selftests/powerpc: Remove redundant cp_abort test

Paste on POWER9 only works on accelerators and no longer on real
memory. Hence this test is broken so remove it.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index f6b1338730db5c17c479980682cafe001bbf9917..201b598558b9c89d3e3c2c6ff8a944f75aeeb8cb 100644 (file)
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -17,7 +17,6 @@ SUB_DIRS = alignment          \
           benchmarks           \
           cache_shape          \
           copyloops            \
-          context_switch       \
           dscr                 \
           mm                   \
           pmu                  \

diff --git a/tools/testing/selftests/powerpc/context_switch/.gitignore b/tools/testing/selftests/powerpc/context_switch/.gitignore
deleted file mode 100644 (file)
index c1431af..0000000
--- a/tools/testing/selftests/powerpc/context_switch/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-cp_abort

diff --git a/tools/testing/selftests/powerpc/context_switch/Makefile b/tools/testing/selftests/powerpc/context_switch/Makefile
deleted file mode 100644 (file)
index e9351bb..0000000
--- a/tools/testing/selftests/powerpc/context_switch/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-TEST_GEN_PROGS := cp_abort
-
-include ../../lib.mk
-
-$(TEST_GEN_PROGS): ../harness.c ../utils.c

diff --git a/tools/testing/selftests/powerpc/context_switch/cp_abort.c b/tools/testing/selftests/powerpc/context_switch/cp_abort.c
deleted file mode 100644 (file)
index 5a5b55a..0000000
--- a/tools/testing/selftests/powerpc/context_switch/cp_abort.c
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * Adapted from Anton Blanchard's context switch microbenchmark.
- *
- * Copyright 2009, Anton Blanchard, IBM Corporation.
- * Copyright 2016, Mikey Neuling, Chris Smart, IBM Corporation.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * This program tests the copy paste abort functionality of a P9
- * (or later) by setting up two processes on the same CPU, one
- * which executes the copy instruction and the other which
- * executes paste.
- *
- * The paste instruction should never succeed, as the cp_abort
- * instruction is called by the kernel during a context switch.
- *
- */
-
-#define _GNU_SOURCE
-
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include "utils.h"
-#include <sched.h>
-
-#define READ_FD 0
-#define WRITE_FD 1
-
-#define NUM_LOOPS 1000
-
-/* This defines the "paste" instruction from Power ISA 3.0 Book II, section 4.4. */
-#define PASTE(RA, RB, L, RC) \
-       .long (0x7c00070c | (RA) << (31-15) | (RB) << (31-20) | (L) << (31-10) | (RC) << (31-31))
-
-int paste(void *i)
-{
-       int cr;
-
-       asm volatile(str(PASTE(0, %1, 1, 1))";"
-                       "mfcr %0;"
-                       : "=r" (cr)
-                       : "b" (i)
-                       : "memory"
-                   );
-       return cr;
-}
-
-/* This defines the "copy" instruction from Power ISA 3.0 Book II, section 4.4. */
-#define COPY(RA, RB, L) \
-       .long (0x7c00060c | (RA) << (31-15) | (RB) << (31-20) | (L) << (31-10))
-
-void copy(void *i)
-{
-       asm volatile(str(COPY(0, %0, 1))";"
-                       :
-                       : "b" (i)
-                       : "memory"
-                   );
-}
-
-int test_cp_abort(void)
-{
-       /* 128 bytes for a full cache line */
-       char buf[128] __cacheline_aligned;
-       cpu_set_t cpuset;
-       int fd1[2], fd2[2], pid;
-       char c;
-
-       /* only run this test on a P9 or later */
-       SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
-
-       /*
-        * Run both processes on the same CPU, so that copy is more likely
-        * to leak into a paste.
-        */
-       CPU_ZERO(&cpuset);
-       CPU_SET(pick_online_cpu(), &cpuset);
-       FAIL_IF(sched_setaffinity(0, sizeof(cpuset), &cpuset));
-
-       FAIL_IF(pipe(fd1) || pipe(fd2));
-
-       pid = fork();
-       FAIL_IF(pid < 0);
-
-       if (!pid) {
-               for (int i = 0; i < NUM_LOOPS; i++) {
-                       FAIL_IF((write(fd1[WRITE_FD], &c, 1)) != 1);
-                       FAIL_IF((read(fd2[READ_FD], &c, 1)) != 1);
-                       /* A paste succeeds if CR0 EQ bit is set */
-                       FAIL_IF(paste(buf) & 0x20000000);
-               }
-       } else {
-               for (int i = 0; i < NUM_LOOPS; i++) {
-                       FAIL_IF((read(fd1[READ_FD], &c, 1)) != 1);
-                       copy(buf);
-                       FAIL_IF((write(fd2[WRITE_FD], &c, 1) != 1));
-               }
-       }
-       return 0;
-
-}
-
-int main(int argc, char *argv[])
-{
-       return test_harness(test_cp_abort, "cp_abort");
-}