static int test_aa(void)
{
struct ww_mutex mutex;
struct ww_acquire_ctx ctx;
int ret;
ww_mutex_init(&mutex, &ww_class);
ww_acquire_init(&ctx, &ww_class);
ww_mutex_lock(&mutex, &ctx);
if (ww_mutex_trylock(&mutex)) {
pr_err("%s: trylocked itself!\n", __func__);
ww_mutex_unlock(&mutex);
ret = -EINVAL;
goto out;
}
ret = ww_mutex_lock(&mutex, &ctx);
if (ret != -EALREADY) {
pr_err("%s: missed deadlock for recursing, ret=%d\n",
__func__, ret);
if (!ret)
ww_mutex_unlock(&mutex);
ret = -EINVAL;
goto out;
}
ret = 0;
out:
ww_mutex_unlock(&mutex);
ww_acquire_fini(&ctx);
return ret;
}
static void test_cycle_work(struct work_struct *work)
{
struct test_cycle *cycle = container_of(work, typeof(*cycle), work);
struct ww_acquire_ctx ctx;
int err;
ww_acquire_init(&ctx, &ww_class);
ww_mutex_lock(&cycle->a_mutex, &ctx);
complete(cycle->a_signal);
wait_for_completion(&cycle->b_signal);
err = ww_mutex_lock(cycle->b_mutex, &ctx);
if (err == -EDEADLK) {
ww_mutex_unlock(&cycle->a_mutex);
ww_mutex_lock_slow(cycle->b_mutex, &ctx);
err = ww_mutex_lock(&cycle->a_mutex, &ctx);
}
if (!err)
ww_mutex_unlock(cycle->b_mutex);
ww_mutex_unlock(&cycle->a_mutex);
ww_acquire_fini(&ctx);
cycle->result = err;
}
static void test_abba_work(struct work_struct *work)
{
struct test_abba *abba = container_of(work, typeof(*abba), work);
struct ww_acquire_ctx ctx;
int err;
ww_acquire_init(&ctx, &ww_class);
ww_mutex_lock(&abba->b_mutex, &ctx);
complete(&abba->b_ready);
wait_for_completion(&abba->a_ready);
err = ww_mutex_lock(&abba->a_mutex, &ctx);
if (abba->resolve && err == -EDEADLK) {
ww_mutex_unlock(&abba->b_mutex);
ww_mutex_lock_slow(&abba->a_mutex, &ctx);
err = ww_mutex_lock(&abba->b_mutex, &ctx);
}
if (!err)
ww_mutex_unlock(&abba->a_mutex);
ww_mutex_unlock(&abba->b_mutex);
ww_acquire_fini(&ctx);
abba->result = err;
}
static int test_abba(bool resolve)
{
struct test_abba abba;
struct ww_acquire_ctx ctx;
int err, ret;
ww_mutex_init(&abba.a_mutex, &ww_class);
ww_mutex_init(&abba.b_mutex, &ww_class);
INIT_WORK_ONSTACK(&abba.work, test_abba_work);
init_completion(&abba.a_ready);
init_completion(&abba.b_ready);
abba.resolve = resolve;
schedule_work(&abba.work);
ww_acquire_init(&ctx, &ww_class);
ww_mutex_lock(&abba.a_mutex, &ctx);
complete(&abba.a_ready);
wait_for_completion(&abba.b_ready);
err = ww_mutex_lock(&abba.b_mutex, &ctx);
if (resolve && err == -EDEADLK) {
ww_mutex_unlock(&abba.a_mutex);
ww_mutex_lock_slow(&abba.b_mutex, &ctx);
err = ww_mutex_lock(&abba.a_mutex, &ctx);
}
if (!err)
ww_mutex_unlock(&abba.b_mutex);
ww_mutex_unlock(&abba.a_mutex);
ww_acquire_fini(&ctx);
flush_work(&abba.work);
destroy_work_on_stack(&abba.work);
ret = 0;
if (resolve) {
if (err || abba.result) {
pr_err("%s: failed to resolve ABBA deadlock, A err=%d, B err=%d\n",
__func__, err, abba.result);
ret = -EINVAL;
}
} else {
if (err != -EDEADLK && abba.result != -EDEADLK) {
pr_err("%s: missed ABBA deadlock, A err=%d, B err=%d\n",
__func__, err, abba.result);
ret = -EINVAL;
}
}
return ret;
}
struct drm_gem_object *
amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sg)
{
struct reservation_object *resv = attach->dmabuf->resv;
struct amdgpu_device *adev = dev->dev_private;
struct amdgpu_bo *bo;
int ret;
ww_mutex_lock(&resv->lock, NULL);
ret = amdgpu_bo_create(adev, attach->dmabuf->size, PAGE_SIZE,
AMDGPU_GEM_DOMAIN_CPU, 0, ttm_bo_type_sg,
resv, &bo);
if (ret)
goto error;
bo->tbo.sg = sg;
bo->tbo.ttm->sg = sg;
bo->allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
bo->preferred_domains = AMDGPU_GEM_DOMAIN_GTT;
if (attach->dmabuf->ops != &amdgpu_dmabuf_ops)
bo->prime_shared_count = 1;
ww_mutex_unlock(&resv->lock);
return &bo->gem_base;
error:
ww_mutex_unlock(&resv->lock);
return ERR_PTR(ret);
}
/**
* drm_modeset_lock - take modeset lock
* @lock: lock to take
* @ctx: acquire ctx
*
* If ctx is not NULL, then its ww acquire context is used and the
* lock will be tracked by the context and can be released by calling
* drm_modeset_drop_locks(). If -EDEADLK is returned, this means a
* deadlock scenario has been detected and it is an error to attempt
* to take any more locks without first calling drm_modeset_backoff().
*/
int drm_modeset_lock(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx)
{
if (ctx)
return modeset_lock(lock, ctx, false, false);
ww_mutex_lock(&lock->mutex, NULL);
return 0;
}
static void stress_inorder_work(struct work_struct *work)
{
struct stress *stress = container_of(work, typeof(*stress), work);
const int nlocks = stress->nlocks;
struct ww_mutex *locks = stress->locks;
struct ww_acquire_ctx ctx;
int *order;
order = get_random_order(nlocks);
if (!order)
return;
do {
int contended = -1;
int n, err;
ww_acquire_init(&ctx, &ww_class);
retry:
err = 0;
for (n = 0; n < nlocks; n++) {
if (n == contended)
continue;
err = ww_mutex_lock(&locks[order[n]], &ctx);
if (err < 0)
break;
}
if (!err)
dummy_load(stress);
if (contended > n)
ww_mutex_unlock(&locks[order[contended]]);
contended = n;
while (n--)
ww_mutex_unlock(&locks[order[n]]);
if (err == -EDEADLK) {
ww_mutex_lock_slow(&locks[order[contended]], &ctx);
goto retry;
}
if (err) {
pr_err_once("stress (%s) failed with %d\n",
__func__, err);
break;
}
ww_acquire_fini(&ctx);
} while (!time_after(jiffies, stress->timeout));
kfree(order);
kfree(stress);
}
/**
* i915_gem_batch_pool_get() - allocate a buffer from the pool
* @pool: the batch buffer pool
* @size: the minimum desired size of the returned buffer
*
* Returns an inactive buffer from @pool with at least @size bytes,
* with the pages pinned. The caller must i915_gem_object_unpin_pages()
* on the returned object.
*
* Note: Callers must hold the struct_mutex
*
* Return: the buffer object or an error pointer
*/
struct drm_i915_gem_object *
i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
size_t size)
{
struct drm_i915_gem_object *obj = NULL;
struct drm_i915_gem_object *tmp;
struct list_head *list;
int n, ret;
lockdep_assert_held(&pool->engine->i915->drm.struct_mutex);
/* Compute a power-of-two bucket, but throw everything greater than
* 16KiB into the same bucket: i.e. the the buckets hold objects of
* (1 page, 2 pages, 4 pages, 8+ pages).
*/
n = fls(size >> PAGE_SHIFT) - 1;
if (n >= ARRAY_SIZE(pool->cache_list))
n = ARRAY_SIZE(pool->cache_list) - 1;
list = &pool->cache_list[n];
list_for_each_entry(tmp, list, batch_pool_link) {
/* The batches are strictly LRU ordered */
if (i915_gem_object_is_active(tmp))
break;
GEM_BUG_ON(!reservation_object_test_signaled_rcu(tmp->resv,
true));
if (tmp->base.size >= size) {
/* Clear the set of shared fences early */
ww_mutex_lock(&tmp->resv->lock, NULL);
reservation_object_add_excl_fence(tmp->resv, NULL);
ww_mutex_unlock(&tmp->resv->lock);
obj = tmp;
break;
}
}
if (obj == NULL) {
obj = i915_gem_object_create_internal(pool->engine->i915, size);
if (IS_ERR(obj))
return obj;
}
ret = i915_gem_object_pin_pages(obj);
if (ret)
return ERR_PTR(ret);
list_move_tail(&obj->batch_pool_link, list);
return obj;
}
static int __test_mutex(unsigned int flags)
{
#define TIMEOUT (HZ / 16)
struct test_mutex mtx;
struct ww_acquire_ctx ctx;
int ret;
ww_mutex_init(&mtx.mutex, &ww_class);
ww_acquire_init(&ctx, &ww_class);
INIT_WORK_ONSTACK(&mtx.work, test_mutex_work);
init_completion(&mtx.ready);
init_completion(&mtx.go);
init_completion(&mtx.done);
mtx.flags = flags;
schedule_work(&mtx.work);
wait_for_completion(&mtx.ready);
ww_mutex_lock(&mtx.mutex, (flags & TEST_MTX_CTX) ? &ctx : NULL);
complete(&mtx.go);
if (flags & TEST_MTX_SPIN) {
unsigned long timeout = jiffies + TIMEOUT;
ret = 0;
do {
if (completion_done(&mtx.done)) {
ret = -EINVAL;
break;
}
cond_resched();
} while (time_before(jiffies, timeout));
} else {
ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
}
ww_mutex_unlock(&mtx.mutex);
ww_acquire_fini(&ctx);
if (ret) {
pr_err("%s(flags=%x): mutual exclusion failure\n",
__func__, flags);
ret = -EINVAL;
}
flush_work(&mtx.work);
destroy_work_on_stack(&mtx.work);
return ret;
#undef TIMEOUT
}
static void test_mutex_work(struct work_struct *work)
{
struct test_mutex *mtx = container_of(work, typeof(*mtx), work);
complete(&mtx->ready);
wait_for_completion(&mtx->go);
if (mtx->flags & TEST_MTX_TRY) {
while (!ww_mutex_trylock(&mtx->mutex))
cond_resched();
} else {
ww_mutex_lock(&mtx->mutex, NULL);
}
complete(&mtx->done);
ww_mutex_unlock(&mtx->mutex);
}
struct drm_gem_object *amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sg)
{
struct reservation_object *resv = attach->dmabuf->resv;
struct amdgpu_device *adev = dev->dev_private;
struct amdgpu_bo *bo;
int ret;
ww_mutex_lock(&resv->lock, NULL);
ret = amdgpu_bo_create(adev, attach->dmabuf->size, PAGE_SIZE, false,
AMDGPU_GEM_DOMAIN_GTT, 0, sg, resv, &bo);
ww_mutex_unlock(&resv->lock);
if (ret)
return ERR_PTR(ret);
return &bo->gem_base;
}
int drm_lock_reservations(struct reservation_object **resvs,
unsigned int num_resvs, struct ww_acquire_ctx *ctx)
{
unsigned int r;
struct reservation_object *slow_res = NULL;
ww_acquire_init(ctx, &reservation_ww_class);
retry:
for (r = 0; r < num_resvs; r++) {
int ret;
/* skip the resv we locked with slow lock */
if (resvs[r] == slow_res) {
slow_res = NULL;
continue;
}
ret = ww_mutex_lock(&resvs[r]->lock, ctx);
if (ret < 0) {
unsigned int slow_r = r;
/*
* undo all the locks we already done,
* in reverse order
*/
while (r > 0) {
r--;
ww_mutex_unlock(&resvs[r]->lock);
}
if (slow_res)
ww_mutex_unlock(&slow_res->lock);
if (ret == -EDEADLK) {
slow_res = resvs[slow_r];
ww_mutex_lock_slow(&slow_res->lock, ctx);
goto retry;
}
ww_acquire_fini(ctx);
return ret;
}
}
ww_acquire_done(ctx);
return 0;
}
static inline int modeset_lock(struct drm_modeset_lock *lock,
struct drm_modeset_acquire_ctx *ctx,
bool interruptible, bool slow)
{
int ret;
WARN_ON(ctx->contended);
if (ctx->trylock_only) {
lockdep_assert_held(&ctx->ww_ctx);
if (!ww_mutex_trylock(&lock->mutex))
return -EBUSY;
else
return 0;
} else if (interruptible && slow) {
ret = ww_mutex_lock_slow_interruptible(&lock->mutex, &ctx->ww_ctx);
} else if (interruptible) {
ret = ww_mutex_lock_interruptible(&lock->mutex, &ctx->ww_ctx);
} else if (slow) {
ww_mutex_lock_slow(&lock->mutex, &ctx->ww_ctx);
ret = 0;
} else {
ret = ww_mutex_lock(&lock->mutex, &ctx->ww_ctx);
}
if (!ret) {
WARN_ON(!list_empty(&lock->head));
list_add(&lock->head, &ctx->locked);
} else if (ret == -EALREADY) {
/* we already hold the lock.. this is fine. For atomic
* we will need to be able to drm_modeset_lock() things
* without having to keep track of what is already locked
* or not.
*/
ret = 0;
} else if (ret == -EDEADLK) {
ctx->contended = lock;
}
return ret;
}
struct drm_gem_object *radeon_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sg)
{
struct reservation_object *resv = attach->dmabuf->resv;
struct radeon_device *rdev = dev->dev_private;
struct radeon_bo *bo;
int ret;
ww_mutex_lock(&resv->lock, NULL);
ret = radeon_bo_create(rdev, attach->dmabuf->size, PAGE_SIZE, false,
RADEON_GEM_DOMAIN_GTT, 0, sg, resv, &bo);
ww_mutex_unlock(&resv->lock);
if (ret)
return ERR_PTR(ret);
mutex_lock(&rdev->gem.mutex);
list_add_tail(&bo->list, &rdev->gem.objects);
mutex_unlock(&rdev->gem.mutex);
bo->prime_shared_count = 1;
return &bo->gem_base;
}