1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2017 Intel Corporation
4  */
5 
6 #include "i915_selftest.h"
7 #include "gem/i915_gem_pm.h"
8 
9 /* max doorbell number + negative test for each client type */
10 #define ATTEMPTS (GUC_NUM_DOORBELLS + GUC_CLIENT_PRIORITY_NUM)
11 
12 static struct intel_guc_client *clients[ATTEMPTS];
13 
14 static bool available_dbs(struct intel_guc *guc, u32 priority)
15 {
16 	unsigned long offset;
17 	unsigned long end;
18 	u16 id;
19 
20 	/* first half is used for normal priority, second half for high */
21 	offset = 0;
22 	end = GUC_NUM_DOORBELLS / 2;
23 	if (priority <= GUC_CLIENT_PRIORITY_HIGH) {
24 		offset = end;
25 		end += offset;
26 	}
27 
28 	id = find_next_zero_bit(guc->doorbell_bitmap, end, offset);
29 	if (id < end)
30 		return true;
31 
32 	return false;
33 }
34 
35 static int check_all_doorbells(struct intel_guc *guc)
36 {
37 	u16 db_id;
38 
39 	pr_info_once("Max number of doorbells: %d", GUC_NUM_DOORBELLS);
40 	for (db_id = 0; db_id < GUC_NUM_DOORBELLS; ++db_id) {
41 		if (!doorbell_ok(guc, db_id)) {
42 			pr_err("doorbell %d, not ok\n", db_id);
43 			return -EIO;
44 		}
45 	}
46 
47 	return 0;
48 }
49 
50 static int ring_doorbell_nop(struct intel_guc_client *client)
51 {
52 	struct guc_process_desc *desc = __get_process_desc(client);
53 	int err;
54 
55 	client->use_nop_wqi = true;
56 
57 	spin_lock_irq(&client->wq_lock);
58 
59 	guc_wq_item_append(client, 0, 0, 0, 0);
60 	guc_ring_doorbell(client);
61 
62 	spin_unlock_irq(&client->wq_lock);
63 
64 	client->use_nop_wqi = false;
65 
66 	/* if there are no issues GuC will update the WQ head and keep the
67 	 * WQ in active status
68 	 */
69 	err = wait_for(READ_ONCE(desc->head) == READ_ONCE(desc->tail), 10);
70 	if (err) {
71 		pr_err("doorbell %u ring failed!\n", client->doorbell_id);
72 		return -EIO;
73 	}
74 
75 	if (desc->wq_status != WQ_STATUS_ACTIVE) {
76 		pr_err("doorbell %u ring put WQ in bad state (%u)!\n",
77 		       client->doorbell_id, desc->wq_status);
78 		return -EIO;
79 	}
80 
81 	return 0;
82 }
83 
84 /*
85  * Basic client sanity check, handy to validate create_clients.
86  */
87 static int validate_client(struct intel_guc_client *client, int client_priority)
88 {
89 	if (client->priority != client_priority ||
90 	    client->doorbell_id == GUC_DOORBELL_INVALID)
91 		return -EINVAL;
92 	else
93 		return 0;
94 }
95 
96 static bool client_doorbell_in_sync(struct intel_guc_client *client)
97 {
98 	return !client || doorbell_ok(client->guc, client->doorbell_id);
99 }
100 
101 /*
102  * Check that we're able to synchronize guc_clients with their doorbells
103  *
104  * We're creating clients and reserving doorbells once, at module load. During
105  * module lifetime, GuC, doorbell HW, and i915 state may go out of sync due to
106  * GuC being reset. In other words - GuC clients are still around, but the
107  * status of their doorbells may be incorrect. This is the reason behind
108  * validating that the doorbells status expected by the driver matches what the
109  * GuC/HW have.
110  */
111 static int igt_guc_clients(void *args)
112 {
113 	struct drm_i915_private *dev_priv = args;
114 	intel_wakeref_t wakeref;
115 	struct intel_guc *guc;
116 	int err = 0;
117 
118 	GEM_BUG_ON(!HAS_GT_UC(dev_priv));
119 	mutex_lock(&dev_priv->drm.struct_mutex);
120 	wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
121 
122 	guc = &dev_priv->gt.uc.guc;
123 	if (!guc) {
124 		pr_err("No guc object!\n");
125 		err = -EINVAL;
126 		goto unlock;
127 	}
128 
129 	err = check_all_doorbells(guc);
130 	if (err)
131 		goto unlock;
132 
133 	/*
134 	 * Get rid of clients created during driver load because the test will
135 	 * recreate them.
136 	 */
137 	guc_clients_disable(guc);
138 	guc_clients_destroy(guc);
139 	if (guc->execbuf_client) {
140 		pr_err("guc_clients_destroy lied!\n");
141 		err = -EINVAL;
142 		goto unlock;
143 	}
144 
145 	err = guc_clients_create(guc);
146 	if (err) {
147 		pr_err("Failed to create clients\n");
148 		goto unlock;
149 	}
150 	GEM_BUG_ON(!guc->execbuf_client);
151 
152 	err = validate_client(guc->execbuf_client,
153 			      GUC_CLIENT_PRIORITY_KMD_NORMAL);
154 	if (err) {
155 		pr_err("execbug client validation failed\n");
156 		goto out;
157 	}
158 
159 	/* the client should now have reserved a doorbell */
160 	if (!has_doorbell(guc->execbuf_client)) {
161 		pr_err("guc_clients_create didn't reserve doorbells\n");
162 		err = -EINVAL;
163 		goto out;
164 	}
165 
166 	/* Now enable the clients */
167 	guc_clients_enable(guc);
168 
169 	/* each client should now have received a doorbell */
170 	if (!client_doorbell_in_sync(guc->execbuf_client)) {
171 		pr_err("failed to initialize the doorbells\n");
172 		err = -EINVAL;
173 		goto out;
174 	}
175 
176 	/*
177 	 * Basic test - an attempt to reallocate a valid doorbell to the
178 	 * client it is currently assigned should not cause a failure.
179 	 */
180 	err = create_doorbell(guc->execbuf_client);
181 
182 out:
183 	/*
184 	 * Leave clean state for other test, plus the driver always destroy the
185 	 * clients during unload.
186 	 */
187 	guc_clients_disable(guc);
188 	guc_clients_destroy(guc);
189 	guc_clients_create(guc);
190 	guc_clients_enable(guc);
191 unlock:
192 	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
193 	mutex_unlock(&dev_priv->drm.struct_mutex);
194 	return err;
195 }
196 
197 /*
198  * Create as many clients as number of doorbells. Note that there's already
199  * client(s)/doorbell(s) created during driver load, but this test creates
200  * its own and do not interact with the existing ones.
201  */
202 static int igt_guc_doorbells(void *arg)
203 {
204 	struct drm_i915_private *dev_priv = arg;
205 	intel_wakeref_t wakeref;
206 	struct intel_guc *guc;
207 	int i, err = 0;
208 	u16 db_id;
209 
210 	GEM_BUG_ON(!HAS_GT_UC(dev_priv));
211 	mutex_lock(&dev_priv->drm.struct_mutex);
212 	wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
213 
214 	guc = &dev_priv->gt.uc.guc;
215 	if (!guc) {
216 		pr_err("No guc object!\n");
217 		err = -EINVAL;
218 		goto unlock;
219 	}
220 
221 	err = check_all_doorbells(guc);
222 	if (err)
223 		goto unlock;
224 
225 	for (i = 0; i < ATTEMPTS; i++) {
226 		clients[i] = guc_client_alloc(guc, i % GUC_CLIENT_PRIORITY_NUM);
227 
228 		if (!clients[i]) {
229 			pr_err("[%d] No guc client\n", i);
230 			err = -EINVAL;
231 			goto out;
232 		}
233 
234 		if (IS_ERR(clients[i])) {
235 			if (PTR_ERR(clients[i]) != -ENOSPC) {
236 				pr_err("[%d] unexpected error\n", i);
237 				err = PTR_ERR(clients[i]);
238 				goto out;
239 			}
240 
241 			if (available_dbs(guc, i % GUC_CLIENT_PRIORITY_NUM)) {
242 				pr_err("[%d] non-db related alloc fail\n", i);
243 				err = -EINVAL;
244 				goto out;
245 			}
246 
247 			/* expected, ran out of dbs for this client type */
248 			continue;
249 		}
250 
251 		/*
252 		 * The check below is only valid because we keep a doorbell
253 		 * assigned during the whole life of the client.
254 		 */
255 		if (clients[i]->stage_id >= GUC_NUM_DOORBELLS) {
256 			pr_err("[%d] more clients than doorbells (%d >= %d)\n",
257 			       i, clients[i]->stage_id, GUC_NUM_DOORBELLS);
258 			err = -EINVAL;
259 			goto out;
260 		}
261 
262 		err = validate_client(clients[i], i % GUC_CLIENT_PRIORITY_NUM);
263 		if (err) {
264 			pr_err("[%d] client_alloc sanity check failed!\n", i);
265 			err = -EINVAL;
266 			goto out;
267 		}
268 
269 		db_id = clients[i]->doorbell_id;
270 
271 		err = __guc_client_enable(clients[i]);
272 		if (err) {
273 			pr_err("[%d] Failed to create a doorbell\n", i);
274 			goto out;
275 		}
276 
277 		/* doorbell id shouldn't change, we are holding the mutex */
278 		if (db_id != clients[i]->doorbell_id) {
279 			pr_err("[%d] doorbell id changed (%d != %d)\n",
280 			       i, db_id, clients[i]->doorbell_id);
281 			err = -EINVAL;
282 			goto out;
283 		}
284 
285 		err = check_all_doorbells(guc);
286 		if (err)
287 			goto out;
288 
289 		err = ring_doorbell_nop(clients[i]);
290 		if (err)
291 			goto out;
292 	}
293 
294 out:
295 	for (i = 0; i < ATTEMPTS; i++)
296 		if (!IS_ERR_OR_NULL(clients[i])) {
297 			__guc_client_disable(clients[i]);
298 			guc_client_free(clients[i]);
299 		}
300 unlock:
301 	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
302 	mutex_unlock(&dev_priv->drm.struct_mutex);
303 	return err;
304 }
305 
306 int intel_guc_live_selftest(struct drm_i915_private *dev_priv)
307 {
308 	static const struct i915_subtest tests[] = {
309 		SUBTEST(igt_guc_clients),
310 		SUBTEST(igt_guc_doorbells),
311 	};
312 
313 	if (!USES_GUC_SUBMISSION(dev_priv))
314 		return 0;
315 
316 	return i915_subtests(tests, dev_priv);
317 }
318