cpupower: Add "perf" option to print AMD P-State information

Add "-c --perf" option in cpupower-frequency-info to get the performance
and frequency values for AMD P-State.

Commit message amended:
Shuah Khan <[e-mail]>

Reviewed-by: Shuah Khan <[e-mail]>
Signed-off-by: Huang Rui <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/power/cpupower/man/cpupower-frequency-info.1

···
 \fB\-n\fR \fB\-\-no-rounding\fR
 Output frequencies and latencies without rounding off values.
 .TP  
+\fB\-c\fR \fB\-\-perf\fR
+Get performances and frequencies capabilities of CPPC, by reading it from hardware (only available on the hardware with CPPC).
+.TP
 .SH "REMARKS"
 .LP 
 By default only values of core zero are displayed. How to display settings of

tools/power/cpupower/utils/cpufreq-info.c

···
 	return 0;
 }
 
+/* --performance / -c */
+
+static int get_perf_cap(unsigned int cpu)
+{
+	if (cpupower_cpu_info.vendor == X86_VENDOR_AMD &&
+	    cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_PSTATE)
+		amd_pstate_show_perf_and_freq(cpu, no_rounding);
+
+	return 0;
+}
+
 static void debug_output_one(unsigned int cpu)
 {
 	struct cpufreq_available_frequencies *freqs;
···
 	if (get_freq_hardware(cpu, 1) < 0)
 		get_freq_kernel(cpu, 1);
 	get_boost_mode(cpu);
+	get_perf_cap(cpu);
 }
 
 static struct option info_opts[] = {
···
 	{"proc",	 no_argument,		 NULL,	 'o'},
 	{"human",	 no_argument,		 NULL,	 'm'},
 	{"no-rounding", no_argument,	 NULL,	 'n'},
+	{"performance", no_argument,	 NULL,	 'c'},
 	{ },
 };
 
···
 	int output_param = 0;
 
 	do {
-		ret = getopt_long(argc, argv, "oefwldpgrasmybn", info_opts,
+		ret = getopt_long(argc, argv, "oefwldpgrasmybnc", info_opts,
 				  NULL);
 		switch (ret) {
 		case '?':
···
 		case 'e':
 		case 's':
 		case 'y':
+		case 'c':
 			if (output_param) {
 				output_param = -1;
 				cont = 0;
···
 			break;
 		case 'y':
 			ret = get_latency(cpu, human);
+			break;
+		case 'c':
+			ret = get_perf_cap(cpu);
 			break;
 		}
 		if (ret)