[v2] selftests/powerpc: Add test to check is DSCR is corrupted.

[Denis Kirjanov]

On 12/2/15, Rashmica Gupta <rashmicy at gmail.com> wrote:
> If the transaction is aborted, the DSCR should be rolled back to the
> checkpointed value before the transaction began. The value written to the
> DSCR when transaction was suspended should only persist if the transaction
> is successful.
>
> Signed-off-by: Rashmica Gupta <rashmicy at gmail.com>
> ---
> No functional changes. Fixed whitespace and styling issues.
>
>  tools/testing/selftests/powerpc/tm/.gitignore |  1 +
>  tools/testing/selftests/powerpc/tm/Makefile   |  2 +-
>  tools/testing/selftests/powerpc/tm/tm-dscr.c  | 95
> +++++++++++++++++++++++++++
>  3 files changed, 97 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..b18360895496
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/tm/tm-dscr.c
> @@ -0,0 +1,95 @@
> +/*
> + * 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.
> + * If the transaction is aborted, the DSCR should be rolled back to the
> + * checkpointed value before the transaction began. The value set to DSCR
> + * while the transaction was suspended should only remain there if the
> + * transaction succeeds.
> + *
> + */
> +
> +#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;
return 1?
> +		} else {
> +			num_loops = atoi(argv[1]);
> +		}
> +	}
> +
> +	printf("Starting, %d loops\n", num_loops);
> +
> +	test_harness(test_dscr, "tm_dscr");
return test_harness(test_dscr, "tm_dscr");
> +}
> --
> 2.5.0
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev