xref: /linux/drivers/gpu/drm/xe/xe_sync.c (revision 8cdcef1c2f82d207aa8b2a02298fbc17191c6261)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 
6 #include "xe_sync.h"
7 
8 #include <linux/kthread.h>
9 #include <linux/sched/mm.h>
10 #include <linux/uaccess.h>
11 
12 #include <drm/drm_print.h>
13 #include <drm/drm_syncobj.h>
14 #include <drm/xe_drm.h>
15 
16 #include "xe_device_types.h"
17 #include "xe_macros.h"
18 #include "xe_sched_job_types.h"
19 
20 #define SYNC_FLAGS_TYPE_MASK 0x3
21 
22 struct user_fence {
23 	struct xe_device *xe;
24 	struct kref refcount;
25 	struct dma_fence_cb cb;
26 	struct work_struct worker;
27 	struct mm_struct *mm;
28 	u64 __user *addr;
29 	u64 value;
30 };
31 
32 static void user_fence_destroy(struct kref *kref)
33 {
34 	struct user_fence *ufence = container_of(kref, struct user_fence,
35 						 refcount);
36 
37 	mmdrop(ufence->mm);
38 	kfree(ufence);
39 }
40 
41 static void user_fence_get(struct user_fence *ufence)
42 {
43 	kref_get(&ufence->refcount);
44 }
45 
46 static void user_fence_put(struct user_fence *ufence)
47 {
48 	kref_put(&ufence->refcount, user_fence_destroy);
49 }
50 
51 static struct user_fence *user_fence_create(struct xe_device *xe, u64 addr,
52 					    u64 value)
53 {
54 	struct user_fence *ufence;
55 
56 	ufence = kmalloc(sizeof(*ufence), GFP_KERNEL);
57 	if (!ufence)
58 		return NULL;
59 
60 	ufence->xe = xe;
61 	kref_init(&ufence->refcount);
62 	ufence->addr = u64_to_user_ptr(addr);
63 	ufence->value = value;
64 	ufence->mm = current->mm;
65 	mmgrab(ufence->mm);
66 
67 	return ufence;
68 }
69 
70 static void user_fence_worker(struct work_struct *w)
71 {
72 	struct user_fence *ufence = container_of(w, struct user_fence, worker);
73 
74 	if (mmget_not_zero(ufence->mm)) {
75 		kthread_use_mm(ufence->mm);
76 		if (copy_to_user(ufence->addr, &ufence->value, sizeof(ufence->value)))
77 			XE_WARN_ON("Copy to user failed");
78 		kthread_unuse_mm(ufence->mm);
79 		mmput(ufence->mm);
80 	}
81 
82 	wake_up_all(&ufence->xe->ufence_wq);
83 	user_fence_put(ufence);
84 }
85 
86 static void kick_ufence(struct user_fence *ufence, struct dma_fence *fence)
87 {
88 	INIT_WORK(&ufence->worker, user_fence_worker);
89 	queue_work(ufence->xe->ordered_wq, &ufence->worker);
90 	dma_fence_put(fence);
91 }
92 
93 static void user_fence_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
94 {
95 	struct user_fence *ufence = container_of(cb, struct user_fence, cb);
96 
97 	kick_ufence(ufence, fence);
98 }
99 
100 int xe_sync_entry_parse(struct xe_device *xe, struct xe_file *xef,
101 			struct xe_sync_entry *sync,
102 			struct drm_xe_sync __user *sync_user,
103 			bool exec, bool in_lr_mode)
104 {
105 	struct drm_xe_sync sync_in;
106 	int err;
107 	bool signal;
108 
109 	if (copy_from_user(&sync_in, sync_user, sizeof(*sync_user)))
110 		return -EFAULT;
111 
112 	if (XE_IOCTL_DBG(xe, sync_in.flags &
113 			 ~(SYNC_FLAGS_TYPE_MASK | DRM_XE_SYNC_FLAG_SIGNAL)) ||
114 	    XE_IOCTL_DBG(xe, sync_in.pad) ||
115 	    XE_IOCTL_DBG(xe, sync_in.reserved[0] || sync_in.reserved[1]))
116 		return -EINVAL;
117 
118 	signal = sync_in.flags & DRM_XE_SYNC_FLAG_SIGNAL;
119 	switch (sync_in.flags & SYNC_FLAGS_TYPE_MASK) {
120 	case DRM_XE_SYNC_FLAG_SYNCOBJ:
121 		if (XE_IOCTL_DBG(xe, in_lr_mode && signal))
122 			return -EOPNOTSUPP;
123 
124 		if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr)))
125 			return -EINVAL;
126 
127 		sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle);
128 		if (XE_IOCTL_DBG(xe, !sync->syncobj))
129 			return -ENOENT;
130 
131 		if (!signal) {
132 			sync->fence = drm_syncobj_fence_get(sync->syncobj);
133 			if (XE_IOCTL_DBG(xe, !sync->fence))
134 				return -EINVAL;
135 		}
136 		break;
137 
138 	case DRM_XE_SYNC_FLAG_TIMELINE_SYNCOBJ:
139 		if (XE_IOCTL_DBG(xe, in_lr_mode && signal))
140 			return -EOPNOTSUPP;
141 
142 		if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr)))
143 			return -EINVAL;
144 
145 		if (XE_IOCTL_DBG(xe, sync_in.timeline_value == 0))
146 			return -EINVAL;
147 
148 		sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle);
149 		if (XE_IOCTL_DBG(xe, !sync->syncobj))
150 			return -ENOENT;
151 
152 		if (signal) {
153 			sync->chain_fence = dma_fence_chain_alloc();
154 			if (!sync->chain_fence)
155 				return -ENOMEM;
156 		} else {
157 			sync->fence = drm_syncobj_fence_get(sync->syncobj);
158 			if (XE_IOCTL_DBG(xe, !sync->fence))
159 				return -EINVAL;
160 
161 			err = dma_fence_chain_find_seqno(&sync->fence,
162 							 sync_in.timeline_value);
163 			if (err)
164 				return err;
165 		}
166 		break;
167 
168 	case DRM_XE_SYNC_FLAG_DMA_BUF:
169 		if (XE_IOCTL_DBG(xe, "TODO"))
170 			return -EINVAL;
171 		break;
172 
173 	case DRM_XE_SYNC_FLAG_USER_FENCE:
174 		if (XE_IOCTL_DBG(xe, !signal))
175 			return -EOPNOTSUPP;
176 
177 		if (XE_IOCTL_DBG(xe, sync_in.addr & 0x7))
178 			return -EINVAL;
179 
180 		if (exec) {
181 			sync->addr = sync_in.addr;
182 		} else {
183 			sync->ufence = user_fence_create(xe, sync_in.addr,
184 							 sync_in.timeline_value);
185 			if (XE_IOCTL_DBG(xe, !sync->ufence))
186 				return -ENOMEM;
187 		}
188 
189 		break;
190 
191 	default:
192 		return -EINVAL;
193 	}
194 
195 	sync->flags = sync_in.flags;
196 	sync->timeline_value = sync_in.timeline_value;
197 
198 	return 0;
199 }
200 
201 int xe_sync_entry_wait(struct xe_sync_entry *sync)
202 {
203 	if (sync->fence)
204 		dma_fence_wait(sync->fence, true);
205 
206 	return 0;
207 }
208 
209 int xe_sync_entry_add_deps(struct xe_sync_entry *sync, struct xe_sched_job *job)
210 {
211 	int err;
212 
213 	if (sync->fence) {
214 		err = drm_sched_job_add_dependency(&job->drm,
215 						   dma_fence_get(sync->fence));
216 		if (err) {
217 			dma_fence_put(sync->fence);
218 			return err;
219 		}
220 	}
221 
222 	return 0;
223 }
224 
225 void xe_sync_entry_signal(struct xe_sync_entry *sync, struct xe_sched_job *job,
226 			  struct dma_fence *fence)
227 {
228 	if (!(sync->flags & DRM_XE_SYNC_FLAG_SIGNAL))
229 		return;
230 
231 	if (sync->chain_fence) {
232 		drm_syncobj_add_point(sync->syncobj, sync->chain_fence,
233 				      fence, sync->timeline_value);
234 		/*
235 		 * The chain's ownership is transferred to the
236 		 * timeline.
237 		 */
238 		sync->chain_fence = NULL;
239 	} else if (sync->syncobj) {
240 		drm_syncobj_replace_fence(sync->syncobj, fence);
241 	} else if (sync->ufence) {
242 		int err;
243 
244 		dma_fence_get(fence);
245 		user_fence_get(sync->ufence);
246 		err = dma_fence_add_callback(fence, &sync->ufence->cb,
247 					     user_fence_cb);
248 		if (err == -ENOENT) {
249 			kick_ufence(sync->ufence, fence);
250 		} else if (err) {
251 			XE_WARN_ON("failed to add user fence");
252 			user_fence_put(sync->ufence);
253 			dma_fence_put(fence);
254 		}
255 	} else if ((sync->flags & SYNC_FLAGS_TYPE_MASK) ==
256 		   DRM_XE_SYNC_FLAG_USER_FENCE) {
257 		job->user_fence.used = true;
258 		job->user_fence.addr = sync->addr;
259 		job->user_fence.value = sync->timeline_value;
260 	}
261 }
262 
263 void xe_sync_entry_cleanup(struct xe_sync_entry *sync)
264 {
265 	if (sync->syncobj)
266 		drm_syncobj_put(sync->syncobj);
267 	if (sync->fence)
268 		dma_fence_put(sync->fence);
269 	if (sync->chain_fence)
270 		dma_fence_put(&sync->chain_fence->base);
271 	if (sync->ufence)
272 		user_fence_put(sync->ufence);
273 }
274