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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/infiniband/sw/rdmavt/rc.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/sw/rdmavt/rc.c')
-rw-r--r--drivers/infiniband/sw/rdmavt/rc.c172
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);
+