1/*	$NetBSD: nouveau_nvkm_falcon_msgq.c,v 1.4 2021/12/19 11:34:45 riastradh Exp $	*/
2
3/*
4 * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25#include <sys/cdefs.h>
26__KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_falcon_msgq.c,v 1.4 2021/12/19 11:34:45 riastradh Exp $");
27
28#include "qmgr.h"
29
30#include <linux/nbsd-namespace.h>
31
32static void
33nvkm_falcon_msgq_open(struct nvkm_falcon_msgq *msgq)
34{
35	mutex_lock(&msgq->mutex);
36	msgq->position = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->tail_reg);
37}
38
39static void
40nvkm_falcon_msgq_close(struct nvkm_falcon_msgq *msgq, bool commit)
41{
42	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
43
44	if (commit)
45		nvkm_falcon_wr32(falcon, msgq->tail_reg, msgq->position);
46
47	mutex_unlock(&msgq->mutex);
48}
49
50static bool
51nvkm_falcon_msgq_empty(struct nvkm_falcon_msgq *msgq)
52{
53	u32 head = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->head_reg);
54	u32 tail = nvkm_falcon_rd32(msgq->qmgr->falcon, msgq->tail_reg);
55	return head == tail;
56}
57
58static int
59nvkm_falcon_msgq_pop(struct nvkm_falcon_msgq *msgq, void *data, u32 size)
60{
61	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
62	u32 head, tail, available;
63
64	head = nvkm_falcon_rd32(falcon, msgq->head_reg);
65	/* has the buffer looped? */
66	if (head < msgq->position)
67		msgq->position = msgq->offset;
68
69	tail = msgq->position;
70
71	available = head - tail;
72	if (size > available) {
73		FLCNQ_ERR(msgq, "requested %d bytes, but only %d available",
74			  size, available);
75		return -EINVAL;
76	}
77
78	nvkm_falcon_read_dmem(falcon, tail, size, 0, data);
79	msgq->position += ALIGN(size, QUEUE_ALIGNMENT);
80	return 0;
81}
82
83static int
84nvkm_falcon_msgq_read(struct nvkm_falcon_msgq *msgq, struct nv_falcon_msg *hdr)
85{
86	int ret = 0;
87
88	nvkm_falcon_msgq_open(msgq);
89
90	if (nvkm_falcon_msgq_empty(msgq))
91		goto close;
92
93	ret = nvkm_falcon_msgq_pop(msgq, hdr, HDR_SIZE);
94	if (ret) {
95		FLCNQ_ERR(msgq, "failed to read message header");
96		goto close;
97	}
98
99	if (hdr->size > MSG_BUF_SIZE) {
100		FLCNQ_ERR(msgq, "message too big, %d bytes", hdr->size);
101		ret = -ENOSPC;
102		goto close;
103	}
104
105	if (hdr->size > HDR_SIZE) {
106		u32 read_size = hdr->size - HDR_SIZE;
107
108		ret = nvkm_falcon_msgq_pop(msgq, (hdr + 1), read_size);
109		if (ret) {
110			FLCNQ_ERR(msgq, "failed to read message data");
111			goto close;
112		}
113	}
114
115	ret = 1;
116close:
117	nvkm_falcon_msgq_close(msgq, (ret >= 0));
118	return ret;
119}
120
121static int
122nvkm_falcon_msgq_exec(struct nvkm_falcon_msgq *msgq, struct nv_falcon_msg *hdr)
123{
124	struct nvkm_falcon_qmgr_seq *seq;
125
126	seq = &msgq->qmgr->seq.id[hdr->seq_id];
127	if (seq->state != SEQ_STATE_USED && seq->state != SEQ_STATE_CANCELLED) {
128		FLCNQ_ERR(msgq, "message for unknown sequence %08x", seq->id);
129		return -EINVAL;
130	}
131
132	if (seq->state == SEQ_STATE_USED) {
133		if (seq->callback)
134			seq->result = seq->callback(seq->priv, hdr);
135	}
136
137	if (seq->async) {
138		nvkm_falcon_qmgr_seq_release(msgq->qmgr, seq);
139		return 0;
140	}
141
142	complete_all(&seq->done);
143	return 0;
144}
145
146void
147nvkm_falcon_msgq_recv(struct nvkm_falcon_msgq *msgq)
148{
149	/*
150	 * We are invoked from a worker thread, so normally we have plenty of
151	 * stack space to work with.
152	 */
153	u8 msg_buffer[MSG_BUF_SIZE];
154	struct nv_falcon_msg *hdr = (void *)msg_buffer;
155
156	while (nvkm_falcon_msgq_read(msgq, hdr) > 0)
157		nvkm_falcon_msgq_exec(msgq, hdr);
158}
159
160int
161nvkm_falcon_msgq_recv_initmsg(struct nvkm_falcon_msgq *msgq,
162			      void *data, u32 size)
163{
164	struct nvkm_falcon *falcon = msgq->qmgr->falcon;
165	struct nv_falcon_msg *hdr = data;
166	int ret;
167
168	msgq->head_reg = falcon->func->msgq.head;
169	msgq->tail_reg = falcon->func->msgq.tail;
170	msgq->offset = nvkm_falcon_rd32(falcon, falcon->func->msgq.tail);
171
172	nvkm_falcon_msgq_open(msgq);
173	ret = nvkm_falcon_msgq_pop(msgq, data, size);
174	if (ret == 0 && hdr->size != size) {
175		FLCN_ERR(falcon, "unexpected init message size %d vs %d",
176			 hdr->size, size);
177		ret = -EINVAL;
178	}
179	nvkm_falcon_msgq_close(msgq, ret == 0);
180	return ret;
181}
182
183void
184nvkm_falcon_msgq_init(struct nvkm_falcon_msgq *msgq,
185		      u32 index, u32 offset, u32 size)
186{
187	const struct nvkm_falcon_func *func = msgq->qmgr->falcon->func;
188
189	msgq->head_reg = func->msgq.head + index * func->msgq.stride;
190	msgq->tail_reg = func->msgq.tail + index * func->msgq.stride;
191	msgq->offset = offset;
192
193	FLCNQ_DBG(msgq, "initialised @ index %d offset 0x%08x size 0x%08x",
194		  index, msgq->offset, size);
195}
196
197void
198nvkm_falcon_msgq_del(struct nvkm_falcon_msgq **pmsgq)
199{
200	struct nvkm_falcon_msgq *msgq = *pmsgq;
201	if (msgq) {
202		mutex_destroy(&msgq->mutex);
203		kfree(*pmsgq);
204		*pmsgq = NULL;
205	}
206}
207
208int
209nvkm_falcon_msgq_new(struct nvkm_falcon_qmgr *qmgr, const char *name,
210		     struct nvkm_falcon_msgq **pmsgq)
211{
212	struct nvkm_falcon_msgq *msgq = *pmsgq;
213
214	if (!(msgq = *pmsgq = kzalloc(sizeof(*msgq), GFP_KERNEL)))
215		return -ENOMEM;
216
217	msgq->qmgr = qmgr;
218	msgq->name = name;
219	mutex_init(&msgq->mutex);
220	return 0;
221}
222