1 /*
2  * Copyright 2014 Advanced Micro Devices, Inc.
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 
24 #include <linux/dma-mapping.h>
25 
26 #include "amdgpu.h"
27 #include "amdgpu_ih.h"
28 
29 /**
30  * amdgpu_ih_ring_init - initialize the IH state
31  *
32  * @adev: amdgpu_device pointer
33  * @ih: ih ring to initialize
34  * @ring_size: ring size to allocate
35  * @use_bus_addr: true when we can use dma_alloc_coherent
36  *
37  * Initializes the IH state and allocates a buffer
38  * for the IH ring buffer.
39  * Returns 0 for success, errors for failure.
40  */
amdgpu_ih_ring_init(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih,unsigned ring_size,bool use_bus_addr)41 int amdgpu_ih_ring_init(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih,
42 			unsigned ring_size, bool use_bus_addr)
43 {
44 	u32 rb_bufsz;
45 	int r;
46 
47 	/* Align ring size */
48 	rb_bufsz = order_base_2(ring_size / 4);
49 	ring_size = (1 << rb_bufsz) * 4;
50 	ih->ring_size = ring_size;
51 	ih->ptr_mask = ih->ring_size - 1;
52 	ih->rptr = 0;
53 	ih->use_bus_addr = use_bus_addr;
54 
55 	if (use_bus_addr) {
56 		dma_addr_t dma_addr;
57 
58 		if (ih->ring)
59 			return 0;
60 
61 		/* add 8 bytes for the rptr/wptr shadows and
62 		 * add them to the end of the ring allocation.
63 		 */
64 		ih->ring = dma_alloc_coherent(adev->dev, ih->ring_size + 8,
65 					      &dma_addr, GFP_KERNEL);
66 		if (ih->ring == NULL)
67 			return -ENOMEM;
68 
69 		ih->gpu_addr = dma_addr;
70 		ih->wptr_addr = dma_addr + ih->ring_size;
71 		ih->wptr_cpu = &ih->ring[ih->ring_size / 4];
72 		ih->rptr_addr = dma_addr + ih->ring_size + 4;
73 		ih->rptr_cpu = &ih->ring[(ih->ring_size / 4) + 1];
74 	} else {
75 		unsigned wptr_offs, rptr_offs;
76 
77 		r = amdgpu_device_wb_get(adev, &wptr_offs);
78 		if (r)
79 			return r;
80 
81 		r = amdgpu_device_wb_get(adev, &rptr_offs);
82 		if (r) {
83 			amdgpu_device_wb_free(adev, wptr_offs);
84 			return r;
85 		}
86 
87 		r = amdgpu_bo_create_kernel(adev, ih->ring_size, PAGE_SIZE,
88 					    AMDGPU_GEM_DOMAIN_GTT,
89 					    &ih->ring_obj, &ih->gpu_addr,
90 					    (void **)&ih->ring);
91 		if (r) {
92 			amdgpu_device_wb_free(adev, rptr_offs);
93 			amdgpu_device_wb_free(adev, wptr_offs);
94 			return r;
95 		}
96 
97 		ih->wptr_addr = adev->wb.gpu_addr + wptr_offs * 4;
98 		ih->wptr_cpu = &adev->wb.wb[wptr_offs];
99 		ih->rptr_addr = adev->wb.gpu_addr + rptr_offs * 4;
100 		ih->rptr_cpu = &adev->wb.wb[rptr_offs];
101 	}
102 
103 	init_waitqueue_head(&ih->wait_process);
104 	return 0;
105 }
106 
107 /**
108  * amdgpu_ih_ring_fini - tear down the IH state
109  *
110  * @adev: amdgpu_device pointer
111  * @ih: ih ring to tear down
112  *
113  * Tears down the IH state and frees buffer
114  * used for the IH ring buffer.
115  */
amdgpu_ih_ring_fini(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih)116 void amdgpu_ih_ring_fini(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
117 {
118 
119 	if (!ih->ring)
120 		return;
121 
122 	if (ih->use_bus_addr) {
123 
124 		/* add 8 bytes for the rptr/wptr shadows and
125 		 * add them to the end of the ring allocation.
126 		 */
127 		dma_free_coherent(adev->dev, ih->ring_size + 8,
128 				  (void *)ih->ring, ih->gpu_addr);
129 		ih->ring = NULL;
130 	} else {
131 		amdgpu_bo_free_kernel(&ih->ring_obj, &ih->gpu_addr,
132 				      (void **)&ih->ring);
133 		amdgpu_device_wb_free(adev, (ih->wptr_addr - ih->gpu_addr) / 4);
134 		amdgpu_device_wb_free(adev, (ih->rptr_addr - ih->gpu_addr) / 4);
135 	}
136 }
137 
138 /**
139  * amdgpu_ih_ring_write - write IV to the ring buffer
140  *
141  * @ih: ih ring to write to
142  * @iv: the iv to write
143  * @num_dw: size of the iv in dw
144  *
145  * Writes an IV to the ring buffer using the CPU and increment the wptr.
146  * Used for testing and delegating IVs to a software ring.
147  */
amdgpu_ih_ring_write(struct amdgpu_ih_ring * ih,const uint32_t * iv,unsigned int num_dw)148 void amdgpu_ih_ring_write(struct amdgpu_ih_ring *ih, const uint32_t *iv,
149 			  unsigned int num_dw)
150 {
151 	uint32_t wptr = le32_to_cpu(*ih->wptr_cpu) >> 2;
152 	unsigned int i;
153 
154 	for (i = 0; i < num_dw; ++i)
155 	        ih->ring[wptr++] = cpu_to_le32(iv[i]);
156 
157 	wptr <<= 2;
158 	wptr &= ih->ptr_mask;
159 
160 	/* Only commit the new wptr if we don't overflow */
161 	if (wptr != READ_ONCE(ih->rptr)) {
162 		wmb();
163 		WRITE_ONCE(*ih->wptr_cpu, cpu_to_le32(wptr));
164 	}
165 }
166 
167 /* Waiter helper that checks current rptr matches or passes checkpoint wptr */
amdgpu_ih_has_checkpoint_processed(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih,uint32_t checkpoint_wptr,uint32_t * prev_rptr)168 static bool amdgpu_ih_has_checkpoint_processed(struct amdgpu_device *adev,
169 					struct amdgpu_ih_ring *ih,
170 					uint32_t checkpoint_wptr,
171 					uint32_t *prev_rptr)
172 {
173 	uint32_t cur_rptr = ih->rptr | (*prev_rptr & ~ih->ptr_mask);
174 
175 	/* rptr has wrapped. */
176 	if (cur_rptr < *prev_rptr)
177 		cur_rptr += ih->ptr_mask + 1;
178 	*prev_rptr = cur_rptr;
179 
180 	/* check ring is empty to workaround missing wptr overflow flag */
181 	return cur_rptr >= checkpoint_wptr ||
182 	       (cur_rptr & ih->ptr_mask) == amdgpu_ih_get_wptr(adev, ih);
183 }
184 
185 /**
186  * amdgpu_ih_wait_on_checkpoint_process - wait to process IVs up to checkpoint
187  *
188  * @adev: amdgpu_device pointer
189  * @ih: ih ring to process
190  *
191  * Used to ensure ring has processed IVs up to the checkpoint write pointer.
192  */
amdgpu_ih_wait_on_checkpoint_process(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih)193 int amdgpu_ih_wait_on_checkpoint_process(struct amdgpu_device *adev,
194 					struct amdgpu_ih_ring *ih)
195 {
196 	uint32_t checkpoint_wptr, rptr;
197 
198 	if (!ih->enabled || adev->shutdown)
199 		return -ENODEV;
200 
201 	checkpoint_wptr = amdgpu_ih_get_wptr(adev, ih);
202 	/* Order wptr with rptr. */
203 	rmb();
204 	rptr = READ_ONCE(ih->rptr);
205 
206 	/* wptr has wrapped. */
207 	if (rptr > checkpoint_wptr)
208 		checkpoint_wptr += ih->ptr_mask + 1;
209 
210 	return wait_event_interruptible(ih->wait_process,
211 				amdgpu_ih_has_checkpoint_processed(adev, ih,
212 						checkpoint_wptr, &rptr));
213 }
214 
215 /**
216  * amdgpu_ih_process - interrupt handler
217  *
218  * @adev: amdgpu_device pointer
219  * @ih: ih ring to process
220  *
221  * Interrupt hander (VI), walk the IH ring.
222  * Returns irq process return code.
223  */
amdgpu_ih_process(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih)224 int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
225 {
226 	unsigned int count;
227 	u32 wptr;
228 
229 	if (!ih->enabled || adev->shutdown)
230 		return IRQ_NONE;
231 
232 	wptr = amdgpu_ih_get_wptr(adev, ih);
233 
234 restart_ih:
235 	count  = AMDGPU_IH_MAX_NUM_IVS;
236 	DRM_DEBUG("%s: rptr %d, wptr %d\n", __func__, ih->rptr, wptr);
237 
238 	/* Order reading of wptr vs. reading of IH ring data */
239 	rmb();
240 
241 	while (ih->rptr != wptr && --count) {
242 		amdgpu_irq_dispatch(adev, ih);
243 		ih->rptr &= ih->ptr_mask;
244 	}
245 
246 	amdgpu_ih_set_rptr(adev, ih);
247 	wake_up_all(&ih->wait_process);
248 
249 	/* make sure wptr hasn't changed while processing */
250 	wptr = amdgpu_ih_get_wptr(adev, ih);
251 	if (wptr != ih->rptr)
252 		goto restart_ih;
253 
254 	return IRQ_HANDLED;
255 }
256 
257 /**
258  * amdgpu_ih_decode_iv_helper - decode an interrupt vector
259  *
260  * @adev: amdgpu_device pointer
261  * @ih: ih ring to process
262  * @entry: IV entry
263  *
264  * Decodes the interrupt vector at the current rptr
265  * position and also advance the position for for Vega10
266  * and later GPUs.
267  */
amdgpu_ih_decode_iv_helper(struct amdgpu_device * adev,struct amdgpu_ih_ring * ih,struct amdgpu_iv_entry * entry)268 void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
269 				struct amdgpu_ih_ring *ih,
270 				struct amdgpu_iv_entry *entry)
271 {
272 	/* wptr/rptr are in bytes! */
273 	u32 ring_index = ih->rptr >> 2;
274 	uint32_t dw[8];
275 
276 	dw[0] = le32_to_cpu(ih->ring[ring_index + 0]);
277 	dw[1] = le32_to_cpu(ih->ring[ring_index + 1]);
278 	dw[2] = le32_to_cpu(ih->ring[ring_index + 2]);
279 	dw[3] = le32_to_cpu(ih->ring[ring_index + 3]);
280 	dw[4] = le32_to_cpu(ih->ring[ring_index + 4]);
281 	dw[5] = le32_to_cpu(ih->ring[ring_index + 5]);
282 	dw[6] = le32_to_cpu(ih->ring[ring_index + 6]);
283 	dw[7] = le32_to_cpu(ih->ring[ring_index + 7]);
284 
285 	entry->client_id = dw[0] & 0xff;
286 	entry->src_id = (dw[0] >> 8) & 0xff;
287 	entry->ring_id = (dw[0] >> 16) & 0xff;
288 	entry->vmid = (dw[0] >> 24) & 0xf;
289 	entry->vmid_src = (dw[0] >> 31);
290 	entry->timestamp = dw[1] | ((u64)(dw[2] & 0xffff) << 32);
291 	entry->timestamp_src = dw[2] >> 31;
292 	entry->pasid = dw[3] & 0xffff;
293 	entry->pasid_src = dw[3] >> 31;
294 	entry->src_data[0] = dw[4];
295 	entry->src_data[1] = dw[5];
296 	entry->src_data[2] = dw[6];
297 	entry->src_data[3] = dw[7];
298 
299 	/* wptr/rptr are in bytes! */
300 	ih->rptr += 32;
301 }
302