tools/arch/x86/intel_sdsi: Add current meter support

Add support to read the 'meter_current' file. The display is the same as
the 'meter_certificate', but will show the current snapshot of the
counters.

Signed-off-by: David E. Box <[e-mail]>
Reviewed-by: Kuppuswamy Sathyanarayanan <[e-mail]>
Reviewed-by: Ilpo Järvinen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Hans de Goede <[e-mail]>

tools/arch/x86/intel_sdsi/intel_sdsi.c

···
 enum command {
 	CMD_SOCKET_INFO,
 	CMD_METER_CERT,
+	CMD_METER_CURRENT_CERT,
 	CMD_STATE_CERT,
 	CMD_PROV_AKC,
 	CMD_PROV_CAP,
···
 	feature[0] = name[3];
 }
 
-static int sdsi_meter_cert_show(struct sdsi_dev *s)
+static int sdsi_meter_cert_show(struct sdsi_dev *s, bool show_current)
 {
 	char buf[METER_CERT_MAX_SIZE] = {0};
 	struct bundle_encoding_counter *bec;
 	struct meter_certificate *mc;
 	uint32_t count = 0;
 	FILE *cert_ptr;
+	char *cert_fname;
 	int ret, size;
 	char name[FEAT_LEN];
 
···
 
 	if (!s->regs.en_features.sdsi) {
 		fprintf(stderr, "SDSi feature is present but not enabled.\n");
-		fprintf(stderr, " Unable to read meter certificate\n");
 		return -1;
 	}
 
···
 		return ret;
 	}
 
-	cert_ptr = fopen("meter_certificate", "r");
+	cert_fname = show_current ? "meter_current" : "meter_certificate";
+	cert_ptr = fopen(cert_fname, "r");
+
 	if (!cert_ptr) {
-		perror("Could not open 'meter_certificate' file");
+		fprintf(stderr, "Could not open '%s' file: %s", cert_fname, strerror(errno));
 		return -1;
 	}
 
 	size = fread(buf, 1, sizeof(buf), cert_ptr);
 	if (!size) {
-		fprintf(stderr, "Could not read 'meter_certificate' file\n");
+		fprintf(stderr, "Could not read '%s' file\n", cert_fname);
 		fclose(cert_ptr);
 		return -1;
 	}
···
 
 static void usage(char *prog)
 {
-	printf("Usage: %s [-l] [-d DEVNO [-i] [-s] [-m] [-a FILE] [-c FILE]]\n", prog);
+	printf("Usage: %s [-l] [-d DEVNO [-i] [-s] [-m | -C] [-a FILE] [-c FILE]\n", prog);
 }
 
 static void show_help(void)
···
 	printf("  %-18s\t%s\n", "-l, --list",           "list available On Demand devices");
 	printf("  %-18s\t%s\n", "-d, --devno DEVNO",    "On Demand device number");
 	printf("  %-18s\t%s\n", "-i, --info",           "show socket information");
-	printf("  %-18s\t%s\n", "-s, --state",          "show state certificate");
-	printf("  %-18s\t%s\n", "-m, --meter",          "show meter certificate");
+	printf("  %-18s\t%s\n", "-s, --state",          "show state certificate data");
+	printf("  %-18s\t%s\n", "-m, --meter",          "show meter certificate data");
+	printf("  %-18s\t%s\n", "-C, --meter_current",  "show live unattested meter data");
 	printf("  %-18s\t%s\n", "-a, --akc FILE",       "provision socket with AKC FILE");
 	printf("  %-18s\t%s\n", "-c, --cap FILE>",      "provision socket with CAP FILE");
 }
···
 	int option_index = 0;
 
 	static struct option long_options[] = {
-		{"akc",		required_argument,	0, 'a'},
-		{"cap",		required_argument,	0, 'c'},
-		{"devno",	required_argument,	0, 'd'},
-		{"help",	no_argument,		0, 'h'},
-		{"info",	no_argument,		0, 'i'},
-		{"list",	no_argument,		0, 'l'},
-		{"meter",	no_argument,		0, 'm'},
-		{"state",	no_argument,		0, 's'},
-		{0,		0,			0, 0 }
+		{"akc",			required_argument,	0, 'a'},
+		{"cap",			required_argument,	0, 'c'},
+		{"devno",		required_argument,	0, 'd'},
+		{"help",		no_argument,		0, 'h'},
+		{"info",		no_argument,		0, 'i'},
+		{"list",		no_argument,		0, 'l'},
+		{"meter",		no_argument,		0, 'm'},
+		{"meter_current",	no_argument,		0, 'C'},
+		{"state",		no_argument,		0, 's'},
+		{0,			0,			0, 0 }
 	};
 
 
 	progname = argv[0];
 
-	while ((opt = getopt_long_only(argc, argv, "+a:c:d:hilms", long_options,
+	while ((opt = getopt_long_only(argc, argv, "+a:c:d:hilmCs", long_options,
 			&option_index)) != -1) {
 		switch (opt) {
 		case 'd':
···
 			break;
 		case 'm':
 			command = CMD_METER_CERT;
+			break;
+		case 'C':
+			command = CMD_METER_CURRENT_CERT;
 			break;
 		case 's':
 			command = CMD_STATE_CERT;
···
 			ret = sdsi_read_reg(s);
 			break;
 		case CMD_METER_CERT:
-			ret = sdsi_meter_cert_show(s);
+			ret = sdsi_meter_cert_show(s, false);
+			break;
+		case CMD_METER_CURRENT_CERT:
+			ret = sdsi_meter_cert_show(s, true);
 			break;
 		case CMD_STATE_CERT:
 			ret = sdsi_state_cert_show(s);