1 files changed, 361 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tests/drm_mm_test.c b/drivers/gpu/drm/tests/drm_mm_test.c
new file mode 100644
index 000000000000..aec9eccdeae9
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_mm_test.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test cases for the drm_mm range manager
+ *
+ * Copyright (c) 2022 Arthur Grillo <arthur.grillo@usp.br>
+ */
+
+#include <kunit/test.h>
+
+#include <linux/prime_numbers.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/vmalloc.h>
+#include <linux/ktime.h>
+
+#include <drm/drm_mm.h>
+#include <drm/drm_print.h>
+
+#include "../lib/drm_random.h"
+
+enum {
+	BEST,
+	BOTTOMUP,
+	TOPDOWN,
+	EVICT,
+};
+
+static const struct insert_mode {
+	const char *name;
+	enum drm_mm_insert_mode mode;
+} insert_modes[] = {
+	[BEST] = { "best", DRM_MM_INSERT_BEST },
+	[BOTTOMUP] = { "bottom-up", DRM_MM_INSERT_LOW },
+	[TOPDOWN] = { "top-down", DRM_MM_INSERT_HIGH },
+	[EVICT] = { "evict", DRM_MM_INSERT_EVICT },
+	{}
+};
+
+static bool assert_no_holes(struct kunit *test, const struct drm_mm *mm)
+{
+	struct drm_mm_node *hole;
+	u64 hole_start, __always_unused hole_end;
+	unsigned long count;
+
+	count = 0;
+	drm_mm_for_each_hole(hole, mm, hole_start, hole_end)
+		count++;
+	if (count) {
+		KUNIT_FAIL(test,
+			   "Expected to find no holes (after reserve), found %lu instead\n", count);
+		return false;
+	}
+
+	drm_mm_for_each_node(hole, mm) {
+		if (drm_mm_hole_follows(hole)) {
+			KUNIT_FAIL(test, "Hole follows node, expected none!\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool assert_one_hole(struct kunit *test, const struct drm_mm *mm, u64 start, u64 end)
+{
+	struct drm_mm_node *hole;
+	u64 hole_start, hole_end;
+	unsigned long count;
+	bool ok = true;
+
+	if (end <= start)
+		return true;
+
+	count = 0;
+	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
+		if (start != hole_start || end != hole_end) {
+			if (ok)
+				KUNIT_FAIL(test,
+					   "empty mm has incorrect hole, found (%llx, %llx), expect (%llx, %llx)\n",
+					   hole_start, hole_end, start, end);
+			ok = false;
+		}
+		count++;
+	}
+	if (count != 1) {
+		KUNIT_FAIL(test, "Expected to find one hole, found %lu instead\n", count);
+		ok = false;
+	}
+
+	return ok;
+}
+
+static u64 misalignment(struct drm_mm_node *node, u64 alignment)
+{
+	u64 rem;
+
+	if (!alignment)
+		return 0;
+
+	div64_u64_rem(node->start, alignment, &rem);
+	return rem;
+}
+
+static bool assert_node(struct kunit *test, struct drm_mm_node *node, struct drm_mm *mm,
+			u64 size, u64 alignment, unsigned long color)
+{
+	bool ok = true;
+
+	if (!drm_mm_node_allocated(node) || node->mm != mm) {
+		KUNIT_FAIL(test, "node not allocated\n");
+		ok = false;
+	}
+
+	if (node->size != size) {
+		KUNIT_FAIL(test, "node has wrong size, found %llu, expected %llu\n",
+			   node->size, size);
+		ok = false;
+	}
+
+	if (misalignment(node, alignment)) {
+		KUNIT_FAIL(test,
+			   "node is misaligned, start %llx rem %llu, expected alignment %llu\n",
+			   node->start, misalignment(node, alignment), alignment);
+		ok = false;
+	}
+
+	if (node->color != color) {
+		KUNIT_FAIL(test, "node has wrong color, found %lu, expected %lu\n",
+			   node->color, color);
+		ok = false;
+	}
+
+	return ok;
+}
+
+static void drm_test_mm_init(struct kunit *test)
+{
+	const unsigned int size = 4096;
+	struct drm_mm mm;
+	struct drm_mm_node tmp;
+
+	/* Start with some simple checks on initialising the struct drm_mm */
+	memset(&mm, 0, sizeof(mm));
+	KUNIT_ASSERT_FALSE_MSG(test, drm_mm_initialized(&mm),
+			       "zeroed mm claims to be initialized\n");
+
+	memset(&mm, 0xff, sizeof(mm));
+	drm_mm_init(&mm, 0, size);
+	if (!drm_mm_initialized(&mm)) {
+		KUNIT_FAIL(test, "mm claims not to be initialized\n");
+		goto out;
+	}
+
+	if (!drm_mm_clean(&mm)) {
+		KUNIT_FAIL(test, "mm not empty on creation\n");
+		goto out;
+	}
+
+	/* After creation, it should all be one massive hole */
+	if (!assert_one_hole(test, &mm, 0, size)) {
+		KUNIT_FAIL(test, "mm not one hole on creation");
+		goto out;
+	}
+
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.start = 0;
+	tmp.size = size;
+	if (drm_mm_reserve_node(&mm, &tmp)) {
+		KUNIT_FAIL(test, "failed to reserve whole drm_mm\n");
+		goto out;
+	}
+
+	/* After filling the range entirely, there should be no holes */
+	if (!assert_no_holes(test, &mm)) {
+		KUNIT_FAIL(test, "mm has holes when filled");
+		goto out;
+	}
+
+	/* And then after emptying it again, the massive hole should be back */
+	drm_mm_remove_node(&tmp);
+	if (!assert_one_hole(test, &mm, 0, size)) {
+		KUNIT_FAIL(test, "mm does not have single hole after emptying");
+		goto out;
+	}
+
+out:
+	drm_mm_takedown(&mm);
+}
+
+static void drm_test_mm_debug(struct kunit *test)
+{
+	struct drm_printer p = drm_dbg_printer(NULL, DRM_UT_CORE, test->name);
+	struct drm_mm mm;
+	struct drm_mm_node nodes[2];
+
+	/* Create a small drm_mm with a couple of nodes and a few holes, and
+	 * check that the debug iterator doesn't explode over a trivial drm_mm.
+	 */
+	drm_mm_init(&mm, 0, 4096);
+
+	memset(nodes, 0, sizeof(nodes));
+	nodes[0].start = 512;
+	nodes[0].size = 1024;
+	KUNIT_ASSERT_FALSE_MSG(test, drm_mm_reserve_node(&mm, &nodes[0]),
+			       "failed to reserve node[0] {start=%lld, size=%lld)\n",
+			       nodes[0].start, nodes[0].size);
+
+	nodes[1].size = 1024;
+	nodes[1].start = 4096 - 512 - nodes[1].size;
+	KUNIT_ASSERT_FALSE_MSG(test, drm_mm_reserve_node(&mm, &nodes[1]),
+			       "failed to reserve node[0] {start=%lld, size=%lld)\n",
+			       nodes[0].start, nodes[0].size);
+
+	drm_mm_print(&mm, &p);
+	KUNIT_SUCCEED(test);
+}
+
+static bool expect_insert(struct kunit *test, struct drm_mm *mm,
+			  struct drm_mm_node *node, u64 size, u64 alignment, unsigned long color,
+			const struct insert_mode *mode)
+{
+	int err;
+
+	err = drm_mm_insert_node_generic(mm, node,
+					 size, alignment, color,
+					 mode->mode);
+	if (err) {
+		KUNIT_FAIL(test,
+			   "insert (size=%llu, alignment=%llu, color=%lu, mode=%s) failed with err=%d\n",
+			   size, alignment, color, mode->name, err);
+		return false;
+	}
+
+	if (!assert_node(test, node, mm, size, alignment, color)) {
+		drm_mm_remove_node(node);
+		return false;
+	}
+
+	return true;
+}
+
+static void drm_test_mm_align_pot(struct kunit *test, int max)
+{
+	struct drm_mm mm;
+	struct drm_mm_node *node, *next;
+	int bit;
+
+	/* Check that we can align to the full u64 address space */
+
+	drm_mm_init(&mm, 1, U64_MAX - 2);
+
+	for (bit = max - 1; bit; bit--) {
+		u64 align, size;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node) {
+			KUNIT_FAIL(test, "failed to allocate node");
+			goto out;
+		}
+
+		align = BIT_ULL(bit);
+		size = BIT_ULL(bit - 1) + 1;
+		if (!expect_insert(test, &mm, node, size, align, bit, &insert_modes[0])) {
+			KUNIT_FAIL(test, "insert failed with alignment=%llx [%d]", align, bit);
+			goto out;
+		}
+
+		cond_resched();
+	}
+
+out:
+	drm_mm_for_each_node_safe(node, next, &mm) {
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+	drm_mm_takedown(&mm);
+}
+
+static void drm_test_mm_align32(struct kunit *test)
+{
+	drm_test_mm_align_pot(test, 32);
+}
+
+static void drm_test_mm_align64(struct kunit *test)
+{
+	drm_test_mm_align_pot(test, 64);
+}
+
+static void drm_test_mm_once(struct kunit *test, unsigned int mode)
+{
+	struct drm_mm mm;
+	struct drm_mm_node rsvd_lo, rsvd_hi, node;
+
+	drm_mm_init(&mm, 0, 7);
+
+	memset(&rsvd_lo, 0, sizeof(rsvd_lo));
+	rsvd_lo.start = 1;
+	rsvd_lo.size = 1;
+	if (drm_mm_reserve_node(&mm, &rsvd_lo)) {
+		KUNIT_FAIL(test, "Could not reserve low node\n");
+		goto err;
+	}
+
+	memset(&rsvd_hi, 0, sizeof(rsvd_hi));
+	rsvd_hi.start = 5;
+	rsvd_hi.size = 1;
+	if (drm_mm_reserve_node(&mm, &rsvd_hi)) {
+		KUNIT_FAIL(test, "Could not reserve low node\n");
+		goto err_lo;
+	}
+
+	if (!drm_mm_hole_follows(&rsvd_lo) || !drm_mm_hole_follows(&rsvd_hi)) {
+		KUNIT_FAIL(test, "Expected a hole after lo and high nodes!\n");
+		goto err_hi;
+	}
+
+	memset(&node, 0, sizeof(node));
+	if (drm_mm_insert_node_generic(&mm, &node, 2, 0, 0, mode)) {
+		KUNIT_FAIL(test, "Could not insert the node into the available hole!\n");
+		goto err_hi;
+	}
+
+	drm_mm_remove_node(&node);
+err_hi:
+	drm_mm_remove_node(&rsvd_hi);
+err_lo:
+	drm_mm_remove_node(&rsvd_lo);
+err:
+	drm_mm_takedown(&mm);
+}
+
+static void drm_test_mm_lowest(struct kunit *test)
+{
+	drm_test_mm_once(test, DRM_MM_INSERT_LOW);
+}
+
+static void drm_test_mm_highest(struct kunit *test)
+{
+	drm_test_mm_once(test, DRM_MM_INSERT_HIGH);
+}
+
+static struct kunit_case drm_mm_tests[] = {
+	KUNIT_CASE(drm_test_mm_init),
+	KUNIT_CASE(drm_test_mm_debug),
+	KUNIT_CASE(drm_test_mm_align32),
+	KUNIT_CASE(drm_test_mm_align64),
+	KUNIT_CASE(drm_test_mm_lowest),
+	KUNIT_CASE(drm_test_mm_highest),
+	{}
+};
+
+static struct kunit_suite drm_mm_test_suite = {
+	.name = "drm_mm",
+	.test_cases = drm_mm_tests,
+};
+
+kunit_test_suite(drm_mm_test_suite);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Test cases for the drm_mm range manager");
+MODULE_LICENSE("GPL");