linux-stable.git/tools/testing/selftests/powerpc, branch v5.8.2

selftests/powerpc: Fix online CPU selection

2020-08-19T06:26:49+00:00

[ Upstream commit dfa03fff86027e58c8dba5c03ae68150d4e513ad ]

The size of the CPU affinity mask must be large enough for
systems with a very large number of CPUs. Otherwise, tests
which try to determine the first online CPU by calling
sched_getaffinity() will fail. This makes sure that the size
of the allocated affinity mask is dependent on the number of
CPUs as reported by get_nprocs_conf().

Fixes: 3752e453f6ba ("selftests/powerpc: Add tests of PMU EBBs")
Reported-by: Shirisha Ganta 
Signed-off-by: Sandipan Das 
Reviewed-by: Kamalesh Babulal 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a408c4b8e9a23bb39b539417a21eb0ff47bb5127.1596084858.git.sandipan@linux.ibm.com
Signed-off-by: Sasha Levin

selftests/powerpc: Fix CPU affinity for child process

2020-08-19T06:26:48+00:00

[ Upstream commit 854eb5022be04f81e318765f089f41a57c8e5d83 ]

On systems with large number of cpus, test fails trying to set
affinity by calling sched_setaffinity() with smaller size for affinity
mask. This patch fixes it by making sure that the size of allocated
affinity mask is dependent on the number of CPUs as reported by
get_nprocs().

Fixes: 00b7ec5c9cf3 ("selftests/powerpc: Import Anton's context_switch2 benchmark")
Reported-by: Shirisha Ganta 
Signed-off-by: Sandipan Das 
Signed-off-by: Harish 
Reviewed-by: Kamalesh Babulal 
Reviewed-by: Satheesh Rajendran 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200609081423.529664-1-harish@linux.ibm.com
Signed-off-by: Sasha Levin

selftests/powerpc: Squash spurious errors due to device removal

2020-08-19T06:26:47+00:00

[ Upstream commit 5f8cf6475828b600ff6d000e580c961ac839cc61 ]

For drivers that don't have the error handling callbacks we implement
recovery by removing the device and re-probing it. This causes the sysfs
directory for the PCI device to be removed which causes the following
spurious error to be printed when checking the PE state:

Breaking 0005:03:00.0...
./eeh-basic.sh: line 13: can't open /sys/bus/pci/devices/0005:03:00.0/eeh_pe_state: no such file
0005:03:00.0, waited 0/60
0005:03:00.0, waited 1/60
0005:03:00.0, waited 2/60
0005:03:00.0, waited 3/60
0005:03:00.0, waited 4/60
0005:03:00.0, waited 5/60
0005:03:00.0, waited 6/60
0005:03:00.0, waited 7/60
0005:03:00.0, Recovered after 8 seconds

We currently try to avoid this by checking if the PE state file exists
before reading from it. This is however inherently racy so re-work the
state checking so that we only read from the file once, and we squash any
errors that occur while reading.

Fixes: 85d86c8aa52e ("selftests/powerpc: Add basic EEH selftest")
Signed-off-by: Oliver O'Halloran 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200727010127.23698-1-oohall@gmail.com
Signed-off-by: Sasha Levin

selftests/powerpc: Use proper error code to check fault address

2020-07-15T13:10:17+00:00

ERR_NX_TRANSLATION(CSB.CC=5) is for internal to VAS for fault handling
and should not used by OS. ERR_NX_AT_FAULT(CSB.CC=250) is the proper
error code should be reported by OS when NX encounters address
translation failure.

This patch uses CC=250 to determine the fault address when the request
is not successful.

Signed-off-by: Haren Myneni 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/0315251705baff94f678c33178491b5008723511.camel@linux.ibm.com

selftests/powerpc: Fix build failure in ebb tests

2020-06-26T02:53:09+00:00

We use OUTPUT directory as TMPOUT for checking no-pie option.

Since commit f2f02ebd8f38 ("kbuild: improve cc-option to clean up all
temporary files") when building powerpc/ from selftests directory, the
OUTPUT directory points to powerpc/pmu/ebb/ and gets removed when
checking for -no-pie option in try-run routine, subsequently build
fails with the following:

  $ make -C powerpc
  ...
  TARGET=ebb; BUILD_TARGET=$OUTPUT/$TARGET; mkdir -p $BUILD_TARGET; make OUTPUT=$BUILD_TARGET -k -C $TARGET all
  make[2]: Entering directory '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb'
  make[2]: *** No rule to make target 'Makefile'.
  make[2]: Failed to remake makefile 'Makefile'.
  make[2]: *** No rule to make target 'ebb.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'ebb_handler.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'trace.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: *** No rule to make target 'busy_loop.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
  make[2]: Target 'all' not remade because of errors.

Fix this by adding a suffix to the OUTPUT directory so that the
failure is avoided.

Fixes: 9686813f6e9d ("selftests/powerpc: Fix try-run when source tree is not writable")
Signed-off-by: Harish 
[mpe: Mention that commit that triggered the breakage]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200625165721.264904-1-harish@linux.ibm.com

selftests/powerpc: Add a test of counting larx/stcx

2020-05-15T01:58:55+00:00

This is based on the count_instructions test.

However this one also counts the number of failed stcx's, and in
conjunction with knowing the size of the stcx loop, can calculate the
total number of instructions executed even in the face of
non-deterministic stcx failures.

Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200426114410.3917383-1-mpe@ellerman.id.au

powerpc/mm: Replace zero-length array with flexible-array

2020-05-15T01:58:54+00:00

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200507185755.GA15014@embeddedor

powerpc: Use trap metadata to prevent double restart rather than zeroing trap

2020-05-15T01:58:54+00:00

It's not very nice to zero trap for this, because then system calls no
longer have trap_is_syscall(regs) invariant, and we can't distinguish
between sc and scv system calls (in a later patch).

Take one last unused bit from the low bits of the pt_regs.trap word
for this instead. There is not a really good reason why it should be
in trap as opposed to another field, but trap has some concept of
flags and it exists. Ideally I think we would move trap to 2-byte
field and have 2 more bytes available independently.

Add a selftests case for this, which can be seen to fail if
trap_norestart() is changed to return false.

Signed-off-by: Nicholas Piggin 
[mpe: Make them static inlines]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200507121332.2233629-4-mpe@ellerman.id.au

selftests/powerpc: Add README for GZIP engine tests

2020-04-21T12:51:34+00:00

Include a README file with the instructions to use the
testcases at selftests/powerpc/nx-gzip.

Signed-off-by: Bulent Abali 
Signed-off-by: Raphael Moreira Zinsly 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200420205538.25181-6-rzinsly@linux.ibm.com

selftests/powerpc: Add NX-GZIP engine decompress testcase

2020-04-21T12:51:34+00:00

Include a decompression testcase for the powerpc NX-GZIP
engine.

Signed-off-by: Bulent Abali 
Signed-off-by: Raphael Moreira Zinsly 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200420205538.25181-5-rzinsly@linux.ibm.com