diff options
author | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2021-07-23 20:21:41 +0300 |
---|---|---|
committer | Matthew Auld <matthew.auld@intel.com> | 2021-07-26 18:37:36 +0300 |
commit | d7b2cb380b3a67894dccf497ded604f52bc05346 (patch) | |
tree | f514540700e40c2d36c1bd7c978c082621fbf617 /drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | |
parent | 76b62448dc8ffc3cfcfc40603d965b710a1840e3 (diff) | |
download | linux-d7b2cb380b3a67894dccf497ded604f52bc05346.tar.xz |
drm/i915/gem: Correct the locking and pin pattern for dma-buf (v8)
If our exported dma-bufs are imported by another instance of our driver,
that instance will typically have the imported dma-bufs locked during
dma_buf_map_attachment(). But the exporter also locks the same reservation
object in the map_dma_buf() callback, which leads to recursive locking.
So taking the lock inside _pin_pages_unlocked() is incorrect.
Additionally, the current pinning code path is contrary to the defined
way that pinning should occur.
Remove the explicit pin/unpin from the map/umap functions and move them
to the attach/detach allowing correct locking to occur, and to match
the static dma-buf drm_prime pattern.
Add a live selftest to exercise both dynamic and non-dynamic
exports.
v2:
- Extend the selftest with a fake dynamic importer.
- Provide real pin and unpin callbacks to not abuse the interface.
v3: (ruhl)
- Remove the dynamic export support and move the pinning into the
attach/detach path.
v4: (ruhl)
- Put pages does not need to assert on the dma-resv
v5: (jason)
- Lock around dma_buf_unmap_attachment() when emulating a dynamic
importer in the subtests.
- Use pin_pages_unlocked
v6: (jason)
- Use dma_buf_attach instead of dma_buf_attach_dynamic in the selftests
v7: (mauld)
- Use __i915_gem_object_get_pages (2 __underscores) instead of the
4 ____underscore version in the selftests
v8: (mauld)
- Drop the kernel doc from the static i915_gem_dmabuf_attach function
- Add missing "err = PTR_ERR()" to a bunch of selftest error cases
Reported-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723172142.3273510-8-jason@jlekstrand.net
Diffstat (limited to 'drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c')
-rw-r--r-- | drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 109 |
1 files changed, 107 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c index dd74bc09ec88..d4ce01e6ee85 100644 --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c @@ -35,7 +35,7 @@ static int igt_dmabuf_export(void *arg) static int igt_dmabuf_import_self(void *arg) { struct drm_i915_private *i915 = arg; - struct drm_i915_gem_object *obj; + struct drm_i915_gem_object *obj, *import_obj; struct drm_gem_object *import; struct dma_buf *dmabuf; int err; @@ -65,14 +65,118 @@ static int igt_dmabuf_import_self(void *arg) err = -EINVAL; goto out_import; } + import_obj = to_intel_bo(import); + + i915_gem_object_lock(import_obj, NULL); + err = __i915_gem_object_get_pages(import_obj); + i915_gem_object_unlock(import_obj); + if (err) { + pr_err("Same object dma-buf get_pages failed!\n"); + goto out_import; + } err = 0; out_import: - i915_gem_object_put(to_intel_bo(import)); + i915_gem_object_put(import_obj); +out_dmabuf: + dma_buf_put(dmabuf); +out: + i915_gem_object_put(obj); + return err; +} + +static int igt_dmabuf_import_same_driver(void *arg) +{ + struct drm_i915_private *i915 = arg; + struct drm_i915_gem_object *obj, *import_obj; + struct drm_gem_object *import; + struct dma_buf *dmabuf; + struct dma_buf_attachment *import_attach; + struct sg_table *st; + long timeout; + int err; + + force_different_devices = true; + obj = i915_gem_object_create_shmem(i915, PAGE_SIZE); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_ret; + } + + dmabuf = i915_gem_prime_export(&obj->base, 0); + if (IS_ERR(dmabuf)) { + pr_err("i915_gem_prime_export failed with err=%ld\n", + PTR_ERR(dmabuf)); + err = PTR_ERR(dmabuf); + goto out; + } + + import = i915_gem_prime_import(&i915->drm, dmabuf); + if (IS_ERR(import)) { + pr_err("i915_gem_prime_import failed with err=%ld\n", + PTR_ERR(import)); + err = PTR_ERR(import); + goto out_dmabuf; + } + + if (import == &obj->base) { + pr_err("i915_gem_prime_import reused gem object!\n"); + err = -EINVAL; + goto out_import; + } + + import_obj = to_intel_bo(import); + + i915_gem_object_lock(import_obj, NULL); + err = __i915_gem_object_get_pages(import_obj); + if (err) { + pr_err("Different objects dma-buf get_pages failed!\n"); + i915_gem_object_unlock(import_obj); + goto out_import; + } + + /* + * If the exported object is not in system memory, something + * weird is going on. TODO: When p2p is supported, this is no + * longer considered weird. + */ + if (obj->mm.region != i915->mm.regions[INTEL_REGION_SMEM]) { + pr_err("Exported dma-buf is not in system memory\n"); + err = -EINVAL; + } + + i915_gem_object_unlock(import_obj); + + /* Now try a fake an importer */ + import_attach = dma_buf_attach(dmabuf, obj->base.dev->dev); + if (IS_ERR(import_attach)) { + err = PTR_ERR(import_attach); + goto out_import; + } + + st = dma_buf_map_attachment(import_attach, DMA_BIDIRECTIONAL); + if (IS_ERR(st)) { + err = PTR_ERR(st); + goto out_detach; + } + + timeout = dma_resv_wait_timeout(dmabuf->resv, false, true, 5 * HZ); + if (!timeout) { + pr_err("dmabuf wait for exclusive fence timed out.\n"); + timeout = -ETIME; + } + err = timeout > 0 ? 0 : timeout; + dma_buf_unmap_attachment(import_attach, st, DMA_BIDIRECTIONAL); +out_detach: + dma_buf_detach(dmabuf, import_attach); +out_import: + i915_gem_object_put(import_obj); out_dmabuf: dma_buf_put(dmabuf); out: i915_gem_object_put(obj); +out_ret: + force_different_devices = false; return err; } @@ -286,6 +390,7 @@ int i915_gem_dmabuf_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { SUBTEST(igt_dmabuf_export), + SUBTEST(igt_dmabuf_import_same_driver), }; return i915_subtests(tests, i915); |