[PATCH v3 3/4] selftests/resctrl: Add support for MBM and MBA tests on AMD

[Babu Moger <babu.moger@xxxxxxx>]

Add support to read UMC (Unified Memory Controller) perf events to compare
the numbers with QoS monitor for AMD.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v3: Made read_from_mc_dir function generic to both AMD and Intel.
    Rest are mostly related to rebase.

v2: Replace perror with ksft_perror.
---
 tools/testing/selftests/resctrl/resctrl_val.c | 80 ++++++++++++-------
 1 file changed, 50 insertions(+), 30 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 23c0e0a1d845..ffacafb535cd 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -11,6 +11,7 @@
 #include "resctrl.h"
 
 #define UNCORE_IMC		"uncore_imc_"
+#define AMD_UMC			"amd_umc_"
 #define READ_FILE_NAME		"events/cas_count_read"
 #define WRITE_FILE_NAME		"events/cas_count_write"
 #define DYN_PMU_PATH		"/sys/bus/event_source/devices"
@@ -128,7 +129,7 @@ static int open_perf_event(int i, int cpu_no, int j)
 }
 
 /* Get type and config (read and write) of an MC counter */
-static int read_from_mc_dir(char *mc_dir, int count)
+static int read_from_mc_dir(char *mc_dir, int count, int vendor)
 {
 	char cas_count_cfg[1024], mc_counter_cfg[1024], mc_counter_type[1024];
 	FILE *fp;
@@ -152,41 +153,56 @@ static int read_from_mc_dir(char *mc_dir, int count)
 	mc_counters_config[count][WRITE].type =
 				mc_counters_config[count][READ].type;
 
-	/* Get read config */
-	sprintf(mc_counter_cfg, "%s%s", mc_dir, READ_FILE_NAME);
-	fp = fopen(mc_counter_cfg, "r");
-	if (!fp) {
-		ksft_perror("Failed to open MC config file");
+	if (vendor == ARCH_AMD) {
+		/*
+		 * Setup the event and umasks for UMC events
+		 * Number of CAS commands sent for reads:
+		 * EventCode = 0x0a, umask = 0x1
+		 * Number of CAS commands sent for writes:
+		 * EventCode = 0x0a, umask = 0x2
+		 */
+		mc_counters_config[count][READ].event = 0xa;
+		mc_counters_config[count][READ].umask = 0x1;
 
-		return -1;
-	}
-	if (fscanf(fp, "%s", cas_count_cfg) <= 0) {
-		ksft_perror("Could not get MC cas count read");
+		mc_counters_config[count][WRITE].event = 0xa;
+		mc_counters_config[count][WRITE].umask = 0x2;
+	} else {
+		/* Get read config */
+		sprintf(mc_counter_cfg, "%s%s", mc_dir, READ_FILE_NAME);
+		fp = fopen(mc_counter_cfg, "r");
+		if (!fp) {
+			ksft_perror("Failed to open MC config file");
+
+			return -1;
+		}
+		if (fscanf(fp, "%s", cas_count_cfg) <= 0) {
+			ksft_perror("Could not get MC cas count read");
+			fclose(fp);
+
+			return -1;
+		}
 		fclose(fp);
 
-		return -1;
-	}
-	fclose(fp);
+		get_event_and_umask(cas_count_cfg, count, READ);
 
-	get_event_and_umask(cas_count_cfg, count, READ);
+		/* Get write config */
+		sprintf(mc_counter_cfg, "%s%s", mc_dir, WRITE_FILE_NAME);
+		fp = fopen(mc_counter_cfg, "r");
+		if (!fp) {
+			ksft_perror("Failed to open MC config file");
 
-	/* Get write config */
-	sprintf(mc_counter_cfg, "%s%s", mc_dir, WRITE_FILE_NAME);
-	fp = fopen(mc_counter_cfg, "r");
-	if (!fp) {
-		ksft_perror("Failed to open MC config file");
+			return -1;
+		}
+		if  (fscanf(fp, "%s", cas_count_cfg) <= 0) {
+			ksft_perror("Could not get MC cas count write");
+			fclose(fp);
 
-		return -1;
-	}
-	if  (fscanf(fp, "%s", cas_count_cfg) <= 0) {
-		ksft_perror("Could not get MC cas count write");
+			return -1;
+		}
 		fclose(fp);
 
-		return -1;
+		get_event_and_umask(cas_count_cfg, count, WRITE);
 	}
-	fclose(fp);
-
-	get_event_and_umask(cas_count_cfg, count, WRITE);
 
 	return 0;
 }
@@ -213,6 +229,8 @@ static int num_of_mem_controllers(void)
 	vendor = get_vendor();
 	if (vendor == ARCH_INTEL) {
 		sysfs_name = UNCORE_IMC;
+	} else if (vendor == ARCH_AMD) {
+		sysfs_name = AMD_UMC;
 	} else {
 		ksft_perror("Unsupported vendor!\n");
 		return -1;
@@ -228,6 +246,7 @@ static int num_of_mem_controllers(void)
 			/*
 			 * imc counters are named as "uncore_imc_<n>", hence
 			 * increment the pointer to point to <n>.
+			 * For AMD, it will be amd_umc_<n>.
 			 */
 			temp = temp + strlen(sysfs_name);
 
@@ -239,7 +258,7 @@ static int num_of_mem_controllers(void)
 			if (temp[0] >= '0' && temp[0] <= '9') {
 				sprintf(mc_dir, "%s/%s/", DYN_PMU_PATH,
 					ep->d_name);
-				ret = read_from_mc_dir(mc_dir, count);
+				ret = read_from_mc_dir(mc_dir, count, vendor);
 				if (ret) {
 					closedir(dp);
 
@@ -250,8 +269,9 @@ static int num_of_mem_controllers(void)
 		}
 		closedir(dp);
 		if (count == 0) {
-			ksft_print_msg("Unable to find MC counters\n");
-
+			ksft_print_msg("Unable to find iMC/UMC counters\n");
+			if (vendor == ARCH_AMD)
+				ksft_print_msg("Try loading amd_uncore module\n");
 			return -1;
 		}
 	} else {
-- 
2.34.1