linux.git/tools/testing/selftests/powerpc, branch v6.8-rc2

selftests/powerpc: Fix spelling mistake "EACCESS" -> "EACCES"

2023-12-21T11:13:55+00:00

There is a spelling mistake of the EACCES error name, fix it.

Signed-off-by: Colin Ian King 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231215112456.13554-1-colin.i.king@gmail.com

powerpc/selftests: Add test for papr-sysparm

2023-12-13T10:38:21+00:00

Consistently testing system parameter access is a bit difficult by
nature -- the set of parameters available depends on the model and
system configuration, and updating a parameter should be considered a
destructive operation reserved for the admin.

So we validate some of the error paths and retrieve the SPLPAR
characteristics string, but not much else.

Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-13-e9eafd0c8c6c@linux.ibm.com

powerpc/selftests: Add test for papr-vpd

2023-12-13T10:38:21+00:00

Add selftests for /dev/papr-vpd, exercising the common expected use
cases:

* Retrieve all VPD by passing an empty location code.
* Retrieve the "system VPD" by passing a location code derived from DT
  root node properties, as done by the vpdupdate command.

The tests also verify that certain intended properties of the driver
hold:

* Passing an unterminated location code to PAPR_VPD_CREATE_HANDLE gets
  EINVAL.
* Passing a NULL location code pointer to PAPR_VPD_CREATE_HANDLE gets
  EFAULT.
* Closing the device node without first issuing a
  PAPR_VPD_CREATE_HANDLE command to it succeeds.
* Releasing a handle without first consuming any data from it
  succeeds.
* Re-reading the contents of a handle returns the same data as the
  first time.

Some minimal validation of the returned data is performed.

The tests are skipped on systems where the papr-vpd driver does not
initialize, making this useful only on PowerVM LPARs at this point.

Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-12-e9eafd0c8c6c@linux.ibm.com

selftests/powerpc: Check all FPRs in fpu_syscall test

2023-12-13T02:29:09+00:00

There is a selftest that checks if FPRs are corrupted across a fork, aka
clone. It was added as part of the series that optimised the clone path
to save the parent's FP state without "giving up" (turning off FP).

See commit 8792468da5e1 ("powerpc: Add the ability to save FPU without
giving it up").

The test encodes the assumption that FPRs 0-13 are volatile across the
syscall, by only checking the volatile FPRs are not changed by the fork.
There was also a comment in the fpu_preempt test alluding to that:

  The check_fpu function in asm only checks the non volatile registers
  as it is reused from the syscall test

It is true that the function call ABI treats f0-f13 as volatile,
however the syscall ABI has since been documented as *not* treating those
registers as volatile. See commit 7b8845a2a2ec ("powerpc/64: Document
the syscall ABI").

So change the test to check all FPRs are not corrupted by the syscall.
Note that this currently fails, because save_fpu() etc. do not restore
f0/vsr0.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-5-mpe@ellerman.id.au

selftests/powerpc: Run fpu_preempt test for 60 seconds

2023-12-13T02:29:09+00:00

The FPU preempt test only runs for 20 seconds, which is not particularly
long. Run it for 60 seconds to increase the chance of detecting
corruption.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-4-mpe@ellerman.id.au

selftests/powerpc: Generate better bit patterns for FPU tests

2023-12-13T02:29:08+00:00

The fpu_preempt test randomly initialises an array of doubles to try and
detect FPU register corruption.

However the values it generates do not occupy the full range of values
possible in the 64-bit double, meaning some partial register corruption
could go undetected.

Without getting too carried away, add some better initialisation to
generate values that occupy more bits.

Sample values before:

  f0             902677510               (raw 0x41cae6e203000000)
  f1             325217596               (raw 0x41b3626d3c000000)
  f2             1856578300              (raw 0x41dbaa48bf000000)
  f3             1247189984              (raw 0x41d295a6f8000000)

And after:

  f0             1.1078153481413311e-09  (raw 0x3e13083932805cc2)
  f1             1.0576648474801922e+17  (raw 0x43777c20eb88c261)
  f2             -6.6245033413594075e-10 (raw 0xbe06c2f989facae9)
  f3             3.0085988827156291e+18  (raw 0x43c4e0585f2df37b)

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-3-mpe@ellerman.id.au

selftests/powerpc: Check all FPRs in fpu_preempt

2023-12-13T02:29:08+00:00

There's a selftest that checks FPRs aren't corrupted by preemption, or
just process scheduling. However it only checks the non-volatile FPRs,
meaning corruption of the volatile FPRs could go undetected.

The check_fpu function it calls is used by several other tests, so for
now add a new routine to check all the FPRs. Increase the size of the
array of FPRs to 32, and initialise them all with random values.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-2-mpe@ellerman.id.au

selftests/powerpc: Fix error handling in FPU/VMX preemption tests

2023-12-13T02:29:08+00:00

The FPU & VMX preemption tests do not check for errors returned by the
low-level asm routines, preempt_fpu() / preempt_vsx() respectively.
That means any register corruption detected by the asm routines does not
result in a test failure.

Fix it by returning the return value of the asm routines from the
pthread child routines.

Fixes: e5ab8be68e44 ("selftests/powerpc: Test preservation of FPU and VMX regs across preemption")
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-1-mpe@ellerman.id.au

selftests/powerpc: Fix emit_tests to work with run_kselftest.sh

2023-09-22T10:29:48+00:00

In order to use run_kselftest.sh the list of tests must be emitted to
populate kselftest-list.txt.

The powerpc Makefile is written to use EMIT_TESTS. But support for
EMIT_TESTS was dropped in commit d4e59a536f50 ("selftests: Use runner.sh
for emit targets"). Although prior to that commit a548de0fe8e1
("selftests: lib.mk: add test execute bit check to EMIT_TESTS") had
already broken run_kselftest.sh for powerpc due to the executable check
using the wrong path.

It can be fixed by replacing the EMIT_TESTS definitions with actual
emit_tests rules in the powerpc Makefiles. This makes run_kselftest.sh
able to run powerpc tests:

  $ cd linux
  $ export ARCH=powerpc
  $ export CROSS_COMPILE=powerpc64le-linux-gnu-
  $ make headers
  $ make -j -C tools/testing/selftests install
  $ grep -c "^powerpc" tools/testing/selftests/kselftest_install/kselftest-list.txt
  182

Fixes: d4e59a536f50 ("selftests: Use runner.sh for emit targets")
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230921072623.828772-1-mpe@ellerman.id.au

powerpc/pseries: Move VPHN constants into vphn.h

2023-08-24T12:33:16+00:00

These don't have any particularly good reason to belong in lppaca.h,
move them into their own header.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230823055317.751786-1-mpe@ellerman.id.au