[Intel-gfx] [PATCH v2] drm/i915/selftests: Test i915_sw_fence/dma_fence interop

[Tvrtko Ursulin]

On 15/01/2018 20:43, Chris Wilson wrote:
> Check that we can successfully wait upon a dma_fence using the
> i915_sw_fence, including the optional timeout mechanism.
> 
> v2: Account for the rounding up of the timeout to the next second.
> Unfortunately, the minimum delay is then 1 second.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/selftests/i915_sw_fence.c | 137 +++++++++++++++++++++++++
>   1 file changed, 137 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
> index ea01d0fe3ace..b51319677110 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c
> @@ -27,6 +27,7 @@
>   #include <linux/prime_numbers.h>
>   
>   #include "../i915_selftest.h"
> +#include "../i915_utils.h"
>   
>   static int __i915_sw_fence_call
>   fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
> @@ -606,6 +607,141 @@ static int test_timer(void *arg)
>   	return -EINVAL;
>   }
>   
> +static const char *mock_name(struct dma_fence *fence)
> +{
> +	return "mock";
> +}
> +
> +static bool mock_enable_signaling(struct dma_fence *fence)
> +{
> +	return true;
> +}
> +
> +static const struct dma_fence_ops mock_fence_ops = {
> +	.get_driver_name = mock_name,
> +	.get_timeline_name = mock_name,
> +	.enable_signaling = mock_enable_signaling,
> +	.wait = dma_fence_default_wait,
> +	.release = dma_fence_free,
> +};
> +
> +static DEFINE_SPINLOCK(mock_fence_lock);
> +
> +static struct dma_fence *alloc_dma_fence(void)
> +{
> +	struct dma_fence *dma;
> +
> +	dma = kmalloc(sizeof(*dma), GFP_KERNEL);
> +	if (dma)
> +		dma_fence_init(dma, &mock_fence_ops, &mock_fence_lock, 0, 0);
> +
> +	return dma;
> +}
> +
> +static struct i915_sw_fence *
> +wrap_dma_fence(struct dma_fence *dma, unsigned long delay)

await_dma_fence?

> +{
> +	struct i915_sw_fence *fence;
> +	int err;
> +
> +	fence = alloc_fence();
> +	if (!fence)
> +		return ERR_PTR(-ENOMEM);
> +
> +	err = i915_sw_fence_await_dma_fence(fence, dma, delay, GFP_NOWAIT);
> +	i915_sw_fence_commit(fence);
> +	if (err < 0) {
> +		free_fence(fence);
> +		return ERR_PTR(err);
> +	}
> +
> +	return fence;
> +}
> +
> +static int test_dma_fence(void *arg)
> +{
> +	struct i915_sw_fence *timeout = NULL, *not = NULL;
> +	unsigned long delay = i915_selftest.timeout_jiffies;
> +	unsigned long end, sleep;
> +	struct dma_fence *dma;
> +	int err;
> +
> +	dma = alloc_dma_fence();
> +	if (!dma)
> +		return -ENOMEM;
> +
> +	timeout = wrap_dma_fence(dma, delay);
> +	if (IS_ERR(timeout)) {
> +		err = PTR_ERR(timeout);
> +		goto err;
> +	}
> +
> +	not = wrap_dma_fence(dma, 0);
> +	if (IS_ERR(not)) {
> +		err = PTR_ERR(not);
> +		goto err;
> +	}
> +
> +	err = -EINVAL;
> +	if (i915_sw_fence_done(timeout) || i915_sw_fence_done(not)) {
> +		pr_err("Fences immediately signaled\n");
> +		goto err;
> +	}
> +
> +	/* We round the timeout for the fence up to the next second */
> +	end = round_jiffies_up(jiffies + delay);
> +
> +	sleep = jiffies_to_usecs(delay) / 3;
> +	usleep_range(sleep, 2 * sleep);
> +	if (time_after(jiffies, end)) {
> +		pr_debug("Slept too long, delay=%lu, skipping!\n", delay);
> +		goto skip;
> +	}
> +
> +	if (i915_sw_fence_done(timeout) || i915_sw_fence_done(not)) {
> +		pr_err("Fences signaled too early\n");
> +		goto err;
> +	}
> +
> +	do {
> +		sleep = jiffies_to_usecs(end - jiffies + 1);
> +		usleep_range(sleep, 2 * sleep);
> +	} while (!time_after(jiffies, end));
> +
> +	if (i915_sw_fence_done(not)) {
> +		pr_err("No tiemout fence signaled!\n");
> +		goto err;
> +	}
> +
> +	if (!i915_sw_fence_done(timeout)) {
> +		pr_err("Timeout fence unsignaled!\n");
> +		goto err;
> +	}
> +
> +skip:
> +	dma_fence_signal(dma);
> +
> +	if (!i915_sw_fence_done(timeout) || !i915_sw_fence_done(not)) {
> +		pr_err("Fences unsignaled\n");
> +		goto err;
> +	}
> +
> +	free_fence(fetch_and_zero(&not));
> +	free_fence(fetch_and_zero(&timeout));

A bit of an overkill with fetch_and_zero.

> +	dma_fence_put(dma);
> +
> +	return 0;
> +
> +err:
> +	dma_fence_signal(dma);
> +	if (!IS_ERR_OR_NULL(timeout))
> +		free_fence(timeout);
> +	if (!IS_ERR_OR_NULL(not))
> +		free_fence(not);
> +	dma_fence_put(dma);
> +	return err;
> +}
> +
>   int i915_sw_fence_mock_selftests(void)
>   {
>   	static const struct i915_subtest tests[] = {
> @@ -618,6 +754,7 @@ int i915_sw_fence_mock_selftests(void)
>   		SUBTEST(test_chain),
>   		SUBTEST(test_ipc),
>   		SUBTEST(test_timer),
> +		SUBTEST(test_dma_fence),
>   	};
>   
>   	return i915_subtests(tests, NULL);
> 

Looks OK anyway.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko