1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
// 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 a data transmission buffer.
*/
struct rxrpc_txbuf *rxrpc_alloc_data_txbuf(struct rxrpc_call *call, size_t data_size,
size_t data_align, gfp_t gfp)
{
struct rxrpc_wire_header *whdr;
struct rxrpc_txbuf *txb;
size_t total, hoff = 0;
void *buf;
txb = kmalloc(sizeof(*txb), gfp);
if (!txb)
return NULL;
if (data_align)
hoff = round_up(sizeof(*whdr), data_align) - sizeof(*whdr);
total = hoff + sizeof(*whdr) + data_size;
mutex_lock(&call->conn->tx_data_alloc_lock);
buf = page_frag_alloc_align(&call->conn->tx_data_alloc, total, gfp,
~(data_align - 1) & ~(L1_CACHE_BYTES - 1));
mutex_unlock(&call->conn->tx_data_alloc_lock);
if (!buf) {
kfree(txb);
return NULL;
}
whdr = buf + hoff;
INIT_LIST_HEAD(&txb->call_link);
INIT_LIST_HEAD(&txb->tx_link);
refcount_set(&txb->ref, 1);
txb->last_sent = KTIME_MIN;
txb->call_debug_id = call->debug_id;
txb->debug_id = atomic_inc_return(&rxrpc_txbuf_debug_ids);
txb->space = data_size;
txb->len = 0;
txb->offset = sizeof(*whdr);
txb->flags = call->conn->out_clientflag;
txb->ack_why = 0;
txb->seq = call->tx_prepared + 1;
txb->serial = 0;
txb->cksum = 0;
txb->nr_kvec = 1;
txb->kvec[0].iov_base = whdr;
txb->kvec[0].iov_len = sizeof(*whdr);
whdr->epoch = htonl(call->conn->proto.epoch);
whdr->cid = htonl(call->cid);
whdr->callNumber = htonl(call->call_id);
whdr->seq = htonl(txb->seq);
whdr->type = RXRPC_PACKET_TYPE_DATA;
whdr->flags = 0;
whdr->userStatus = 0;
whdr->securityIndex = call->security_ix;
whdr->_rsvd = 0;
whdr->serviceId = htons(call->dest_srx.srx_service);
trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 1,
rxrpc_txbuf_alloc_data);
atomic_inc(&rxrpc_nr_txbuf);
return txb;
}
/*
* Allocate and partially initialise an ACK packet.
*/
struct rxrpc_txbuf *rxrpc_alloc_ack_txbuf(struct rxrpc_call *call, size_t sack_size)
{
struct rxrpc_wire_header *whdr;
struct rxrpc_acktrailer *trailer;
struct rxrpc_ackpacket *ack;
struct rxrpc_txbuf *txb;
gfp_t gfp = rcu_read_lock_held() ? GFP_ATOMIC | __GFP_NOWARN : GFP_NOFS;
void *buf, *buf2 = NULL;
u8 *filler;
txb = kmalloc(sizeof(*txb), gfp);
if (!txb)
return NULL;
buf = page_frag_alloc(&call->local->tx_alloc,
sizeof(*whdr) + sizeof(*ack) + 1 + 3 + sizeof(*trailer), gfp);
if (!buf) {
kfree(txb);
return NULL;
}
if (sack_size) {
buf2 = page_frag_alloc(&call->local->tx_alloc, sack_size, gfp);
if (!buf2) {
page_frag_free(buf);
kfree(txb);
return NULL;
}
}
whdr = buf;
ack = buf + sizeof(*whdr);
filler = buf + sizeof(*whdr) + sizeof(*ack) + 1;
trailer = buf + sizeof(*whdr) + sizeof(*ack) + 1 + 3;
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 = 0;
txb->len = sizeof(*whdr) + sizeof(*ack) + 3 + sizeof(*trailer);
txb->offset = 0;
txb->flags = call->conn->out_clientflag;
txb->ack_rwind = 0;
txb->seq = 0;
txb->serial = 0;
txb->cksum = 0;
txb->nr_kvec = 3;
txb->kvec[0].iov_base = whdr;
txb->kvec[0].iov_len = sizeof(*whdr) + sizeof(*ack);
txb->kvec[1].iov_base = buf2;
txb->kvec[1].iov_len = sack_size;
txb->kvec[2].iov_base = filler;
txb->kvec[2].iov_len = 3 + sizeof(*trailer);
whdr->epoch = htonl(call->conn->proto.epoch);
whdr->cid = htonl(call->cid);
whdr->callNumber = htonl(call->call_id);
whdr->seq = 0;
whdr->type = RXRPC_PACKET_TYPE_ACK;
whdr->flags = 0;
whdr->userStatus = 0;
whdr->securityIndex = call->security_ix;
whdr->_rsvd = 0;
whdr->serviceId = htons(call->dest_srx.srx_service);
get_page(virt_to_head_page(trailer));
trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 1,
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 rxrpc_txbuf *txb)
{
int i;
trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 0,
rxrpc_txbuf_free);
for (i = 0; i < txb->nr_kvec; i++)
if (txb->kvec[i].iov_base)
page_frag_free(txb->kvec[i].iov_base);
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)
rxrpc_free_txbuf(txb);
}
}
/*
* 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);
while ((txb = list_first_entry_or_null(&call->tx_buffer,
struct rxrpc_txbuf, call_link))) {
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);
rxrpc_put_txbuf(txb, rxrpc_txbuf_put_rotated);
if (after(call->acks_hard_ack, call->tx_bottom + 128))
wake = true;
}
if (wake)
wake_up(&call->waitq);
}
|
