selftests/powerpc: Test TM and VMX register state

Test that the VMX checkpointed register state is maintained when a VMX
unavailable exception is taken during a transaction.

Thanks to Breno Leitao <brenohl@br.ibm.com> and
Gustavo Bueno Romero <gromero@br.ibm.com> for the original test this
is based heavily on.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Add to .gitignore, always build it 64-bit to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 122 insertions, 1 deletions

diff --git a/tools/testing/selftests/powerpc/tm/.gitignore b/tools/testing/selftests/powerpc/tm/.gitignore
index 427621792229..2f1f7b013293 100644
--- a/tools/testing/selftests/powerpc/tm/.gitignore
+++ b/tools/testing/selftests/powerpc/tm/.gitignore
@@ -11,3 +11,4 @@ tm-signal-context-chk-fpu
 tm-signal-context-chk-gpr
 tm-signal-context-chk-vmx
 tm-signal-context-chk-vsx
+tm-vmx-unavail
diff --git a/tools/testing/selftests/powerpc/tm/Makefile b/tools/testing/selftests/powerpc/tm/Makefile
index 5576ee6a51f2..958c11c14acd 100644
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -2,7 +2,8 @@ SIGNAL_CONTEXT_CHK_TESTS := tm-signal-context-chk-gpr tm-signal-context-chk-fpu
         tm-signal-context-chk-vmx tm-signal-context-chk-vsx
 
 TEST_GEN_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack \
-        tm-vmxcopy tm-fork tm-tar tm-tmspr $(SIGNAL_CONTEXT_CHK_TESTS)
+        tm-vmxcopy tm-fork tm-tar tm-tmspr tm-vmx-unavail \
+        $(SIGNAL_CONTEXT_CHK_TESTS)
 
 include ../../lib.mk
 
@@ -13,6 +14,7 @@ CFLAGS += -mhtm
 $(OUTPUT)/tm-syscall: tm-syscall-asm.S
 $(OUTPUT)/tm-syscall: CFLAGS += -I../../../../../usr/include
 $(OUTPUT)/tm-tmspr: CFLAGS += -pthread
+$(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64
 
 SIGNAL_CONTEXT_CHK_TESTS := $(patsubst %,$(OUTPUT)/%,$(SIGNAL_CONTEXT_CHK_TESTS))
 $(SIGNAL_CONTEXT_CHK_TESTS): tm-signal.S
diff --git a/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c b/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c
new file mode 100644
index 000000000000..137185ba4937
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-vmx-unavail.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2017, Michael Neuling, IBM Corp.
+ * Licensed under GPLv2.
+ * Original: Breno Leitao <brenohl@br.ibm.com> &
+ *           Gustavo Bueno Romero <gromero@br.ibm.com>
+ * Edited: Michael Neuling
+ *
+ * Force VMX unavailable during a transaction and see if it corrupts
+ * the checkpointed VMX register state after the abort.
+ */
+
+#include <inttypes.h>
+#include <htmintrin.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <pthread.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include "tm.h"
+#include "utils.h"
+
+int passed;
+
+void *worker(void *unused)
+{
+        __int128 vmx0;
+        uint64_t texasr;
+
+        asm goto (
+                "li       3, 1;"  /* Stick non-zero value in VMX0 */
+                "std      3, 0(%[vmx0_ptr]);"
+                "lvx      0, 0, %[vmx0_ptr];"
+
+                /* Wait here a bit so we get scheduled out 255 times */
+                "lis      3, 0x3fff;"
+                "1: ;"
+                "addi     3, 3, -1;"
+                "cmpdi    3, 0;"
+                "bne      1b;"
+
+                /* Kernel will hopefully turn VMX off now */
+
+                "tbegin. ;"
+                "beq      failure;"
+
+                /* Cause VMX unavail. Any VMX instruction */
+                "vaddcuw  0,0,0;"
+
+                "tend. ;"
+                "b        %l[success];"
+
+                /* Check VMX0 sanity after abort */
+                "failure: ;"
+                "lvx       1,  0, %[vmx0_ptr];"
+                "vcmpequb. 2,  0, 1;"
+                "bc        4, 24, %l[value_mismatch];"
+                "b        %l[value_match];"
+                :
+                : [vmx0_ptr] "r"(&vmx0)
+                : "r3"
+                : success, value_match, value_mismatch
+                );
+
+        /* HTM aborted and VMX0 is corrupted */
+value_mismatch:
+        texasr = __builtin_get_texasr();
+
+        printf("\n\n==============\n\n");
+        printf("Failure with error: %lx\n",   _TEXASR_FAILURE_CODE(texasr));
+        printf("Summary error     : %lx\n",   _TEXASR_FAILURE_SUMMARY(texasr));
+        printf("TFIAR exact       : %lx\n\n", _TEXASR_TFIAR_EXACT(texasr));
+
+        passed = 0;
+        return NULL;
+
+        /* HTM aborted but VMX0 is correct */
+value_match:
+//      printf("!");
+        return NULL;
+
+success:
+//      printf(".");
+        return NULL;
+}
+
+int tm_vmx_unavail_test()
+{
+        int threads;
+        pthread_t *thread;
+
+        SKIP_IF(!have_htm());
+
+        passed = 1;
+
+        threads = sysconf(_SC_NPROCESSORS_ONLN) * 4;
+        thread = malloc(sizeof(pthread_t)*threads);
+        if (!thread)
+                return EXIT_FAILURE;
+
+        for (uint64_t i = 0; i < threads; i++)
+                pthread_create(&thread[i], NULL, &worker, NULL);
+
+        for (uint64_t i = 0; i < threads; i++)
+                pthread_join(thread[i], NULL);
+
+        free(thread);
+
+        return passed ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+
+int main(int argc, char **argv)
+{
+        return test_harness(tm_vmx_unavail_test, "tm_vmx_unavail_test");
+}