| // 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 = call; |
| 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_top + 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->service_id); |
| |
| 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); |
| |
| _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; |
| |
| ASSERTCMP(txb->seq, ==, call->tx_bottom + 1); |
| call->tx_bottom++; |
| 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); |
| } |
| |
| spin_unlock(&call->tx_lock); |
| } |