1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (c) 2015-2016 Quantenna Communications. All rights reserved. */
3
4 #include <linux/types.h>
5 #include <linux/export.h>
6 #include <linux/slab.h>
7
8 #include "core.h"
9 #include "commands.h"
10 #include "event.h"
11 #include "bus.h"
12
13 #define QTNF_DEF_SYNC_CMD_TIMEOUT (5 * HZ)
14
qtnf_trans_send_cmd_with_resp(struct qtnf_bus * bus,struct sk_buff * cmd_skb,struct sk_buff ** response_skb)15 int qtnf_trans_send_cmd_with_resp(struct qtnf_bus *bus, struct sk_buff *cmd_skb,
16 struct sk_buff **response_skb)
17 {
18 struct qtnf_cmd_ctl_node *ctl_node = &bus->trans.curr_cmd;
19 struct qlink_cmd *cmd = (void *)cmd_skb->data;
20 int ret = 0;
21 long status;
22 bool resp_not_handled = true;
23 struct sk_buff *resp_skb = NULL;
24
25 if (unlikely(!response_skb)) {
26 dev_kfree_skb(cmd_skb);
27 return -EFAULT;
28 }
29
30 spin_lock(&ctl_node->resp_lock);
31 ctl_node->seq_num++;
32 cmd->seq_num = cpu_to_le16(ctl_node->seq_num);
33 WARN(ctl_node->resp_skb, "qtnfmac: response skb not empty\n");
34 ctl_node->waiting_for_resp = true;
35 spin_unlock(&ctl_node->resp_lock);
36
37 ret = qtnf_bus_control_tx(bus, cmd_skb);
38 dev_kfree_skb(cmd_skb);
39
40 if (unlikely(ret))
41 goto out;
42
43 status = wait_for_completion_interruptible_timeout(
44 &ctl_node->cmd_resp_completion,
45 QTNF_DEF_SYNC_CMD_TIMEOUT);
46
47 spin_lock(&ctl_node->resp_lock);
48 resp_not_handled = ctl_node->waiting_for_resp;
49 resp_skb = ctl_node->resp_skb;
50 ctl_node->resp_skb = NULL;
51 ctl_node->waiting_for_resp = false;
52 spin_unlock(&ctl_node->resp_lock);
53
54 if (unlikely(status <= 0)) {
55 if (status == 0) {
56 ret = -ETIMEDOUT;
57 pr_err("response timeout\n");
58 } else {
59 ret = -EINTR;
60 pr_debug("interrupted\n");
61 }
62 }
63
64 if (unlikely(!resp_skb || resp_not_handled)) {
65 if (!ret)
66 ret = -EFAULT;
67
68 goto out;
69 }
70
71 ret = 0;
72 *response_skb = resp_skb;
73
74 out:
75 if (unlikely(resp_skb && resp_not_handled))
76 dev_kfree_skb(resp_skb);
77
78 return ret;
79 }
80
qtnf_trans_signal_cmdresp(struct qtnf_bus * bus,struct sk_buff * skb)81 static void qtnf_trans_signal_cmdresp(struct qtnf_bus *bus, struct sk_buff *skb)
82 {
83 struct qtnf_cmd_ctl_node *ctl_node = &bus->trans.curr_cmd;
84 const struct qlink_resp *resp = (const struct qlink_resp *)skb->data;
85 const u16 recvd_seq_num = le16_to_cpu(resp->seq_num);
86
87 spin_lock(&ctl_node->resp_lock);
88
89 if (unlikely(!ctl_node->waiting_for_resp)) {
90 pr_err("unexpected response\n");
91 goto out_err;
92 }
93
94 if (unlikely(recvd_seq_num != ctl_node->seq_num)) {
95 pr_err("seq num mismatch\n");
96 goto out_err;
97 }
98
99 ctl_node->resp_skb = skb;
100 ctl_node->waiting_for_resp = false;
101
102 spin_unlock(&ctl_node->resp_lock);
103
104 complete(&ctl_node->cmd_resp_completion);
105 return;
106
107 out_err:
108 spin_unlock(&ctl_node->resp_lock);
109 dev_kfree_skb(skb);
110 }
111
qtnf_trans_event_enqueue(struct qtnf_bus * bus,struct sk_buff * skb)112 static int qtnf_trans_event_enqueue(struct qtnf_bus *bus, struct sk_buff *skb)
113 {
114 struct qtnf_qlink_transport *trans = &bus->trans;
115
116 if (likely(skb_queue_len(&trans->event_queue) <
117 trans->event_queue_max_len)) {
118 skb_queue_tail(&trans->event_queue, skb);
119 queue_work(bus->workqueue, &bus->event_work);
120 } else {
121 pr_warn("event dropped due to queue overflow\n");
122 dev_kfree_skb(skb);
123 return -1;
124 }
125
126 return 0;
127 }
128
qtnf_trans_init(struct qtnf_bus * bus)129 void qtnf_trans_init(struct qtnf_bus *bus)
130 {
131 struct qtnf_qlink_transport *trans = &bus->trans;
132
133 init_completion(&trans->curr_cmd.cmd_resp_completion);
134 spin_lock_init(&trans->curr_cmd.resp_lock);
135
136 spin_lock(&trans->curr_cmd.resp_lock);
137 trans->curr_cmd.seq_num = 0;
138 trans->curr_cmd.waiting_for_resp = false;
139 trans->curr_cmd.resp_skb = NULL;
140 spin_unlock(&trans->curr_cmd.resp_lock);
141
142 /* Init event handling related fields */
143 skb_queue_head_init(&trans->event_queue);
144 trans->event_queue_max_len = QTNF_MAX_EVENT_QUEUE_LEN;
145 }
146
qtnf_trans_free_events(struct qtnf_bus * bus)147 static void qtnf_trans_free_events(struct qtnf_bus *bus)
148 {
149 struct sk_buff_head *event_queue = &bus->trans.event_queue;
150 struct sk_buff *current_event_skb = skb_dequeue(event_queue);
151
152 while (current_event_skb) {
153 dev_kfree_skb_any(current_event_skb);
154 current_event_skb = skb_dequeue(event_queue);
155 }
156 }
157
qtnf_trans_free(struct qtnf_bus * bus)158 void qtnf_trans_free(struct qtnf_bus *bus)
159 {
160 if (!bus) {
161 pr_err("invalid bus pointer\n");
162 return;
163 }
164
165 qtnf_trans_free_events(bus);
166 }
167
qtnf_trans_handle_rx_ctl_packet(struct qtnf_bus * bus,struct sk_buff * skb)168 int qtnf_trans_handle_rx_ctl_packet(struct qtnf_bus *bus, struct sk_buff *skb)
169 {
170 const struct qlink_msg_header *header = (void *)skb->data;
171 int ret = -1;
172
173 if (unlikely(skb->len < sizeof(*header))) {
174 pr_warn("packet is too small: %u\n", skb->len);
175 dev_kfree_skb(skb);
176 return -EINVAL;
177 }
178
179 if (unlikely(skb->len != le16_to_cpu(header->len))) {
180 pr_warn("cmd reply length mismatch: %u != %u\n",
181 skb->len, le16_to_cpu(header->len));
182 dev_kfree_skb(skb);
183 return -EFAULT;
184 }
185
186 switch (le16_to_cpu(header->type)) {
187 case QLINK_MSG_TYPE_CMDRSP:
188 if (unlikely(skb->len < sizeof(struct qlink_cmd))) {
189 pr_warn("cmd reply too short: %u\n", skb->len);
190 dev_kfree_skb(skb);
191 break;
192 }
193
194 qtnf_trans_signal_cmdresp(bus, skb);
195 break;
196 case QLINK_MSG_TYPE_EVENT:
197 if (unlikely(skb->len < sizeof(struct qlink_event))) {
198 pr_warn("event too short: %u\n", skb->len);
199 dev_kfree_skb(skb);
200 break;
201 }
202
203 ret = qtnf_trans_event_enqueue(bus, skb);
204 break;
205 default:
206 pr_warn("unknown packet type: %x\n", le16_to_cpu(header->type));
207 dev_kfree_skb(skb);
208 break;
209 }
210
211 return ret;
212 }
213 EXPORT_SYMBOL_GPL(qtnf_trans_handle_rx_ctl_packet);
214