From: Bob Pearson <rpearsonhpe@gmail.com>
Date: Wed, 23 Feb 2022 17:07:06 -0600
Subject: RDMA/rxe: Cleanup rxe_mcast.c
Patch-mainline: v5.18-rc1
Git-commit: 6090a0c4c7c6156f267ee217f6577eecd610a652
References: jsc#PED-1111
Finish adding subroutine comment headers to subroutines in
rxe_mcast.c. Make minor api change cleanups.
Link: https://lore.kernel.org/r/20220223230706.50332-5-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/sw/rxe/rxe_mcast.c | 97 +++++++++++++++++++++++++++-------
1 file changed, 78 insertions(+), 19 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe_mcast.c
+++ b/drivers/infiniband/sw/rxe/rxe_mcast.c
@@ -1,12 +1,33 @@
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
+ * Copyright (c) 2022 Hewlett Packard Enterprise, Inc. All rights reserved.
* Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
* Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
*/
+/*
+ * rxe_mcast.c implements driver support for multicast transport.
+ * It is based on two data structures struct rxe_mcg ('mcg') and
+ * struct rxe_mca ('mca'). An mcg is allocated each time a qp is
+ * attached to a new mgid for the first time. These are indexed by
+ * a red-black tree using the mgid. This data structure is searched
+ * for the mcg when a multicast packet is received and when another
+ * qp is attached to the same mgid. It is cleaned up when the last qp
+ * is detached from the mcg. Each time a qp is attached to an mcg an
+ * mca is created. It holds a pointer to the qp and is added to a list
+ * of qp's that are attached to the mcg. The qp_list is used to replicate
+ * mcast packets in the rxe receive path.
+ */
+
#include "rxe.h"
-#include "rxe_loc.h"
+/**
+ * rxe_mcast_add - add multicast address to rxe device
+ * @rxe: rxe device object
+ * @mgid: multicast address as a gid
+ *
+ * Returns 0 on success else an error
+ */
static int rxe_mcast_add(struct rxe_dev *rxe, union ib_gid *mgid)
{
unsigned char ll_addr[ETH_ALEN];
@@ -16,6 +37,13 @@ static int rxe_mcast_add(struct rxe_dev
return dev_mc_add(rxe->ndev, ll_addr);
}
+/**
+ * rxe_mcast_delete - delete multicast address from rxe device
+ * @rxe: rxe device object
+ * @mgid: multicast address as a gid
+ *
+ * Returns 0 on success else an error
+ */
static int rxe_mcast_delete(struct rxe_dev *rxe, union ib_gid *mgid)
{
unsigned char ll_addr[ETH_ALEN];
@@ -216,7 +244,7 @@ err_dec:
/**
* rxe_cleanup_mcg - cleanup mcg for kref_put
- * @kref:
+ * @kref: struct kref embnedded in mcg
*/
void rxe_cleanup_mcg(struct kref *kref)
{
@@ -299,9 +327,17 @@ static int __rxe_init_mca(struct rxe_qp
return 0;
}
-static int rxe_attach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp,
- struct rxe_mcg *mcg)
+/**
+ * rxe_attach_mcg - attach qp to mcg if not already attached
+ * @qp: qp object
+ * @mcg: mcg object
+ *
+ * Context: caller must hold reference on qp and mcg.
+ * Returns: 0 on success else an error
+ */
+static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
{
+ struct rxe_dev *rxe = mcg->rxe;
struct rxe_mca *mca, *tmp;
unsigned long flags;
int err;
@@ -358,17 +394,19 @@ static void __rxe_cleanup_mca(struct rxe
kfree(mca);
}
-static int rxe_detach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp,
- union ib_gid *mgid)
+/**
+ * rxe_detach_mcg - detach qp from mcg
+ * @mcg: mcg object
+ * @qp: qp object
+ *
+ * Returns: 0 on success else an error if qp is not attached.
+ */
+static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
{
- struct rxe_mcg *mcg;
+ struct rxe_dev *rxe = mcg->rxe;
struct rxe_mca *mca, *tmp;
unsigned long flags;
- mcg = rxe_lookup_mcg(rxe, mgid);
- if (!mcg)
- return -EINVAL;
-
spin_lock_irqsave(&rxe->mcg_lock, flags);
list_for_each_entry_safe(mca, tmp, &mcg->qp_list, qp_list) {
if (mca->qp == qp) {
@@ -378,16 +416,11 @@ static int rxe_detach_mcg(struct rxe_dev
* mcast group falls to zero go ahead and
* tear it down. This will not free the
* object since we are still holding a ref
- * from the get key above
+ * from the caller
*/
if (atomic_read(&mcg->qp_num) <= 0)
__rxe_destroy_mcg(mcg);
- /* drop the ref from get key. This will free the
- * object if qp_num is zero.
- */
- kref_put(&mcg->ref_cnt, rxe_cleanup_mcg);
-
spin_unlock_irqrestore(&rxe->mcg_lock, flags);
return 0;
}
@@ -398,6 +431,14 @@ static int rxe_detach_mcg(struct rxe_dev
return -EINVAL;
}
+/**
+ * rxe_attach_mcast - attach qp to multicast group (see IBA-11.3.1)
+ * @ibqp: (IB) qp object
+ * @mgid: multicast IP address
+ * @mlid: multicast LID, ignored for RoCEv2 (see IBA-A17.5.6)
+ *
+ * Returns: 0 on success else an errno
+ */
int rxe_attach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid)
{
int err;
@@ -410,20 +451,38 @@ int rxe_attach_mcast(struct ib_qp *ibqp,
if (IS_ERR(mcg))
return PTR_ERR(mcg);
- err = rxe_attach_mcg(rxe, qp, mcg);
+ err = rxe_attach_mcg(mcg, qp);
/* if we failed to attach the first qp to mcg tear it down */
if (atomic_read(&mcg->qp_num) == 0)
rxe_destroy_mcg(mcg);
kref_put(&mcg->ref_cnt, rxe_cleanup_mcg);
+
return err;
}
+/**
+ * rxe_detach_mcast - detach qp from multicast group (see IBA-11.3.2)
+ * @ibqp: address of (IB) qp object
+ * @mgid: multicast IP address
+ * @mlid: multicast LID, ignored for RoCEv2 (see IBA-A17.5.6)
+ *
+ * Returns: 0 on success else an errno
+ */
int rxe_detach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid)
{
struct rxe_dev *rxe = to_rdev(ibqp->device);
struct rxe_qp *qp = to_rqp(ibqp);
+ struct rxe_mcg *mcg;
+ int err;
+
+ mcg = rxe_lookup_mcg(rxe, mgid);
+ if (!mcg)
+ return -EINVAL;
- return rxe_detach_mcg(rxe, qp, mgid);
+ err = rxe_detach_mcg(mcg, qp);
+ kref_put(&mcg->ref_cnt, rxe_cleanup_mcg);
+
+ return err;
}