Commit 33654ef4 authored by Christian König's avatar Christian König Committed by Thomas Hellström

drm/i915: remove questionable fence optimization during copy

First of all as discussed multiple times now kernel copies *must* always
wait for all fences in a BO before actually doing the copy. This is
mandatory.

Additional to that drop the handling when there can't be a shared slot
allocated on the source BO and just properly return an error code.
Otherwise this code path would only be tested under out of memory
conditions.
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211221200050.436316-3-thomas.hellstrom@linux.intel.comSigned-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
parent 11930817
......@@ -195,19 +195,14 @@ static int i915_deps_add_dependency(struct i915_deps *deps,
}
static int i915_deps_add_resv(struct i915_deps *deps, struct dma_resv *resv,
bool all, const bool no_excl,
const struct ttm_operation_ctx *ctx)
{
struct dma_resv_iter iter;
struct dma_fence *fence;
int ret;
dma_resv_assert_held(resv);
dma_resv_for_each_fence(&iter, resv, all, fence) {
int ret;
if (no_excl && dma_resv_iter_is_exclusive(&iter))
continue;
dma_resv_for_each_fence(&iter, resv, true, fence) {
ret = i915_deps_add_dependency(deps, fence, ctx);
if (ret)
return ret;
......@@ -634,11 +629,7 @@ prev_deps(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
ret = i915_deps_add_dependency(deps, bo->moving, ctx);
if (!ret)
/*
* TODO: Only await excl fence here, and shared fences before
* signaling the migration fence.
*/
ret = i915_deps_add_resv(deps, bo->base.resv, true, false, ctx);
ret = i915_deps_add_resv(deps, bo->base.resv, ctx);
return ret;
}
......@@ -768,22 +759,21 @@ int i915_gem_obj_copy_ttm(struct drm_i915_gem_object *dst,
struct i915_refct_sgt *dst_rsgt;
struct dma_fence *copy_fence;
struct i915_deps deps;
int ret, shared_err;
int ret;
assert_object_held(dst);
assert_object_held(src);
i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
/*
* We plan to add a shared fence only for the source. If that
* fails, we await all source fences before commencing
* the copy instead of only the exclusive.
*/
shared_err = dma_resv_reserve_shared(src_bo->base.resv, 1);
ret = i915_deps_add_resv(&deps, dst_bo->base.resv, true, false, &ctx);
if (!ret)
ret = i915_deps_add_resv(&deps, src_bo->base.resv,
!!shared_err, false, &ctx);
ret = dma_resv_reserve_shared(src_bo->base.resv, 1);
if (ret)
return ret;
ret = i915_deps_add_resv(&deps, dst_bo->base.resv, &ctx);
if (ret)
return ret;
ret = i915_deps_add_resv(&deps, src_bo->base.resv, &ctx);
if (ret)
return ret;
......@@ -798,12 +788,7 @@ int i915_gem_obj_copy_ttm(struct drm_i915_gem_object *dst,
return PTR_ERR_OR_ZERO(copy_fence);
dma_resv_add_excl_fence(dst_bo->base.resv, copy_fence);
/* If we failed to reserve a shared slot, add an exclusive fence */
if (shared_err)
dma_resv_add_excl_fence(src_bo->base.resv, copy_fence);
else
dma_resv_add_shared_fence(src_bo->base.resv, copy_fence);
dma_resv_add_shared_fence(src_bo->base.resv, copy_fence);
dma_fence_put(copy_fence);
......
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