[PATCH 070/109] drm/i915/selftests: Check MI_STORE_DWORD_IMM coherency

Chris Wilson chris at chris-wilson.co.uk
Wed Jan 2 16:47:27 UTC 2019


We use MI_STORE_DWORD_IMM internally (e.g. for gpu relocations) and so
require that its are writes flushed to memory on demand. Verify this with
a selftest.

v2: Use variable lengths of submission queues as the delay between
submit and checking is also crucially important for error detection.
v4: Deny the shrinker by keeping everything pinned while still wanted.
v5: Check each engine individually and ensemble.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 .../drm/i915/selftests/i915_gem_coherency.c   | 592 ++++++++++++++++++
 1 file changed, 592 insertions(+)

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
index fd89a5a33c1a..1869fd28bbe0 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
@@ -26,6 +26,7 @@
 
 #include "../i915_selftest.h"
 #include "i915_random.h"
+#include "igt_flush_test.h"
 
 static int cpu_set(struct drm_i915_gem_object *obj,
 		   unsigned long offset,
@@ -387,10 +388,601 @@ static int igt_gem_coherency(void *arg)
 	goto unlock;
 }
 
+#define DW_PER_PAGE (PAGE_SIZE / sizeof(u32))
+
+struct live_test {
+	struct drm_i915_private *i915;
+	const char *func;
+	const char *name;
+
+	unsigned int reset_global;
+	unsigned int reset_engine[I915_NUM_ENGINES];
+};
+
+static int begin_live_test(struct live_test *t,
+			   struct drm_i915_private *i915,
+			   const char *func,
+			   const char *name)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err;
+
+	t->i915 = i915;
+	t->func = func;
+	t->name = name;
+
+	err = i915_gem_wait_for_idle(i915,
+				     I915_WAIT_LOCKED,
+				     MAX_SCHEDULE_TIMEOUT);
+	if (err) {
+		pr_err("%s(%s): failed to idle before, with err=%d!",
+		       func, name, err);
+		return err;
+	}
+
+	i915->gpu_error.missed_irq_rings = 0;
+	t->reset_global = i915_reset_count(&i915->gpu_error);
+
+	for_each_engine(engine, i915, id)
+		t->reset_engine[id] =
+		i915_reset_engine_count(&i915->gpu_error, engine);
+
+	return 0;
+}
+
+static int end_live_test(struct live_test *t)
+{
+	struct drm_i915_private *i915 = t->i915;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	if (igt_flush_test(i915, I915_WAIT_LOCKED))
+		return -EIO;
+
+	if (t->reset_global != i915_reset_count(&i915->gpu_error)) {
+		pr_err("%s(%s): GPU was reset %d times!\n",
+		       t->func, t->name,
+		       i915_reset_count(&i915->gpu_error) - t->reset_global);
+		return -EIO;
+	}
+
+	for_each_engine(engine, i915, id) {
+		if (t->reset_engine[id] ==
+		    i915_reset_engine_count(&i915->gpu_error, engine))
+			continue;
+
+		pr_err("%s(%s): engine '%s' was reset %d times!\n",
+		       t->func, t->name, engine->name,
+		       i915_reset_engine_count(&i915->gpu_error, engine) -
+		       t->reset_engine[id]);
+		return -EIO;
+	}
+
+	if (i915->gpu_error.missed_irq_rings) {
+		pr_err("%s(%s): Missed interrupts on engines %lx\n",
+		       t->func, t->name, i915->gpu_error.missed_irq_rings);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int cpu_fill(struct drm_i915_gem_object *obj, u32 value)
+{
+	const bool has_llc = HAS_LLC(to_i915(obj->base.dev));
+	unsigned int n, need_flush;
+	int err;
+
+	err = i915_gem_obj_prepare_shmem_write(obj, &need_flush);
+	if (err)
+		return err;
+
+	for (n = 0; n < obj->base.size >> PAGE_SHIFT; n++) {
+		u32 *map;
+
+		map = kmap_atomic(i915_gem_object_get_page(obj, n));
+		memset32(map, value, DW_PER_PAGE);
+		if (!has_llc)
+			drm_clflush_virt_range(map, PAGE_SIZE);
+		kunmap_atomic(map);
+	}
+
+	i915_gem_obj_finish_shmem_access(obj);
+	obj->read_domains = I915_GEM_DOMAIN_GTT | I915_GEM_DOMAIN_CPU;
+	obj->write_domain = 0;
+	return 0;
+}
+
+static struct drm_i915_gem_object *
+create_test_object(struct drm_i915_private *i915,
+		   unsigned int num_pages,
+		   struct drm_file *file,
+		   struct list_head *objects)
+{
+	struct drm_i915_gem_object *obj;
+	int err;
+
+	obj = i915_gem_object_create_internal(i915, num_pages << PAGE_SHIFT);
+	if (IS_ERR(obj))
+		return obj;
+
+	err = i915_gem_object_pin_pages(obj);
+	if (err)
+		goto err_put;
+
+	err = idr_alloc(&file->object_idr, &obj->base, 1, 0, GFP_KERNEL);
+	if (err < 0)
+		goto err_unpin;
+
+	obj->base.handle_count++;
+	obj->scratch = err;
+
+	err = cpu_fill(obj, STACK_MAGIC);
+	if (err)
+		goto err_remove;
+
+	err = i915_gem_object_set_to_gtt_domain(obj, false);
+	if (err)
+		goto err_remove;
+
+	list_add_tail(&obj->st_link, objects);
+	return obj;
+
+err_remove:
+	idr_remove(&file->object_idr, obj->scratch);
+err_unpin:
+	i915_gem_object_unpin_pages(obj);
+err_put:
+	i915_gem_object_put(obj);
+	return ERR_PTR(err);
+}
+
+static struct i915_vma *
+gpu_fill_dw(struct i915_vma *vma, u64 offset, unsigned long count, u32 value)
+{
+	struct drm_i915_gem_object *obj;
+	const int gen = INTEL_GEN(vma->vm->i915);
+	unsigned long n, size;
+	u32 *cmd;
+	int err;
+
+	size = (4 * count + 1) * sizeof(u32);
+	size = round_up(size, PAGE_SIZE);
+	obj = i915_gem_object_create_internal(vma->vm->i915, size);
+	if (IS_ERR(obj))
+		return ERR_CAST(obj);
+
+	cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
+	if (IS_ERR(cmd)) {
+		err = PTR_ERR(cmd);
+		goto err;
+	}
+
+	GEM_BUG_ON(offset + (count - 1) * PAGE_SIZE > vma->node.size);
+	offset += vma->node.start;
+
+	for (n = 0; n < count; n++) {
+		if (gen >= 8) {
+			*cmd++ = MI_STORE_DWORD_IMM_GEN4;
+			*cmd++ = lower_32_bits(offset);
+			*cmd++ = upper_32_bits(offset);
+			*cmd++ = value;
+		} else if (gen >= 4) {
+			*cmd++ = MI_STORE_DWORD_IMM_GEN4 |
+				(gen < 6 ? MI_USE_GGTT : 0);
+			*cmd++ = 0;
+			*cmd++ = offset;
+			*cmd++ = value;
+		} else {
+			*cmd++ = MI_STORE_DWORD_IMM | MI_MEM_VIRTUAL;
+			*cmd++ = offset;
+			*cmd++ = value;
+		}
+		offset += PAGE_SIZE;
+	}
+	*cmd = MI_BATCH_BUFFER_END;
+	i915_gem_object_unpin_map(obj);
+
+	err = i915_gem_object_set_to_gtt_domain(obj, false);
+	if (err)
+		goto err;
+
+	vma = i915_vma_instance(obj, vma->vm, NULL);
+	if (IS_ERR(vma)) {
+		err = PTR_ERR(vma);
+		goto err;
+	}
+
+	err = i915_vma_pin(vma, 0, 0, PIN_USER);
+	if (err)
+		goto err;
+
+	return vma;
+
+err:
+	i915_gem_object_put(obj);
+	return ERR_PTR(err);
+}
+
+static int gpu_fill(struct drm_i915_gem_object *obj,
+		    struct i915_gem_context *ctx,
+		    struct intel_engine_cs *engine,
+		    unsigned int dw)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct i915_address_space *vm =
+		ctx->ppgtt ? &ctx->ppgtt->vm : &i915->ggtt.vm;
+	struct i915_request *rq;
+	struct i915_vma *vma;
+	struct i915_vma *batch;
+	unsigned int flags;
+	int err;
+
+	GEM_BUG_ON(obj->base.size > vm->total);
+	GEM_BUG_ON(!intel_engine_can_store_dword(engine));
+
+	vma = i915_vma_instance(obj, vm, NULL);
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
+
+	err = i915_vma_pin(vma, 0, 0, PIN_USER);
+	if (err)
+		return err;
+
+	batch = gpu_fill_dw(vma,
+			    dw * sizeof(u32),
+			    obj->base.size >> PAGE_SHIFT,
+			    engine->id << 16 | dw);
+	if (IS_ERR(batch)) {
+		err = PTR_ERR(batch);
+		goto err_vma;
+	}
+
+	rq = i915_request_alloc(engine, ctx);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_batch;
+	}
+
+	flags = 0;
+	if (INTEL_GEN(vm->i915) <= 5)
+		flags |= I915_DISPATCH_SECURE;
+
+	err = engine->emit_bb_start(rq,
+				    batch->node.start, batch->node.size,
+				    flags);
+	if (err)
+		goto err_request;
+
+	err = i915_vma_move_to_active(batch, rq, 0);
+	if (err)
+		goto skip_request;
+
+	err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
+	if (err)
+		goto skip_request;
+
+	i915_gem_chipset_flush(vm->i915);
+	i915_request_add(rq);
+
+	i915_gem_object_set_active_reference(batch->obj);
+	i915_vma_unpin(batch);
+	i915_vma_close(batch);
+
+	i915_vma_unpin(vma);
+
+	return 0;
+
+skip_request:
+	i915_request_skip(rq, err);
+err_request:
+	i915_request_add(rq);
+err_batch:
+	i915_vma_unpin(batch);
+	i915_vma_put(batch);
+err_vma:
+	i915_vma_unpin(vma);
+	return err;
+}
+
+static int coherency_check(struct drm_i915_gem_object *obj,
+			   unsigned int idx, unsigned int max)
+{
+	unsigned long n, npages = obj->base.size >> PAGE_SHIFT;
+	unsigned int m, needs_flush;
+	unsigned int errors = 0;
+	int err;
+
+	err = i915_gem_obj_prepare_shmem_read(obj, &needs_flush);
+	if (err)
+		return err;
+
+	for (n = 0; n < npages; n++) {
+		u32 *map;
+
+		map = kmap_atomic(i915_gem_object_get_page(obj, n));
+		if (needs_flush & CLFLUSH_BEFORE)
+			drm_clflush_virt_range(map, PAGE_SIZE);
+
+		for (m = 0; m < max; m++) {
+			u32 x = map[m];
+
+			if ((x & 0xffff) != m) {
+				if (errors++ < 5) {
+					pr_err("Invalid value at page %d:%ld/%ld, offset %d: found %x expected %x\n",
+					       idx, n, npages, m, x, m);
+				}
+				err = -EINVAL;
+			}
+		}
+
+		for (; m < DW_PER_PAGE; m++) {
+			u32 x = map[m];
+
+			if (x != STACK_MAGIC) {
+				if (errors++ < 5) {
+					pr_err("Invalid value at page %d:%ld/%ld, offset %d: found %x expected %x\n",
+					       idx, n, npages, m,
+					       x, STACK_MAGIC);
+				}
+				err = -EINVAL;
+			}
+		}
+
+		kunmap_atomic(map);
+		if (errors) {
+			pr_err("Found %d errors on page %d:%ld/%ld\n",
+			       errors, idx, n, npages);
+			break;
+		}
+	}
+
+	i915_gem_obj_finish_shmem_access(obj);
+	return err;
+}
+
+struct igt_mi_store_dw {
+	struct drm_i915_private *i915;
+	struct i915_gem_context *ctx;
+	struct drm_file *file;
+};
+
+static int igt_mi_store_dw__engine(struct igt_mi_store_dw *igt,
+				   struct intel_engine_cs *engine)
+{
+	struct i915_address_space *const vm =
+		igt->ctx->ppgtt ? &igt->ctx->ppgtt->vm : &igt->i915->ggtt.vm;
+	unsigned long timeout;
+	unsigned long npages;
+	struct live_test t;
+	int err = 0;
+
+	npages = 0;
+	for (timeout = 1;
+	     !err && timeout < i915_selftest.timeout_jiffies;
+	     timeout = next_prime_number(2 * timeout)) {
+		unsigned long end_time = jiffies + timeout;
+		struct drm_i915_gem_object *obj = NULL, *on;
+		unsigned long ndwords, width, dw, id;
+		LIST_HEAD(objects);
+
+		err = begin_live_test(&t, igt->i915, __func__, "");
+		if (err)
+			break;
+
+		dw = 0;
+		width = 0;
+		ndwords = 0;
+		while (!time_after(jiffies, end_time)) {
+			intel_wakeref_t wakeref;
+
+			if (!obj) {
+				npages = next_prime_number(2 * npages);
+				if (npages >= vm->total >> PAGE_SHIFT)
+					goto done;
+
+				obj = create_test_object(igt->i915,
+							 npages,
+							 igt->file,
+							 &objects);
+				if (IS_ERR(obj)) {
+					err = PTR_ERR(obj);
+					goto free;
+				}
+			}
+
+			with_intel_runtime_pm(igt->i915, wakeref)
+				err = gpu_fill(obj, igt->ctx, engine, dw);
+			if (err) {
+				pr_err("Failed to fill dword %lu [%lu] with gpu (%s), err=%d\n",
+				       ndwords, dw, engine->name, err);
+				goto free;
+			}
+
+			if (++dw == DW_PER_PAGE) {
+				obj = NULL;
+				dw = 0;
+			}
+
+			ndwords += npages;
+			width++;
+		}
+done:
+		pr_info("Submitted %lu/%lu dwords to %s in %lu jiffies\n",
+			ndwords, width, engine->name, timeout);
+
+free:
+		dw = 0;
+		id = 0;
+		list_for_each_entry_safe(obj, on, &objects, st_link) {
+			unsigned int num_writes =
+				min_t(unsigned int, width - dw, DW_PER_PAGE);
+
+			if (err == 0)
+				err = coherency_check(obj, id++, num_writes);
+
+			dw += num_writes;
+
+			GEM_BUG_ON(--obj->base.handle_count);
+			idr_remove(&igt->file->object_idr, obj->scratch);
+			i915_gem_object_unpin_pages(obj);
+			i915_gem_object_put(obj);
+		}
+
+		if (end_live_test(&t))
+			err = -EIO;
+
+		i915_retire_requests(igt->i915);
+	}
+
+	return err;
+}
+
+static int igt_mi_store_dw__all(struct igt_mi_store_dw *igt)
+{
+	struct i915_address_space * const vm =
+		igt->ctx->ppgtt ? &igt->ctx->ppgtt->vm : &igt->i915->ggtt.vm;
+	unsigned long timeout;
+	unsigned long npages;
+	struct live_test t;
+	int err = 0;
+
+	if (!IS_ENABLED(CONFIG_BROKEN)) /* XXX */
+		return 0;
+
+	npages = 0;
+	for (timeout = 1;
+	     !err && timeout < i915_selftest.timeout_jiffies;
+	     timeout = next_prime_number(2 * timeout)) {
+		unsigned long end_time = jiffies + timeout;
+		struct drm_i915_gem_object *obj = NULL, *on;
+		struct intel_engine_cs *engine;
+		unsigned long ndwords, width, dw, id;
+		LIST_HEAD(objects);
+
+		err = begin_live_test(&t, igt->i915, __func__, "");
+		if (err)
+			break;
+
+		dw = 0;
+		width = 0;
+		ndwords = 0;
+		while (!time_after(jiffies, end_time)) {
+			for_each_engine(engine, igt->i915, id) {
+				intel_wakeref_t wakeref;
+
+				if (!intel_engine_can_store_dword(engine))
+					continue;
+
+				if (!obj) {
+					npages = next_prime_number(2 * npages);
+					if (npages >= vm->total >> PAGE_SHIFT)
+						goto done;
+
+					obj = create_test_object(igt->i915,
+								 npages,
+								 igt->file,
+								 &objects);
+					if (IS_ERR(obj)) {
+						err = PTR_ERR(obj);
+						goto free;
+					}
+				}
+
+				with_intel_runtime_pm(igt->i915, wakeref)
+					err = gpu_fill(obj, igt->ctx, engine, dw);
+				if (err) {
+					pr_err("Failed to fill dword %lu [%lu] with gpu (%s), err=%d\n",
+					       ndwords, dw, engine->name, err);
+					goto free;
+				}
+
+				if (++dw == DW_PER_PAGE) {
+					obj = NULL;
+					dw = 0;
+				}
+
+				ndwords += npages;
+				width++;
+			}
+		}
+done:
+		dw = 0;
+		for_each_engine(engine, igt->i915, id)
+			dw += intel_engine_can_store_dword(engine);
+		pr_info("Submitted %lu/%lu dwords (across %lu engines) in %lu jiffies\n",
+			ndwords, width, dw, timeout);
+
+free:
+		dw = 0;
+		id = 0;
+		list_for_each_entry_safe(obj, on, &objects, st_link) {
+			unsigned int num_writes =
+				min_t(unsigned int, width - dw, DW_PER_PAGE);
+
+			if (err == 0)
+				err = coherency_check(obj, id++, num_writes);
+
+			dw += num_writes;
+
+			GEM_BUG_ON(--obj->base.handle_count);
+			idr_remove(&igt->file->object_idr, obj->scratch);
+			i915_gem_object_unpin_pages(obj);
+			i915_gem_object_put(obj);
+		}
+
+		if (end_live_test(&t))
+			err = -EIO;
+
+		i915_retire_requests(igt->i915);
+	}
+
+	return err;
+}
+
+static int igt_mi_store_dw(void *arg)
+{
+	struct igt_mi_store_dw igt = { .i915 = arg };
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err;
+
+	igt.file = mock_file(igt.i915);
+	if (IS_ERR(igt.file))
+		return PTR_ERR(igt.file);
+
+	mutex_lock(&igt.i915->drm.struct_mutex);
+
+	igt.ctx = live_context(igt.i915, igt.file);
+	if (IS_ERR(igt.ctx)) {
+		err = PTR_ERR(igt.ctx);
+		goto out_unlock;
+	}
+
+	for_each_engine(engine, igt.i915, id) {
+		if (!intel_engine_can_store_dword(engine))
+			continue;
+
+		err = igt_mi_store_dw__engine(&igt, engine);
+		if (err)
+			goto out_unlock;
+	}
+
+	err = igt_mi_store_dw__all(&igt);
+
+out_unlock:
+	mutex_unlock(&igt.i915->drm.struct_mutex);
+
+	mock_file_free(igt.i915, igt.file);
+	return err;
+}
+
 int i915_gem_coherency_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
 		SUBTEST(igt_gem_coherency),
+		SUBTEST(igt_mi_store_dw),
 	};
 
 	return i915_subtests(tests, i915);
-- 
2.20.1



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