main: Address by linux CPU number with PPC host backend

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@neuling.org>

1 files changed, 105 insertions, 2 deletions

diff --git a/src/main.c b/src/main.c
index 2b34820..fcdab67 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;
 }