| Message ID | 20201021103606.241395-1-matthew.auld@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/i915/region: fix max size calculation | expand |
Quoting Matthew Auld (2020-10-21 11:36:06) > We are incorrectly limiting the max allocation size as per the mm > max_order, which is effectively the largest power-of-two that we can fit > in the region size. However, it's normal to setup the region or > allocator with a non-power-of-two size(for example 3G), which we should > already handle correctly, except it seems for the early too-big-check. > > v2: make sure we also exercise the I915_BO_ALLOC_CONTIGUOUS path, which > is quite different, since for that we are actually limited by the > largest power-of-two that we can fit within the region size. (Chris) > > Fixes: b908be543e44 ("drm/i915: support creating LMEM objects") > Signed-off-by: Matthew Auld <matthew.auld@intel.com> > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Cc: CQ Tang <cq.tang@intel.com> > --- > drivers/gpu/drm/i915/intel_memory_region.c | 2 +- > .../drm/i915/selftests/intel_memory_region.c | 77 +++++++++++++++++++ > drivers/gpu/drm/i915/selftests/mock_region.c | 2 +- > 3 files changed, 79 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c > index 6b5e9d88646d..180e1078ef7c 100644 > --- a/drivers/gpu/drm/i915/intel_memory_region.c > +++ b/drivers/gpu/drm/i915/intel_memory_region.c > @@ -87,7 +87,7 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem, > min_order = ilog2(size) - ilog2(mem->mm.chunk_size); > } > > - if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size) > + if (size > mem->mm.size) > return -E2BIG; > > n_pages = size >> ilog2(mem->mm.chunk_size); > diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c > index 334b0648e253..0aeba8e3af28 100644 > --- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c > +++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c > @@ -261,6 +261,82 @@ static int igt_mock_contiguous(void *arg) > return err; > } > > +static int igt_mock_splintered_region(void *arg) > +{ > + struct intel_memory_region *mem = arg; > + struct drm_i915_private *i915 = mem->i915; > + struct drm_i915_gem_object *obj; > + unsigned int expected_order; > + LIST_HEAD(objects); > + u64 size; > + int err = 0; > + > + /* > + * Sanity check we can still allocate everything even if the > + * mm.max_order != mm.size. i.e our starting address space size is not a > + * power-of-two. > + */ > + > + size = (SZ_4G - 1) & PAGE_MASK; > + mem = mock_region_create(i915, 0, size, PAGE_SIZE, 0); > + if (IS_ERR(mem)) > + return PTR_ERR(mem); > + > + if (mem->mm.size != size) { > + pr_err("%s size mismatch(%llu != %llu)\n", > + __func__, mem->mm.size, size); > + err = -EINVAL; > + goto out_put; > + } > + > + expected_order = get_order(rounddown_pow_of_two(size)); > + if (mem->mm.max_order != expected_order) { > + pr_err("%s order mismatch(%u != %u)\n", > + __func__, mem->mm.max_order, expected_order); > + err = -EINVAL; > + goto out_put; > + } > + > + obj = igt_object_create(mem, &objects, size, 0); > + if (IS_ERR(obj)) { > + err = PTR_ERR(obj); > + goto out_close; > + } > + > + close_objects(mem, &objects); > + > + /* > + * While we should be able allocate everything without any flag > + * restrictions, if we consider I915_BO_ALLOC_CONTIGUOUS then we are > + * actually limited to the largest power-of-two for the region size i.e > + * max_order, due to the inner workings of the buddy allocator. So make > + * sure that does indeed hold true. > + */ > + > + obj = igt_object_create(mem, &objects, size, I915_BO_ALLOC_CONTIGUOUS); > + if (!IS_ERR(obj)) { > + pr_err("%s too large contiguous allocation was not rejected\n", > + __func__); > + err = -EINVAL; > + goto out_close; > + } > + > + obj = igt_object_create(mem, &objects, rounddown_pow_of_two(size), > + I915_BO_ALLOC_CONTIGUOUS); > + if (IS_ERR(obj)) { > + pr_err("%s largest possible contiguous allocation failed\n", > + __func__); > + err = PTR_ERR(obj); > + goto out_close; > + } > + > +out_close: > + close_objects(mem, &objects); > +out_put: > + intel_memory_region_put(mem); > + return err; > +} > + > static int igt_gpu_write_dw(struct intel_context *ce, > struct i915_vma *vma, > u32 dword, > @@ -771,6 +847,7 @@ int intel_memory_region_mock_selftests(void) > static const struct i915_subtest tests[] = { > SUBTEST(igt_mock_fill), > SUBTEST(igt_mock_contiguous), > + SUBTEST(igt_mock_splintered_region), > }; > struct intel_memory_region *mem; > struct drm_i915_private *i915; > diff --git a/drivers/gpu/drm/i915/selftests/mock_region.c b/drivers/gpu/drm/i915/selftests/mock_region.c > index 09660f5a0a4c..979d96f27c43 100644 > --- a/drivers/gpu/drm/i915/selftests/mock_region.c > +++ b/drivers/gpu/drm/i915/selftests/mock_region.c > @@ -24,7 +24,7 @@ mock_object_create(struct intel_memory_region *mem, > struct drm_i915_private *i915 = mem->i915; > struct drm_i915_gem_object *obj; > > - if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size) > + if (size > mem->mm.size) > return ERR_PTR(-E2BIG); Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> -Chris
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c index 6b5e9d88646d..180e1078ef7c 100644 --- a/drivers/gpu/drm/i915/intel_memory_region.c +++ b/drivers/gpu/drm/i915/intel_memory_region.c @@ -87,7 +87,7 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem, min_order = ilog2(size) - ilog2(mem->mm.chunk_size); } - if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size) + if (size > mem->mm.size) return -E2BIG; n_pages = size >> ilog2(mem->mm.chunk_size); diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c index 334b0648e253..0aeba8e3af28 100644 --- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c +++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c @@ -261,6 +261,82 @@ static int igt_mock_contiguous(void *arg) return err; } +static int igt_mock_splintered_region(void *arg) +{ + struct intel_memory_region *mem = arg; + struct drm_i915_private *i915 = mem->i915; + struct drm_i915_gem_object *obj; + unsigned int expected_order; + LIST_HEAD(objects); + u64 size; + int err = 0; + + /* + * Sanity check we can still allocate everything even if the + * mm.max_order != mm.size. i.e our starting address space size is not a + * power-of-two. + */ + + size = (SZ_4G - 1) & PAGE_MASK; + mem = mock_region_create(i915, 0, size, PAGE_SIZE, 0); + if (IS_ERR(mem)) + return PTR_ERR(mem); + + if (mem->mm.size != size) { + pr_err("%s size mismatch(%llu != %llu)\n", + __func__, mem->mm.size, size); + err = -EINVAL; + goto out_put; + } + + expected_order = get_order(rounddown_pow_of_two(size)); + if (mem->mm.max_order != expected_order) { + pr_err("%s order mismatch(%u != %u)\n", + __func__, mem->mm.max_order, expected_order); + err = -EINVAL; + goto out_put; + } + + obj = igt_object_create(mem, &objects, size, 0); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_close; + } + + close_objects(mem, &objects); + + /* + * While we should be able allocate everything without any flag + * restrictions, if we consider I915_BO_ALLOC_CONTIGUOUS then we are + * actually limited to the largest power-of-two for the region size i.e + * max_order, due to the inner workings of the buddy allocator. So make + * sure that does indeed hold true. + */ + + obj = igt_object_create(mem, &objects, size, I915_BO_ALLOC_CONTIGUOUS); + if (!IS_ERR(obj)) { + pr_err("%s too large contiguous allocation was not rejected\n", + __func__); + err = -EINVAL; + goto out_close; + } + + obj = igt_object_create(mem, &objects, rounddown_pow_of_two(size), + I915_BO_ALLOC_CONTIGUOUS); + if (IS_ERR(obj)) { + pr_err("%s largest possible contiguous allocation failed\n", + __func__); + err = PTR_ERR(obj); + goto out_close; + } + +out_close: + close_objects(mem, &objects); +out_put: + intel_memory_region_put(mem); + return err; +} + static int igt_gpu_write_dw(struct intel_context *ce, struct i915_vma *vma, u32 dword, @@ -771,6 +847,7 @@ int intel_memory_region_mock_selftests(void) static const struct i915_subtest tests[] = { SUBTEST(igt_mock_fill), SUBTEST(igt_mock_contiguous), + SUBTEST(igt_mock_splintered_region), }; struct intel_memory_region *mem; struct drm_i915_private *i915; diff --git a/drivers/gpu/drm/i915/selftests/mock_region.c b/drivers/gpu/drm/i915/selftests/mock_region.c index 09660f5a0a4c..979d96f27c43 100644 --- a/drivers/gpu/drm/i915/selftests/mock_region.c +++ b/drivers/gpu/drm/i915/selftests/mock_region.c @@ -24,7 +24,7 @@ mock_object_create(struct intel_memory_region *mem, struct drm_i915_private *i915 = mem->i915; struct drm_i915_gem_object *obj; - if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size) + if (size > mem->mm.size) return ERR_PTR(-E2BIG); obj = i915_gem_object_alloc();
We are incorrectly limiting the max allocation size as per the mm max_order, which is effectively the largest power-of-two that we can fit in the region size. However, it's normal to setup the region or allocator with a non-power-of-two size(for example 3G), which we should already handle correctly, except it seems for the early too-big-check. v2: make sure we also exercise the I915_BO_ALLOC_CONTIGUOUS path, which is quite different, since for that we are actually limited by the largest power-of-two that we can fit within the region size. (Chris) Fixes: b908be543e44 ("drm/i915: support creating LMEM objects") Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: CQ Tang <cq.tang@intel.com> --- drivers/gpu/drm/i915/intel_memory_region.c | 2 +- .../drm/i915/selftests/intel_memory_region.c | 77 +++++++++++++++++++ drivers/gpu/drm/i915/selftests/mock_region.c | 2 +- 3 files changed, 79 insertions(+), 2 deletions(-)