Add a test to check if FP/VSX registers are sane (restored correctly) after
a VSX unavailable exception is caught in the middle of a transaction.

Signed-off-by: Gustavo Romero <grom...@linux.vnet.ibm.com>
Signed-off-by: Breno Leitao <lei...@debian.org>
---
 tools/testing/selftests/powerpc/tm/Makefile        |   3 +-
 .../testing/selftests/powerpc/tm/tm-vsx-unavail.c  | 144 +++++++++++++++++++++
 2 files changed, 146 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c

diff --git a/tools/testing/selftests/powerpc/tm/Makefile 
b/tools/testing/selftests/powerpc/tm/Makefile
index 958c11c..d0ffbb8 100644
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -2,7 +2,7 @@ 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 tm-vmx-unavail \
+       tm-vmxcopy tm-fork tm-tar tm-tmspr tm-vmx-unavail tm-vsx-unavail \
        $(SIGNAL_CONTEXT_CHK_TESTS)
 
 include ../../lib.mk
@@ -15,6 +15,7 @@ $(OUTPUT)/tm-syscall: tm-syscall-asm.S
 $(OUTPUT)/tm-syscall: CFLAGS += -I../../../../../usr/include
 $(OUTPUT)/tm-tmspr: CFLAGS += -pthread
 $(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64
+$(OUTPUT)/tm-vsx-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-vsx-unavail.c 
b/tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c
new file mode 100644
index 0000000..7ff933a
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2017, Gustavo Romero and Breno Leitao, IBM Corp.
+ * Licensed under GPLv2.
+ *
+ * Force VSX unavailable exception during a transaction and see
+ * if it corrupts the checkpointed FP registers state after the abort.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <sched.h>
+
+#include "tm.h"
+#include "utils.h"
+
+int passed;
+
+void *ping(void *not_used)
+{
+       asm goto(
+               // r3 = 0x5555555555555555
+               "lis  3, 0x5555    ;"
+               "ori  3, 3, 0x5555 ;"
+               "sldi 3, 3, 32     ;"
+               "oris 3, 3, 0x5555 ;"
+               "ori  3, 3, 0x5555 ;"
+
+               //r4 = 0xFFFFFFFFFFFFFFFF
+               "lis  4, 0xFFFF    ;"
+               "ori  4, 4, 0xFFFF ;"
+               "sldi 4, 4, 32     ;"
+               "oris 4, 4, 0xFFFF ;"
+               "ori  4, 4, 0xFFFF ;"
+
+               // vs33 and vs34 will just be used to construct vs0 from r3 and
+               // r4. Both won't be used in any other place after that.
+               "mtvsrd 33, 3      ;"
+               "mtvsrd 34, 4      ;"
+
+               // vs0 = (r3 || r4) = 0x5555555555555555FFFFFFFFFFFFFFFF
+               "xxmrghd 0, 33, 34 ;"
+
+
+               // Wait ~8s so we have a sufficient amount of context
+               // switches so load_fp and load_vec overflow and MSR.FP, MSR.VEC
+               // and MSR.VSX are disabled.
+               "       lis      7, 0x1       ;"
+               "       ori      7, 7, 0xBFFE ;"
+               "       sldi     7, 7, 15     ;"
+               "1:     addi     7, 7, -1     ;"
+               "       cmpdi    7, 0         ;"
+               "       bne      1b           ;"
+
+               // Any floating-point instruction in here.
+               // N.B. 'fmr' is *not touching* any previously set register,
+               // i.e. it's not touching vs0.
+               "fmr    10, 10     ;"
+
+               // vs0 is *still* 0x5555555555555555FFFFFFFFFFFFFFFF, right?
+               // Get in a transaction and cause a VSX unavailable exception.
+               "2:     tbegin.               ;" // Begin HTM
+               "       beq      3f           ;" // Failure handler
+               "       xxmrghd  10, 10, 10   ;" // VSX unavailable in TM
+               "       tend.                 ;" // End HTM
+               "3:     nop                   ;" // Fall through to code below
+
+               // Immediately after a transaction failure we save vs0 to two
+               // general purpose registers to check its value. We need to have
+               // the same value as before we entered in transactional state.
+
+               // vs0 should be *still* 0x5555555555555555FFFFFFFFFFFFFFFF
+
+               // Save high half - MSB (64bit).
+               "mfvsrd  5, 0                 ;"
+
+               // Save low half - LSB (64bit).
+               // We mess with vs3, but it's not important.
+               "xxsldwi 3, 0, 0, 2           ;"
+               "mfvsrd  6, 3                 ;"
+
+               // N.B. r3 and r4 never changed since they were used to
+               // construct the initial vs0 value, hence we can use them to do
+               // the comparison. r3 and r4 will be destroy but it's ok.
+               "cmpd  3, 5                ;" // compare r3 to r5
+               "bne   %[value_mismatch]      ;"
+               "cmpd  4, 6                ;" // compare r4 to r6
+               "bne   %[value_mismatch]      ;"
+               "b     %[value_ok]            ;"
+               :
+               :
+               : "r3", "r4", "vs33", "vs34", "vs0",
+                 "vs10", "fr10", "r7", "r5", "r6", "vs3"
+               : value_mismatch, value_ok
+               );
+value_mismatch:
+               passed = 0;
+               return NULL;
+value_ok:
+               passed = 1;
+               return NULL;
+}
+
+void *pong(void *not_used)
+{
+       while (1)
+               sched_yield(); // will be classed as interactive-like thread
+}
+
+int tm_vsx_unavail_test(void)
+{
+       pthread_t t0, t1;
+       pthread_attr_t attr;
+       cpu_set_t cpuset;
+
+       // Set only CPU 0 in the mask. Both threads will be bound to cpu 0
+       CPU_ZERO(&cpuset);
+       CPU_SET(0, &cpuset);
+
+       // Init pthread attribute
+       pthread_attr_init(&attr);
+
+       // Set CPU 0 mask into the pthread attribute
+       pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
+
+       // 'pong' thread used to induce context switches on 'ping' thread
+       pthread_create(&t1, &attr /* bound to cpu 0 */, pong, NULL);
+
+       printf("Checking if FP/VSX is sane after a VSX exception in TM...\n");
+
+       pthread_create(&t0, &attr /* bound to cpu 0 as well */, ping, NULL);
+       pthread_join(t0, NULL);
+
+       return passed ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+int main(int argc, char **argv)
+{
+       return test_harness(tm_vsx_unavail_test, "tm_vsx_unavail_test");
+}
-- 
2.7.4

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