[Intel-gfx] [PATCH] drm/i915/selftests: Add coverage of mocs registers

[Kumar Valsan, Prathap]

On Fri, Oct 18, 2019 at 01:06:39PM +0100, Chris Wilson wrote:
> Probe the mocs registers for new contexts and across GPU resets. Similar
> to intel_workarounds, we have tables of what register values we expect
> to see, so verify that user contexts are affected by them. In the
> future, we should add tests similar to intel_sseu to cover dynamic
> reconfigurations.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Prathap Kumar Valsan <prathap.kumar.valsan at intel.com>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> ---
> +static int check_l3cc_table(struct intel_engine_cs *engine,
> +			    const struct drm_i915_mocs_table *table,
> +			    const u32 *vaddr, int *offset)
> +{
> +	u16 unused_value = table->table[I915_MOCS_PTE].l3cc_value;
> +	unsigned int i;
> +	u32 expect;
> +
> +	if (1) { /* XXX skip MCR read back */
> +		*offset += table->n_entries / 2;
> +		return 0;
> +	}
Not checking l3cc table?

> +
> +	for (i = 0; i < table->size / 2; i++) {
> +		u16 low = get_entry_l3cc(table, 2 * i);
> +		u16 high = get_entry_l3cc(table, 2 * i + 1);
> +
> +		expect = l3cc_combine(table, low, high);
> +		if (vaddr[*offset] != expect) {
> +			pr_err("%s: Invalid L3CC[%d] entry, found %08x, expected %08x\n",
> +			       engine->name, i, vaddr[*offset], expect);
> +			return -EINVAL;
> +		}
> +		++*offset;
> +	}
> +
> +	/* Odd table size - 1 left over */
> +	if (table->size & 1) {
> +		u16 low = get_entry_l3cc(table, 2 * i);
> +
> +		expect = l3cc_combine(table, low, unused_value);
> +		if (vaddr[*offset] != expect) {
> +			pr_err("%s: Invalid L3CC[%d] entry, found %08x, expected %08x\n",
> +			       engine->name, i, vaddr[*offset], expect);
> +			return -EINVAL;
> +		}
> +		++*offset;
> +		i++;
> +	}
> +
> +	/* All remaining entries are also unused */
> +	for (; i < table->n_entries / 2; i++) {
> +		expect = l3cc_combine(table, unused_value, unused_value);
> +		if (vaddr[*offset] != expect) {
> +			pr_err("%s: Invalid L3CC[%d] entry, found %08x, expected %08x\n",
> +			       engine->name, i, vaddr[*offset], expect);
> +			return -EINVAL;
> +		}
> +		++*offset;
> +	}
> +
> +	return 0;
> +}
> +
> +static int check_mocs_engine(struct live_mocs *arg,
> +			     struct intel_context *ce)
> +{
> +	struct i915_vma *vma = arg->scratch;
> +	struct i915_request *rq;
> +	int offset;
> +	int err;
> +
> +	memset32(arg->vaddr, STACK_MAGIC, PAGE_SIZE / sizeof(u32));
> +
> +	rq = intel_context_create_request(ce);
> +	if (IS_ERR(rq))
> +		return PTR_ERR(rq);
> +
> +	i915_vma_lock(vma);
> +	err = i915_request_await_object(rq, vma->obj, true);
> +	if (!err)
> +		err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
> +	i915_vma_unlock(vma);
> +
> +	offset = 0;
> +	if (!err)
> +		err = read_mocs_table(rq, &arg->table, vma, &offset);
> +	if (!err && ce->engine->class == RENDER_CLASS)
> +		err = read_l3cc_table(rq, &arg->table, vma, &offset);
> +
> +	err = request_add_sync(rq, err);
> +	if (err)
> +		return err;
> +
> +	offset = 0;
> +	if (!err)
> +		err = check_mocs_table(ce->engine, &arg->table,
> +				       arg->vaddr, &offset);
> +	if (!err && ce->engine->class == RENDER_CLASS)
> +		err = check_l3cc_table(ce->engine, &arg->table,
> +				       arg->vaddr, &offset);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static int live_mocs_clean(void *arg)
> +{
> +	struct intel_gt *gt = arg;
> +	struct intel_engine_cs *engine;
> +	enum intel_engine_id id;
> +	struct live_mocs mocs;
> +	int err;
> +
> +	err = live_mocs_init(&mocs, gt);
> +	if (err)
> +		return err;
> +
> +	for_each_engine(engine, gt, id) {
> +		struct intel_context *ce;
> +
> +		ce = intel_context_create(engine->kernel_context->gem_context,
> +					  engine);
> +		if (IS_ERR(ce)) {
> +			err = PTR_ERR(ce);
> +			break;
> +		}
> +
> +		err = check_mocs_engine(&mocs, ce);
> +		intel_context_put(ce);
Need a _get() to pair with _put()?

> +		if (err)
> +			break;
> +	}
> +
> +	live_mocs_fini(&mocs);
> +
> +	return err;
> +}
> +
[snip]
> diff --git a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
> index 6daf6599ec79..1a6abcffce81 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
> +++ b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
> @@ -16,6 +16,7 @@ selftest(gt_engines, intel_engine_live_selftests)
>  selftest(gt_timelines, intel_timeline_live_selftests)
>  selftest(gt_contexts, intel_context_live_selftests)
>  selftest(gt_lrc, intel_lrc_live_selftests)
> +selftest(gt_mocs, intel_mocs_live_selftests)
>  selftest(gt_pm, intel_gt_pm_live_selftests)
>  selftest(requests, i915_request_live_selftests)
>  selftest(active, i915_active_live_selftests)

Regards,
Prathap
> -- 
> 2.23.0
>