drm/i915/selftests: Add tiled blits selftest

Extend coverage of the blitter client by exercising conversion to and
from tiled sources. In the process we perform spot checks to verify that
the tiling/detiling is being applied correctly, along with position
invariance of the tiling parameters.
Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200430064957.14942-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/selftests/i915_gem_client_blt.c

@@ -7,9 +7,12 @@
 
 #include "gt/intel_engine_user.h"
 #include "gt/intel_gt.h"
+#include "gt/intel_gpu_commands.h"
+#include "gem/i915_gem_lmem.h"
 
 #include "selftests/igt_flush_test.h"
 #include "selftests/mock_drm.h"
+#include "selftests/i915_random.h"
 #include "huge_gem_object.h"
 #include "mock_context.h"
 
@@ -127,10 +130,602 @@ static int igt_client_fill(void *arg)
 	} while (1);
 }
 
+#define WIDTH 512
+#define HEIGHT 32
+
+struct blit_buffer {
+	struct i915_vma *vma;
+	u32 start_val;
+	u32 tiling;
+};
+
+struct tiled_blits {
+	struct intel_context *ce;
+	struct blit_buffer buffers[3];
+	struct blit_buffer scratch;
+	struct i915_vma *batch;
+	u64 hole;
+	u32 width;
+	u32 height;
+};
+
+static int prepare_blit(const struct tiled_blits *t,
+			struct blit_buffer *dst,
+			struct blit_buffer *src,
+			struct drm_i915_gem_object *batch)
+{
+	const int gen = INTEL_GEN(to_i915(batch->base.dev));
+	bool use_64b_reloc = gen >= 8;
+	u32 src_pitch, dst_pitch;
+	u32 cmd, *cs;
+
+	cs = i915_gem_object_pin_map(batch, I915_MAP_WC);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = MI_LOAD_REGISTER_IMM(1);
+	*cs++ = i915_mmio_reg_offset(BCS_SWCTRL);
+	cmd = (BCS_SRC_Y | BCS_DST_Y) << 16;
+	if (src->tiling == I915_TILING_Y)
+		cmd |= BCS_SRC_Y;
+	if (dst->tiling == I915_TILING_Y)
+		cmd |= BCS_DST_Y;
+	*cs++ = cmd;
+
+	cmd = MI_FLUSH_DW;
+	if (gen >= 8)
+		cmd++;
+	*cs++ = cmd;
+	*cs++ = 0;
+	*cs++ = 0;
+	*cs++ = 0;
+
+	cmd = XY_SRC_COPY_BLT_CMD | BLT_WRITE_RGBA | (8 - 2);
+	if (gen >= 8)
+		cmd += 2;
+
+	src_pitch = t->width * 4;
+	if (src->tiling) {
+		cmd |= XY_SRC_COPY_BLT_SRC_TILED;
+		src_pitch /= 4;
+	}
+
+	dst_pitch = t->width * 4;
+	if (dst->tiling) {
+		cmd |= XY_SRC_COPY_BLT_DST_TILED;
+		dst_pitch /= 4;
+	}
+
+	*cs++ = cmd;
+	*cs++ = BLT_DEPTH_32 | BLT_ROP_SRC_COPY | dst_pitch;
+	*cs++ = 0;
+	*cs++ = t->height << 16 | t->width;
+	*cs++ = lower_32_bits(dst->vma->node.start);
+	if (use_64b_reloc)
+		*cs++ = upper_32_bits(dst->vma->node.start);
+	*cs++ = 0;
+	*cs++ = src_pitch;
+	*cs++ = lower_32_bits(src->vma->node.start);
+	if (use_64b_reloc)
+		*cs++ = upper_32_bits(src->vma->node.start);
+
+	*cs++ = MI_BATCH_BUFFER_END;
+
+	i915_gem_object_flush_map(batch);
+	i915_gem_object_unpin_map(batch);
+
+	return 0;
+}
+
+static void tiled_blits_destroy_buffers(struct tiled_blits *t)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(t->buffers); i++)
+		i915_vma_put(t->buffers[i].vma);
+
+	i915_vma_put(t->scratch.vma);
+	i915_vma_put(t->batch);
+}
+
+static struct i915_vma *
+__create_vma(struct tiled_blits *t, size_t size, bool lmem)
+{
+	struct drm_i915_private *i915 = t->ce->vm->i915;
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+
+	if (lmem)
+		obj = i915_gem_object_create_lmem(i915, size, 0);
+	else
+		obj = i915_gem_object_create_shmem(i915, size);
+	if (IS_ERR(obj))
+		return ERR_CAST(obj);
+
+	vma = i915_vma_instance(obj, t->ce->vm, NULL);
+	if (IS_ERR(vma))
+		i915_gem_object_put(obj);
+
+	return vma;
+}
+
+static struct i915_vma *create_vma(struct tiled_blits *t, bool lmem)
+{
+	return __create_vma(t, PAGE_ALIGN(t->width * t->height * 4), lmem);
+}
+
+static int tiled_blits_create_buffers(struct tiled_blits *t,
+				      int width, int height,
+				      struct rnd_state *prng)
+{
+	struct drm_i915_private *i915 = t->ce->engine->i915;
+	int i;
+
+	t->width = width;
+	t->height = height;
+
+	t->batch = __create_vma(t, PAGE_SIZE, false);
+	if (IS_ERR(t->batch))
+		return PTR_ERR(t->batch);
+
+	t->scratch.vma = create_vma(t, false);
+	if (IS_ERR(t->scratch.vma)) {
+		i915_vma_put(t->batch);
+		return PTR_ERR(t->scratch.vma);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(t->buffers); i++) {
+		struct i915_vma *vma;
+
+		vma = create_vma(t, HAS_LMEM(i915) && i % 2);
+		if (IS_ERR(vma)) {
+			tiled_blits_destroy_buffers(t);
+			return PTR_ERR(vma);
+		}
+
+		t->buffers[i].vma = vma;
+		t->buffers[i].tiling =
+			i915_prandom_u32_max_state(I915_TILING_Y + 1, prng);
+	}
+
+	return 0;
+}
+
+static void fill_scratch(struct tiled_blits *t, u32 *vaddr, u32 val)
+{
+	int i;
+
+	t->scratch.start_val = val;
+	for (i = 0; i < t->width * t->height; i++)
+		vaddr[i] = val++;
+
+	i915_gem_object_flush_map(t->scratch.vma->obj);
+}
+
+static void hexdump(const void *buf, size_t len)
+{
+	const size_t rowsize = 8 * sizeof(u32);
+	const void *prev = NULL;
+	bool skip = false;
+	size_t pos;
+
+	for (pos = 0; pos < len; pos += rowsize) {
+		char line[128];
+
+		if (prev && !memcmp(prev, buf + pos, rowsize)) {
+			if (!skip) {
+				pr_info("*\n");
+				skip = true;
+			}
+			continue;
+		}
+
+		WARN_ON_ONCE(hex_dump_to_buffer(buf + pos, len - pos,
+						rowsize, sizeof(u32),
+						line, sizeof(line),
+						false) >= sizeof(line));
+		pr_info("[%04zx] %s\n", pos, line);
+
+		prev = buf + pos;
+		skip = false;
+	}
+}
+
+static u64 swizzle_bit(unsigned int bit, u64 offset)
+{
+	return (offset & BIT_ULL(bit)) >> (bit - 6);
+}
+
+static u64 tiled_offset(const struct intel_gt *gt,
+			u64 v,
+			unsigned int stride,
+			unsigned int tiling)
+{
+	unsigned int swizzle;
+	u64 x, y;
+
+	if (tiling == I915_TILING_NONE)
+		return v;
+
+	y = div64_u64_rem(v, stride, &x);
+
+	if (tiling == I915_TILING_X) {
+		v = div64_u64_rem(y, 8, &y) * stride * 8;
+		v += y * 512;
+		v += div64_u64_rem(x, 512, &x) << 12;
+		v += x;
+
+		swizzle = gt->ggtt->bit_6_swizzle_x;
+	} else {
+		const unsigned int ytile_span = 16;
+		const unsigned int ytile_height = 512;
+
+		v = div64_u64_rem(y, 32, &y) * stride * 32;
+		v += y * ytile_span;
+		v += div64_u64_rem(x, ytile_span, &x) * ytile_height;
+		v += x;
+
+		swizzle = gt->ggtt->bit_6_swizzle_y;
+	}
+
+	switch (swizzle) {
+	case I915_BIT_6_SWIZZLE_9:
+		v ^= swizzle_bit(9, v);
+		break;
+	case I915_BIT_6_SWIZZLE_9_10:
+		v ^= swizzle_bit(9, v) ^ swizzle_bit(10, v);
+		break;
+	case I915_BIT_6_SWIZZLE_9_11:
+		v ^= swizzle_bit(9, v) ^ swizzle_bit(11, v);
+		break;
+	case I915_BIT_6_SWIZZLE_9_10_11:
+		v ^= swizzle_bit(9, v) ^ swizzle_bit(10, v) ^ swizzle_bit(11, v);
+		break;
+	}
+
+	return v;
+}
+
+static const char *repr_tiling(int tiling)
+{
+	switch (tiling) {
+	case I915_TILING_NONE: return "linear";
+	case I915_TILING_X: return "X";
+	case I915_TILING_Y: return "Y";
+	default: return "unknown";
+	}
+}
+
+static int verify_buffer(const struct tiled_blits *t,
+			 struct blit_buffer *buf,
+			 struct rnd_state *prng)
+{
+	const u32 *vaddr;
+	int ret = 0;
+	int x, y, p;
+
+	x = i915_prandom_u32_max_state(t->width, prng);
+	y = i915_prandom_u32_max_state(t->height, prng);
+	p = y * t->width + x;
+
+	vaddr = i915_gem_object_pin_map(buf->vma->obj, I915_MAP_WC);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
+
+	if (vaddr[0] != buf->start_val) {
+		ret = -EINVAL;
+	} else {
+		u64 v = tiled_offset(buf->vma->vm->gt,
+				     p * 4, t->width * 4,
+				     buf->tiling);
+
+		if (vaddr[v / sizeof(*vaddr)] != buf->start_val + p)
+			ret = -EINVAL;
+	}
+	if (ret) {
+		pr_err("Invalid %s tiling detected at (%d, %d), start_val %x\n",
+		       repr_tiling(buf->tiling),
+		       x, y, buf->start_val);
+		hexdump(vaddr, 4096);
+	}
+
+	i915_gem_object_unpin_map(buf->vma->obj);
+	return ret;
+}
+
+static int move_to_active(struct i915_vma *vma,
+			  struct i915_request *rq,
+			  unsigned int flags)
+{
+	int err;
+
+	i915_vma_lock(vma);
+	err = i915_request_await_object(rq, vma->obj, false);
+	if (err == 0)
+		err = i915_vma_move_to_active(vma, rq, flags);
+	i915_vma_unlock(vma);
+
+	return err;
+}
+
+static int pin_buffer(struct i915_vma *vma, u64 addr)
+{
+	int err;
+
+	if (drm_mm_node_allocated(&vma->node) && vma->node.start != addr) {
+		err = i915_vma_unbind(vma);
+		if (err)
+			return err;
+	}
+
+	err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_OFFSET_FIXED | addr);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int
+tiled_blit(struct tiled_blits *t,
+	   struct blit_buffer *dst, u64 dst_addr,
+	   struct blit_buffer *src, u64 src_addr)
+{
+	struct i915_request *rq;
+	int err;
+
+	err = pin_buffer(src->vma, src_addr);
+	if (err) {
+		pr_err("Cannot pin src @ %llx\n", src_addr);
+		return err;
+	}
+
+	err = pin_buffer(dst->vma, dst_addr);
+	if (err) {
+		pr_err("Cannot pin dst @ %llx\n", dst_addr);
+		goto err_src;
+	}
+
+	err = i915_vma_pin(t->batch, 0, 0, PIN_USER | PIN_HIGH);
+	if (err) {
+		pr_err("cannot pin batch\n");
+		goto err_dst;
+	}
+
+	err = prepare_blit(t, dst, src, t->batch->obj);
+	if (err)
+		goto err_bb;
+
+	rq = intel_context_create_request(t->ce);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_bb;
+	}
+
+	err = move_to_active(t->batch, rq, 0);
+	if (!err)
+		err = move_to_active(src->vma, rq, 0);
+	if (!err)
+		err = move_to_active(dst->vma, rq, 0);
+	if (!err)
+		err = rq->engine->emit_bb_start(rq,
+						t->batch->node.start,
+						t->batch->node.size,
+						0);
+	i915_request_get(rq);
+	i915_request_add(rq);
+	if (i915_request_wait(rq, 0, HZ / 2) < 0)
+		err = -ETIME;
+	i915_request_put(rq);
+
+	dst->start_val = src->start_val;
+err_bb:
+	i915_vma_unpin(t->batch);
+err_dst:
+	i915_vma_unpin(dst->vma);
+err_src:
+	i915_vma_unpin(src->vma);
+	return err;
+}
+
+static struct tiled_blits *
+tiled_blits_create(struct intel_engine_cs *engine, struct rnd_state *prng)
+{
+	struct drm_mm_node hole;
+	struct tiled_blits *t;
+	u64 hole_size;
+	int err;
+
+	t = kzalloc(sizeof(*t), GFP_KERNEL);
+	if (!t)
+		return ERR_PTR(-ENOMEM);
+
+	t->ce = intel_context_create(engine);
+	if (IS_ERR(t->ce)) {
+		err = PTR_ERR(t->ce);
+		goto err_free;
+	}
+
+	hole_size = 2 * PAGE_ALIGN(WIDTH * HEIGHT * 4);
+	hole_size *= 2; /* room to maneuver */
+	hole_size += 2 * I915_GTT_MIN_ALIGNMENT;
+
+	mutex_lock(&t->ce->vm->mutex);
+	memset(&hole, 0, sizeof(hole));
+	err = drm_mm_insert_node_in_range(&t->ce->vm->mm, &hole,
+					  hole_size, 0, I915_COLOR_UNEVICTABLE,
+					  0, U64_MAX,
+					  DRM_MM_INSERT_BEST);
+	if (!err)
+		drm_mm_remove_node(&hole);
+	mutex_unlock(&t->ce->vm->mutex);
+	if (err) {
+		err = -ENODEV;
+		goto err_put;
+	}
+
+	t->hole = hole.start + I915_GTT_MIN_ALIGNMENT;
+	pr_info("Using hole at %llx\n", t->hole);
+
+	err = tiled_blits_create_buffers(t, WIDTH, HEIGHT, prng);
+	if (err)
+		goto err_put;
+
+	return t;
+
+err_put:
+	intel_context_put(t->ce);
+err_free:
+	kfree(t);
+	return ERR_PTR(err);
+}
+
+static void tiled_blits_destroy(struct tiled_blits *t)
+{
+	tiled_blits_destroy_buffers(t);
+
+	intel_context_put(t->ce);
+	kfree(t);
+}
+
+static int tiled_blits_prepare(struct tiled_blits *t,
+			       struct rnd_state *prng)
+{
+	u64 offset = PAGE_ALIGN(t->width * t->height * 4);
+	u32 *map;
+	int err;
+	int i;
+
+	map = i915_gem_object_pin_map(t->scratch.vma->obj, I915_MAP_WC);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	/* Use scratch to fill objects */
+	for (i = 0; i < ARRAY_SIZE(t->buffers); i++) {
+		fill_scratch(t, map, prandom_u32_state(prng));
+		GEM_BUG_ON(verify_buffer(t, &t->scratch, prng));
+
+		err = tiled_blit(t,
+				 &t->buffers[i], t->hole + offset,
+				 &t->scratch, t->hole);
+		if (err == 0)
+			err = verify_buffer(t, &t->buffers[i], prng);
+		if (err) {
+			pr_err("Failed to create buffer %d\n", i);
+			break;
+		}
+	}
+
+	i915_gem_object_unpin_map(t->scratch.vma->obj);
+	return err;
+}
+
+static int tiled_blits_bounce(struct tiled_blits *t, struct rnd_state *prng)
+{
+	u64 offset =
+		round_up(t->width * t->height * 4, 2 * I915_GTT_MIN_ALIGNMENT);
+	int err;
+
+	/* We want to check position invariant tiling across GTT eviction */
+
+	err = tiled_blit(t,
+			 &t->buffers[1], t->hole + offset / 2,
+			 &t->buffers[0], t->hole + 2 * offset);
+	if (err)
+		return err;
+
+	/* Reposition so that we overlap the old addresses, and slightly off */
+	err = tiled_blit(t,
+			 &t->buffers[2], t->hole + I915_GTT_MIN_ALIGNMENT,
+			 &t->buffers[1], t->hole + 3 * offset / 2);
+	if (err)
+		return err;
+
+	err = verify_buffer(t, &t->buffers[2], prng);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int __igt_client_tiled_blits(struct intel_engine_cs *engine,
+				    struct rnd_state *prng)
+{
+	struct tiled_blits *t;
+	int err;
+
+	t = tiled_blits_create(engine, prng);
+	if (IS_ERR(t))
+		return PTR_ERR(t);
+
+	err = tiled_blits_prepare(t, prng);
+	if (err)
+		goto out;
+
+	err = tiled_blits_bounce(t, prng);
+	if (err)
+		goto out;
+
+out:
+	tiled_blits_destroy(t);
+	return err;
+}
+
+static bool has_bit17_swizzle(int sw)
+{
+	return (sw == I915_BIT_6_SWIZZLE_9_10_17 ||
+		sw == I915_BIT_6_SWIZZLE_9_17);
+}
+
+static bool bad_swizzling(struct drm_i915_private *i915)
+{
+	struct i915_ggtt *ggtt = &i915->ggtt;
+
+	if (i915->quirks & QUIRK_PIN_SWIZZLED_PAGES)
+		return true;
+
+	if (has_bit17_swizzle(ggtt->bit_6_swizzle_x) ||
+	    has_bit17_swizzle(ggtt->bit_6_swizzle_y))
+		return true;
+
+	return false;
+}
+
+static int igt_client_tiled_blits(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	I915_RND_STATE(prng);
+	int inst = 0;
+
+	/* Test requires explicit BLT tiling controls */
+	if (INTEL_GEN(i915) < 4)
+		return 0;
+
+	if (bad_swizzling(i915)) /* Requires sane (sub-page) swizzling */
+		return 0;
+
+	do {
+		struct intel_engine_cs *engine;
+		int err;
+
+		engine = intel_engine_lookup_user(i915,
+						  I915_ENGINE_CLASS_COPY,
+						  inst++);
+		if (!engine)
+			return 0;
+
+		err = __igt_client_tiled_blits(engine, &prng);
+		if (err == -ENODEV)
+			err = 0;
+		if (err)
+			return err;
+	} while (1);
+}
+
 int i915_gem_client_blt_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
 		SUBTEST(igt_client_fill),
+		SUBTEST(igt_client_tiled_blits),
 	};
 
 	if (intel_gt_is_wedged(&i915->gt))

drivers/gpu/drm/i915/i915_reg.h

@@ -561,6 +561,8 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
  * Registers used only by the command parser
  */
 #define BCS_SWCTRL _MMIO(0x22200)
+#define   BCS_SRC_Y REG_BIT(0)
+#define   BCS_DST_Y REG_BIT(1)
 
 /* There are 16 GPR registers */
 #define BCS_GPR(n)	_MMIO(0x22600 + (n) * 8)