[igt-dev] [PATCH i-g-t, v3] tests/i915/i915_module_load: Test resizable bar support

[Matthew Auld]

On 28/06/2022 14:04, priyanka.dandamudi at intel.com wrote:
> From: Priyanka Dandamudi <priyanka.dandamudi at intel.com>
> 
> New test named resize bar has been added which tests whether
> bar gets resized with different supported sizes.
> 
> v2: Added code to check for bad bar sizes.
> Modified code to check for support of lmem_bar_size modparam.(Petri)
> 
> v3: Added test description.(Kamil)
> Updated driver_load_unload() name to driver_load_with_lmem_bar_size().
> Used for_each_memory_region() to check for lmem instance and some minor
> code modifications.(Matt)
> 
> Note:Test gets executed when
> 1. modparam lmem_bar_size gets added.
> 2. small bar bits gets enabled.
> 
> Cc: Matthew Auld <matthew.auld at intel.com>
> Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi at intel.com>
> ---
>   tests/i915/i915_module_load.c | 87 +++++++++++++++++++++++++++++++++++
>   1 file changed, 87 insertions(+)
> 
> diff --git a/tests/i915/i915_module_load.c b/tests/i915/i915_module_load.c
> index 4705f3d6..cd036b95 100644
> --- a/tests/i915/i915_module_load.c
> +++ b/tests/i915/i915_module_load.c
> @@ -38,6 +38,9 @@
>   #include "igt_sysfs.h"
>   #include "igt_core.h"
>   
> +#define BAR_SIZE_SHIFT 20
> +#define MIN_BAR_SIZE 256
> +
>   IGT_TEST_DESCRIPTION("Tests the i915 module loading.");
>   
>   static void store_all(int i915)
> @@ -260,6 +263,45 @@ static void load_and_check_i915(void)
>   	gem_sanitycheck();
>   }
>   
> +static uint32_t  driver_load_with_lmem_bar_size(uint32_t lmem_bar_size, bool check_support)
> +{
> +	int i915 = -1;
> +	char lmem_bar[64];
> +
> +	igt_i915_driver_unload();
> +	if (lmem_bar_size == 0)
> +		igt_assert_eq(igt_i915_driver_load(NULL), 0);
> +	else {
> +		sprintf(lmem_bar, "lmem_bar_size=%u", lmem_bar_size);
> +		igt_assert_eq(igt_i915_driver_load(lmem_bar), 0);
> +	}
> +
> +	i915 = __drm_open_driver(DRIVER_INTEL);
> +	igt_require_fd(i915);
> +	igt_require_gem(i915);
> +	igt_require(gem_has_lmem(i915));
> +
> +	if (check_support) {
> +		char *tmp;
> +
> +		tmp = __igt_params_get(i915, "lmem_bar_size");
> +		if (!tmp)
> +			igt_skip("lmem_bar_size modparam not supported on this kernel. Skipping the test.\n");
> +		free(tmp);
> +	}
> +
> +	for_each_memory_region(r, i915)

Add some braces here.

> +		if (r->ci.memory_class == I915_MEMORY_CLASS_DEVICE) {
> +			lmem_bar_size = (r->cpu_size >> BAR_SIZE_SHIFT);

I just pushed the IGT changes for this (cpu_size), so hopefully this 
will now build and skip when run. Can you resend?

Otherwise assuming this works as expected,
Reviewed-by: Matthew Auld <matthew.auld at intel.com>

> +
> +			igt_skip_on_f(lmem_bar_size == 0, "CPU visible size should be greater than zero. Skipping for older kernel.\n");
> +		}
> +
> +	close(i915);
> +
> +	return lmem_bar_size;
> +}
> +
>   igt_main
>   {
>   	igt_describe("Check if i915 and friends are not yet loaded, then load them.");
> @@ -320,5 +362,50 @@ igt_main
>   		/* inject_fault() leaves the module unloaded */
>   	}
>   
> +	igt_describe("Check whether lmem bar size can be resized to only supported sizes.");
> +	igt_subtest("resize-bar") {
> +		uint32_t result_bar_size;
> +		uint32_t lmem_bar_size;
> +		int i915 = -1;
> +
> +		if (igt_kmod_is_loaded("i915")) {
> +			i915 = __drm_open_driver(DRIVER_INTEL);
> +			igt_require_fd(i915);
> +			igt_require_gem(i915);
> +			igt_require(gem_has_lmem(i915));
> +			igt_skip_on_f(igt_sysfs_get_num_gt(i915) > 1, "Skips for more than one lmem instance.\n");
> +			close(i915);
> +		}
> +
> +		/* Test for lmem_bar_size modparam support */
> +		lmem_bar_size = driver_load_with_lmem_bar_size(MIN_BAR_SIZE, true);
> +		igt_assert_eq(lmem_bar_size, MIN_BAR_SIZE);
> +
> +		lmem_bar_size = driver_load_with_lmem_bar_size(0, false);
> +
> +		lmem_bar_size = roundup_power_of_two(lmem_bar_size);
> +
> +		igt_skip_on_f(lmem_bar_size == MIN_BAR_SIZE, "Bar is already set to minimum size.\n");
> +
> +		while (lmem_bar_size > MIN_BAR_SIZE) {
> +			lmem_bar_size = lmem_bar_size >> 1;
> +
> +			result_bar_size = driver_load_with_lmem_bar_size(lmem_bar_size, false);
> +
> +			igt_assert_f(lmem_bar_size == result_bar_size, "Bar couldn't be resized.\n");
> +		}
> +
> +		/* Test with unsupported sizes */
> +		lmem_bar_size = 80;
> +		result_bar_size = driver_load_with_lmem_bar_size(lmem_bar_size, false);
> +		igt_assert_f(lmem_bar_size != result_bar_size, "Bar resized to unsupported size.\n");
> +
> +		lmem_bar_size = 16400;
> +		result_bar_size = driver_load_with_lmem_bar_size(lmem_bar_size, false);
> +		igt_assert_f(lmem_bar_size != result_bar_size, "Bar resized to unsupported size.\n");
> +
> +		igt_i915_driver_unload();
> +	}
> +
>   	/* Subtests should unload the module themselves if they use modparams */
>   }