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 bool
26nvkm_falcon_cmdq_has_room(struct nvkm_falcon_cmdq *cmdq, u32 size, bool *rewind)
27{
28	u32 head = nvkm_falcon_rd32(cmdq->qmgr->falcon, cmdq->head_reg);
29	u32 tail = nvkm_falcon_rd32(cmdq->qmgr->falcon, cmdq->tail_reg);
30	u32 free;
31
32	size = ALIGN(size, QUEUE_ALIGNMENT);
33
34	if (head >= tail) {
35		free = cmdq->offset + cmdq->size - head;
36		free -= HDR_SIZE;
37
38		if (size > free) {
39			*rewind = true;
40			head = cmdq->offset;
41		}
42	}
43
44	if (head < tail)
45		free = tail - head - 1;
46
47	return size <= free;
48}
49
50static void
51nvkm_falcon_cmdq_push(struct nvkm_falcon_cmdq *cmdq, void *data, u32 size)
52{
53	struct nvkm_falcon *falcon = cmdq->qmgr->falcon;
54	nvkm_falcon_pio_wr(falcon, data, 0, 0, DMEM, cmdq->position, size, 0, false);
55	cmdq->position += ALIGN(size, QUEUE_ALIGNMENT);
56}
57
58static void
59nvkm_falcon_cmdq_rewind(struct nvkm_falcon_cmdq *cmdq)
60{
61	struct nvfw_falcon_cmd cmd;
62
63	cmd.unit_id = NV_FALCON_CMD_UNIT_ID_REWIND;
64	cmd.size = sizeof(cmd);
65	nvkm_falcon_cmdq_push(cmdq, &cmd, cmd.size);
66
67	cmdq->position = cmdq->offset;
68}
69
70static int
71nvkm_falcon_cmdq_open(struct nvkm_falcon_cmdq *cmdq, u32 size)
72{
73	struct nvkm_falcon *falcon = cmdq->qmgr->falcon;
74	bool rewind = false;
75
76	mutex_lock(&cmdq->mutex);
77
78	if (!nvkm_falcon_cmdq_has_room(cmdq, size, &rewind)) {
79		FLCNQ_DBG(cmdq, "queue full");
80		mutex_unlock(&cmdq->mutex);
81		return -EAGAIN;
82	}
83
84	cmdq->position = nvkm_falcon_rd32(falcon, cmdq->head_reg);
85
86	if (rewind)
87		nvkm_falcon_cmdq_rewind(cmdq);
88
89	return 0;
90}
91
92static void
93nvkm_falcon_cmdq_close(struct nvkm_falcon_cmdq *cmdq)
94{
95	nvkm_falcon_wr32(cmdq->qmgr->falcon, cmdq->head_reg, cmdq->position);
96	mutex_unlock(&cmdq->mutex);
97}
98
99static int
100nvkm_falcon_cmdq_write(struct nvkm_falcon_cmdq *cmdq, struct nvfw_falcon_cmd *cmd)
101{
102	static unsigned timeout = 2000;
103	unsigned long end_jiffies = jiffies + msecs_to_jiffies(timeout);
104	int ret = -EAGAIN;
105
106	while (ret == -EAGAIN && time_before(jiffies, end_jiffies))
107		ret = nvkm_falcon_cmdq_open(cmdq, cmd->size);
108	if (ret) {
109		FLCNQ_ERR(cmdq, "timeout waiting for queue space");
110		return ret;
111	}
112
113	nvkm_falcon_cmdq_push(cmdq, cmd, cmd->size);
114	nvkm_falcon_cmdq_close(cmdq);
115	return ret;
116}
117
118/* specifies that we want to know the command status in the answer message */
119#define CMD_FLAGS_STATUS BIT(0)
120/* specifies that we want an interrupt when the answer message is queued */
121#define CMD_FLAGS_INTR BIT(1)
122
123int
124nvkm_falcon_cmdq_send(struct nvkm_falcon_cmdq *cmdq, struct nvfw_falcon_cmd *cmd,
125		      nvkm_falcon_qmgr_callback cb, void *priv,
126		      unsigned long timeout)
127{
128	struct nvkm_falcon_qmgr_seq *seq;
129	int ret;
130
131	if (!wait_for_completion_timeout(&cmdq->ready,
132					 msecs_to_jiffies(1000))) {
133		FLCNQ_ERR(cmdq, "timeout waiting for queue ready");
134		return -ETIMEDOUT;
135	}
136
137	seq = nvkm_falcon_qmgr_seq_acquire(cmdq->qmgr);
138	if (IS_ERR(seq))
139		return PTR_ERR(seq);
140
141	cmd->seq_id = seq->id;
142	cmd->ctrl_flags = CMD_FLAGS_STATUS | CMD_FLAGS_INTR;
143
144	seq->state = SEQ_STATE_USED;
145	seq->async = !timeout;
146	seq->callback = cb;
147	seq->priv = priv;
148
149	ret = nvkm_falcon_cmdq_write(cmdq, cmd);
150	if (ret) {
151		seq->state = SEQ_STATE_PENDING;
152		nvkm_falcon_qmgr_seq_release(cmdq->qmgr, seq);
153		return ret;
154	}
155
156	if (!seq->async) {
157		if (!wait_for_completion_timeout(&seq->done, timeout)) {
158			FLCNQ_ERR(cmdq, "timeout waiting for reply");
159			return -ETIMEDOUT;
160		}
161		ret = seq->result;
162		nvkm_falcon_qmgr_seq_release(cmdq->qmgr, seq);
163	}
164
165	return ret;
166}
167
168void
169nvkm_falcon_cmdq_fini(struct nvkm_falcon_cmdq *cmdq)
170{
171	reinit_completion(&cmdq->ready);
172}
173
174void
175nvkm_falcon_cmdq_init(struct nvkm_falcon_cmdq *cmdq,
176		      u32 index, u32 offset, u32 size)
177{
178	const struct nvkm_falcon_func *func = cmdq->qmgr->falcon->func;
179
180	cmdq->head_reg = func->cmdq.head + index * func->cmdq.stride;
181	cmdq->tail_reg = func->cmdq.tail + index * func->cmdq.stride;
182	cmdq->offset = offset;
183	cmdq->size = size;
184	complete_all(&cmdq->ready);
185
186	FLCNQ_DBG(cmdq, "initialised @ index %d offset 0x%08x size 0x%08x",
187		  index, cmdq->offset, cmdq->size);
188}
189
190void
191nvkm_falcon_cmdq_del(struct nvkm_falcon_cmdq **pcmdq)
192{
193	struct nvkm_falcon_cmdq *cmdq = *pcmdq;
194	if (cmdq) {
195		kfree(*pcmdq);
196		*pcmdq = NULL;
197	}
198}
199
200int
201nvkm_falcon_cmdq_new(struct nvkm_falcon_qmgr *qmgr, const char *name,
202		     struct nvkm_falcon_cmdq **pcmdq)
203{
204	struct nvkm_falcon_cmdq *cmdq = *pcmdq;
205
206	if (!(cmdq = *pcmdq = kzalloc(sizeof(*cmdq), GFP_KERNEL)))
207		return -ENOMEM;
208
209	cmdq->qmgr = qmgr;
210	cmdq->name = name;
211	mutex_init(&cmdq->mutex);
212	init_completion(&cmdq->ready);
213	return 0;
214}
215