1 /*
2  * Copyright (C) 2007 Ben Skeggs.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial
15  * portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  *
25  */
26 
27 #include "drmP.h"
28 #include "drm.h"
29 #include "nouveau_drv.h"
30 #include "nouveau_dma.h"
31 #include "nouveau_ramht.h"
32 
33 void
34 nouveau_dma_pre_init(struct nouveau_channel *chan)
35 {
36 	struct drm_nouveau_private *dev_priv = chan->dev->dev_private;
37 	struct nouveau_bo *pushbuf = chan->pushbuf_bo;
38 
39 	if (dev_priv->card_type >= NV_50) {
40 		const int ib_size = pushbuf->bo.mem.size / 2;
41 
42 		chan->dma.ib_base = (pushbuf->bo.mem.size - ib_size) >> 2;
43 		chan->dma.ib_max = (ib_size / 8) - 1;
44 		chan->dma.ib_put = 0;
45 		chan->dma.ib_free = chan->dma.ib_max - chan->dma.ib_put;
46 
47 		chan->dma.max = (pushbuf->bo.mem.size - ib_size) >> 2;
48 	} else {
49 		chan->dma.max  = (pushbuf->bo.mem.size >> 2) - 2;
50 	}
51 
52 	chan->dma.put  = 0;
53 	chan->dma.cur  = chan->dma.put;
54 	chan->dma.free = chan->dma.max - chan->dma.cur;
55 }
56 
57 int
58 nouveau_dma_init(struct nouveau_channel *chan)
59 {
60 	struct drm_device *dev = chan->dev;
61 	struct drm_nouveau_private *dev_priv = dev->dev_private;
62 	int ret, i;
63 
64 	if (dev_priv->card_type >= NV_C0) {
65 		ret = nouveau_gpuobj_gr_new(chan, 0x9039, 0x9039);
66 		if (ret)
67 			return ret;
68 
69 		ret = RING_SPACE(chan, 2);
70 		if (ret)
71 			return ret;
72 
73 		BEGIN_NVC0(chan, 2, NvSubM2MF, 0x0000, 1);
74 		OUT_RING  (chan, 0x00009039);
75 		FIRE_RING (chan);
76 		return 0;
77 	}
78 
79 	/* Create NV_MEMORY_TO_MEMORY_FORMAT for buffer moves */
80 	ret = nouveau_gpuobj_gr_new(chan, NvM2MF, dev_priv->card_type < NV_50 ?
81 				    0x0039 : 0x5039);
82 	if (ret)
83 		return ret;
84 
85 	/* NV_MEMORY_TO_MEMORY_FORMAT requires a notifier object */
86 	ret = nouveau_notifier_alloc(chan, NvNotify0, 32, 0xfe0, 0x1000,
87 				     &chan->m2mf_ntfy);
88 	if (ret)
89 		return ret;
90 
91 	/* Insert NOPS for NOUVEAU_DMA_SKIPS */
92 	ret = RING_SPACE(chan, NOUVEAU_DMA_SKIPS);
93 	if (ret)
94 		return ret;
95 
96 	for (i = 0; i < NOUVEAU_DMA_SKIPS; i++)
97 		OUT_RING(chan, 0);
98 
99 	/* Initialise NV_MEMORY_TO_MEMORY_FORMAT */
100 	ret = RING_SPACE(chan, 6);
101 	if (ret)
102 		return ret;
103 	BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_NAME, 1);
104 	OUT_RING  (chan, NvM2MF);
105 	BEGIN_RING(chan, NvSubM2MF, NV_MEMORY_TO_MEMORY_FORMAT_DMA_NOTIFY, 3);
106 	OUT_RING  (chan, NvNotify0);
107 	OUT_RING  (chan, chan->vram_handle);
108 	OUT_RING  (chan, chan->gart_handle);
109 
110 	/* Sit back and pray the channel works.. */
111 	FIRE_RING(chan);
112 
113 	return 0;
114 }
115 
116 void
117 OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
118 {
119 	bool is_iomem;
120 	u32 *mem = ttm_kmap_obj_virtual(&chan->pushbuf_bo->kmap, &is_iomem);
121 	mem = &mem[chan->dma.cur];
122 	if (is_iomem)
123 		memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
124 	else
125 		memcpy(mem, data, nr_dwords * 4);
126 	chan->dma.cur += nr_dwords;
127 }
128 
129 /* Fetch and adjust GPU GET pointer
130  *
131  * Returns:
132  *  value >= 0, the adjusted GET pointer
133  *  -EINVAL if GET pointer currently outside main push buffer
134  *  -EBUSY if timeout exceeded
135  */
136 static inline int
137 READ_GET(struct nouveau_channel *chan, uint64_t *prev_get, int *timeout)
138 {
139 	uint64_t val;
140 
141 	val = nvchan_rd32(chan, chan->user_get);
142         if (chan->user_get_hi)
143                 val |= (uint64_t)nvchan_rd32(chan, chan->user_get_hi) << 32;
144 
145 	/* reset counter as long as GET is still advancing, this is
146 	 * to avoid misdetecting a GPU lockup if the GPU happens to
147 	 * just be processing an operation that takes a long time
148 	 */
149 	if (val != *prev_get) {
150 		*prev_get = val;
151 		*timeout = 0;
152 	}
153 
154 	if ((++*timeout & 0xff) == 0) {
155 		DRM_UDELAY(1);
156 		if (*timeout > 100000)
157 			return -EBUSY;
158 	}
159 
160 	if (val < chan->pushbuf_base ||
161 	    val > chan->pushbuf_base + (chan->dma.max << 2))
162 		return -EINVAL;
163 
164 	return (val - chan->pushbuf_base) >> 2;
165 }
166 
167 void
168 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
169 	      int delta, int length)
170 {
171 	struct nouveau_bo *pb = chan->pushbuf_bo;
172 	struct nouveau_vma *vma;
173 	int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
174 	u64 offset;
175 
176 	vma = nouveau_bo_vma_find(bo, chan->vm);
177 	BUG_ON(!vma);
178 	offset = vma->offset + delta;
179 
180 	BUG_ON(chan->dma.ib_free < 1);
181 	nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
182 	nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
183 
184 	chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
185 
186 	DRM_MEMORYBARRIER();
187 	/* Flush writes. */
188 	nouveau_bo_rd32(pb, 0);
189 
190 	nvchan_wr32(chan, 0x8c, chan->dma.ib_put);
191 	chan->dma.ib_free--;
192 }
193 
194 static int
195 nv50_dma_push_wait(struct nouveau_channel *chan, int count)
196 {
197 	uint32_t cnt = 0, prev_get = 0;
198 
199 	while (chan->dma.ib_free < count) {
200 		uint32_t get = nvchan_rd32(chan, 0x88);
201 		if (get != prev_get) {
202 			prev_get = get;
203 			cnt = 0;
204 		}
205 
206 		if ((++cnt & 0xff) == 0) {
207 			DRM_UDELAY(1);
208 			if (cnt > 100000)
209 				return -EBUSY;
210 		}
211 
212 		chan->dma.ib_free = get - chan->dma.ib_put;
213 		if (chan->dma.ib_free <= 0)
214 			chan->dma.ib_free += chan->dma.ib_max;
215 	}
216 
217 	return 0;
218 }
219 
220 static int
221 nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
222 {
223 	uint64_t prev_get = 0;
224 	int ret, cnt = 0;
225 
226 	ret = nv50_dma_push_wait(chan, slots + 1);
227 	if (unlikely(ret))
228 		return ret;
229 
230 	while (chan->dma.free < count) {
231 		int get = READ_GET(chan, &prev_get, &cnt);
232 		if (unlikely(get < 0)) {
233 			if (get == -EINVAL)
234 				continue;
235 
236 			return get;
237 		}
238 
239 		if (get <= chan->dma.cur) {
240 			chan->dma.free = chan->dma.max - chan->dma.cur;
241 			if (chan->dma.free >= count)
242 				break;
243 
244 			FIRE_RING(chan);
245 			do {
246 				get = READ_GET(chan, &prev_get, &cnt);
247 				if (unlikely(get < 0)) {
248 					if (get == -EINVAL)
249 						continue;
250 					return get;
251 				}
252 			} while (get == 0);
253 			chan->dma.cur = 0;
254 			chan->dma.put = 0;
255 		}
256 
257 		chan->dma.free = get - chan->dma.cur - 1;
258 	}
259 
260 	return 0;
261 }
262 
263 int
264 nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
265 {
266 	uint64_t prev_get = 0;
267 	int cnt = 0, get;
268 
269 	if (chan->dma.ib_max)
270 		return nv50_dma_wait(chan, slots, size);
271 
272 	while (chan->dma.free < size) {
273 		get = READ_GET(chan, &prev_get, &cnt);
274 		if (unlikely(get == -EBUSY))
275 			return -EBUSY;
276 
277 		/* loop until we have a usable GET pointer.  the value
278 		 * we read from the GPU may be outside the main ring if
279 		 * PFIFO is processing a buffer called from the main ring,
280 		 * discard these values until something sensible is seen.
281 		 *
282 		 * the other case we discard GET is while the GPU is fetching
283 		 * from the SKIPS area, so the code below doesn't have to deal
284 		 * with some fun corner cases.
285 		 */
286 		if (unlikely(get == -EINVAL) || get < NOUVEAU_DMA_SKIPS)
287 			continue;
288 
289 		if (get <= chan->dma.cur) {
290 			/* engine is fetching behind us, or is completely
291 			 * idle (GET == PUT) so we have free space up until
292 			 * the end of the push buffer
293 			 *
294 			 * we can only hit that path once per call due to
295 			 * looping back to the beginning of the push buffer,
296 			 * we'll hit the fetching-ahead-of-us path from that
297 			 * point on.
298 			 *
299 			 * the *one* exception to that rule is if we read
300 			 * GET==PUT, in which case the below conditional will
301 			 * always succeed and break us out of the wait loop.
302 			 */
303 			chan->dma.free = chan->dma.max - chan->dma.cur;
304 			if (chan->dma.free >= size)
305 				break;
306 
307 			/* not enough space left at the end of the push buffer,
308 			 * instruct the GPU to jump back to the start right
309 			 * after processing the currently pending commands.
310 			 */
311 			OUT_RING(chan, chan->pushbuf_base | 0x20000000);
312 
313 			/* wait for GET to depart from the skips area.
314 			 * prevents writing GET==PUT and causing a race
315 			 * condition that causes us to think the GPU is
316 			 * idle when it's not.
317 			 */
318 			do {
319 				get = READ_GET(chan, &prev_get, &cnt);
320 				if (unlikely(get == -EBUSY))
321 					return -EBUSY;
322 				if (unlikely(get == -EINVAL))
323 					continue;
324 			} while (get <= NOUVEAU_DMA_SKIPS);
325 			WRITE_PUT(NOUVEAU_DMA_SKIPS);
326 
327 			/* we're now submitting commands at the start of
328 			 * the push buffer.
329 			 */
330 			chan->dma.cur  =
331 			chan->dma.put  = NOUVEAU_DMA_SKIPS;
332 		}
333 
334 		/* engine fetching ahead of us, we have space up until the
335 		 * current GET pointer.  the "- 1" is to ensure there's
336 		 * space left to emit a jump back to the beginning of the
337 		 * push buffer if we require it.  we can never get GET == PUT
338 		 * here, so this is safe.
339 		 */
340 		chan->dma.free = get - chan->dma.cur - 1;
341 	}
342 
343 	return 0;
344 }
345 
346