bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-25 10:02:31 -04:00
Code Issues Packages Projects Releases Wiki Activity

dma-buf: add dma_resv_replace_fences v2

Browse Source 
This function allows to replace fences from the shared fence list when
we can gurantee that the operation represented by the original fence has
finished or no accesses to the resources protected by the dma_resv
object any more when the new fence finishes.

Then use this function in the amdkfd code when BOs are unmapped from the
process.

v2: add an example when this is usefull.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321135856.1331-1-christian.koenig@amd.com
This commit is contained in:
Christian König
2021-09-24 10:55:45 +02:00
parent f30bceab16
commit 548e7432dc
3 changed files with 54 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
View File

@@ -253,53 +253,18 @@ void amdgpu_amdkfd_release_notify(struct amdgpu_bo *bo)
static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
struct amdgpu_amdkfd_fence *ef)
{
struct dma_resv *resv = bo->tbo.base.resv;
struct dma_resv_list *old, *new;
unsigned int i, j, k;
struct dma_fence *replacement;
if (!ef)
return -EINVAL;
old = dma_resv_shared_list(resv);
if (!old)
return 0;
new = kmalloc(struct_size(new, shared, old->shared_max), GFP_KERNEL);
if (!new)
return -ENOMEM;
/* Go through all the shared fences in the resevation object and sort
* the interesting ones to the end of the list.
/* TODO: Instead of block before we should use the fence of the page
* table update and TLB flush here directly.
*/
for (i = 0, j = old->shared_count, k = 0; i < old->shared_count; ++i) {
struct dma_fence *f;
f = rcu_dereference_protected(old->shared[i],
dma_resv_held(resv));
if (f->context == ef->base.context)
RCU_INIT_POINTER(new->shared[--j], f);
else
RCU_INIT_POINTER(new->shared[k++], f);
}
new->shared_max = old->shared_max;
new->shared_count = k;
/* Install the new fence list, seqcount provides the barriers */
write_seqcount_begin(&resv->seq);
RCU_INIT_POINTER(resv->fence, new);
write_seqcount_end(&resv->seq);
/* Drop the references to the removed fences or move them to ef_list */
for (i = j; i < old->shared_count; ++i) {
struct dma_fence *f;
f = rcu_dereference_protected(new->shared[i],
dma_resv_held(resv));
dma_fence_put(f);
}
kfree_rcu(old, rcu);
replacement = dma_fence_get_stub();
dma_resv_replace_fences(bo->tbo.base.resv, ef->base.context,
replacement);
dma_fence_put(replacement);
return 0;
}