From 09a729b178be1cb20ffce620f7e5bfc04c4a13c0 Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Wed, 21 Oct 2020 11:36:06 +0100 Subject: [PATCH] drm/i915/region: fix max size calculation 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 Cc: Chris Wilson Cc: CQ Tang Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20201021103606.241395-1-matthew.auld@intel.com (cherry picked from commit 83ebef47f8ebe320d5c5673db82f9903a4f40a69) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/i915/intel_memory_region.c | 2 +- .../gpu/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 6b5e9d8..180e107 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 334b064..0aeba8e 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 @@ err_close_objects: 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 09660f5..979d96f 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(); -- 2.7.4