1/*
2 * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 */
23#include "qmgr.h"
24
25static void
26nvkm_falcon_msgq_open(struct nvkm_falcon_msgq *msgq)
27{
28	spin_lock(&msgq->lock);
29	msgq->position = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->tail_reg);
30}
31
32static void
33nvkm_falcon_msgq_close(struct nvkm_falcon_msgq *msgq, bool commit)
34{
35	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
36
37	if (commit)
38		nvkm_falcon_wr32(falcon, msgq->tail_reg, msgq->position);
39
40	spin_unlock(&msgq->lock);
41}
42
43bool
44nvkm_falcon_msgq_empty(struct nvkm_falcon_msgq *msgq)
45{
46	u32 head = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->head_reg);
47	u32 tail = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->tail_reg);
48	return head == tail;
49}
50
51static int
52nvkm_falcon_msgq_pop(struct nvkm_falcon_msgq *msgq, void *data, u32 size)
53{
54	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
55	u32 head, tail, available;
56
57	head = nvkm_falcon_rd32(falcon, msgq->head_reg);
58	/* has the buffer looped? */
59	if (head < msgq->position)
60		msgq->position = msgq->offset;
61
62	tail = msgq->position;
63
64	available = head - tail;
65	if (size > available) {
66		FLCNQ_ERR(msgq, "requested %d bytes, but only %d available",
67			  size, available);
68		return -EINVAL;
69	}
70
71	nvkm_falcon_pio_rd(falcon, 0, DMEM, tail, data, 0, size);
72	msgq->position += ALIGN(size, QUEUE_ALIGNMENT);
73	return 0;
74}
75
76static int
77nvkm_falcon_msgq_read(struct nvkm_falcon_msgq *msgq, struct nvfw_falcon_msg *hdr)
78{
79	int ret = 0;
80
81	nvkm_falcon_msgq_open(msgq);
82
83	if (nvkm_falcon_msgq_empty(msgq))
84		goto close;
85
86	ret = nvkm_falcon_msgq_pop(msgq, hdr, HDR_SIZE);
87	if (ret) {
88		FLCNQ_ERR(msgq, "failed to read message header");
89		goto close;
90	}
91
92	if (hdr->size > MSG_BUF_SIZE) {
93		FLCNQ_ERR(msgq, "message too big, %d bytes", hdr->size);
94		ret = -ENOSPC;
95		goto close;
96	}
97
98	if (hdr->size > HDR_SIZE) {
99		u32 read_size = hdr->size - HDR_SIZE;
100
101		ret = nvkm_falcon_msgq_pop(msgq, (hdr + 1), read_size);
102		if (ret) {
103			FLCNQ_ERR(msgq, "failed to read message data");
104			goto close;
105		}
106	}
107
108	ret = 1;
109close:
110	nvkm_falcon_msgq_close(msgq, (ret >= 0));
111	return ret;
112}
113
114static int
115nvkm_falcon_msgq_exec(struct nvkm_falcon_msgq *msgq, struct nvfw_falcon_msg *hdr)
116{
117	struct nvkm_falcon_qmgr_seq *seq;
118
119	seq = &msgq->qmgr->seq.id[hdr->seq_id];
120	if (seq->state != SEQ_STATE_USED && seq->state != SEQ_STATE_CANCELLED) {
121		FLCNQ_ERR(msgq, "message for unknown sequence %08x", seq->id);
122		return -EINVAL;
123	}
124
125	if (seq->state == SEQ_STATE_USED) {
126		if (seq->callback)
127			seq->result = seq->callback(seq->priv, hdr);
128	}
129
130	if (seq->async) {
131		nvkm_falcon_qmgr_seq_release(msgq->qmgr, seq);
132		return 0;
133	}
134
135	complete_all(&seq->done);
136	return 0;
137}
138
139void
140nvkm_falcon_msgq_recv(struct nvkm_falcon_msgq *msgq)
141{
142	/*
143	 * We are invoked from a worker thread, so normally we have plenty of
144	 * stack space to work with.
145	 */
146	u8 msg_buffer[MSG_BUF_SIZE];
147	struct nvfw_falcon_msg *hdr = (void *)msg_buffer;
148
149	while (nvkm_falcon_msgq_read(msgq, hdr) > 0)
150		nvkm_falcon_msgq_exec(msgq, hdr);
151}
152
153int
154nvkm_falcon_msgq_recv_initmsg(struct nvkm_falcon_msgq *msgq,
155			      void *data, u32 size)
156{
157	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
158	struct nvfw_falcon_msg *hdr = data;
159	int ret;
160
161	msgq->head_reg = falcon->func->msgq.head;
162	msgq->tail_reg = falcon->func->msgq.tail;
163	msgq->offset = nvkm_falcon_rd32(falcon, falcon->func->msgq.tail);
164
165	nvkm_falcon_msgq_open(msgq);
166	ret = nvkm_falcon_msgq_pop(msgq, data, size);
167	if (ret == 0 && hdr->size != size) {
168		FLCN_ERR(falcon, "unexpected init message size %d vs %d",
169			 hdr->size, size);
170		ret = -EINVAL;
171	}
172	nvkm_falcon_msgq_close(msgq, ret == 0);
173	return ret;
174}
175
176void
177nvkm_falcon_msgq_init(struct nvkm_falcon_msgq *msgq,
178		      u32 index, u32 offset, u32 size)
179{
180	const struct nvkm_falcon_func *func = msgq->qmgr->falcon->func;
181
182	msgq->head_reg = func->msgq.head + index * func->msgq.stride;
183	msgq->tail_reg = func->msgq.tail + index * func->msgq.stride;
184	msgq->offset = offset;
185
186	FLCNQ_DBG(msgq, "initialised @ index %d offset 0x%08x size 0x%08x",
187		  index, msgq->offset, size);
188}
189
190void
191nvkm_falcon_msgq_del(struct nvkm_falcon_msgq **pmsgq)
192{
193	struct nvkm_falcon_msgq *msgq = *pmsgq;
194	if (msgq) {
195		kfree(*pmsgq);
196		*pmsgq = NULL;
197	}
198}
199
200int
201nvkm_falcon_msgq_new(struct nvkm_falcon_qmgr *qmgr, const char *name,
202		     struct nvkm_falcon_msgq **pmsgq)
203{
204	struct nvkm_falcon_msgq *msgq = *pmsgq;
205
206	if (!(msgq = *pmsgq = kzalloc(sizeof(*msgq), GFP_KERNEL)))
207		return -ENOMEM;
208
209	msgq->qmgr = qmgr;
210	msgq->name = name;
211	spin_lock_init(&msgq->lock);
212	return 0;
213}
214