drm/i915: add gtt misalignment test

add test to check handling of misaligned offsets and sizes

v4:
	* remove spurious blank lines
	* explicitly cast intel_region_id to intel_memory_type in misaligned_pin
Reported-by: kernel test robot <lkp@intel.com>
v6:
	* use NEEDS_COMPACT_PT instead of hard coding for DG2
v7:
	* use i915_vma_unbind_unlocked in misalignment test
v8:
	* handle stolen smem region returning -ENODEV due to
	  uninitialized on some setups
	* avoid trying to test bad alignments on single page hole regions

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

1 files changed, 126 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 0d80509ef3c4..cc814abb0105 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -26,10 +26,12 @@
 #include <linux/prime_numbers.h>
 
 #include "gem/i915_gem_context.h"
+#include "gem/i915_gem_region.h"
 #include "gem/i915_gem_internal.h"
 #include "gem/selftests/mock_context.h"
 #include "gt/intel_context.h"
 #include "gt/intel_gpu_commands.h"
+#include "gt/intel_gtt.h"
 
 #include "i915_random.h"
 #include "i915_selftest.h"
@@ -1068,6 +1070,118 @@ err_purge:
 	return err;
 }
 
+static int misaligned_case(struct i915_address_space *vm, struct intel_memory_region *mr,
+			   u64 addr, u64 size, unsigned long flags)
+{
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	int err = 0;
+	u64 expected_vma_size, expected_node_size;
+	bool is_stolen = mr->type == INTEL_MEMORY_STOLEN_SYSTEM ||
+			 mr->type == INTEL_MEMORY_STOLEN_LOCAL;
+
+	obj = i915_gem_object_create_region(mr, size, 0, 0);
+	if (IS_ERR(obj)) {
+		/* if iGVT-g or DMAR is active, stolen mem will be uninitialized */
+		if (PTR_ERR(obj) == -ENODEV && is_stolen)
+			return 0;
+		return PTR_ERR(obj);
+	}
+
+	vma = i915_vma_instance(obj, vm, NULL);
+	if (IS_ERR(vma)) {
+		err = PTR_ERR(vma);
+		goto err_put;
+	}
+
+	err = i915_vma_pin(vma, 0, 0, addr | flags);
+	if (err)
+		goto err_put;
+	i915_vma_unpin(vma);
+
+	if (!drm_mm_node_allocated(&vma->node)) {
+		err = -EINVAL;
+		goto err_put;
+	}
+
+	if (i915_vma_misplaced(vma, 0, 0, addr | flags)) {
+		err = -EINVAL;
+		goto err_put;
+	}
+
+	expected_vma_size = round_up(size, 1 << (ffs(vma->resource->page_sizes_gtt) - 1));
+	expected_node_size = expected_vma_size;
+
+	if (NEEDS_COMPACT_PT(vm->i915) && i915_gem_object_is_lmem(obj)) {
+		/* compact-pt should expand lmem node to 2MB */
+		expected_vma_size = round_up(size, I915_GTT_PAGE_SIZE_64K);
+		expected_node_size = round_up(size, I915_GTT_PAGE_SIZE_2M);
+	}
+
+	if (vma->size != expected_vma_size || vma->node.size != expected_node_size) {
+		err = i915_vma_unbind_unlocked(vma);
+		err = -EBADSLT;
+		goto err_put;
+	}
+
+	err = i915_vma_unbind_unlocked(vma);
+	if (err)
+		goto err_put;
+
+	GEM_BUG_ON(drm_mm_node_allocated(&vma->node));
+
+err_put:
+	i915_gem_object_put(obj);
+	cleanup_freed_objects(vm->i915);
+	return err;
+}
+
+static int misaligned_pin(struct i915_address_space *vm,
+			  u64 hole_start, u64 hole_end,
+			  unsigned long end_time)
+{
+	struct intel_memory_region *mr;
+	enum intel_region_id id;
+	unsigned long flags = PIN_OFFSET_FIXED | PIN_USER;
+	int err = 0;
+	u64 hole_size = hole_end - hole_start;
+
+	if (i915_is_ggtt(vm))
+		flags |= PIN_GLOBAL;
+
+	for_each_memory_region(mr, vm->i915, id) {
+		u64 min_alignment = i915_vm_min_alignment(vm, (enum intel_memory_type)id);
+		u64 size = min_alignment;
+		u64 addr = round_down(hole_start + (hole_size / 2), min_alignment);
+
+		/* avoid -ENOSPC on very small hole setups */
+		if (hole_size < 3 * min_alignment)
+			continue;
+
+		/* we can't test < 4k alignment due to flags being encoded in lower bits */
+		if (min_alignment != I915_GTT_PAGE_SIZE_4K) {
+			err = misaligned_case(vm, mr, addr + (min_alignment / 2), size, flags);
+			/* misaligned should error with -EINVAL*/
+			if (!err)
+				err = -EBADSLT;
+			if (err != -EINVAL)
+				return err;
+		}
+
+		/* test for vma->size expansion to min page size */
+		err = misaligned_case(vm, mr, addr, PAGE_SIZE, flags);
+		if (err)
+			return err;
+
+		/* test for intermediate size not expanding vma->size for large alignments */
+		err = misaligned_case(vm, mr, addr, size / 2, flags);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static int exercise_ppgtt(struct drm_i915_private *dev_priv,
 			  int (*func)(struct i915_address_space *vm,
 				      u64 hole_start, u64 hole_end,
@@ -1137,6 +1251,11 @@ static int igt_ppgtt_shrink_boom(void *arg)
 	return exercise_ppgtt(arg, shrink_boom);
 }
 
+static int igt_ppgtt_misaligned_pin(void *arg)
+{
+	return exercise_ppgtt(arg, misaligned_pin);
+}
+
 static int sort_holes(void *priv, const struct list_head *A,
 		      const struct list_head *B)
 {
@@ -1209,6 +1328,11 @@ static int igt_ggtt_lowlevel(void *arg)
 	return exercise_ggtt(arg, lowlevel_hole);
 }
 
+static int igt_ggtt_misaligned_pin(void *arg)
+{
+	return exercise_ggtt(arg, misaligned_pin);
+}
+
 static int igt_ggtt_page(void *arg)
 {
 	const unsigned int count = PAGE_SIZE/sizeof(u32);
@@ -2181,12 +2305,14 @@ int i915_gem_gtt_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(igt_ppgtt_fill),
 		SUBTEST(igt_ppgtt_shrink),
 		SUBTEST(igt_ppgtt_shrink_boom),
+		SUBTEST(igt_ppgtt_misaligned_pin),
 		SUBTEST(igt_ggtt_lowlevel),
 		SUBTEST(igt_ggtt_drunk),
 		SUBTEST(igt_ggtt_walk),
 		SUBTEST(igt_ggtt_pot),
 		SUBTEST(igt_ggtt_fill),
 		SUBTEST(igt_ggtt_page),
+		SUBTEST(igt_ggtt_misaligned_pin),
 		SUBTEST(igt_cs_tlb),
 	};