Commit 83ebef47 authored by Matthew Auld's avatar Matthew Auld Committed by Chris Wilson

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: b908be54 ("drm/i915: support creating LMEM objects")
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: CQ Tang <cq.tang@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201021103606.241395-1-matthew.auld@intel.com
parent 8f2b4b68
...@@ -87,7 +87,7 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem, ...@@ -87,7 +87,7 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
min_order = ilog2(size) - ilog2(mem->mm.chunk_size); 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; return -E2BIG;
n_pages = size >> ilog2(mem->mm.chunk_size); n_pages = size >> ilog2(mem->mm.chunk_size);
......
...@@ -261,6 +261,82 @@ static int igt_mock_contiguous(void *arg) ...@@ -261,6 +261,82 @@ static int igt_mock_contiguous(void *arg)
return err; 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, static int igt_gpu_write_dw(struct intel_context *ce,
struct i915_vma *vma, struct i915_vma *vma,
u32 dword, u32 dword,
...@@ -771,6 +847,7 @@ int intel_memory_region_mock_selftests(void) ...@@ -771,6 +847,7 @@ int intel_memory_region_mock_selftests(void)
static const struct i915_subtest tests[] = { static const struct i915_subtest tests[] = {
SUBTEST(igt_mock_fill), SUBTEST(igt_mock_fill),
SUBTEST(igt_mock_contiguous), SUBTEST(igt_mock_contiguous),
SUBTEST(igt_mock_splintered_region),
}; };
struct intel_memory_region *mem; struct intel_memory_region *mem;
struct drm_i915_private *i915; struct drm_i915_private *i915;
......
...@@ -24,7 +24,7 @@ mock_object_create(struct intel_memory_region *mem, ...@@ -24,7 +24,7 @@ mock_object_create(struct intel_memory_region *mem,
struct drm_i915_private *i915 = mem->i915; struct drm_i915_private *i915 = mem->i915;
struct drm_i915_gem_object *obj; 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); return ERR_PTR(-E2BIG);
obj = i915_gem_object_alloc(); obj = i915_gem_object_alloc();
......
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