As part of the enumeration interface for setting vector lengths it is valid to set vector lengths not supported in the system, these will be rounded to a supported vector length and returned from the prctl(). Add a test which exercises this for every valid vector length and makes sure that the return value is as expected and that this is reflected in the actual system state.
Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/arm64/fp/vec-syscfg.c | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+)
diff --git a/tools/testing/selftests/arm64/fp/vec-syscfg.c b/tools/testing/selftests/arm64/fp/vec-syscfg.c index 9d6ac843e651..de11cd2f5d79 100644 --- a/tools/testing/selftests/arm64/fp/vec-syscfg.c +++ b/tools/testing/selftests/arm64/fp/vec-syscfg.c @@ -540,6 +540,76 @@ static void prctl_set_onexec(struct vec_data *data) file_write_integer(data->default_vl_file, data->default_vl); }
+/* For each VQ verify that setting via prctl() does the right thing */ +static void prctl_set_all_vqs(struct vec_data *data) +{ + int ret, vq, vl, new_vl; + int errors = 0; + + for (vq = SVE_VQ_MIN; vq <= SVE_VQ_MAX; vq++) { + vl = sve_vl_from_vq(vq); + + /* Attempt to set the VL */ + ret = prctl(data->prctl_set, vl); + if (ret < 0) { + errors++; + ksft_print_msg("%s prctl set failed for %d: %d (%s)\n", + data->name, vl, + errno, strerror(errno)); + continue; + } + + new_vl = ret & PR_SVE_VL_LEN_MASK; + + /* Check that we actually have the reported new VL */ + if (data->rdvl() != new_vl) { + ksft_print_msg("Set %s VL %d but RDVL reports %d\n", + data->name, new_vl, data->rdvl()); + errors++; + } + + /* Was that the VL we asked for? */ + if (new_vl == vl) + continue; + + /* Should round up to the minimum VL if below it */ + if (vl < data->min_vl) { + if (new_vl != data->min_vl) { + ksft_print_msg("%s VL %d returned %d not minimum %d\n", + data->name, vl, new_vl, + data->min_vl); + errors++; + } + + continue; + } + + /* Should round down to maximum VL if above it */ + if (vl > data->max_vl) { + if (new_vl != data->max_vl) { + ksft_print_msg("%s VL %d returned %d not maximum %d\n", + data->name, vl, new_vl, + data->max_vl); + errors++; + } + + continue; + } + + /* Otherwise we should've rounded down */ + if (!(new_vl < vl)) { + ksft_print_msg("%s VL %d returned %d, did not round down\n", + data->name, vl, new_vl); + errors++; + + continue; + } + } + + ksft_test_result(errors == 0, "%s prctl() set all VLs, %d errors\n", + data->name, errors); +} + typedef void (*test_type)(struct vec_data *);
static const test_type tests[] = { @@ -557,6 +627,7 @@ static const test_type tests[] = { prctl_set_no_child, prctl_set_for_child, prctl_set_onexec, + prctl_set_all_vqs, };
int main(void)