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author | Athira Rajeev <atrajeev@linux.vnet.ibm.com> | 2021-05-25 09:51:43 -0400 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-17 00:09:11 +1000 |
commit | d81090ed44c0d15abf2b07663d5f0b9e5ba51525 (patch) | |
tree | 8119f2165e397588cb71d9ee6de697b3f79febb2 /tools/testing/selftests/powerpc | |
parent | 45677c9aebe926192e59475b35a1ff35ff2d4217 (diff) | |
download | linux-stable-d81090ed44c0d15abf2b07663d5f0b9e5ba51525.tar.gz linux-stable-d81090ed44c0d15abf2b07663d5f0b9e5ba51525.tar.bz2 linux-stable-d81090ed44c0d15abf2b07663d5f0b9e5ba51525.zip |
selftests/powerpc: EBB selftest for MMCR0 control for PMU SPRs in ISA v3.1
With the MMCR0 control bit (PMCCEXT) in ISA v3.1, read access to
group B registers is restricted when MMCR0 PMCC=0b00. In other
platforms (like power9), the older behaviour works where group B
PMU SPRs are readable.
Patch creates a selftest which verifies that the test takes a
SIGILL when attempting to read PMU registers via helper function
"dump_ebb_state" for ISA v3.1.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com <mailto:rnsastry@linux.ibm.com>>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1621950703-1532-3-git-send-email-atrajeev@linux.vnet.ibm.com
Diffstat (limited to 'tools/testing/selftests/powerpc')
-rw-r--r-- | tools/testing/selftests/powerpc/pmu/ebb/Makefile | 2 | ||||
-rw-r--r-- | tools/testing/selftests/powerpc/pmu/ebb/regs_access_pmccext_test.c | 63 |
2 files changed, 64 insertions, 1 deletions
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/Makefile b/tools/testing/selftests/powerpc/pmu/ebb/Makefile index c5ecb4634094..010160690227 100644 --- a/tools/testing/selftests/powerpc/pmu/ebb/Makefile +++ b/tools/testing/selftests/powerpc/pmu/ebb/Makefile @@ -24,7 +24,7 @@ TEST_GEN_PROGS := reg_access_test event_attributes_test cycles_test \ fork_cleanup_test ebb_on_child_test \ ebb_on_willing_child_test back_to_back_ebbs_test \ lost_exception_test no_handler_test \ - cycles_with_mmcr2_test + cycles_with_mmcr2_test regs_access_pmccext_test top_srcdir = ../../../../../.. include ../../../lib.mk diff --git a/tools/testing/selftests/powerpc/pmu/ebb/regs_access_pmccext_test.c b/tools/testing/selftests/powerpc/pmu/ebb/regs_access_pmccext_test.c new file mode 100644 index 000000000000..1eda8e9932e8 --- /dev/null +++ b/tools/testing/selftests/powerpc/pmu/ebb/regs_access_pmccext_test.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2021, Athira Rajeev, IBM Corp. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <setjmp.h> +#include <signal.h> + +#include "ebb.h" + + +/* + * Test that closing the EBB event clears MMCR0_PMCC and + * sets MMCR0_PMCCEXT preventing further read access to the + * group B PMU registers. + */ + +static int regs_access_pmccext(void) +{ + struct event event; + + SKIP_IF(!ebb_is_supported()); + + event_init_named(&event, 0x1001e, "cycles"); + event_leader_ebb_init(&event); + + FAIL_IF(event_open(&event)); + + ebb_enable_pmc_counting(1); + setup_ebb_handler(standard_ebb_callee); + ebb_global_enable(); + FAIL_IF(ebb_event_enable(&event)); + + mtspr(SPRN_PMC1, pmc_sample_period(sample_period)); + + while (ebb_state.stats.ebb_count < 1) + FAIL_IF(core_busy_loop()); + + ebb_global_disable(); + event_close(&event); + + FAIL_IF(ebb_state.stats.ebb_count == 0); + + /* + * For ISA v3.1, verify the test takes a SIGILL when reading + * PMU regs after the event is closed. With the control bit + * in MMCR0 (PMCCEXT) restricting access to group B PMU regs, + * sigill is expected. + */ + if (have_hwcap2(PPC_FEATURE2_ARCH_3_1)) + FAIL_IF(catch_sigill(dump_ebb_state)); + else + dump_ebb_state(); + + return 0; +} + +int main(void) +{ + return test_harness(regs_access_pmccext, "regs_access_pmccext"); +} |