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/*
* Copyright 2019 Collabora, Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Authors (Collabora):
* Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
*/
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <xf86drm.h>
#include <pthread.h>
#include "drm-uapi/panfrost_drm.h"
#include "pan_bo.h"
#include "pan_screen.h"
#include "pan_util.h"
#include "pandecode/decode.h"
#include "os/os_mman.h"
#include "util/u_inlines.h"
#include "util/u_math.h"
/* This file implements a userspace BO cache. Allocating and freeing
* GPU-visible buffers is very expensive, and even the extra kernel roundtrips
* adds more work than we would like at this point. So caching BOs in userspace
* solves both of these problems and does not require kernel updates.
*
* Cached BOs are sorted into a bucket based on rounding their size down to the
* nearest power-of-two. Each bucket contains a linked list of free panfrost_bo
* objects. Putting a BO into the cache is accomplished by adding it to the
* corresponding bucket. Getting a BO from the cache consists of finding the
* appropriate bucket and sorting. A cache eviction is a kernel-level free of a
* BO and removing it from the bucket. We special case evicting all BOs from
* the cache, since that's what helpful in practice and avoids extra logic
* around the linked list.
*/
static struct panfrost_bo *
panfrost_bo_alloc(struct panfrost_screen *screen, size_t size,
uint32_t flags)
{
struct drm_panfrost_create_bo create_bo = { .size = size };
struct panfrost_bo *bo;
int ret;
if (screen->kernel_version->version_major > 1 ||
screen->kernel_version->version_minor >= 1) {
if (flags & PAN_BO_GROWABLE)
create_bo.flags |= PANFROST_BO_HEAP;
if (!(flags & PAN_BO_EXECUTE))
create_bo.flags |= PANFROST_BO_NOEXEC;
}
ret = drmIoctl(screen->fd, DRM_IOCTL_PANFROST_CREATE_BO, &create_bo);
if (ret) {
DBG("DRM_IOCTL_PANFROST_CREATE_BO failed: %m\n");
return NULL;
}
bo = rzalloc(screen, struct panfrost_bo);
assert(bo);
bo->size = create_bo.size;
bo->gpu = create_bo.offset;
bo->gem_handle = create_bo.handle;
bo->flags = flags;
bo->screen = screen;
return bo;
}
static void
panfrost_bo_free(struct panfrost_bo *bo)
{
struct drm_gem_close gem_close = { .handle = bo->gem_handle };
int ret;
ret = drmIoctl(bo->screen->fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
if (ret) {
fprintf(stderr, "DRM_IOCTL_GEM_CLOSE failed: %m\n");
assert(0);
}
ralloc_free(bo);
}
/* Returns true if the BO is ready, false otherwise.
* access_type is encoding the type of access one wants to ensure is done.
* Say you want to make sure all writers are done writing, you should pass
* PAN_BO_ACCESS_WRITE.
* If you want to wait for all users, you should pass PAN_BO_ACCESS_RW.
* PAN_BO_ACCESS_READ would work too as waiting for readers implies
* waiting for writers as well, but we want to make things explicit and waiting
* only for readers is impossible.
*/
bool
panfrost_bo_wait(struct panfrost_bo *bo, int64_t timeout_ns,
uint32_t access_type)
{
struct drm_panfrost_wait_bo req = {
.handle = bo->gem_handle,
.timeout_ns = timeout_ns,
};
int ret;
assert(access_type == PAN_BO_ACCESS_WRITE ||
access_type == PAN_BO_ACCESS_RW);
/* If the BO has been exported or imported we can't rely on the cached
* state, we need to call the WAIT_BO ioctl.
*/
if (!(bo->flags & (PAN_BO_IMPORTED | PAN_BO_EXPORTED))) {
/* If ->gpu_access is 0, the BO is idle, no need to wait. */
if (!bo->gpu_access)
return true;
/* If the caller only wants to wait for writers and no
* writes are pending, we don't have to wait.
*/
if (access_type == PAN_BO_ACCESS_WRITE &&
!(bo->gpu_access & PAN_BO_ACCESS_WRITE))
return true;
}
/* The ioctl returns >= 0 value when the BO we are waiting for is ready
* -1 otherwise.
*/
ret = drmIoctl(bo->screen->fd, DRM_IOCTL_PANFROST_WAIT_BO, &req);
if (ret != -1) {
/* Set gpu_access to 0 so that the next call to bo_wait()
* doesn't have to call the WAIT_BO ioctl.
*/
bo->gpu_access = 0;
return true;
}
/* If errno is not ETIMEDOUT or EBUSY that means the handle we passed
* is invalid, which shouldn't happen here.
*/
assert(errno == ETIMEDOUT || errno == EBUSY);
return false;
}
/* Helper to calculate the bucket index of a BO */
static unsigned
pan_bucket_index(unsigned size)
{
/* Round down to POT to compute a bucket index */
unsigned bucket_index = util_logbase2(size);
/* Clamp the bucket index; all huge allocations will be
* sorted into the largest bucket */
bucket_index = MIN2(bucket_index, MAX_BO_CACHE_BUCKET);
/* The minimum bucket size must equal the minimum allocation
* size; the maximum we clamped */
assert(bucket_index >= MIN_BO_CACHE_BUCKET);
assert(bucket_index <= MAX_BO_CACHE_BUCKET);
/* Reindex from 0 */
return (bucket_index - MIN_BO_CACHE_BUCKET);
}
static struct list_head *
pan_bucket(struct panfrost_screen *screen, unsigned size)
{
return &screen->bo_cache.buckets[pan_bucket_index(size)];
}
/* Tries to fetch a BO of sufficient size with the appropriate flags from the
* BO cache. If it succeeds, it returns that BO and removes the BO from the
* cache. If it fails, it returns NULL signaling the caller to allocate a new
* BO. */
static struct panfrost_bo *
panfrost_bo_cache_fetch(struct panfrost_screen *screen,
size_t size, uint32_t flags, bool dontwait)
{
pthread_mutex_lock(&screen->bo_cache.lock);
struct list_head *bucket = pan_bucket(screen, size);
struct panfrost_bo *bo = NULL;
/* Iterate the bucket looking for something suitable */
list_for_each_entry_safe(struct panfrost_bo, entry, bucket,
bucket_link) {
if (entry->size < size || entry->flags != flags)
continue;
if (!panfrost_bo_wait(entry, dontwait ? 0 : INT64_MAX,
PAN_BO_ACCESS_RW))
continue;
struct drm_panfrost_madvise madv = {
.handle = entry->gem_handle,
.madv = PANFROST_MADV_WILLNEED,
};
int ret;
/* This one works, splice it out of the cache */
list_del(&entry->bucket_link);
list_del(&entry->lru_link);
ret = drmIoctl(screen->fd, DRM_IOCTL_PANFROST_MADVISE, &madv);
if (!ret && !madv.retained) {
panfrost_bo_free(entry);
continue;
}
/* Let's go! */
bo = entry;
break;
}
pthread_mutex_unlock(&screen->bo_cache.lock);
return bo;
}
static void
panfrost_bo_cache_evict_stale_bos(struct panfrost_screen *screen)
{
struct timespec time;
clock_gettime(CLOCK_MONOTONIC, &time);
list_for_each_entry_safe(struct panfrost_bo, entry,
&screen->bo_cache.lru, lru_link) {
/* We want all entries that have been used more than 1 sec
* ago to be dropped, others can be kept.
* Note the <= 2 check and not <= 1. It's here to account for
* the fact that we're only testing ->tv_sec, not ->tv_nsec.
* That means we might keep entries that are between 1 and 2
* seconds old, but we don't really care, as long as unused BOs
* are dropped at some point.
*/
if (time.tv_sec - entry->last_used <= 2)
break;
list_del(&entry->bucket_link);
list_del(&entry->lru_link);
panfrost_bo_free(entry);
}
}
/* Tries to add a BO to the cache. Returns if it was
* successful */
static bool
panfrost_bo_cache_put(struct panfrost_bo *bo)
{
struct panfrost_screen *screen = bo->screen;
if (bo->flags & PAN_BO_DONT_REUSE)
return false;
pthread_mutex_lock(&screen->bo_cache.lock);
struct list_head *bucket = pan_bucket(screen, bo->size);
struct drm_panfrost_madvise madv;
struct timespec time;
madv.handle = bo->gem_handle;
madv.madv = PANFROST_MADV_DONTNEED;
madv.retained = 0;
drmIoctl(screen->fd, DRM_IOCTL_PANFROST_MADVISE, &madv);
/* Add us to the bucket */
list_addtail(&bo->bucket_link, bucket);
/* Add us to the LRU list and update the last_used field. */
list_addtail(&bo->lru_link, &screen->bo_cache.lru);
clock_gettime(CLOCK_MONOTONIC, &time);
bo->last_used = time.tv_sec;
/* Let's do some cleanup in the BO cache while we hold the
* lock.
*/
panfrost_bo_cache_evict_stale_bos(screen);
pthread_mutex_unlock(&screen->bo_cache.lock);
return true;
}
/* Evicts all BOs from the cache. Called during context
* destroy or during low-memory situations (to free up
* memory that may be unused by us just sitting in our
* cache, but still reserved from the perspective of the
* OS) */
void
panfrost_bo_cache_evict_all(
struct panfrost_screen *screen)
{
pthread_mutex_lock(&screen->bo_cache.lock);
for (unsigned i = 0; i < ARRAY_SIZE(screen->bo_cache.buckets); ++i) {
struct list_head *bucket = &screen->bo_cache.buckets[i];
list_for_each_entry_safe(struct panfrost_bo, entry, bucket,
bucket_link) {
list_del(&entry->bucket_link);
list_del(&entry->lru_link);
panfrost_bo_free(entry);
}
}
pthread_mutex_unlock(&screen->bo_cache.lock);
}
void
panfrost_bo_mmap(struct panfrost_bo *bo)
{
struct drm_panfrost_mmap_bo mmap_bo = { .handle = bo->gem_handle };
int ret;
if (bo->cpu)
return;
ret = drmIoctl(bo->screen->fd, DRM_IOCTL_PANFROST_MMAP_BO, &mmap_bo);
if (ret) {
fprintf(stderr, "DRM_IOCTL_PANFROST_MMAP_BO failed: %m\n");
assert(0);
}
bo->cpu = os_mmap(NULL, bo->size, PROT_READ | PROT_WRITE, MAP_SHARED,
bo->screen->fd, mmap_bo.offset);
if (bo->cpu == MAP_FAILED) {
fprintf(stderr, "mmap failed: %p %m\n", bo->cpu);
assert(0);
}
/* Record the mmap if we're tracing */
if (pan_debug & (PAN_DBG_TRACE | PAN_DBG_SYNC))
pandecode_inject_mmap(bo->gpu, bo->cpu, bo->size, NULL);
}
static void
panfrost_bo_munmap(struct panfrost_bo *bo)
{
if (!bo->cpu)
return;
if (os_munmap((void *) (uintptr_t)bo->cpu, bo->size)) {
perror("munmap");
abort();
}
bo->cpu = NULL;
}
struct panfrost_bo *
panfrost_bo_create(struct panfrost_screen *screen, size_t size,
uint32_t flags)
{
struct panfrost_bo *bo;
/* Kernel will fail (confusingly) with EPERM otherwise */
assert(size > 0);
/* To maximize BO cache usage, don't allocate tiny BOs */
size = MAX2(size, 4096);
/* GROWABLE BOs cannot be mmapped */
if (flags & PAN_BO_GROWABLE)
assert(flags & PAN_BO_INVISIBLE);
/* Before creating a BO, we first want to check the cache but without
* waiting for BO readiness (BOs in the cache can still be referenced
* by jobs that are not finished yet).
* If the cached allocation fails we fall back on fresh BO allocation,
* and if that fails too, we try one more time to allocate from the
* cache, but this time we accept to wait.
*/
bo = panfrost_bo_cache_fetch(screen, size, flags, true);
if (!bo)
bo = panfrost_bo_alloc(screen, size, flags);
if (!bo)
bo = panfrost_bo_cache_fetch(screen, size, flags, false);
if (!bo)
fprintf(stderr, "BO creation failed\n");
assert(bo);
/* Only mmap now if we know we need to. For CPU-invisible buffers, we
* never map since we don't care about their contents; they're purely
* for GPU-internal use. But we do trace them anyway. */
if (!(flags & (PAN_BO_INVISIBLE | PAN_BO_DELAY_MMAP)))
panfrost_bo_mmap(bo);
else if (flags & PAN_BO_INVISIBLE) {
if (pan_debug & (PAN_DBG_TRACE | PAN_DBG_SYNC))
pandecode_inject_mmap(bo->gpu, NULL, bo->size, NULL);
}
pipe_reference_init(&bo->reference, 1);
pthread_mutex_lock(&screen->active_bos_lock);
_mesa_set_add(bo->screen->active_bos, bo);
pthread_mutex_unlock(&screen->active_bos_lock);
return bo;
}
void
panfrost_bo_reference(struct panfrost_bo *bo)
{
if (bo)
pipe_reference(NULL, &bo->reference);
}
void
panfrost_bo_unreference(struct panfrost_bo *bo)
{
if (!bo)
return;
if (!pipe_reference(&bo->reference, NULL))
return;
struct panfrost_screen *screen = bo->screen;
pthread_mutex_lock(&screen->active_bos_lock);
/* Someone might have imported this BO while we were waiting for the
* lock, let's make sure it's still not referenced before freeing it.
*/
if (!pipe_is_referenced(&bo->reference)) {
_mesa_set_remove_key(bo->screen->active_bos, bo);
/* When the reference count goes to zero, we need to cleanup */
panfrost_bo_munmap(bo);
/* Rather than freeing the BO now, we'll cache the BO for later
* allocations if we're allowed to.
*/
if (!panfrost_bo_cache_put(bo))
panfrost_bo_free(bo);
}
pthread_mutex_unlock(&screen->active_bos_lock);
}
struct panfrost_bo *
panfrost_bo_import(struct panfrost_screen *screen, int fd)
{
struct panfrost_bo *bo, *newbo = rzalloc(screen, struct panfrost_bo);
struct drm_panfrost_get_bo_offset get_bo_offset = {0,};
struct set_entry *entry;
ASSERTED int ret;
unsigned gem_handle;
newbo->screen = screen;
ret = drmPrimeFDToHandle(screen->fd, fd, &gem_handle);
assert(!ret);
newbo->gem_handle = gem_handle;
pthread_mutex_lock(&screen->active_bos_lock);
entry = _mesa_set_search_or_add(screen->active_bos, newbo);
assert(entry);
bo = (struct panfrost_bo *)entry->key;
if (newbo == bo) {
get_bo_offset.handle = gem_handle;
ret = drmIoctl(screen->fd, DRM_IOCTL_PANFROST_GET_BO_OFFSET, &get_bo_offset);
assert(!ret);
newbo->gpu = (mali_ptr) get_bo_offset.offset;
newbo->size = lseek(fd, 0, SEEK_END);
newbo->flags |= PAN_BO_DONT_REUSE | PAN_BO_IMPORTED;
assert(newbo->size > 0);
pipe_reference_init(&newbo->reference, 1);
// TODO map and unmap on demand?
panfrost_bo_mmap(newbo);
} else {
ralloc_free(newbo);
/* !pipe_is_referenced(&bo->reference) can happen if the BO
* was being released but panfrost_bo_import() acquired the
* lock before panfrost_bo_unreference(). In that case, refcnt
* is 0 and we can't use panfrost_bo_reference() directly, we
* have to re-initialize it with pipe_reference_init().
* Note that panfrost_bo_unreference() checks
* pipe_is_referenced() value just after acquiring the lock to
* make sure the object is not freed if panfrost_bo_import()
* acquired it in the meantime.
*/
if (!pipe_is_referenced(&bo->reference))
pipe_reference_init(&newbo->reference, 1);
else
panfrost_bo_reference(bo);
assert(bo->cpu);
}
pthread_mutex_unlock(&screen->active_bos_lock);
return bo;
}
int
panfrost_bo_export(struct panfrost_bo *bo)
{
struct drm_prime_handle args = {
.handle = bo->gem_handle,
.flags = DRM_CLOEXEC,
};
int ret = drmIoctl(bo->screen->fd, DRM_IOCTL_PRIME_HANDLE_TO_FD, &args);
if (ret == -1)
return -1;
bo->flags |= PAN_BO_DONT_REUSE | PAN_BO_EXPORTED;
return args.fd;
}
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