[PATCH] cpufreq: Add test cases to validate the frequency and pstate table

[Shilpasri G Bhat]

Add test case to parse CPU frequency and pstate table to check for
invalid entries that are beyond the specified minimum and maximum
limits.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
---
 src/cpu/cpufreq/cpufreq.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)

diff --git a/src/cpu/cpufreq/cpufreq.c b/src/cpu/cpufreq/cpufreq.c
index 8ab5292..1a9c9fd 100644
--- a/src/cpu/cpufreq/cpufreq.c
+++ b/src/cpu/cpufreq/cpufreq.c
@@ -30,6 +30,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <dirent.h>
 #include <stdint.h>
@@ -393,6 +394,142 @@ static int cpufreq_test_cpu_performance(fwts_framework *fw)
 	return FWTS_OK;
 }
 
+static int cpufreq_test_frequency_limits(fwts_framework *fw)
+{
+	char path[PATH_MAX];
+	int min, max, i;
+	bool ok = true;
+
+	cpu_mkpath(path, sizeof(path), &cpus[0], "cpuinfo_min_freq");
+	if (fwts_get_int(path, &min) != FWTS_OK) {
+		fwts_log_warning(fw, "Failed to read the minimum CPU frequency %s",
+				 path);
+		return FWTS_ERROR;
+	}
+
+	cpu_mkpath(path, sizeof(path), &cpus[0], "cpuinfo_max_freq");
+	if (fwts_get_int(path, &max) != FWTS_OK) {
+		fwts_log_warning(fw, "Failed to read the maximum CPU frequency %s",
+				 path);
+		return FWTS_ERROR;
+	}
+
+	for (i = 0; i < cpus[0].n_freqs; i++) {
+		if (cpus[0].freqs[i].Hz > (uint64_t)max) {
+			fwts_log_warning(fw, "%s is greater than max frequency %s",
+					 hz_to_human(cpus[0].freqs[i].Hz),
+					 hz_to_human(max));
+			ok = false;
+		}
+		if (cpus[0].freqs[i].Hz < (uint64_t)min) {
+			fwts_log_warning(fw, "%s is lesser than min frequency %s",
+					 hz_to_human(cpus[0].freqs[i].Hz),
+					 hz_to_human(min));
+			ok = false;
+		}
+	}
+	if (ok)
+		fwts_passed(fw, "CPU frequencies are within the min and max limits");
+	else
+		fwts_failed(fw, LOG_LEVEL_MEDIUM, "CPUFreqLimitsTest",
+			     "Contains frequencies beyond max and min limits");
+	return FWTS_OK;
+}
+
+static int read_device_tree_file(const char *path, int *val)
+{
+	int fd;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	if (read(fd, val, sizeof(*val)) < 0)
+		return FWTS_ERROR;
+
+	*val = be32toh(*val);
+	close(fd);
+	return FWTS_OK;
+}
+
+static int read_device_tree_array(const char *path, int *arr, int *len)
+{
+	int fd;
+	int i = 0;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	while(1) {
+		if (read(fd, (arr + i), sizeof(arr[i])) <= 0)
+			break;
+		arr[i] = be32toh(arr[i]);
+		i++;
+	}
+
+	*len = (!i) ? i : i - 1;
+	close(fd);
+	return FWTS_OK;
+}
+
+static int cpufreq_test_pstate_limits(fwts_framework *fw)
+{
+	char *dev_tree_path = "/proc/device-tree/ibm,opal/power-mgt/";
+	int pstate_min, pstate_max, pstates[MAX_FREQS], nr_pstates, len;
+	char path[PATH_MAX];
+	bool ok = true;
+	int i;
+
+#if !defined(__PPC64__)
+	fwts_skipped(fw, "Test case applicable to PPC64 only");
+	return FWTS_SKIP;
+#endif
+
+	snprintf(path, sizeof(path), "%sibm,pstate-max", dev_tree_path);
+	if (read_device_tree_file(path, &pstate_max) < 0) {
+		fwts_log_warning(fw, "Failed to read the max pstate %s\n", path);
+		return FWTS_ERROR;
+	}
+
+	snprintf(path, sizeof(path), "%sibm,pstate-min", dev_tree_path);
+	if (read_device_tree_file(path, &pstate_min) < 0) {
+		fwts_log_warning(fw, "Failed to read the min pstate %s\n", path);
+		return FWTS_ERROR;
+	}
+
+	snprintf(path, sizeof(path), "%sibm,pstate-ids", dev_tree_path);
+	if (read_device_tree_array(path, pstates, &len) < 0 || !len) {
+		fwts_log_warning(fw, "Failed to read the pstate-id array %s\n", path);
+		return FWTS_ERROR;
+	}
+
+	nr_pstates = pstate_max - pstate_min;
+	if (len != nr_pstates)
+		fwts_log_warning(fw, "Wrong number of pstates. Expected %d pstates, but found %d pstates\n",
+				 nr_pstates, len);
+
+	for (i = 0; i < nr_pstates; i++) {
+		if (pstates[i] > pstate_max) {
+			fwts_log_warning(fw, "Invalid Pstate id %d greater than max pstate %d\n",
+					  pstates[i], pstate_max);
+			ok = false;
+		}
+		if (pstates[i] < pstate_min) {
+			fwts_log_warning(fw, "Invalid Pstate id %d lesser than min pstate %d\n",
+					  pstates[i], pstate_min);
+			ok = false;
+		}
+	}
+
+	if (ok)
+		fwts_passed(fw, "CPU pstates are within the min and max limits");
+	else
+		fwts_failed(fw, LOG_LEVEL_MEDIUM, "CPUPstateLimitsTest",
+			     "Contains pstates beyond max and min limits");
+	return FWTS_OK;
+}
+
 static int sw_tests_possible(fwts_framework *fw)
 {
 	int i, online_cpus = 0;
@@ -861,6 +998,8 @@ static fwts_framework_minor_test cpufreq_tests[] = {
 	{ cpufreq_test_sw_any,		"CPU frequency SW_ANY control" },
 	{ cpufreq_test_sw_all,		"CPU frequency SW_ALL control" },
 	{ cpufreq_test_cpu_performance,	"CPU frequency performance tests." },
+	{ cpufreq_test_frequency_limits, "CPU frequency limits test" },
+	{ cpufreq_test_pstate_limits,	"CPU Pstate limits test (device_tree)" },
 	{ NULL, NULL }
 };
 
-- 
1.9.3