[PATCH v4 2/3] selftests/resctrl: Replace counter index references with pointers

[Yifan Wu <wuyifan50@huawei.com>]

Replace direct counter number references with pointers to remove the
dependency on fixed array indexing and enable the use of different
data structures for counter management.

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Yifan Wu <wuyifan50@huawei.com>
---
 tools/testing/selftests/resctrl/resctrl_val.c | 62 +++++++++----------
 1 file changed, 29 insertions(+), 33 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index a72dc4ae61fe..f4111da26fc2 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -42,40 +42,37 @@ static struct imc_counter_config imc_counters_config[MAX_IMCS];
 LIST_HEAD(imc_counters_list);
 static const struct resctrl_test *current_test;
 
-static void read_mem_bw_initialize_perf_event_attr(int i)
+static void read_mem_bw_initialize_perf_event_attr(struct imc_counter_config *imc_counter)
 {
-	memset(&imc_counters_config[i].pe, 0,
-	       sizeof(struct perf_event_attr));
-	imc_counters_config[i].pe.type = imc_counters_config[i].type;
-	imc_counters_config[i].pe.size = sizeof(struct perf_event_attr);
-	imc_counters_config[i].pe.disabled = 1;
-	imc_counters_config[i].pe.inherit = 1;
-	imc_counters_config[i].pe.exclude_guest = 0;
-	imc_counters_config[i].pe.config =
-		imc_counters_config[i].umask << 8 |
-		imc_counters_config[i].event;
-	imc_counters_config[i].pe.sample_type = PERF_SAMPLE_IDENTIFIER;
-	imc_counters_config[i].pe.read_format =
+	memset(&imc_counter->pe, 0, sizeof(struct perf_event_attr));
+	imc_counter->pe.type = imc_counter->type;
+	imc_counter->pe.size = sizeof(struct perf_event_attr);
+	imc_counter->pe.disabled = 1;
+	imc_counter->pe.inherit = 1;
+	imc_counter->pe.exclude_guest = 0;
+	imc_counter->pe.config = imc_counter->umask << 8 | imc_counter->event;
+	imc_counter->pe.sample_type = PERF_SAMPLE_IDENTIFIER;
+	imc_counter->pe.read_format =
 		PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING;
 }
 
-static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(int i)
+static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(struct imc_counter_config *imc_counter)
 {
-	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_RESET, 0);
-	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_ENABLE, 0);
+	ioctl(imc_counter->fd, PERF_EVENT_IOC_RESET, 0);
+	ioctl(imc_counter->fd, PERF_EVENT_IOC_ENABLE, 0);
 }
 
-static void read_mem_bw_ioctl_perf_event_ioc_disable(int i)
+static void read_mem_bw_ioctl_perf_event_ioc_disable(struct imc_counter_config *imc_counter)
 {
-	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_DISABLE, 0);
+	ioctl(imc_counter->fd, PERF_EVENT_IOC_DISABLE, 0);
 }
 
 /*
  * get_read_event_and_umask:	Parse config into event and umask
  * @cas_count_cfg:	Config
- * @count:		iMC number
+ * @imc_counter:	iMC counter config
  */
-static void get_read_event_and_umask(char *cas_count_cfg, unsigned int count)
+static void get_read_event_and_umask(char *cas_count_cfg, struct imc_counter_config *imc_counter)
 {
 	char *token[MAX_TOKENS];
 	int i = 0;
@@ -89,21 +86,20 @@ static void get_read_event_and_umask(char *cas_count_cfg, unsigned int count)
 		if (!token[i])
 			break;
 		if (strcmp(token[i], "event") == 0)
-			imc_counters_config[count].event = strtol(token[i + 1], NULL, 16);
+			imc_counter->event = strtol(token[i + 1], NULL, 16);
 		if (strcmp(token[i], "umask") == 0)
-			imc_counters_config[count].umask = strtol(token[i + 1], NULL, 16);
+			imc_counter->umask = strtol(token[i + 1], NULL, 16);
 	}
 }
 
-static int open_perf_read_event(int i, int cpu_no)
+static int open_perf_read_event(int cpu_no, struct imc_counter_config *imc_counter)
 {
-	imc_counters_config[i].fd =
-		perf_event_open(&imc_counters_config[i].pe, -1, cpu_no, -1,
-				PERF_FLAG_FD_CLOEXEC);
+	imc_counter->fd = perf_event_open(&imc_counter->pe, -1, cpu_no, -1,
+					  PERF_FLAG_FD_CLOEXEC);
 
-	if (imc_counters_config[i].fd == -1) {
+	if (imc_counter->fd == -1) {
 		fprintf(stderr, "Error opening leader %llx\n",
-			imc_counters_config[i].pe.config);
+			imc_counter->pe.config);
 
 		return -1;
 	}
@@ -177,7 +173,7 @@ static int parse_imc_read_bw_events(char *imc_dir, unsigned int type,
 		}
 
 		imc_counters_config[*count].type = type;
-		get_read_event_and_umask(cas_count_cfg, *count);
+		get_read_event_and_umask(cas_count_cfg, &imc_counters_config[*count]);
 		/* Do not fail after incrementing *count. */
 		*count += 1;
 		list_add(&imc_counter->entry, &imc_counters_list);
@@ -311,7 +307,7 @@ int initialize_read_mem_bw_imc(void)
 
 	/* Initialize perf_event_attr structures for all iMC's */
 	for (imc = 0; imc < imcs; imc++)
-		read_mem_bw_initialize_perf_event_attr(imc);
+		read_mem_bw_initialize_perf_event_attr(&imc_counters_config[imc]);
 
 	return 0;
 }
@@ -350,7 +346,7 @@ static int perf_open_imc_read_mem_bw(int cpu_no)
 		imc_counters_config[imc].fd = -1;
 
 	for (imc = 0; imc < imcs; imc++) {
-		ret = open_perf_read_event(imc, cpu_no);
+		ret = open_perf_read_event(cpu_no, &imc_counters_config[imc]);
 		if (ret)
 			goto close_fds;
 	}
@@ -373,13 +369,13 @@ static void do_imc_read_mem_bw_test(void)
 	int imc;
 
 	for (imc = 0; imc < imcs; imc++)
-		read_mem_bw_ioctl_perf_event_ioc_reset_enable(imc);
+		read_mem_bw_ioctl_perf_event_ioc_reset_enable(&imc_counters_config[imc]);
 
 	sleep(1);
 
 	/* Stop counters after a second to get results. */
 	for (imc = 0; imc < imcs; imc++)
-		read_mem_bw_ioctl_perf_event_ioc_disable(imc);
+		read_mem_bw_ioctl_perf_event_ioc_disable(&imc_counters_config[imc]);
 }
 
 /*
-- 
2.33.0