diff options
Diffstat (limited to 'net/rxrpc/txbuf.c')
| -rw-r--r-- | net/rxrpc/txbuf.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/net/rxrpc/txbuf.c b/net/rxrpc/txbuf.c new file mode 100644 index 000000000000..d2cf2aac3adb --- /dev/null +++ b/net/rxrpc/txbuf.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxRPC Tx data buffering. + * + * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include "ar-internal.h" + +static atomic_t rxrpc_txbuf_debug_ids; +atomic_t rxrpc_nr_txbuf; + +/* + * Allocate and partially initialise an I/O request structure. + */ +struct rxrpc_txbuf *rxrpc_alloc_txbuf(struct rxrpc_call *call, u8 packet_type, + gfp_t gfp) +{ + struct rxrpc_txbuf *txb; + + txb = kmalloc(sizeof(*txb), gfp); + if (txb) { + INIT_LIST_HEAD(&txb->call_link); + INIT_LIST_HEAD(&txb->tx_link); + refcount_set(&txb->ref, 1); + txb->call_debug_id = call->debug_id; + txb->debug_id = atomic_inc_return(&rxrpc_txbuf_debug_ids); + txb->space = sizeof(txb->data); + txb->len = 0; + txb->offset = 0; + txb->flags = 0; + txb->ack_why = 0; + txb->seq = call->tx_prepared + 1; + txb->wire.epoch = htonl(call->conn->proto.epoch); + txb->wire.cid = htonl(call->cid); + txb->wire.callNumber = htonl(call->call_id); + txb->wire.seq = htonl(txb->seq); + txb->wire.type = packet_type; + txb->wire.flags = call->conn->out_clientflag; + txb->wire.userStatus = 0; + txb->wire.securityIndex = call->security_ix; + txb->wire._rsvd = 0; + txb->wire.serviceId = htons(call->dest_srx.srx_service); + + trace_rxrpc_txbuf(txb->debug_id, + txb->call_debug_id, txb->seq, 1, + packet_type == RXRPC_PACKET_TYPE_DATA ? + rxrpc_txbuf_alloc_data : + rxrpc_txbuf_alloc_ack); + atomic_inc(&rxrpc_nr_txbuf); + } + + return txb; +} + +void rxrpc_get_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what) +{ + int r; + + __refcount_inc(&txb->ref, &r); + trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, r + 1, what); +} + +void rxrpc_see_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what) +{ + int r = refcount_read(&txb->ref); + + trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, r, what); +} + +static void rxrpc_free_txbuf(struct rcu_head *rcu) +{ + struct rxrpc_txbuf *txb = container_of(rcu, struct rxrpc_txbuf, rcu); + + trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 0, + rxrpc_txbuf_free); + kfree(txb); + atomic_dec(&rxrpc_nr_txbuf); +} + +void rxrpc_put_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what) +{ + unsigned int debug_id, call_debug_id; + rxrpc_seq_t seq; + bool dead; + int r; + + if (txb) { + debug_id = txb->debug_id; + call_debug_id = txb->call_debug_id; + seq = txb->seq; + dead = __refcount_dec_and_test(&txb->ref, &r); + trace_rxrpc_txbuf(debug_id, call_debug_id, seq, r - 1, what); + if (dead) + call_rcu(&txb->rcu, rxrpc_free_txbuf); + } +} + +/* + * Shrink the transmit buffer. + */ +void rxrpc_shrink_call_tx_buffer(struct rxrpc_call *call) +{ + struct rxrpc_txbuf *txb; + rxrpc_seq_t hard_ack = smp_load_acquire(&call->acks_hard_ack); + bool wake = false; + + _enter("%x/%x/%x", call->tx_bottom, call->acks_hard_ack, call->tx_top); + + for (;;) { + spin_lock(&call->tx_lock); + txb = list_first_entry_or_null(&call->tx_buffer, + struct rxrpc_txbuf, call_link); + if (!txb) + break; + hard_ack = smp_load_acquire(&call->acks_hard_ack); + if (before(hard_ack, txb->seq)) + break; + + if (txb->seq != call->tx_bottom + 1) + rxrpc_see_txbuf(txb, rxrpc_txbuf_see_out_of_step); + ASSERTCMP(txb->seq, ==, call->tx_bottom + 1); + smp_store_release(&call->tx_bottom, call->tx_bottom + 1); + list_del_rcu(&txb->call_link); + + trace_rxrpc_txqueue(call, rxrpc_txqueue_dequeue); + + spin_unlock(&call->tx_lock); + + rxrpc_put_txbuf(txb, rxrpc_txbuf_put_rotated); + if (after(call->acks_hard_ack, call->tx_bottom + 128)) + wake = true; + } + + spin_unlock(&call->tx_lock); + + if (wake) + wake_up(&call->waitq); +} |