drm/i915/ttm: switch over to ttm_buddy_man

Move back to the buddy allocator for managing device local memory, and
restore the lost mock selftests. Keep around the range manager related
bits, since we likely need this for managing stolen at some point. For
stolen we also don't need to reserve anything so no need to support a
generic reserve interface.

v2(Thomas):
    - bo->page_alignment is in page units, not bytes

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210616152501.394518-6-matthew.auld@intel.com

2 files changed, 128 insertions, 54 deletions

diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index c85d516b85cd..118a66c29695 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -20,7 +20,9 @@
 #include "gem/selftests/mock_context.h"
 #include "gt/intel_engine_user.h"
 #include "gt/intel_gt.h"
+#include "i915_buddy.h"
 #include "i915_memcpy.h"
+#include "i915_ttm_buddy_manager.h"
 #include "selftests/igt_flush_test.h"
 #include "selftests/i915_random.h"
 
@@ -57,10 +59,9 @@ static int igt_mock_fill(void *arg)
 	LIST_HEAD(objects);
 	int err = 0;
 
-	page_size = mem->chunk_size;
+	page_size = PAGE_SIZE;
+	max_pages = div64_u64(total, page_size);
 	rem = total;
-retry:
-	max_pages = div64_u64(rem, page_size);
 
 	for_each_prime_number_from(page_num, 1, max_pages) {
 		resource_size_t size = page_num * page_size;
@@ -86,11 +87,6 @@ retry:
 		err = 0;
 	if (err == -ENXIO) {
 		if (page_num * page_size <= rem) {
-			if (mem->is_range_manager && max_pages > 1) {
-				max_pages >>= 1;
-				goto retry;
-			}
-
 			pr_err("%s failed, space still left in region\n",
 			       __func__);
 			err = -EINVAL;
@@ -157,6 +153,7 @@ static bool is_contiguous(struct drm_i915_gem_object *obj)
 static int igt_mock_reserve(void *arg)
 {
 	struct intel_memory_region *mem = arg;
+	struct drm_i915_private *i915 = mem->i915;
 	resource_size_t avail = resource_size(&mem->region);
 	struct drm_i915_gem_object *obj;
 	const u32 chunk_size = SZ_32M;
@@ -166,16 +163,18 @@ static int igt_mock_reserve(void *arg)
 	LIST_HEAD(objects);
 	int err = 0;
 
-	if (!list_empty(&mem->reserved)) {
-		pr_err("%s region reserved list is not empty\n", __func__);
-		return -EINVAL;
-	}
-
 	count = avail / chunk_size;
 	order = i915_random_order(count, &prng);
 	if (!order)
 		return 0;
 
+	mem = mock_region_create(i915, 0, SZ_2G, I915_GTT_PAGE_SIZE_4K, 0);
+	if (IS_ERR(mem)) {
+		pr_err("failed to create memory region\n");
+		err = PTR_ERR(mem);
+		goto out_close;
+	}
+
 	/* Reserve a bunch of ranges within the region */
 	for (i = 0; i < count; ++i) {
 		u64 start = order[i] * chunk_size;
@@ -205,18 +204,12 @@ static int igt_mock_reserve(void *arg)
 	do {
 		u32 size = i915_prandom_u32_max_state(cur_avail, &prng);
 
-retry:
 		size = max_t(u32, round_up(size, PAGE_SIZE), PAGE_SIZE);
 		obj = igt_object_create(mem, &objects, size, 0);
 		if (IS_ERR(obj)) {
-			if (PTR_ERR(obj) == -ENXIO) {
-				if (mem->is_range_manager &&
-				    size > mem->chunk_size) {
-					size >>= 1;
-					goto retry;
-				}
+			if (PTR_ERR(obj) == -ENXIO)
 				break;
-			}
+
 			err = PTR_ERR(obj);
 			goto out_close;
 		}
@@ -232,7 +225,7 @@ retry:
 out_close:
 	kfree(order);
 	close_objects(mem, &objects);
-	intel_memory_region_unreserve(mem);
+	intel_memory_region_put(mem);
 	return err;
 }
 
@@ -252,7 +245,7 @@ static int igt_mock_contiguous(void *arg)
 	total = resource_size(&mem->region);
 
 	/* Min size */
-	obj = igt_object_create(mem, &objects, mem->chunk_size,
+	obj = igt_object_create(mem, &objects, PAGE_SIZE,
 				I915_BO_ALLOC_CONTIGUOUS);
 	if (IS_ERR(obj))
 		return PTR_ERR(obj);
@@ -333,17 +326,15 @@ static int igt_mock_contiguous(void *arg)
 	min = target;
 	target = total >> 1;
 
-	if (!mem->is_range_manager) {
-		/* Make sure we can still allocate all the fragmented space */
-		obj = igt_object_create(mem, &objects, target, 0);
-		if (IS_ERR(obj)) {
-			err = PTR_ERR(obj);
-			goto err_close_objects;
-		}
-
-		igt_object_release(obj);
+	/* Make sure we can still allocate all the fragmented space */
+	obj = igt_object_create(mem, &objects, target, 0);
+	if (IS_ERR(obj)) {
+		err = PTR_ERR(obj);
+		goto err_close_objects;
 	}
 
+	igt_object_release(obj);
+
 	/*
 	 * Even though we have enough free space, we don't have a big enough
 	 * contiguous block. Make sure that holds true.
@@ -362,7 +353,7 @@ static int igt_mock_contiguous(void *arg)
 		}
 
 		target >>= 1;
-	} while (target >= mem->chunk_size);
+	} while (target >= PAGE_SIZE);
 
 err_close_objects:
 	list_splice_tail(&holes, &objects);
@@ -374,7 +365,9 @@ static int igt_mock_splintered_region(void *arg)
 {
 	struct intel_memory_region *mem = arg;
 	struct drm_i915_private *i915 = mem->i915;
+	struct i915_ttm_buddy_resource *res;
 	struct drm_i915_gem_object *obj;
+	struct i915_buddy_mm *mm;
 	unsigned int expected_order;
 	LIST_HEAD(objects);
 	u64 size;
@@ -382,7 +375,7 @@ static int igt_mock_splintered_region(void *arg)
 
 	/*
 	 * Sanity check we can still allocate everything even if the
-	 * max_order != mm.size. i.e our starting address space size is not a
+	 * mm.max_order != mm.size. i.e our starting address space size is not a
 	 * power-of-two.
 	 */
 
@@ -391,20 +384,29 @@ static int igt_mock_splintered_region(void *arg)
 	if (IS_ERR(mem))
 		return PTR_ERR(mem);
 
-	expected_order = get_order(rounddown_pow_of_two(size));
-	if (mem->max_order != expected_order) {
-		pr_err("%s order mismatch(%u != %u)\n",
-		       __func__, mem->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;
 	}
 
+	res = to_ttm_buddy_resource(obj->mm.res);
+	mm = res->mm;
+	if (mm->size != size) {
+		pr_err("%s size mismatch(%llu != %llu)\n",
+		       __func__, mm->size, size);
+		err = -EINVAL;
+		goto out_put;
+	}
+
+	expected_order = get_order(rounddown_pow_of_two(size));
+	if (mm->max_order != expected_order) {
+		pr_err("%s order mismatch(%u != %u)\n",
+		       __func__, mm->max_order, expected_order);
+		err = -EINVAL;
+		goto out_put;
+	}
+
 	close_objects(mem, &objects);
 
 	/*
@@ -415,15 +417,12 @@ static int igt_mock_splintered_region(void *arg)
 	 * sure that does indeed hold true.
 	 */
 
-	if (!mem->is_range_manager) {
-		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, 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),
@@ -442,6 +441,74 @@ out_put:
 	return err;
 }
 
+#ifndef SZ_8G
+#define SZ_8G BIT_ULL(33)
+#endif
+
+static int igt_mock_max_segment(void *arg)
+{
+	const unsigned int max_segment = rounddown(UINT_MAX, PAGE_SIZE);
+	struct intel_memory_region *mem = arg;
+	struct drm_i915_private *i915 = mem->i915;
+	struct i915_ttm_buddy_resource *res;
+	struct drm_i915_gem_object *obj;
+	struct i915_buddy_block *block;
+	struct i915_buddy_mm *mm;
+	struct list_head *blocks;
+	struct scatterlist *sg;
+	LIST_HEAD(objects);
+	u64 size;
+	int err = 0;
+
+	/*
+	 * While we may create very large contiguous blocks, we may need
+	 * to break those down for consumption elsewhere. In particular,
+	 * dma-mapping with scatterlist elements have an implicit limit of
+	 * UINT_MAX on each element.
+	 */
+
+	size = SZ_8G;
+	mem = mock_region_create(i915, 0, size, PAGE_SIZE, 0);
+	if (IS_ERR(mem))
+		return PTR_ERR(mem);
+
+	obj = igt_object_create(mem, &objects, size, 0);
+	if (IS_ERR(obj)) {
+		err = PTR_ERR(obj);
+		goto out_put;
+	}
+
+	res = to_ttm_buddy_resource(obj->mm.res);
+	blocks = &res->blocks;
+	mm = res->mm;
+	size = 0;
+	list_for_each_entry(block, blocks, link) {
+		if (i915_buddy_block_size(mm, block) > size)
+			size = i915_buddy_block_size(mm, block);
+	}
+	if (size < max_segment) {
+		pr_err("%s: Failed to create a huge contiguous block [> %u], largest block %lld\n",
+		       __func__, max_segment, size);
+		err = -EINVAL;
+		goto out_close;
+	}
+
+	for (sg = obj->mm.pages->sgl; sg; sg = sg_next(sg)) {
+		if (sg->length > max_segment) {
+			pr_err("%s: Created an oversized scatterlist entry, %u > %u\n",
+			       __func__, sg->length, max_segment);
+			err = -EINVAL;
+			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,
@@ -1046,6 +1113,7 @@ int intel_memory_region_mock_selftests(void)
 		SUBTEST(igt_mock_fill),
 		SUBTEST(igt_mock_contiguous),
 		SUBTEST(igt_mock_splintered_region),
+		SUBTEST(igt_mock_max_segment),
 	};
 	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 6120d43fe504..3b3264311c91 100644
--- a/drivers/gpu/drm/i915/selftests/mock_region.c
+++ b/drivers/gpu/drm/i915/selftests/mock_region.c
@@ -3,6 +3,7 @@
  * Copyright © 2019-2021 Intel Corporation
  */
 
+#include <drm/ttm/ttm_placement.h>
 #include <linux/scatterlist.h>
 
 #include <drm/ttm/ttm_placement.h>
@@ -25,10 +26,11 @@ static int mock_region_get_pages(struct drm_i915_gem_object *obj)
 {
 	unsigned int flags;
 	struct sg_table *pages;
+	int err;
 
 	flags = I915_ALLOC_MIN_PAGE_SIZE;
 	if (obj->flags & I915_BO_ALLOC_CONTIGUOUS)
-		flags |= I915_ALLOC_CONTIGUOUS;
+		flags |= TTM_PL_FLAG_CONTIGUOUS;
 
 	obj->mm.res = intel_region_ttm_resource_alloc(obj->mm.region,
 						      obj->base.size,
@@ -38,13 +40,17 @@ static int mock_region_get_pages(struct drm_i915_gem_object *obj)
 
 	pages = intel_region_ttm_resource_to_st(obj->mm.region, obj->mm.res);
 	if (IS_ERR(pages)) {
-		intel_region_ttm_resource_free(obj->mm.region, obj->mm.res);
-		return PTR_ERR(pages);
+		err = PTR_ERR(pages);
+		goto err_free_resource;
 	}
 
 	__i915_gem_object_set_pages(obj, pages, i915_sg_dma_sizes(pages->sgl));
 
 	return 0;
+
+err_free_resource:
+	intel_region_ttm_resource_free(obj->mm.region, obj->mm.res);
+	return err;
 }
 
 static const struct drm_i915_gem_object_ops mock_region_obj_ops = {