Re: [Intel-gfx] [PATCH 10/20] drm/i915/selftests: mock test io_size

Thomas Hellström
2022-02-02T10:25:10Z

On 1/26/22 16:21, Matthew Auld wrote:
> Check that mappable vs non-mappable matches our expectations.
>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

> ---
> .../drm/i915/selftests/intel_memory_region.c | 143 ++++++++++++++++++
> 1 file changed, 143 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
> index 247f65f02bbf..04ae29779206 100644
> --- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
> +++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
> @@ -17,6 +17,7 @@
> #include "gem/i915_gem_context.h"
> #include "gem/i915_gem_lmem.h"
> #include "gem/i915_gem_region.h"
> +#include "gem/i915_gem_ttm.h"
> #include "gem/selftests/igt_gem_utils.h"
> #include "gem/selftests/mock_context.h"
> #include "gt/intel_engine_pm.h"
> @@ -512,6 +513,147 @@ static int igt_mock_max_segment(void *arg)
> return err;
> }
>
> +static u64 igt_object_mappable_total(struct drm_i915_gem_object *obj)
> +{
> + struct intel_memory_region *mr = obj->mm.region;
> + struct i915_ttm_buddy_resource *bman_res =
> + to_ttm_buddy_resource(obj->mm.res);
> + struct drm_buddy *mm = bman_res->mm;
> + struct drm_buddy_block *block;
> + u64 total;
> +
> + total = 0;
> + list_for_each_entry(block, &bman_res->blocks, link) {
> + u64 start = drm_buddy_block_offset(block);
> + u64 end = start + drm_buddy_block_size(mm, block);
> +
> + if (start < mr->io_size)
> + total += min_t(u64, end, mr->io_size) - start;
> + }
> +
> + return total;
> +}
> +
> +static int igt_mock_io_size(void *arg)
> +{
> + struct intel_memory_region *mr = arg;
> + struct drm_i915_private *i915 = mr->i915;
> + struct drm_i915_gem_object *obj;
> + u64 mappable_theft_total;
> + u64 io_size;
> + u64 total;
> + u64 ps;
> + u64 rem;
> + u64 size;
> + I915_RND_STATE(prng);
> + LIST_HEAD(objects);
> + int err = 0;
> +
> + ps = SZ_4K;
> + if (i915_prandom_u64_state(&prng) & 1)
> + ps = SZ_64K; /* For something like DG2 */
> +
> + div64_u64_rem(i915_prandom_u64_state(&prng), SZ_8G, &total);
> + total = round_down(total, ps);
> + total = max_t(u64, total, SZ_1G);
> +
> + div64_u64_rem(i915_prandom_u64_state(&prng), total - ps, &io_size);
> + io_size = round_down(io_size, ps);
> + io_size = max_t(u64, io_size, SZ_256M); /* 256M seems to be the common lower limit */
> +
> + pr_info("%s with ps=%llx, io_size=%llx, total=%llx\n",
> + __func__, ps, io_size, total);
> +
> + mr = mock_region_create(i915, 0, total, ps, 0, io_size);
> + if (IS_ERR(mr)) {
> + err = PTR_ERR(mr);
> + goto out_err;
> + }
> +
> + mappable_theft_total = 0;
> + rem = total - io_size;
> + do {
> + div64_u64_rem(i915_prandom_u64_state(&prng), rem, &size);
> + size = round_down(size, ps);
> + size = max(size, ps);
> +
> + obj = igt_object_create(mr, &objects, size,
> + I915_BO_ALLOC_TOPDOWN);
> + if (IS_ERR(obj)) {
> + pr_err("%s TOPDOWN failed with rem=%llx, size=%llx\n",
> + __func__, rem, size);
> + err = PTR_ERR(obj);
> + goto out_close;
> + }
> +
> + mappable_theft_total += igt_object_mappable_total(obj);
> + rem -= size;
> + } while (rem);
> +
> + pr_info("%s mappable theft=(%lluMiB/%lluMiB), total=%lluMiB\n",
> + __func__,
> + (u64)mappable_theft_total >> 20,
> + (u64)io_size >> 20,
> + (u64)total >> 20);
> +
> + /*
> + * Even if we allocate all of the non-mappable portion, we should still
> + * be able to dip into the mappable portion.
> + */
> + obj = igt_object_create(mr, &objects, io_size,
> + I915_BO_ALLOC_TOPDOWN);
> + if (IS_ERR(obj)) {
> + pr_err("%s allocation unexpectedly failed\n", __func__);
> + err = PTR_ERR(obj);
> + goto out_close;
> + }
> +
> + close_objects(mr, &objects);
> +
> + rem = io_size;
> + do {
> + div64_u64_rem(i915_prandom_u64_state(&prng), rem, &size);
> + size = round_down(size, ps);
> + size = max(size, ps);
> +
> + obj = igt_object_create(mr, &objects, size, 0);
> + if (IS_ERR(obj)) {
> + pr_err("%s MAPPABLE failed with rem=%llx, size=%llx\n",
> + __func__, rem, size);
> + err = PTR_ERR(obj);
> + goto out_close;
> + }
> +
> + if (igt_object_mappable_total(obj) != size) {
> + pr_err("%s allocation is not mappable(size=%llx)\n",
> + __func__, size);
> + err = -EINVAL;
> + goto out_close;
> + }
> + rem -= size;
> + } while (rem);
> +
> + /*
> + * We assume CPU access is required by default, which should result in a
> + * failure here, even though the non-mappable portion is free.
> + */
> + obj = igt_object_create(mr, &objects, ps, 0);
> + if (!IS_ERR(obj)) {
> + pr_err("%s allocation unexpectedly succeeded\n", __func__);
> + err = -EINVAL;
> + goto out_close;
> + }
> +
> +out_close:
> + close_objects(mr, &objects);
> + intel_memory_region_destroy(mr);
> +out_err:
> + if (err == -ENOMEM)
> + err = 0;
> +
> + return err;
> +}
> +
> static int igt_gpu_write_dw(struct intel_context *ce,
> struct i915_vma *vma,
> u32 dword,
> @@ -1179,6 +1321,7 @@ int intel_memory_region_mock_selftests(void)
> SUBTEST(igt_mock_contiguous),
> SUBTEST(igt_mock_splintered_region),
> SUBTEST(igt_mock_max_segment),
> + SUBTEST(igt_mock_io_size),
> };
> struct intel_memory_region *mem;
> struct drm_i915_private *i915;