selftests/powerpc: Add TM test to check if TAR is corrupted

tm-signal-stack

tm-vmxcopy

tm-fork

tm-tar

TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack tm-vmxcopy tm-fork

TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack tm-vmxcopy tm-fork tm-tar

all: $(TEST_PROGS)

/*

 * 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 tar is corrupted.

 * If the transaction is aborted, the TAR should be rolled back to the

 * checkpointed value before the transaction began. The value written to

 * TAR in suspended mode should only remain in TAR if the transaction

 * completes.

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include "tm.h"

#include "utils.h"

int	num_loops	= 10000;

int test_tar(void)

{

	int i;

	SKIP_IF(!have_htm());

	for (i = 0; i < num_loops; i++)

	{

		uint64_t result = 0;

		asm __volatile__(

			"li	7, 1;"

			"mtspr	%[tar], 7;"	/* tar = 1 */

			"tbegin.;"

			"beq	3f;"

			"li	4, 0x7000;"	/* Loop lots, to use time */

			"2:;"			/* Start loop */

			"li	7, 2;"

			"mtspr	%[tar], 7;"	/* tar = 2 */

			"tsuspend.;"

			"li	7, 3;"

			"mtspr	%[tar], 7;"	/* tar = 3 */

			"tresume.;"

			"subi	4, 4, 1;"

			"cmpdi	4, 0;"

			"bne	2b;"

			"tend.;"

			/* Transaction sucess! TAR should be 3 */

			"mfspr  7, %[tar];"

			"ori	%[res], 7, 4;"  // res = 3|4 = 7

			"b	4f;"

			/* Abort handler. TAR should be rolled back to 1 */

			"3:;"

			"mfspr  7, %[tar];"

			"ori	%[res], 7, 8;"	// res = 1|8 = 9

			"4:;"

			: [res]"=r"(result)

			: [tar]"i"(SPRN_TAR)

			   : "memory", "r0", "r4", "r7");

		/* If result is anything else other than 7 or 9, the tar

		 * 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 1;

		} else {

			num_loops = atoi(argv[1]);

		}

	}

	printf("Starting, %d loops\n", num_loops);

	return test_harness(test_tar, "tm_tar");

}