[Pdbg] [PATCH v4 2/2] main: Address by linux CPU number with PPC host backend

[Alistair Popple]

Looks good. Thanks!

On Wednesday, 18 July 2018 3:59:48 PM AEST Michael Neuling wrote:
> With the PPC host backend used for HTM it's difficult to match up the
> hardware numbers used pdbg with linux CPU numbers that people want to
> affinitise a workload against (ie. taskset -c <cpu number>).
> 
> This adds a new "-l <cpu>" options so users can address the CPU to
> target using linux CPU numbers. This is only available when using the
> host backend on POWER machines.
> 
> Signed-off-by: Michael Neuling <mikey at neuling.org>
> ---
> v4:
>   Add check for mixing -l with -p/-c/-l/-a
> 
> v3:
>   Fix l_list size
> 
> v2:
>   Fix POWER9
>   rebase on upstream
>   Reduce #ifdef ugliness
> ---
>  src/main.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 105 insertions(+), 2 deletions(-)
> 
> diff --git a/src/main.c b/src/main.c
> index 2b348208fb..fcdab672fa 100644
> --- a/src/main.c
> +++ b/src/main.c
> @@ -139,6 +139,9 @@ static void print_usage(char *pname)
>  	printf("\t-p, --processor=<0-%d>|<range>|<list>\n", MAX_PROCESSORS-1);
>  	printf("\t-c, --chip=<0-%d>|<range>|<list>\n", MAX_CHIPS-1);
>  	printf("\t-t, --thread=<0-%d>|<range>|<list>\n", MAX_THREADS-1);
> +#ifdef TARGET_PPC
> +	printf("\t-l, --cpu=<0-%d>|<range>|<list>\n", MAX_PROCESSORS-1);
> +#endif
>  	printf("\t-a, --all\n");
>  	printf("\t\tRun command on all possible processors/chips/threads (default)\n");
>  	printf("\t-b, --backend=backend\n");
> @@ -242,6 +245,68 @@ static bool parse_list(const char *arg, int max, int *list, int *count)
>  	return true;
>  }
>  
> +#ifdef TARGET_PPC
> +int get_pir(int linux_cpu)
> +{
> +	char *filename;
> +	FILE *file;
> +	int pir = -1;
> +
> +	if(asprintf(&filename, "/sys/devices/system/cpu/cpu%i/pir",
> +		    linux_cpu) < 0)
> +		return -1;
> +
> +	file = fopen(filename, "r");
> +	if (!file) {
> +		PR_ERROR("Invalid Linux CPU number %" PRIi32 "\n", linux_cpu);
> +		goto out2;
> +	}
> +
> +	if(fscanf(file, "%" PRIx32 "\n", &pir) != 1) {
> +		PR_ERROR("fscanf() didn't match: %m\n");
> +		pir = -1;
> +		goto out1;
> +	}
> +
> +out1:
> +	fclose(file);
> +out2:
> +	free(filename);
> +	return pir;
> +}
> +
> +/* Stolen from skiboot */
> +#define P9_PIR2GCID(pir) (((pir) >> 8) & 0x7f)
> +#define P9_PIR2COREID(pir) (((pir) >> 2) & 0x3f)
> +#define P9_PIR2THREADID(pir) ((pir) & 0x3)
> +#define P8_PIR2GCID(pir) (((pir) >> 7) & 0x3f)
> +#define P8_PIR2COREID(pir) (((pir) >> 3) & 0xf)
> +#define P8_PIR2THREADID(pir) ((pir) & 0x7)
> +
> +void pir_map(int pir, int *chip, int *core, int *thread)
> +{
> +	assert(chip && core && thread);
> +
> +	if (!strncmp(device_node, "p9", 2)) {
> +		*chip = P9_PIR2GCID(pir);
> +		*core = P9_PIR2COREID(pir);
> +		*thread = P9_PIR2THREADID(pir);
> +	} else if (!strncmp(device_node, "p8", 2)) {
> +		*chip = P8_PIR2GCID(pir);
> +		*core = P8_PIR2COREID(pir);
> +		*thread = P8_PIR2THREADID(pir);
> +	} else
> +		assert(0);
> +
> +}
> +
> +#define PPC_OPTS "l:"
> +#else
> +int get_pir(int linux_cpu) { return -1; }
> +void pir_map(int pir, int *chip, int *core, int *thread) {}
> +#define PPC_OPTS
> +#endif
> +
>  static bool parse_options(int argc, char *argv[])
>  {
>  	int c;
> @@ -249,7 +314,8 @@ static bool parse_options(int argc, char *argv[])
>  	int p_list[MAX_PROCESSORS];
>  	int c_list[MAX_CHIPS];
>  	int t_list[MAX_THREADS];
> -	int p_count = 0, c_count = 0, t_count = 0;
> +	int l_list[MAX_PROCESSORS * MAX_THREADS * MAX_CHIPS];
> +	int p_count = 0, c_count = 0, t_count = 0, l_count = 0;
>  	int i, j, k;
>  	struct option long_opts[] = {
>  		{"all",			no_argument,		NULL,	'a'},
> @@ -260,6 +326,9 @@ static bool parse_options(int argc, char *argv[])
>  		{"processor",		required_argument,	NULL,	'p'},
>  		{"slave-address",	required_argument,	NULL,	's'},
>  		{"thread",		required_argument,	NULL,	't'},
> +#ifdef TARGET_PPC
> +		{"cpu",			required_argument,	NULL,	'l'},
> +#endif
>  		{"debug",		required_argument,	NULL,	'D'},
>  		{"version",		no_argument,		NULL,	'V'},
>  		{NULL,			0,			NULL,     0}
> @@ -269,9 +338,11 @@ static bool parse_options(int argc, char *argv[])
>  	memset(p_list, 0, sizeof(p_list));
>  	memset(c_list, 0, sizeof(c_list));
>  	memset(t_list, 0, sizeof(t_list));
> +	memset(l_list, 0, sizeof(l_list));
>  
>  	do {
> -		c = getopt_long(argc, argv, "+ab:c:d:hp:s:t:D:V", long_opts, NULL);
> +		c = getopt_long(argc, argv, "+ab:c:d:hp:s:t:D:V" PPC_OPTS,
> +				long_opts, NULL);
>  		if (c == -1)
>  			break;
>  
> @@ -317,6 +388,13 @@ static bool parse_options(int argc, char *argv[])
>  			}
>  			break;
>  
> +		case 'l':
> +			if (!parse_list(optarg, MAX_PROCESSORS, l_list, &l_count)) {
> +				fprintf(stderr, "Failed to parse '-l %s'\n", optarg);
> +				opt_error = true;
> +			}
> +			break;
> +
>  		case 'b':
>  			if (strcmp(optarg, "fsi") == 0) {
>  				backend = FSI;
> @@ -370,6 +448,11 @@ static bool parse_options(int argc, char *argv[])
>  		return false;
>  	}
>  
> +	if ((c_count > 0 || t_count > 0 || p_count > 0) && (l_count > 0)) {
> +		fprintf(stderr, "Can't mix -l with -p/-c/-t/-a\n");
> +		return false;
> +	}
> +
>  	if ((c_count > 0 || t_count > 0) && p_count == 0) {
>  		fprintf(stderr, "No processor(s) selected\n");
>  		fprintf(stderr, "Use -p or -a to select processor(s)\n");
> @@ -403,6 +486,26 @@ static bool parse_options(int argc, char *argv[])
>  		}
>  	}
>  
> +	if (l_count) {
> +		int pir = -1, i, chip, core, thread;
> +
> +		for (i = 0; i < MAX_PROCESSORS; i++) {
> +			if (l_list[i] == 1) {
> +				pir = get_pir(i);
> +				if (pir < 0)
> +					return true;
> +				break;
> +			}
> +		}
> +		if (pir < 0)
> +			return true;
> +
> +		pir_map(pir, &chip, &core, &thread);
> +
> +		threadsel[chip][core][thread] = 1;
> +		chipsel[chip][core] = &threadsel[chip][core][thread];
> +		processorsel[chip] = &chipsel[chip][core];
> +	}
>  	return true;
>  }
>  
>