On Mon, 5 Feb 2024, Maciej Wieczor-Retman wrote: > Add tests for both L2 and L3 CAT to verify the return values > generated by writing non-contiguous CBMs don't contradict the > reported non-contiguous support information. > > Use a logical XOR to confirm return value of write_schemata() and > non-contiguous CBMs support information match. > > Signed-off-by: Maciej Wieczor-Retman <[email protected]> > --- > Changelog v4: > - Return failure instead of error on check of cpuid against sparse_masks > and on contiguous write_schemata fail. (Reinette) > > Changelog v3: > - Roll back __cpuid_count part. (Reinette) > - Update function name to read sparse_masks file. > - Roll back get_cache_level() changes. > - Add ksft_print_msg() to contiguous schemata write error handling > (Reinette). > > Changelog v2: > - Redo the patch message. (Ilpo) > - Tidy up __cpuid_count calls. (Ilpo) > - Remove redundant AND in noncont_mask calculations (Ilpo) > - Fix bit_center offset. > - Add newline before function return. (Ilpo) > - Group non-contiguous tests with CAT tests. (Ilpo) > - Use a helper for reading sparse_masks file. (Ilpo) > - Make get_cache_level() available in other source files. (Ilpo) > > tools/testing/selftests/resctrl/cat_test.c | 81 +++++++++++++++++++ > tools/testing/selftests/resctrl/resctrl.h | 2 + > .../testing/selftests/resctrl/resctrl_tests.c | 2 + > 3 files changed, 85 insertions(+) > > diff --git a/tools/testing/selftests/resctrl/cat_test.c > b/tools/testing/selftests/resctrl/cat_test.c > index 39fc9303b8e8..20eb978e624b 100644 > --- a/tools/testing/selftests/resctrl/cat_test.c > +++ b/tools/testing/selftests/resctrl/cat_test.c > @@ -294,6 +294,71 @@ static int cat_run_test(const struct resctrl_test *test, > const struct user_param > return ret; > } > > +static int noncont_cat_run_test(const struct resctrl_test *test, > + const struct user_params *uparams) > +{ > + unsigned long full_cache_mask, cont_mask, noncont_mask; > + unsigned int eax, ebx, ecx, edx, ret, sparse_masks; > + char schemata[64]; > + int bit_center; > + > + /* Check to compare sparse_masks content to CPUID output. */ > + ret = resource_info_unsigned_get(test->resource, "sparse_masks", > &sparse_masks); > + if (ret) > + return ret; > + > + if (!strcmp(test->resource, "L3")) > + __cpuid_count(0x10, 1, eax, ebx, ecx, edx); > + else if (!strcmp(test->resource, "L2")) > + __cpuid_count(0x10, 2, eax, ebx, ecx, edx); > + else > + return -EINVAL; > + > + if (sparse_masks != ((ecx >> 3) & 1)) { > + ksft_print_msg("CPUID output doesn't match 'sparse_masks' file > content!\n"); > + return 1; > + } > + > + /* Write checks initialization. */ > + ret = get_full_cbm(test->resource, &full_cache_mask); > + if (ret < 0) > + return ret; > + bit_center = count_bits(full_cache_mask) / 2; > + cont_mask = full_cache_mask >> bit_center; > + > + /* Contiguous mask write check. */ > + snprintf(schemata, sizeof(schemata), "%lx", cont_mask); > + ret = write_schemata("", schemata, uparams->cpu, test->resource); > + if (ret) { > + ksft_print_msg("Write of contiguous CBM failed\n"); > + return 1; > + } > + > + /* > + * Non-contiguous mask write check. CBM has a 0xf hole approximately in > the middle. > + * Output is compared with support information to catch any edge case > errors. > + */ > + noncont_mask = ~(0xf << (bit_center - 2)) & full_cache_mask;
To be on the safe side, I think the types could be made to match here with 0xfUL to avoid sizeof(int) vs sizeof(unsigned long) related bit drops in the & (although it feel somewhat theoretical given the bitmask sizes we are currently seeing). Reviewed-by: Ilpo Järvinen <[email protected]> -- i.
