xref: /openbmc/linux/drivers/gpu/host1x/hw/cdma_hw.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Tegra host1x Command DMA
4  *
5  * Copyright (c) 2010-2013, NVIDIA Corporation.
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/scatterlist.h>
10 #include <linux/dma-mapping.h>
11 
12 #include "../cdma.h"
13 #include "../channel.h"
14 #include "../dev.h"
15 #include "../debug.h"
16 
17 /*
18  * Put the restart at the end of pushbuffer memory
19  */
20 static void push_buffer_init(struct push_buffer *pb)
21 {
22 	*(u32 *)(pb->mapped + pb->size) = host1x_opcode_restart(0);
23 }
24 
25 /*
26  * Increment timedout buffer's syncpt via CPU.
27  */
28 static void cdma_timeout_cpu_incr(struct host1x_cdma *cdma, u32 getptr,
29 				u32 syncpt_incrs, u32 syncval, u32 nr_slots)
30 {
31 	unsigned int i;
32 
33 	for (i = 0; i < syncpt_incrs; i++)
34 		host1x_syncpt_incr(cdma->timeout.syncpt);
35 
36 	/* after CPU incr, ensure shadow is up to date */
37 	host1x_syncpt_load(cdma->timeout.syncpt);
38 }
39 
40 /*
41  * Start channel DMA
42  */
43 static void cdma_start(struct host1x_cdma *cdma)
44 {
45 	struct host1x_channel *ch = cdma_to_channel(cdma);
46 	u64 start, end;
47 
48 	if (cdma->running)
49 		return;
50 
51 	cdma->last_pos = cdma->push_buffer.pos;
52 	start = cdma->push_buffer.dma;
53 	end = cdma->push_buffer.size + 4;
54 
55 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP,
56 			 HOST1X_CHANNEL_DMACTRL);
57 
58 	/* set base, put and end pointer */
59 	host1x_ch_writel(ch, lower_32_bits(start), HOST1X_CHANNEL_DMASTART);
60 #if HOST1X_HW >= 6
61 	host1x_ch_writel(ch, upper_32_bits(start), HOST1X_CHANNEL_DMASTART_HI);
62 #endif
63 	host1x_ch_writel(ch, cdma->push_buffer.pos, HOST1X_CHANNEL_DMAPUT);
64 #if HOST1X_HW >= 6
65 	host1x_ch_writel(ch, 0, HOST1X_CHANNEL_DMAPUT_HI);
66 #endif
67 	host1x_ch_writel(ch, lower_32_bits(end), HOST1X_CHANNEL_DMAEND);
68 #if HOST1X_HW >= 6
69 	host1x_ch_writel(ch, upper_32_bits(end), HOST1X_CHANNEL_DMAEND_HI);
70 #endif
71 
72 	/* reset GET */
73 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP |
74 			 HOST1X_CHANNEL_DMACTRL_DMAGETRST |
75 			 HOST1X_CHANNEL_DMACTRL_DMAINITGET,
76 			 HOST1X_CHANNEL_DMACTRL);
77 
78 	/* start the command DMA */
79 	host1x_ch_writel(ch, 0, HOST1X_CHANNEL_DMACTRL);
80 
81 	cdma->running = true;
82 }
83 
84 /*
85  * Similar to cdma_start(), but rather than starting from an idle
86  * state (where DMA GET is set to DMA PUT), on a timeout we restore
87  * DMA GET from an explicit value (so DMA may again be pending).
88  */
89 static void cdma_timeout_restart(struct host1x_cdma *cdma, u32 getptr)
90 {
91 	struct host1x *host1x = cdma_to_host1x(cdma);
92 	struct host1x_channel *ch = cdma_to_channel(cdma);
93 	u64 start, end;
94 
95 	if (cdma->running)
96 		return;
97 
98 	cdma->last_pos = cdma->push_buffer.pos;
99 
100 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP,
101 			 HOST1X_CHANNEL_DMACTRL);
102 
103 	start = cdma->push_buffer.dma;
104 	end = cdma->push_buffer.size + 4;
105 
106 	/* set base, end pointer (all of memory) */
107 	host1x_ch_writel(ch, lower_32_bits(start), HOST1X_CHANNEL_DMASTART);
108 #if HOST1X_HW >= 6
109 	host1x_ch_writel(ch, upper_32_bits(start), HOST1X_CHANNEL_DMASTART_HI);
110 #endif
111 	host1x_ch_writel(ch, lower_32_bits(end), HOST1X_CHANNEL_DMAEND);
112 #if HOST1X_HW >= 6
113 	host1x_ch_writel(ch, upper_32_bits(end), HOST1X_CHANNEL_DMAEND_HI);
114 #endif
115 
116 	/* set GET, by loading the value in PUT (then reset GET) */
117 	host1x_ch_writel(ch, getptr, HOST1X_CHANNEL_DMAPUT);
118 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP |
119 			 HOST1X_CHANNEL_DMACTRL_DMAGETRST |
120 			 HOST1X_CHANNEL_DMACTRL_DMAINITGET,
121 			 HOST1X_CHANNEL_DMACTRL);
122 
123 	dev_dbg(host1x->dev,
124 		"%s: DMA GET 0x%x, PUT HW 0x%x / shadow 0x%x\n", __func__,
125 		host1x_ch_readl(ch, HOST1X_CHANNEL_DMAGET),
126 		host1x_ch_readl(ch, HOST1X_CHANNEL_DMAPUT),
127 		cdma->last_pos);
128 
129 	/* deassert GET reset and set PUT */
130 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP,
131 			 HOST1X_CHANNEL_DMACTRL);
132 	host1x_ch_writel(ch, cdma->push_buffer.pos, HOST1X_CHANNEL_DMAPUT);
133 
134 	/* start the command DMA */
135 	host1x_ch_writel(ch, 0, HOST1X_CHANNEL_DMACTRL);
136 
137 	cdma->running = true;
138 }
139 
140 /*
141  * Kick channel DMA into action by writing its PUT offset (if it has changed)
142  */
143 static void cdma_flush(struct host1x_cdma *cdma)
144 {
145 	struct host1x_channel *ch = cdma_to_channel(cdma);
146 
147 	if (cdma->push_buffer.pos != cdma->last_pos) {
148 		host1x_ch_writel(ch, cdma->push_buffer.pos,
149 				 HOST1X_CHANNEL_DMAPUT);
150 		cdma->last_pos = cdma->push_buffer.pos;
151 	}
152 }
153 
154 static void cdma_stop(struct host1x_cdma *cdma)
155 {
156 	struct host1x_channel *ch = cdma_to_channel(cdma);
157 
158 	mutex_lock(&cdma->lock);
159 
160 	if (cdma->running) {
161 		host1x_cdma_wait_locked(cdma, CDMA_EVENT_SYNC_QUEUE_EMPTY);
162 		host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP,
163 				 HOST1X_CHANNEL_DMACTRL);
164 		cdma->running = false;
165 	}
166 
167 	mutex_unlock(&cdma->lock);
168 }
169 
170 static void cdma_hw_cmdproc_stop(struct host1x *host, struct host1x_channel *ch,
171 				 bool stop)
172 {
173 #if HOST1X_HW >= 6
174 	host1x_ch_writel(ch, stop ? 0x1 : 0x0, HOST1X_CHANNEL_CMDPROC_STOP);
175 #else
176 	u32 cmdproc_stop = host1x_sync_readl(host, HOST1X_SYNC_CMDPROC_STOP);
177 	if (stop)
178 		cmdproc_stop |= BIT(ch->id);
179 	else
180 		cmdproc_stop &= ~BIT(ch->id);
181 	host1x_sync_writel(host, cmdproc_stop, HOST1X_SYNC_CMDPROC_STOP);
182 #endif
183 }
184 
185 static void cdma_hw_teardown(struct host1x *host, struct host1x_channel *ch)
186 {
187 #if HOST1X_HW >= 6
188 	host1x_ch_writel(ch, 0x1, HOST1X_CHANNEL_TEARDOWN);
189 #else
190 	host1x_sync_writel(host, BIT(ch->id), HOST1X_SYNC_CH_TEARDOWN);
191 #endif
192 }
193 
194 /*
195  * Stops both channel's command processor and CDMA immediately.
196  * Also, tears down the channel and resets corresponding module.
197  */
198 static void cdma_freeze(struct host1x_cdma *cdma)
199 {
200 	struct host1x *host = cdma_to_host1x(cdma);
201 	struct host1x_channel *ch = cdma_to_channel(cdma);
202 
203 	if (cdma->torndown && !cdma->running) {
204 		dev_warn(host->dev, "Already torn down\n");
205 		return;
206 	}
207 
208 	dev_dbg(host->dev, "freezing channel (id %d)\n", ch->id);
209 
210 	cdma_hw_cmdproc_stop(host, ch, true);
211 
212 	dev_dbg(host->dev, "%s: DMA GET 0x%x, PUT HW 0x%x / shadow 0x%x\n",
213 		__func__, host1x_ch_readl(ch, HOST1X_CHANNEL_DMAGET),
214 		host1x_ch_readl(ch, HOST1X_CHANNEL_DMAPUT),
215 		cdma->last_pos);
216 
217 	host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP,
218 			 HOST1X_CHANNEL_DMACTRL);
219 
220 	cdma_hw_teardown(host, ch);
221 
222 	cdma->running = false;
223 	cdma->torndown = true;
224 }
225 
226 static void cdma_resume(struct host1x_cdma *cdma, u32 getptr)
227 {
228 	struct host1x *host1x = cdma_to_host1x(cdma);
229 	struct host1x_channel *ch = cdma_to_channel(cdma);
230 
231 	dev_dbg(host1x->dev,
232 		"resuming channel (id %u, DMAGET restart = 0x%x)\n",
233 		ch->id, getptr);
234 
235 	cdma_hw_cmdproc_stop(host1x, ch, false);
236 
237 	cdma->torndown = false;
238 	cdma_timeout_restart(cdma, getptr);
239 }
240 
241 /*
242  * If this timeout fires, it indicates the current sync_queue entry has
243  * exceeded its TTL and the userctx should be timed out and remaining
244  * submits already issued cleaned up (future submits return an error).
245  */
246 static void cdma_timeout_handler(struct work_struct *work)
247 {
248 	u32 syncpt_val;
249 	struct host1x_cdma *cdma;
250 	struct host1x *host1x;
251 	struct host1x_channel *ch;
252 
253 	cdma = container_of(to_delayed_work(work), struct host1x_cdma,
254 			    timeout.wq);
255 	host1x = cdma_to_host1x(cdma);
256 	ch = cdma_to_channel(cdma);
257 
258 	host1x_debug_dump(cdma_to_host1x(cdma));
259 
260 	mutex_lock(&cdma->lock);
261 
262 	if (!cdma->timeout.client) {
263 		dev_dbg(host1x->dev,
264 			"cdma_timeout: expired, but has no clientid\n");
265 		mutex_unlock(&cdma->lock);
266 		return;
267 	}
268 
269 	/* stop processing to get a clean snapshot */
270 	cdma_hw_cmdproc_stop(host1x, ch, true);
271 
272 	syncpt_val = host1x_syncpt_load(cdma->timeout.syncpt);
273 
274 	/* has buffer actually completed? */
275 	if ((s32)(syncpt_val - cdma->timeout.syncpt_val) >= 0) {
276 		dev_dbg(host1x->dev,
277 			"cdma_timeout: expired, but buffer had completed\n");
278 		/* restore */
279 		cdma_hw_cmdproc_stop(host1x, ch, false);
280 		mutex_unlock(&cdma->lock);
281 		return;
282 	}
283 
284 	dev_warn(host1x->dev, "%s: timeout: %u (%s), HW thresh %d, done %d\n",
285 		 __func__, cdma->timeout.syncpt->id, cdma->timeout.syncpt->name,
286 		 syncpt_val, cdma->timeout.syncpt_val);
287 
288 	/* stop HW, resetting channel/module */
289 	host1x_hw_cdma_freeze(host1x, cdma);
290 
291 	host1x_cdma_update_sync_queue(cdma, ch->dev);
292 	mutex_unlock(&cdma->lock);
293 }
294 
295 /*
296  * Init timeout resources
297  */
298 static int cdma_timeout_init(struct host1x_cdma *cdma, unsigned int syncpt)
299 {
300 	INIT_DELAYED_WORK(&cdma->timeout.wq, cdma_timeout_handler);
301 	cdma->timeout.initialized = true;
302 
303 	return 0;
304 }
305 
306 /*
307  * Clean up timeout resources
308  */
309 static void cdma_timeout_destroy(struct host1x_cdma *cdma)
310 {
311 	if (cdma->timeout.initialized)
312 		cancel_delayed_work(&cdma->timeout.wq);
313 
314 	cdma->timeout.initialized = false;
315 }
316 
317 static const struct host1x_cdma_ops host1x_cdma_ops = {
318 	.start = cdma_start,
319 	.stop = cdma_stop,
320 	.flush = cdma_flush,
321 
322 	.timeout_init = cdma_timeout_init,
323 	.timeout_destroy = cdma_timeout_destroy,
324 	.freeze = cdma_freeze,
325 	.resume = cdma_resume,
326 	.timeout_cpu_incr = cdma_timeout_cpu_incr,
327 };
328 
329 static const struct host1x_pushbuffer_ops host1x_pushbuffer_ops = {
330 	.init = push_buffer_init,
331 };
332