1 /**********************************************************
2  * Copyright 2009-2011 VMware, Inc.  All rights reserved.
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5  * obtaining a copy of this software and associated documentation
6  * files (the "Software"), to deal in the Software without
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9  * of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
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12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
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15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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22  * SOFTWARE.
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24  **********************************************************/
25 /*
26  * TODO:
27  *
28  * Fencing is currently a bit inefficient, since we need to call the
29  * kernel do determine a fence object signaled status if the fence is not
30  * signaled. This can be greatly improved upon by using the fact that the
31  * execbuf ioctl returns the last signaled fence seqno, as does the
32  * fence signaled ioctl. We should set up a ring of fence objects and
33  * walk through them checking for signaled status each time we receive a
34  * new passed fence seqno.
35  */
36 
37 #include "util/u_memory.h"
38 #include "util/u_atomic.h"
39 
40 #include "pipebuffer/pb_buffer_fenced.h"
41 
42 #include "vmw_screen.h"
43 #include "vmw_fence.h"
44 
45 struct vmw_fence_ops
46 {
47    struct pb_fence_ops base;
48 
49    struct vmw_winsys_screen *vws;
50 };
51 
52 struct vmw_fence
53 {
54    int32_t refcount;
55    uint32_t handle;
56    uint32_t mask;
57    int32_t signalled;
58 };
59 
60 /**
61  * vmw_fence - return the vmw_fence object identified by a
62  * struct pipe_fence_handle *
63  *
64  * @fence: The opaque pipe fence handle.
65  */
66 static INLINE struct vmw_fence *
vmw_fence(struct pipe_fence_handle * fence)67 vmw_fence(struct pipe_fence_handle *fence)
68 {
69    return (struct vmw_fence *) fence;
70 }
71 
72 /**
73  * vmw_fence_create - Create a user-space fence object.
74  *
75  * @handle: Handle identifying the kernel fence object.
76  * @mask: Mask of flags that this fence object may signal.
77  *
78  * Returns NULL on failure.
79  */
80 struct pipe_fence_handle *
vmw_fence_create(uint32_t handle,uint32_t mask)81 vmw_fence_create(uint32_t handle, uint32_t mask)
82 {
83    struct vmw_fence *fence = CALLOC_STRUCT(vmw_fence);
84 
85    if (!fence)
86       return NULL;
87 
88    p_atomic_set(&fence->refcount, 1);
89    fence->handle = handle;
90    fence->mask = mask;
91    p_atomic_set(&fence->signalled, 0);
92 
93    return (struct pipe_fence_handle *) fence;
94 }
95 
96 /**
97  * vmw_fence_ops - Return the vmw_fence_ops structure backing a
98  * struct pb_fence_ops pointer.
99  *
100  * @ops: Pointer to a struct pb_fence_ops.
101  *
102  */
103 static INLINE struct vmw_fence_ops *
vmw_fence_ops(struct pb_fence_ops * ops)104 vmw_fence_ops(struct pb_fence_ops *ops)
105 {
106    assert(ops);
107    return (struct vmw_fence_ops *)ops;
108 }
109 
110 
111 
112 /**
113  * vmw_fence_reference - Reference / unreference a vmw fence object.
114  *
115  * @vws: Pointer to the winsys screen.
116  * @ptr: Pointer to reference transfer destination.
117  * @fence: Pointer to object to reference. May be NULL.
118  */
119 void
vmw_fence_reference(struct vmw_winsys_screen * vws,struct pipe_fence_handle ** ptr,struct pipe_fence_handle * fence)120 vmw_fence_reference(struct vmw_winsys_screen *vws,
121 		    struct pipe_fence_handle **ptr,
122 		    struct pipe_fence_handle *fence)
123 {
124    if (*ptr) {
125       struct vmw_fence *vfence = vmw_fence(*ptr);
126 
127       if (p_atomic_dec_zero(&vfence->refcount)) {
128 	 vmw_ioctl_fence_unref(vws, vfence->handle);
129 	 FREE(vfence);
130       }
131    }
132 
133    if (fence) {
134       struct vmw_fence *vfence = vmw_fence(fence);
135 
136       p_atomic_inc(&vfence->refcount);
137    }
138 
139    *ptr = fence;
140 }
141 
142 
143 /**
144  * vmw_fence_signalled - Check whether a fence object is signalled.
145  *
146  * @vws: Pointer to the winsys screen.
147  * @fence: Handle to the fence object.
148  * @flag: Fence flags to check. If the fence object can't signal
149  * a flag, it is assumed to be already signaled.
150  *
151  * Returns 0 if the fence object was signaled, nonzero otherwise.
152  */
153 int
vmw_fence_signalled(struct vmw_winsys_screen * vws,struct pipe_fence_handle * fence,unsigned flag)154 vmw_fence_signalled(struct vmw_winsys_screen *vws,
155 		   struct pipe_fence_handle *fence,
156 		   unsigned flag)
157 {
158    struct vmw_fence *vfence;
159    int32_t vflags = SVGA_FENCE_FLAG_EXEC;
160    int ret;
161    uint32_t old;
162 
163    if (!fence)
164       return 0;
165 
166    vfence = vmw_fence(fence);
167    old = p_atomic_read(&vfence->signalled);
168 
169    vflags &= ~vfence->mask;
170 
171    if ((old & vflags) == vflags)
172       return 0;
173 
174    ret = vmw_ioctl_fence_signalled(vws, vfence->handle, vflags);
175 
176    if (ret == 0) {
177       int32_t prev = old;
178 
179       do {
180 	 old = prev;
181 	 prev = p_atomic_cmpxchg(&vfence->signalled, old, old | vflags);
182       } while (prev != old);
183    }
184 
185    return ret;
186 }
187 
188 /**
189  * vmw_fence_finish - Wait for a fence object to signal.
190  *
191  * @vws: Pointer to the winsys screen.
192  * @fence: Handle to the fence object.
193  * @flag: Fence flags to wait for. If the fence object can't signal
194  * a flag, it is assumed to be already signaled.
195  *
196  * Returns 0 if the wait succeeded. Nonzero otherwise.
197  */
198 int
vmw_fence_finish(struct vmw_winsys_screen * vws,struct pipe_fence_handle * fence,unsigned flag)199 vmw_fence_finish(struct vmw_winsys_screen *vws,
200 		 struct pipe_fence_handle *fence,
201 		 unsigned flag)
202 {
203    struct vmw_fence *vfence;
204    int32_t vflags = SVGA_FENCE_FLAG_EXEC;
205    int ret;
206    uint32_t old;
207 
208    if (!fence)
209       return 0;
210 
211    vfence = vmw_fence(fence);
212    old = p_atomic_read(&vfence->signalled);
213    vflags &= ~vfence->mask;
214 
215    if ((old & vflags) == vflags)
216       return 0;
217 
218    ret = vmw_ioctl_fence_finish(vws, vfence->handle, vflags);
219 
220    if (ret == 0) {
221       int32_t prev = old;
222 
223       do {
224 	 old = prev;
225 	 prev = p_atomic_cmpxchg(&vfence->signalled, old, old | vflags);
226       } while (prev != old);
227    }
228 
229    return ret;
230 }
231 
232 
233 /**
234  * vmw_fence_ops_fence_reference - wrapper for the pb_fence_ops api.
235  *
236  * wrapper around vmw_fence_reference.
237  */
238 static void
vmw_fence_ops_fence_reference(struct pb_fence_ops * ops,struct pipe_fence_handle ** ptr,struct pipe_fence_handle * fence)239 vmw_fence_ops_fence_reference(struct pb_fence_ops *ops,
240                               struct pipe_fence_handle **ptr,
241                               struct pipe_fence_handle *fence)
242 {
243    struct vmw_winsys_screen *vws = vmw_fence_ops(ops)->vws;
244 
245    vmw_fence_reference(vws, ptr, fence);
246 }
247 
248 /**
249  * vmw_fence_ops_fence_signalled - wrapper for the pb_fence_ops api.
250  *
251  * wrapper around vmw_fence_signalled.
252  */
253 static int
vmw_fence_ops_fence_signalled(struct pb_fence_ops * ops,struct pipe_fence_handle * fence,unsigned flag)254 vmw_fence_ops_fence_signalled(struct pb_fence_ops *ops,
255                               struct pipe_fence_handle *fence,
256                               unsigned flag)
257 {
258    struct vmw_winsys_screen *vws = vmw_fence_ops(ops)->vws;
259 
260    return vmw_fence_signalled(vws, fence, flag);
261 }
262 
263 
264 /**
265  * vmw_fence_ops_fence_finish - wrapper for the pb_fence_ops api.
266  *
267  * wrapper around vmw_fence_finish.
268  */
269 static int
vmw_fence_ops_fence_finish(struct pb_fence_ops * ops,struct pipe_fence_handle * fence,unsigned flag)270 vmw_fence_ops_fence_finish(struct pb_fence_ops *ops,
271                            struct pipe_fence_handle *fence,
272                            unsigned flag)
273 {
274    struct vmw_winsys_screen *vws = vmw_fence_ops(ops)->vws;
275 
276    return vmw_fence_finish(vws, fence, flag);
277 }
278 
279 
280 /**
281  * vmw_fence_ops_destroy - Destroy a pb_fence_ops function table.
282  *
283  * @ops: The function table to destroy.
284  *
285  * Part of the pb_fence_ops api.
286  */
287 static void
vmw_fence_ops_destroy(struct pb_fence_ops * ops)288 vmw_fence_ops_destroy(struct pb_fence_ops *ops)
289 {
290    FREE(ops);
291 }
292 
293 
294 /**
295  * vmw_fence_ops_create - Create a pb_fence_ops function table.
296  *
297  * @vws: Pointer to a struct vmw_winsys_screen.
298  *
299  * Returns a pointer to a pb_fence_ops function table to interface
300  * with pipe_buffer. This function is typically called on driver setup.
301  *
302  * Returns NULL on failure.
303  */
304 struct pb_fence_ops *
vmw_fence_ops_create(struct vmw_winsys_screen * vws)305 vmw_fence_ops_create(struct vmw_winsys_screen *vws)
306 {
307    struct vmw_fence_ops *ops;
308 
309    ops = CALLOC_STRUCT(vmw_fence_ops);
310    if(!ops)
311       return NULL;
312 
313    ops->base.destroy = &vmw_fence_ops_destroy;
314    ops->base.fence_reference = &vmw_fence_ops_fence_reference;
315    ops->base.fence_signalled = &vmw_fence_ops_fence_signalled;
316    ops->base.fence_finish = &vmw_fence_ops_fence_finish;
317 
318    ops->vws = vws;
319 
320    return &ops->base;
321 }
322 
323 
324