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