If the transaction is aborted, the DSCR should be rolled back to the
checkpointed value before the transaction began.
Signed-off-by: Rashmica Gupta <rashm...@gmail.com>
---
To check this yourself, undo the changes from the patch "powerpc/tm: Fix
context switching TAR, PPR and DSCR SPRs".
tools/testing/selftests/powerpc/tm/.gitignore | 1 +
tools/testing/selftests/powerpc/tm/Makefile | 2 +-
tools/testing/selftests/powerpc/tm/tm-dscr.c | 91 +++++++++++++++++++++++++++
3 files changed, 93 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/tm/tm-dscr.c
diff --git a/tools/testing/selftests/powerpc/tm/.gitignore
b/tools/testing/selftests/powerpc/tm/.gitignore
index d0c7c97e9b13..76eae258feeb 100644
--- a/tools/testing/selftests/powerpc/tm/.gitignore
+++ b/tools/testing/selftests/powerpc/tm/.gitignore
@@ -3,3 +3,4 @@ tm-syscall
tm-signal-msr-resv
tm-signal-stack
tm-fork
+tm-dscr
diff --git a/tools/testing/selftests/powerpc/tm/Makefile
b/tools/testing/selftests/powerpc/tm/Makefile
index f7d4727662aa..59eec240339d 100644
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -1,4 +1,4 @@
-TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack
tm-fork
+TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack
tm-fork tm-dscr
all: $(TEST_PROGS)
diff --git a/tools/testing/selftests/powerpc/tm/tm-dscr.c
b/tools/testing/selftests/powerpc/tm/tm-dscr.c
new file mode 100644
index 000000000000..ac44e259c86d
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-dscr.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2015, Michael Neuling, IBM Corp.
+ * Licensed under GPLv2.
+ * Original: Michael Neuling 19/7/2013
+ * Edited: Rashmica Gupta 01/12/2015
+ *
+ * Do some transactions, see if the dscr is corrupted.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "tm.h"
+#include "utils.h"
+
+#define SPRN_DSCR 0x3
+
+int num_loops = 10000;
+
+int test_dscr(void)
+{
+ int i;
+
+ SKIP_IF(!have_htm());
+
+ for (i = 0; i < num_loops; i++)
+ {
+ uint64_t result = 0;
+ asm __volatile__(
+ "li 7, 1;"
+ "mtspr %[dscr], 7;" // dscr = 1
+ "tbegin.;"
+ "beq 3f ;"
+ "li 4, 0x7000;" // Loop lots, to use time
+ "2: ;" // Start loop
+ "li 7, 2;"
+ "mtspr %[dscr], 7;" // dscr = 2
+ "tsuspend.;"
+ "li 7, 3;"
+ "mtspr %[dscr], 7;" // dscr = 3
+ "tresume.;"
+ "subi 4, 4, 1;"
+ "cmpdi 4, 0;"
+ "bne 2b;"
+ "tend.;"
+
+ // Transaction sucess! DSCR should be 3.
+ "mfspr 7, %[dscr];"
+ "ori %[res], 7, 4;" // res = 3|4 = 7
+ "b 4f;"
+
+ // Abort handler. DSCR should be rolled back to 1.
+ "3:;"
+ "mfspr 7, %[dscr];"
+ "ori %[res], 7, 8;" // res = 1|8 = 9
+ "4:;"
+
+ : [res]"=r"(result)
+ : [dscr]"i"(SPRN_DSCR)
+ : "memory", "r0", "r4", "r7");
+
+ // If result is anything else other than 7 or 9, the dscr
+ // value must have been corrupted.
+ if ((result != 7) && (result != 9))
+ return 1;
+
+ }
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+
+ // A low number of iterations (eg 100) can cause a false pass.
+ if (argc > 1) {
+ if (strcmp(argv[1], "-h") == 0) {
+ printf("Syntax:\n\t%s [<num loops>]\n",
+ argv[0]);
+ return 0;
+ } else {
+ num_loops = atoi(argv[1]);
+ }
+ }
+
+ printf("Starting, %d loops\n", num_loops);
+
+ test_harness(test_dscr, "tm_dscr");
+}
--
2.5.0
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