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author | Eric Anholt <eric@anholt.net> | 2019-04-02 01:26:33 +0300 |
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committer | Eric Anholt <eric@anholt.net> | 2019-04-17 01:32:20 +0300 |
commit | 5d5a179d3e90a8385b115e4bd19826ea0bcc6d11 (patch) | |
tree | 498a12878d4de2308f1cc88f23ffeb4a509f8a51 /drivers/gpu/drm/drm_gem.c | |
parent | c8f005684c98f4d9942baec13ad98054dbf312a0 (diff) | |
download | linux-5d5a179d3e90a8385b115e4bd19826ea0bcc6d11.tar.xz |
drm: Add helpers for setting up an array of dma_fence dependencies.
I needed to add implicit dependency support for v3d, and Rob Herring
has been working on it for panfrost, and I had recently looked at the
lima implementation so I think this will be a good intersection of
what we all want and simplify our scheduler implementations.
v2: Rebase on xa_limit_32b API change, and tiny checkpatch cleanups on
the way in (unsigned int vs unsigned, extra return before
EXPORT_SYMBOL_GPL)
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190401222635.25013-6-eric@anholt.net
Reviewed-and-tested-by: Qiang Yu <yuq825@gmail.com> (v1)
Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
-rw-r--r-- | drivers/gpu/drm/drm_gem.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index e93043b64c2d..fae4676707b6 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1367,3 +1367,96 @@ drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, ww_acquire_fini(acquire_ctx); } EXPORT_SYMBOL(drm_gem_unlock_reservations); + +/** + * drm_gem_fence_array_add - Adds the fence to an array of fences to be + * waited on, deduplicating fences from the same context. + * + * @fence_array array of dma_fence * for the job to block on. + * @fence the dma_fence to add to the list of dependencies. + * + * Returns: + * 0 on success, or an error on failing to expand the array. + */ +int drm_gem_fence_array_add(struct xarray *fence_array, + struct dma_fence *fence) +{ + struct dma_fence *entry; + unsigned long index; + u32 id = 0; + int ret; + + if (!fence) + return 0; + + /* Deduplicate if we already depend on a fence from the same context. + * This lets the size of the array of deps scale with the number of + * engines involved, rather than the number of BOs. + */ + xa_for_each(fence_array, index, entry) { + if (entry->context != fence->context) + continue; + + if (dma_fence_is_later(fence, entry)) { + dma_fence_put(entry); + xa_store(fence_array, index, fence, GFP_KERNEL); + } else { + dma_fence_put(fence); + } + return 0; + } + + ret = xa_alloc(fence_array, &id, fence, xa_limit_32b, GFP_KERNEL); + if (ret != 0) + dma_fence_put(fence); + + return ret; +} +EXPORT_SYMBOL(drm_gem_fence_array_add); + +/** + * drm_gem_fence_array_add_implicit - Adds the implicit dependencies tracked + * in the GEM object's reservation object to an array of dma_fences for use in + * scheduling a rendering job. + * + * This should be called after drm_gem_lock_reservations() on your array of + * GEM objects used in the job but before updating the reservations with your + * own fences. + * + * @fence_array array of dma_fence * for the job to block on. + * @obj the gem object to add new dependencies from. + * @write whether the job might write the object (so we need to depend on + * shared fences in the reservation object). + */ +int drm_gem_fence_array_add_implicit(struct xarray *fence_array, + struct drm_gem_object *obj, + bool write) +{ + int ret; + struct dma_fence **fences; + unsigned int i, fence_count; + + if (!write) { + struct dma_fence *fence = + reservation_object_get_excl_rcu(obj->resv); + + return drm_gem_fence_array_add(fence_array, fence); + } + + ret = reservation_object_get_fences_rcu(obj->resv, NULL, + &fence_count, &fences); + if (ret || !fence_count) + return ret; + + for (i = 0; i < fence_count; i++) { + ret = drm_gem_fence_array_add(fence_array, fences[i]); + if (ret) + break; + } + + for (; i < fence_count; i++) + dma_fence_put(fences[i]); + kfree(fences); + return ret; +} +EXPORT_SYMBOL(drm_gem_fence_array_add_implicit); |