2 * Copyright 2019 Collabora, Ltd.
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:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * Authors (Collabora):
24 * Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
31 #include "drm-uapi/panfrost_drm.h"
37 #include "os/os_mman.h"
39 #include "util/u_inlines.h"
40 #include "util/u_math.h"
42 /* This file implements a userspace BO cache. Allocating and freeing
43 * GPU-visible buffers is very expensive, and even the extra kernel roundtrips
44 * adds more work than we would like at this point. So caching BOs in userspace
45 * solves both of these problems and does not require kernel updates.
47 * Cached BOs are sorted into a bucket based on rounding their size down to the
48 * nearest power-of-two. Each bucket contains a linked list of free panfrost_bo
49 * objects. Putting a BO into the cache is accomplished by adding it to the
50 * corresponding bucket. Getting a BO from the cache consists of finding the
51 * appropriate bucket and sorting. A cache eviction is a kernel-level free of a
52 * BO and removing it from the bucket. We special case evicting all BOs from
53 * the cache, since that's what helpful in practice and avoids extra logic
54 * around the linked list.
57 static struct panfrost_bo
*
58 panfrost_bo_alloc(struct panfrost_device
*dev
, size_t size
,
61 struct drm_panfrost_create_bo create_bo
= { .size
= size
};
62 struct panfrost_bo
*bo
;
65 if (dev
->kernel_version
->version_major
> 1 ||
66 dev
->kernel_version
->version_minor
>= 1) {
67 if (flags
& PAN_BO_GROWABLE
)
68 create_bo
.flags
|= PANFROST_BO_HEAP
;
69 if (!(flags
& PAN_BO_EXECUTE
))
70 create_bo
.flags
|= PANFROST_BO_NOEXEC
;
73 ret
= drmIoctl(dev
->fd
, DRM_IOCTL_PANFROST_CREATE_BO
, &create_bo
);
75 fprintf(stderr
, "DRM_IOCTL_PANFROST_CREATE_BO failed: %m\n");
79 bo
= pan_lookup_bo(dev
, create_bo
.handle
);
80 assert(!memcmp(bo
, &((struct panfrost_bo
){}), sizeof(*bo
)));
82 bo
->size
= create_bo
.size
;
83 bo
->gpu
= create_bo
.offset
;
84 bo
->gem_handle
= create_bo
.handle
;
91 panfrost_bo_free(struct panfrost_bo
*bo
)
93 struct drm_gem_close gem_close
= { .handle
= bo
->gem_handle
};
96 ret
= drmIoctl(bo
->dev
->fd
, DRM_IOCTL_GEM_CLOSE
, &gem_close
);
98 fprintf(stderr
, "DRM_IOCTL_GEM_CLOSE failed: %m\n");
102 /* BO will be freed with the sparse array, but zero to indicate free */
103 memset(bo
, 0, sizeof(*bo
));
106 /* Returns true if the BO is ready, false otherwise.
107 * access_type is encoding the type of access one wants to ensure is done.
108 * Waiting is always done for writers, but if wait_readers is set then readers
109 * are also waited for.
112 panfrost_bo_wait(struct panfrost_bo
*bo
, int64_t timeout_ns
, bool wait_readers
)
114 struct drm_panfrost_wait_bo req
= {
115 .handle
= bo
->gem_handle
,
116 .timeout_ns
= timeout_ns
,
120 /* If the BO has been exported or imported we can't rely on the cached
121 * state, we need to call the WAIT_BO ioctl.
123 if (!(bo
->flags
& PAN_BO_SHARED
)) {
124 /* If ->gpu_access is 0, the BO is idle, no need to wait. */
128 /* If the caller only wants to wait for writers and no
129 * writes are pending, we don't have to wait.
131 if (!wait_readers
&& !(bo
->gpu_access
& PAN_BO_ACCESS_WRITE
))
135 /* The ioctl returns >= 0 value when the BO we are waiting for is ready
138 ret
= drmIoctl(bo
->dev
->fd
, DRM_IOCTL_PANFROST_WAIT_BO
, &req
);
140 /* Set gpu_access to 0 so that the next call to bo_wait()
141 * doesn't have to call the WAIT_BO ioctl.
147 /* If errno is not ETIMEDOUT or EBUSY that means the handle we passed
148 * is invalid, which shouldn't happen here.
150 assert(errno
== ETIMEDOUT
|| errno
== EBUSY
);
154 /* Helper to calculate the bucket index of a BO */
157 pan_bucket_index(unsigned size
)
159 /* Round down to POT to compute a bucket index */
161 unsigned bucket_index
= util_logbase2(size
);
163 /* Clamp the bucket index; all huge allocations will be
164 * sorted into the largest bucket */
166 bucket_index
= MIN2(bucket_index
, MAX_BO_CACHE_BUCKET
);
168 /* The minimum bucket size must equal the minimum allocation
169 * size; the maximum we clamped */
171 assert(bucket_index
>= MIN_BO_CACHE_BUCKET
);
172 assert(bucket_index
<= MAX_BO_CACHE_BUCKET
);
175 return (bucket_index
- MIN_BO_CACHE_BUCKET
);
178 static struct list_head
*
179 pan_bucket(struct panfrost_device
*dev
, unsigned size
)
181 return &dev
->bo_cache
.buckets
[pan_bucket_index(size
)];
184 /* Tries to fetch a BO of sufficient size with the appropriate flags from the
185 * BO cache. If it succeeds, it returns that BO and removes the BO from the
186 * cache. If it fails, it returns NULL signaling the caller to allocate a new
189 static struct panfrost_bo
*
190 panfrost_bo_cache_fetch(struct panfrost_device
*dev
,
191 size_t size
, uint32_t flags
, bool dontwait
)
193 pthread_mutex_lock(&dev
->bo_cache
.lock
);
194 struct list_head
*bucket
= pan_bucket(dev
, size
);
195 struct panfrost_bo
*bo
= NULL
;
197 /* Iterate the bucket looking for something suitable */
198 list_for_each_entry_safe(struct panfrost_bo
, entry
, bucket
,
200 if (entry
->size
< size
|| entry
->flags
!= flags
)
203 if (!panfrost_bo_wait(entry
, dontwait
? 0 : INT64_MAX
,
207 struct drm_panfrost_madvise madv
= {
208 .handle
= entry
->gem_handle
,
209 .madv
= PANFROST_MADV_WILLNEED
,
213 /* This one works, splice it out of the cache */
214 list_del(&entry
->bucket_link
);
215 list_del(&entry
->lru_link
);
217 ret
= drmIoctl(dev
->fd
, DRM_IOCTL_PANFROST_MADVISE
, &madv
);
218 if (!ret
&& !madv
.retained
) {
219 panfrost_bo_free(entry
);
226 pthread_mutex_unlock(&dev
->bo_cache
.lock
);
232 panfrost_bo_cache_evict_stale_bos(struct panfrost_device
*dev
)
234 struct timespec time
;
236 clock_gettime(CLOCK_MONOTONIC
, &time
);
237 list_for_each_entry_safe(struct panfrost_bo
, entry
,
238 &dev
->bo_cache
.lru
, lru_link
) {
239 /* We want all entries that have been used more than 1 sec
240 * ago to be dropped, others can be kept.
241 * Note the <= 2 check and not <= 1. It's here to account for
242 * the fact that we're only testing ->tv_sec, not ->tv_nsec.
243 * That means we might keep entries that are between 1 and 2
244 * seconds old, but we don't really care, as long as unused BOs
245 * are dropped at some point.
247 if (time
.tv_sec
- entry
->last_used
<= 2)
250 list_del(&entry
->bucket_link
);
251 list_del(&entry
->lru_link
);
252 panfrost_bo_free(entry
);
256 /* Tries to add a BO to the cache. Returns if it was
260 panfrost_bo_cache_put(struct panfrost_bo
*bo
)
262 struct panfrost_device
*dev
= bo
->dev
;
264 if (bo
->flags
& PAN_BO_SHARED
)
267 pthread_mutex_lock(&dev
->bo_cache
.lock
);
268 struct list_head
*bucket
= pan_bucket(dev
, MAX2(bo
->size
, 4096));
269 struct drm_panfrost_madvise madv
;
270 struct timespec time
;
272 madv
.handle
= bo
->gem_handle
;
273 madv
.madv
= PANFROST_MADV_DONTNEED
;
276 drmIoctl(dev
->fd
, DRM_IOCTL_PANFROST_MADVISE
, &madv
);
278 /* Add us to the bucket */
279 list_addtail(&bo
->bucket_link
, bucket
);
281 /* Add us to the LRU list and update the last_used field. */
282 list_addtail(&bo
->lru_link
, &dev
->bo_cache
.lru
);
283 clock_gettime(CLOCK_MONOTONIC
, &time
);
284 bo
->last_used
= time
.tv_sec
;
286 /* Let's do some cleanup in the BO cache while we hold the
289 panfrost_bo_cache_evict_stale_bos(dev
);
290 pthread_mutex_unlock(&dev
->bo_cache
.lock
);
295 /* Evicts all BOs from the cache. Called during context
296 * destroy or during low-memory situations (to free up
297 * memory that may be unused by us just sitting in our
298 * cache, but still reserved from the perspective of the
302 panfrost_bo_cache_evict_all(
303 struct panfrost_device
*dev
)
305 pthread_mutex_lock(&dev
->bo_cache
.lock
);
306 for (unsigned i
= 0; i
< ARRAY_SIZE(dev
->bo_cache
.buckets
); ++i
) {
307 struct list_head
*bucket
= &dev
->bo_cache
.buckets
[i
];
309 list_for_each_entry_safe(struct panfrost_bo
, entry
, bucket
,
311 list_del(&entry
->bucket_link
);
312 list_del(&entry
->lru_link
);
313 panfrost_bo_free(entry
);
316 pthread_mutex_unlock(&dev
->bo_cache
.lock
);
320 panfrost_bo_mmap(struct panfrost_bo
*bo
)
322 struct drm_panfrost_mmap_bo mmap_bo
= { .handle
= bo
->gem_handle
};
328 ret
= drmIoctl(bo
->dev
->fd
, DRM_IOCTL_PANFROST_MMAP_BO
, &mmap_bo
);
330 fprintf(stderr
, "DRM_IOCTL_PANFROST_MMAP_BO failed: %m\n");
334 bo
->cpu
= os_mmap(NULL
, bo
->size
, PROT_READ
| PROT_WRITE
, MAP_SHARED
,
335 bo
->dev
->fd
, mmap_bo
.offset
);
336 if (bo
->cpu
== MAP_FAILED
) {
337 fprintf(stderr
, "mmap failed: %p %m\n", bo
->cpu
);
343 panfrost_bo_munmap(struct panfrost_bo
*bo
)
348 if (os_munmap((void *) (uintptr_t)bo
->cpu
, bo
->size
)) {
357 panfrost_bo_create(struct panfrost_device
*dev
, size_t size
,
360 struct panfrost_bo
*bo
;
362 /* Kernel will fail (confusingly) with EPERM otherwise */
365 /* To maximize BO cache usage, don't allocate tiny BOs */
366 size
= MAX2(size
, 4096);
368 /* GROWABLE BOs cannot be mmapped */
369 if (flags
& PAN_BO_GROWABLE
)
370 assert(flags
& PAN_BO_INVISIBLE
);
372 /* Before creating a BO, we first want to check the cache but without
373 * waiting for BO readiness (BOs in the cache can still be referenced
374 * by jobs that are not finished yet).
375 * If the cached allocation fails we fall back on fresh BO allocation,
376 * and if that fails too, we try one more time to allocate from the
377 * cache, but this time we accept to wait.
379 bo
= panfrost_bo_cache_fetch(dev
, size
, flags
, true);
381 bo
= panfrost_bo_alloc(dev
, size
, flags
);
383 bo
= panfrost_bo_cache_fetch(dev
, size
, flags
, false);
386 fprintf(stderr
, "BO creation failed\n");
390 /* Only mmap now if we know we need to. For CPU-invisible buffers, we
391 * never map since we don't care about their contents; they're purely
392 * for GPU-internal use. But we do trace them anyway. */
394 if (!(flags
& (PAN_BO_INVISIBLE
| PAN_BO_DELAY_MMAP
)))
395 panfrost_bo_mmap(bo
);
397 p_atomic_set(&bo
->refcnt
, 1);
399 if (dev
->debug
& (PAN_DBG_TRACE
| PAN_DBG_SYNC
)) {
400 if (flags
& PAN_BO_INVISIBLE
)
401 pandecode_inject_mmap(bo
->gpu
, NULL
, bo
->size
, NULL
);
402 else if (!(flags
& PAN_BO_DELAY_MMAP
))
403 pandecode_inject_mmap(bo
->gpu
, bo
->cpu
, bo
->size
, NULL
);
410 panfrost_bo_reference(struct panfrost_bo
*bo
)
413 ASSERTED
int count
= p_atomic_inc_return(&bo
->refcnt
);
419 panfrost_bo_unreference(struct panfrost_bo
*bo
)
424 /* Don't return to cache if there are still references */
425 if (p_atomic_dec_return(&bo
->refcnt
))
428 struct panfrost_device
*dev
= bo
->dev
;
430 pthread_mutex_lock(&dev
->bo_map_lock
);
432 /* Someone might have imported this BO while we were waiting for the
433 * lock, let's make sure it's still not referenced before freeing it.
435 if (p_atomic_read(&bo
->refcnt
) == 0) {
436 /* When the reference count goes to zero, we need to cleanup */
437 panfrost_bo_munmap(bo
);
439 /* Rather than freeing the BO now, we'll cache the BO for later
440 * allocations if we're allowed to.
442 if (!panfrost_bo_cache_put(bo
))
443 panfrost_bo_free(bo
);
446 pthread_mutex_unlock(&dev
->bo_map_lock
);
450 panfrost_bo_import(struct panfrost_device
*dev
, int fd
)
452 struct panfrost_bo
*bo
;
453 struct drm_panfrost_get_bo_offset get_bo_offset
= {0,};
457 ret
= drmPrimeFDToHandle(dev
->fd
, fd
, &gem_handle
);
460 pthread_mutex_lock(&dev
->bo_map_lock
);
461 bo
= pan_lookup_bo(dev
, gem_handle
);
464 get_bo_offset
.handle
= gem_handle
;
465 ret
= drmIoctl(dev
->fd
, DRM_IOCTL_PANFROST_GET_BO_OFFSET
, &get_bo_offset
);
469 bo
->gpu
= (mali_ptr
) get_bo_offset
.offset
;
470 bo
->size
= lseek(fd
, 0, SEEK_END
);
471 bo
->flags
= PAN_BO_SHARED
;
472 bo
->gem_handle
= gem_handle
;
473 assert(bo
->size
> 0);
474 p_atomic_set(&bo
->refcnt
, 1);
475 // TODO map and unmap on demand?
476 panfrost_bo_mmap(bo
);
478 /* bo->refcnt == 0 can happen if the BO
479 * was being released but panfrost_bo_import() acquired the
480 * lock before panfrost_bo_unreference(). In that case, refcnt
481 * is 0 and we can't use panfrost_bo_reference() directly, we
482 * have to re-initialize the refcnt().
483 * Note that panfrost_bo_unreference() checks
484 * refcnt value just after acquiring the lock to
485 * make sure the object is not freed if panfrost_bo_import()
486 * acquired it in the meantime.
488 if (p_atomic_read(&bo
->refcnt
) == 0)
489 p_atomic_set(&bo
->refcnt
, 1);
491 panfrost_bo_reference(bo
);
494 pthread_mutex_unlock(&dev
->bo_map_lock
);
500 panfrost_bo_export(struct panfrost_bo
*bo
)
502 struct drm_prime_handle args
= {
503 .handle
= bo
->gem_handle
,
504 .flags
= DRM_CLOEXEC
,
507 int ret
= drmIoctl(bo
->dev
->fd
, DRM_IOCTL_PRIME_HANDLE_TO_FD
, &args
);
511 bo
->flags
|= PAN_BO_SHARED
;