[PATCH 1/2] selftests/powerpc: Allow choice of CI memory location in alignment_handler test

Alistair Popple alistair at popple.id.au
Wed Jun 17 16:31:14 AEST 2020


I've tested these on Mambo and they pass so:

Tested-by: Alistair Popple <alistair at popple.id.au>

On Wednesday, 20 May 2020 12:11:02 PM AEST Jordan Niethe wrote:
> The alignment handler selftest needs cache-inhibited memory and
> currently /dev/fb0 is relied on to provided this. This prevents running
> the test on systems without /dev/fb0 (e.g., mambo). Read the commandline
> arguments for an optional path to be used instead, as well as an
> optional offset to be for mmaping this path.
> 
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
>  .../powerpc/alignment/alignment_handler.c     | 63 ++++++++++++-------
>  1 file changed, 42 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/testing/selftests/powerpc/alignment/alignment_handler.c b/tools/testing/selftests/powerpc/alignment/alignment_handler.c
> index 0453c50c949c..eb6aba323f8b 100644
> --- a/tools/testing/selftests/powerpc/alignment/alignment_handler.c
> +++ b/tools/testing/selftests/powerpc/alignment/alignment_handler.c
> @@ -9,7 +9,17 @@
>   * This selftest exercises the powerpc alignment fault handler.
>   *
>   * We create two sets of source and destination buffers, one in regular memory,
> - * the other cache-inhibited (we use /dev/fb0 for this).
> + * the other cache-inhibited (by default we use /dev/fb0 for this, but an
> + * alterative path for cache-inhibited memory may be provided).
> + *
> + * One way to get cache-inhibited memory is to use the "mem" kernel parameter
> + * to limit the kernel to less memory than actually exists.  Addresses above
> + * the limit may still be accessed but will be treated as cache-inhibited. For
> + * example, if there is actually 4GB of memory and the parameter "mem=3GB" is
> + * used, memory from address 0xC0000000 onwards is treated as cache-inhibited.
> + * To access this region /dev/mem is used. The kernel should be configured
> + * without CONFIG_STRICT_DEVMEM. In this case use:
> + *         ./alignment_handler /dev/mem 0xc0000000
>   *
>   * We initialise the source buffers, then use whichever set of load/store
>   * instructions is under test to copy bytes from the source buffers to the
> @@ -53,6 +63,8 @@ int bufsize;
>  int debug;
>  int testing;
>  volatile int gotsig;
> +char *cipath = "/dev/fb0";
> +long cioffset;
>  
>  void sighandler(int sig, siginfo_t *info, void *ctx)
>  {
> @@ -195,17 +207,18 @@ int do_test(char *test_name, void (*test_func)(char *, char *))
>  
>  	printf("\tDoing %s:\t", test_name);
>  
> -	fd = open("/dev/fb0", O_RDWR);
> +	fd = open(cipath, O_RDWR);
>  	if (fd < 0) {
>  		printf("\n");
> -		perror("Can't open /dev/fb0 now?");
> +		perror("Can't open ci file now?");
>  		return 1;
>  	}
>  
> -	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
> -		   fd, 0x0);
> -	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
> -		   fd, bufsize);
> +	ci0 = mmap(NULL, bufsize, PROT_WRITE | PROT_READ, MAP_SHARED,
> +		   fd, cioffset);
> +	ci1 = mmap(NULL, bufsize, PROT_WRITE | PROT_READ, MAP_SHARED,
> +		   fd, cioffset + bufsize);
> +
>  	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
>  		printf("\n");
>  		perror("mmap failed");
> @@ -270,11 +283,11 @@ int do_test(char *test_name, void (*test_func)(char *, char *))
>  	return rc;
>  }
>  
> -static bool can_open_fb0(void)
> +static bool can_open_cifile(void)
>  {
>  	int fd;
>  
> -	fd = open("/dev/fb0", O_RDWR);
> +	fd = open(cipath, O_RDWR);
>  	if (fd < 0)
>  		return false;
>  
> @@ -286,7 +299,7 @@ int test_alignment_handler_vsx_206(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
>  
>  	printf("VSX: 2.06B\n");
> @@ -304,7 +317,7 @@ int test_alignment_handler_vsx_207(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
>  
>  	printf("VSX: 2.07B\n");
> @@ -320,7 +333,7 @@ int test_alignment_handler_vsx_300(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  
>  	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
>  	printf("VSX: 3.00B\n");
> @@ -352,7 +365,7 @@ int test_alignment_handler_integer(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  
>  	printf("Integer\n");
>  	LOAD_DFORM_TEST(lbz);
> @@ -408,7 +421,7 @@ int test_alignment_handler_integer_206(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
>  
>  	printf("Integer: 2.06\n");
> @@ -423,7 +436,7 @@ int test_alignment_handler_vmx(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC));
>  
>  	printf("VMX\n");
> @@ -451,7 +464,7 @@ int test_alignment_handler_fp(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  
>  	printf("Floating point\n");
>  	LOAD_FLOAT_DFORM_TEST(lfd);
> @@ -479,7 +492,7 @@ int test_alignment_handler_fp_205(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_05));
>  
>  	printf("Floating point: 2.05\n");
> @@ -497,7 +510,7 @@ int test_alignment_handler_fp_206(void)
>  {
>  	int rc = 0;
>  
> -	SKIP_IF(!can_open_fb0());
> +	SKIP_IF(!can_open_cifile());
>  	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
>  
>  	printf("Floating point: 2.06\n");
> @@ -509,11 +522,12 @@ int test_alignment_handler_fp_206(void)
>  
>  void usage(char *prog)
>  {
> -	printf("Usage: %s [options]\n", prog);
> +	printf("Usage: %s [options] [path [offset]]\n", prog);
>  	printf("  -d	Enable debug error output\n");
>  	printf("\n");
> -	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
> -	printf("framebuffer at /dev/fb0.\n");
> +	printf("This test requires a POWER8 or POWER9 CPU and either a ");
> +	printf("usable framebuffer at /dev/fb0 or the path to usable ");
> +	printf("cache-inhibited memory and optional offset to be provided\n");
>  }
>  
>  int main(int argc, char *argv[])
> @@ -533,6 +547,13 @@ int main(int argc, char *argv[])
>  			exit(1);
>  		}
>  	}
> +	argc -= optind;
> +	argv += optind;
> +
> +	if (argc > 0)
> +		cipath = argv[0];
> +	if (argc > 1)
> +		cioffset = strtol(argv[1], 0, 0x10);
>  
>  	bufsize = getpagesize();
>  
> 






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