, qp->s_lsn) > 0) {
+			qp->s_lsn = credit;
+			if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
+				qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
+				rdi->driver_f.schedule_send(qp);
+			}
+		}
+	}
+}
+EXPORT_SYMBOL(rvt_get_credit);
+
+/**
+ * rvt_restart_sge - rewind the sge state for a wqe
+ * @ss: the sge state pointer
+ * @wqe: the wqe to rewind
+ * @len: the data length from the start of the wqe in bytes
+ *
+ * Returns the remaining data length.
+ */
+u32 rvt_restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe, u32 len)
+{
+	ss->sge = wqe->sg_list[0];
+	ss->sg_list = wqe->sg_list + 1;
+	ss->num_sge = wqe->wr.num_sge;
+	ss->total_len = wqe->length;
+	rvt_skip_sge(ss, len, false);
+	return wqe->length - len;
+}
+EXPORT_SYMBOL(rvt_restart_sge);
+