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