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 "nouveau_drm.h"
28 #include "nouveau_dma.h"
29
30 void
OUT_RINGp(struct nouveau_channel * chan,const void * data,unsigned nr_dwords)31 OUT_RINGp(struct nouveau_channel *chan, const void *data, unsigned nr_dwords)
32 {
33 bool is_iomem;
34 u32 *mem = ttm_kmap_obj_virtual(&chan->push.buffer->kmap, &is_iomem);
35 mem = &mem[chan->dma.cur];
36 if (is_iomem)
37 memcpy_toio((void __force __iomem *)mem, data, nr_dwords * 4);
38 else
39 memcpy(mem, data, nr_dwords * 4);
40 chan->dma.cur += nr_dwords;
41 }
42
43 /* Fetch and adjust GPU GET pointer
44 *
45 * Returns:
46 * value >= 0, the adjusted GET pointer
47 * -EINVAL if GET pointer currently outside main push buffer
48 * -EBUSY if timeout exceeded
49 */
50 static inline int
READ_GET(struct nouveau_channel * chan,uint64_t * prev_get,int * timeout)51 READ_GET(struct nouveau_channel *chan, uint64_t *prev_get, int *timeout)
52 {
53 uint64_t val;
54
55 val = nvif_rd32(chan, chan->user_get);
56 if (chan->user_get_hi)
57 val |= (uint64_t)nvif_rd32(chan, chan->user_get_hi) << 32;
58
59 /* reset counter as long as GET is still advancing, this is
60 * to avoid misdetecting a GPU lockup if the GPU happens to
61 * just be processing an operation that takes a long time
62 */
63 if (val != *prev_get) {
64 *prev_get = val;
65 *timeout = 0;
66 }
67
68 if ((++*timeout & 0xff) == 0) {
69 udelay(1);
70 if (*timeout > 100000)
71 return -EBUSY;
72 }
73
74 if (val < chan->push.vma.offset ||
75 val > chan->push.vma.offset + (chan->dma.max << 2))
76 return -EINVAL;
77
78 return (val - chan->push.vma.offset) >> 2;
79 }
80
81 void
nv50_dma_push(struct nouveau_channel * chan,struct nouveau_bo * bo,int delta,int length)82 nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
83 int delta, int length)
84 {
85 struct nouveau_cli *cli = (void *)nvif_client(&chan->device->base);
86 struct nouveau_bo *pb = chan->push.buffer;
87 struct nouveau_vma *vma;
88 int ip = (chan->dma.ib_put * 2) + chan->dma.ib_base;
89 u64 offset;
90
91 vma = nouveau_bo_vma_find(bo, cli->vm);
92 BUG_ON(!vma);
93 offset = vma->offset + delta;
94
95 BUG_ON(chan->dma.ib_free < 1);
96
97 nouveau_bo_wr32(pb, ip++, lower_32_bits(offset));
98 nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
99
100 chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
101
102 mb();
103 /* Flush writes. */
104 nouveau_bo_rd32(pb, 0);
105
106 nvif_wr32(chan, 0x8c, chan->dma.ib_put);
107 chan->dma.ib_free--;
108 }
109
110 static int
nv50_dma_push_wait(struct nouveau_channel * chan,int count)111 nv50_dma_push_wait(struct nouveau_channel *chan, int count)
112 {
113 uint32_t cnt = 0, prev_get = 0;
114
115 while (chan->dma.ib_free < count) {
116 uint32_t get = nvif_rd32(chan, 0x88);
117 if (get != prev_get) {
118 prev_get = get;
119 cnt = 0;
120 }
121
122 if ((++cnt & 0xff) == 0) {
123 DRM_UDELAY(1);
124 if (cnt > 100000)
125 return -EBUSY;
126 }
127
128 chan->dma.ib_free = get - chan->dma.ib_put;
129 if (chan->dma.ib_free <= 0)
130 chan->dma.ib_free += chan->dma.ib_max;
131 }
132
133 return 0;
134 }
135
136 static int
nv50_dma_wait(struct nouveau_channel * chan,int slots,int count)137 nv50_dma_wait(struct nouveau_channel *chan, int slots, int count)
138 {
139 uint64_t prev_get = 0;
140 int ret, cnt = 0;
141
142 ret = nv50_dma_push_wait(chan, slots + 1);
143 if (unlikely(ret))
144 return ret;
145
146 while (chan->dma.free < count) {
147 int get = READ_GET(chan, &prev_get, &cnt);
148 if (unlikely(get < 0)) {
149 if (get == -EINVAL)
150 continue;
151
152 return get;
153 }
154
155 if (get <= chan->dma.cur) {
156 chan->dma.free = chan->dma.max - chan->dma.cur;
157 if (chan->dma.free >= count)
158 break;
159
160 FIRE_RING(chan);
161 do {
162 get = READ_GET(chan, &prev_get, &cnt);
163 if (unlikely(get < 0)) {
164 if (get == -EINVAL)
165 continue;
166 return get;
167 }
168 } while (get == 0);
169 chan->dma.cur = 0;
170 chan->dma.put = 0;
171 }
172
173 chan->dma.free = get - chan->dma.cur - 1;
174 }
175
176 return 0;
177 }
178
179 int
nouveau_dma_wait(struct nouveau_channel * chan,int slots,int size)180 nouveau_dma_wait(struct nouveau_channel *chan, int slots, int size)
181 {
182 uint64_t prev_get = 0;
183 int cnt = 0, get;
184
185 if (chan->dma.ib_max)
186 return nv50_dma_wait(chan, slots, size);
187
188 while (chan->dma.free < size) {
189 get = READ_GET(chan, &prev_get, &cnt);
190 if (unlikely(get == -EBUSY))
191 return -EBUSY;
192
193 /* loop until we have a usable GET pointer. the value
194 * we read from the GPU may be outside the main ring if
195 * PFIFO is processing a buffer called from the main ring,
196 * discard these values until something sensible is seen.
197 *
198 * the other case we discard GET is while the GPU is fetching
199 * from the SKIPS area, so the code below doesn't have to deal
200 * with some fun corner cases.
201 */
202 if (unlikely(get == -EINVAL) || get < NOUVEAU_DMA_SKIPS)
203 continue;
204
205 if (get <= chan->dma.cur) {
206 /* engine is fetching behind us, or is completely
207 * idle (GET == PUT) so we have free space up until
208 * the end of the push buffer
209 *
210 * we can only hit that path once per call due to
211 * looping back to the beginning of the push buffer,
212 * we'll hit the fetching-ahead-of-us path from that
213 * point on.
214 *
215 * the *one* exception to that rule is if we read
216 * GET==PUT, in which case the below conditional will
217 * always succeed and break us out of the wait loop.
218 */
219 chan->dma.free = chan->dma.max - chan->dma.cur;
220 if (chan->dma.free >= size)
221 break;
222
223 /* not enough space left at the end of the push buffer,
224 * instruct the GPU to jump back to the start right
225 * after processing the currently pending commands.
226 */
227 OUT_RING(chan, chan->push.vma.offset | 0x20000000);
228
229 /* wait for GET to depart from the skips area.
230 * prevents writing GET==PUT and causing a race
231 * condition that causes us to think the GPU is
232 * idle when it's not.
233 */
234 do {
235 get = READ_GET(chan, &prev_get, &cnt);
236 if (unlikely(get == -EBUSY))
237 return -EBUSY;
238 if (unlikely(get == -EINVAL))
239 continue;
240 } while (get <= NOUVEAU_DMA_SKIPS);
241 WRITE_PUT(NOUVEAU_DMA_SKIPS);
242
243 /* we're now submitting commands at the start of
244 * the push buffer.
245 */
246 chan->dma.cur =
247 chan->dma.put = NOUVEAU_DMA_SKIPS;
248 }
249
250 /* engine fetching ahead of us, we have space up until the
251 * current GET pointer. the "- 1" is to ensure there's
252 * space left to emit a jump back to the beginning of the
253 * push buffer if we require it. we can never get GET == PUT
254 * here, so this is safe.
255 */
256 chan->dma.free = get - chan->dma.cur - 1;
257 }
258
259 return 0;
260 }
261
262