[igt-dev] [PATCH] tests/i915/i915_module_load: Test resizable bar support

[Dandamudi, Priyanka]

> -----Original Message-----
> From: Latvala, Petri <petri.latvala at intel.com>
> Sent: 15 June 2022 12:09 PM
> To: Dandamudi, Priyanka <priyanka.dandamudi at intel.com>
> Cc: Auld, Matthew <matthew.auld at intel.com>; igt-dev at lists.freedesktop.org
> Subject: Re: [igt-dev] [PATCH] tests/i915/i915_module_load: Test resizable bar
> support
> 
> On Wed, Jun 15, 2022 at 11:11:46AM +0530, 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.
> >
> > Cc: Matthew Auld <matthew.auld at intel.com>
> > Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi at intel.com>
> > ---
> >  tests/i915/i915_module_load.c | 64
> > +++++++++++++++++++++++++++++++++++
> >  1 file changed, 64 insertions(+)
> >
> > diff --git a/tests/i915/i915_module_load.c
> > b/tests/i915/i915_module_load.c index f5f98acc2..b334ef612 100644
> > --- a/tests/i915/i915_module_load.c
> > +++ b/tests/i915/i915_module_load.c
> > @@ -37,6 +37,9 @@
> >  #include "igt_sysfs.h"
> >  #include "igt_core.h"
> >
> > +#define BAR_SIZE_SHIFT 20
> > +#define BYTE 1024
> > +
> >  IGT_TEST_DESCRIPTION("Tests the i915 module loading.");
> >
> >  static void store_all(int i915)
> > @@ -236,6 +239,28 @@ hda_dynamic_debug(bool enable)
> >  	fclose(fp);
> >  }
> >
> > +static int driver_load_unload(struct drm_i915_query_memory_regions
> > +**regions, uint32_t lmem_bar_size) {
> > +	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_has_lmem(i915));
> > +	*regions = gem_get_query_memory_regions(i915);
> > +	igt_require(*regions);
> > +
> > +	return i915;
> > +}
> > +
> >  igt_main
> >  {
> >  	igt_describe("Verify the basic functionality of i915 driver after
> > it's reloaded."); @@ -286,5 +311,44 @@ igt_main
> >  		/* inject_fault() leaves the module unloaded */
> >  	}
> >
> > +	igt_subtest("resize-bar") {
> > +		struct drm_i915_query_memory_regions *regions;
> > +		struct drm_i915_memory_region_info *region;
> > +		uint32_t lmem_bar_size;
> > +		uint32_t small_bar;
> > +		bool bar_check = false;
> > +		int i915 = -1;
> > +
> > +		i915 = driver_load_unload(&regions, 0);
> 
> Before the unload, do this:
> 
> i915 = drm_open_driver(DRIVER_INTEL);
> igt_require(gem_has_lmem(i915);
> close(i915);
> 
[Dandamudi, Priyanka] 
The above work iam doing in driver_load_unload method.

> That way we can avoid an unnecessary reload cycle on integrated.
> 
> Which kernel version has the lmem_bar_size parameter? You might want to
> check its existence too. gem_lmem_swapping has an example of how it's done,
> with the param "lmem_size".
> 
> 
> --
> Petri Latvala
> 
[Dandamudi, Priyanka] 
lmem_size will also allow to resize the bar eg:62MB which is not expected as 256MB is the minimum size.
lmem_bar_size is a new modparam which is being added from the driver side to test different supported sizes.
> 
> 
> > +
> > +		for (unsigned int i = 0; i < (regions)->num_regions; i++)
> > +			for_each_if(((region) = &(regions)->regions[i])-
> >region.memory_class == I915_MEMORY_CLASS_DEVICE) {
> > +				lmem_bar_size = ceil((float)(region-
> >probed_size >> BAR_SIZE_SHIFT)/BYTE)*BYTE;
> > +				small_bar = (region->rsvd1[0] >>
> BAR_SIZE_SHIFT);
> > +				if (small_bar < lmem_bar_size)
> > +					bar_check = true;
> > +			}
> > +		while (lmem_bar_size >= 256) {
> > +
> > +			close(i915);
> > +
> > +			i915 = driver_load_unload(&regions, lmem_bar_size);
> > +
> > +			for (unsigned int i = 0; i < (regions)->num_regions; i++)
> > +				for_each_if(((region) = &(regions)->regions[i])-
> >region.memory_class == I915_MEMORY_CLASS_DEVICE) {
> > +					igt_assert_f(((region->probed_size >>
> BAR_SIZE_SHIFT) == lmem_bar_size),
> > +							 "Failed to set bar
> size");
> > +					if (bar_check)
> > +						igt_assert_f((small_bar ==
> (region->rsvd1[0] >> BAR_SIZE_SHIFT)),
> > +								 "Small bar is
> not set properly");
> > +					else
> > +						igt_assert_f(region-
> >probed_size == region->rsvd1[0], "Small bar and"
> > +								" lmem bar
> values need to be same");
> > +			}
> > +		lmem_bar_size = lmem_bar_size >> 1;
> > +		}
> > +		igt_i915_driver_unload();
> > +	}
> > +
> >  	/* Subtests should unload the module themselves if they use
> modparams */
> >  }
> > --
> > 2.27.0
> >