selftests/resctrl: Add ->init() callback into resctrl_val_param

The struct resctrl_val_param is there to customize behavior inside
resctrl_val() which is currently not used to full extent and there are
number of strcmp()s for test name in resctrl_val done by resctrl_val().

Create ->init() hook into the struct resctrl_val_param to cleanly
do per test initialization.

Remove also unused branches to setup paths and the related #defines
for CMT test.

While touching kerneldoc, make the adjacent line consistent with the
newly added form (callback vs call back).
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/cmt_test.c

@@ -16,6 +16,17 @@
 #define MAX_DIFF		2000000
 #define MAX_DIFF_PERCENT	15
 
+#define CON_MON_LCC_OCCUP_PATH		\
+	"%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy"
+
+static int cmt_init(const struct resctrl_val_param *param, int domain_id)
+{
+	sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
+		param->ctrlgrp, param->mongrp, domain_id);
+
+	return 0;
+}
+
 static int cmt_setup(const struct resctrl_test *test,
 		     const struct user_params *uparams,
 		     struct resctrl_val_param *p)
@@ -139,6 +150,7 @@ static int cmt_run_test(const struct resctrl_test *test, const struct user_param
 		.filename	= RESULT_FILE_NAME,
 		.mask		= ~(long_mask << n) & long_mask,
 		.num_of_runs	= 0,
+		.init		= cmt_init,
 		.setup		= cmt_setup,
 		.measure	= cmt_measure,
 	};

tools/testing/selftests/resctrl/mba_test.c

@@ -17,6 +17,19 @@
 #define ALLOCATION_MIN		10
 #define ALLOCATION_STEP		10
 
+static int mba_init(const struct resctrl_val_param *param, int domain_id)
+{
+	int ret;
+
+	ret = initialize_mem_bw_imc();
+	if (ret)
+		return ret;
+
+	initialize_mem_bw_resctrl(param, domain_id);
+
+	return 0;
+}
+
 /*
  * Change schemata percentage from 100 to 10%. Write schemata to specified
  * con_mon grp, mon_grp in resctrl FS.
@@ -156,6 +169,7 @@ static int mba_run_test(const struct resctrl_test *test, const struct user_param
 		.mongrp		= "m1",
 		.filename	= RESULT_FILE_NAME,
 		.bw_report	= "reads",
+		.init		= mba_init,
 		.setup		= mba_setup,
 		.measure	= mba_measure,
 	};

tools/testing/selftests/resctrl/mbm_test.c

@@ -86,6 +86,19 @@ static int check_results(size_t span)
 	return ret;
 }
 
+static int mbm_init(const struct resctrl_val_param *param, int domain_id)
+{
+	int ret;
+
+	ret = initialize_mem_bw_imc();
+	if (ret)
+		return ret;
+
+	initialize_mem_bw_resctrl(param, domain_id);
+
+	return 0;
+}
+
 static int mbm_setup(const struct resctrl_test *test,
 		     const struct user_params *uparams,
 		     struct resctrl_val_param *p)
@@ -123,6 +136,7 @@ static int mbm_run_test(const struct resctrl_test *test, const struct user_param
 		.ctrlgrp	= "c1",
 		.filename	= RESULT_FILE_NAME,
 		.bw_report	= "reads",
+		.init		= mbm_init,
 		.setup		= mbm_setup,
 		.measure	= mbm_measure,
 	};

tools/testing/selftests/resctrl/resctrl.h

@@ -86,7 +86,8 @@ struct resctrl_test {
  * @mongrp:		Name of the monitor group (mon grp)
  * @filename:		Name of file to which the o/p should be written
  * @bw_report:		Bandwidth report type (reads vs writes)
- * @setup:		Call back function to setup test environment
+ * @init:		Callback function to initialize test environment
+ * @setup:		Callback function to setup per test run environment
  * @measure:		Callback that performs the measurement (a single test)
  */
 struct resctrl_val_param {
@@ -97,6 +98,8 @@ struct resctrl_val_param {
 	char		*bw_report;
 	unsigned long	mask;
 	int		num_of_runs;
+	int		(*init)(const struct resctrl_val_param *param,
+				int domain_id);
 	int		(*setup)(const struct resctrl_test *test,
 				 const struct user_params *uparams,
 				 struct resctrl_val_param *param);
@@ -149,8 +152,11 @@ unsigned char *alloc_buffer(size_t buf_size, int memflush);
 void mem_flush(unsigned char *buf, size_t buf_size);
 void fill_cache_read(unsigned char *buf, size_t buf_size, bool once);
 int run_fill_buf(size_t buf_size, int memflush, int op, bool once);
+int initialize_mem_bw_imc(void);
 int measure_mem_bw(const struct user_params *uparams,
 		   struct resctrl_val_param *param, pid_t bm_pid);
+void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,
+			       int domain_id);
 int resctrl_val(const struct resctrl_test *test,
 		const struct user_params *uparams,
 		const char * const *benchmark_cmd,

tools/testing/selftests/resctrl/resctrl_val.c

@@ -23,18 +23,6 @@
 #define CON_MBM_LOCAL_BYTES_PATH		\
 	"%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
 
-#define CON_MON_LCC_OCCUP_PATH		\
-	"%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy"
-
-#define CON_LCC_OCCUP_PATH		\
-	"%s/%s/mon_data/mon_L3_%02d/llc_occupancy"
-
-#define MON_LCC_OCCUP_PATH		\
-	"%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy"
-
-#define LCC_OCCUP_PATH			\
-	"%s/mon_data/mon_L3_%02d/llc_occupancy"
-
 struct membw_read_format {
 	__u64 value;         /* The value of the event */
 	__u64 time_enabled;  /* if PERF_FORMAT_TOTAL_TIME_ENABLED */
@@ -268,7 +256,7 @@ static int num_of_imcs(void)
 	return count;
 }
 
-static int initialize_mem_bw_imc(void)
+int initialize_mem_bw_imc(void)
 {
 	int imc, j;
 
@@ -424,24 +412,18 @@ static int get_mem_bw_imc(char *bw_report, float *bw_imc)
 
 /*
  * initialize_mem_bw_resctrl:	Appropriately populate "mbm_total_path"
- * @ctrlgrp:			Name of the control monitor group (con_mon grp)
- * @domain_id:			Domain ID (cache ID; for MB, L3 cache ID)
+ * @param:	Parameters passed to resctrl_val()
+ * @domain_id:	Domain ID (cache ID; for MB, L3 cache ID)
  */
-static void initialize_mem_bw_resctrl(const char *ctrlgrp, int domain_id)
+void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,
+			       int domain_id)
 {
 	sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
-		ctrlgrp, domain_id);
+		param->ctrlgrp, domain_id);
 }
 
 /*
- * Get MBM Local bytes as reported by resctrl FS
- * For MBM,
- * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon grp
- * 2. If only con_mon grp is given, then read from con_mon grp
- * 3. If both are not given, then read from root con_mon grp
- * For MBA,
- * 1. If con_mon grp is given, then read from it
- * 2. If con_mon grp is not given, then read from root con_mon grp
+ * Open file to read MBM local bytes from resctrl FS
  */
 static FILE *open_mem_bw_resctrl(const char *mbm_bw_file)
 {
@@ -454,6 +436,9 @@ static FILE *open_mem_bw_resctrl(const char *mbm_bw_file)
 	return fp;
 }
 
+/*
+ * Get MBM Local bytes as reported by resctrl FS
+ */
 static int get_mem_bw_resctrl(FILE *fp, unsigned long *mbm_total)
 {
 	if (fscanf(fp, "%lu\n", mbm_total) <= 0) {
@@ -566,35 +551,6 @@ static int print_results_bw(char *filename, pid_t bm_pid, float bw_imc,
 	return 0;
 }
 
-static void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num)
-{
-	if (strlen(ctrlgrp) && strlen(mongrp))
-		sprintf(llc_occup_path,	CON_MON_LCC_OCCUP_PATH,	RESCTRL_PATH,
-			ctrlgrp, mongrp, sock_num);
-	else if (!strlen(ctrlgrp) && strlen(mongrp))
-		sprintf(llc_occup_path,	MON_LCC_OCCUP_PATH, RESCTRL_PATH,
-			mongrp, sock_num);
-	else if (strlen(ctrlgrp) && !strlen(mongrp))
-		sprintf(llc_occup_path,	CON_LCC_OCCUP_PATH, RESCTRL_PATH,
-			ctrlgrp, sock_num);
-	else if (!strlen(ctrlgrp) && !strlen(mongrp))
-		sprintf(llc_occup_path, LCC_OCCUP_PATH,	RESCTRL_PATH, sock_num);
-}
-
-/*
- * initialize_llc_occu_resctrl:	Appropriately populate "llc_occup_path"
- * @ctrlgrp:			Name of the control monitor group (con_mon grp)
- * @mongrp:			Name of the monitor group (mon grp)
- * @domain_id:			Domain ID (cache ID; for MB, L3 cache ID)
- * @resctrl_val:		Resctrl feature (Eg: cat, cmt.. etc)
- */
-static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
-					int domain_id, char *resctrl_val)
-{
-	if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
-		set_cmt_path(ctrlgrp, mongrp, domain_id);
-}
-
 /*
  * measure_mem_bw - Measures memory bandwidth numbers while benchmark runs
  * @uparams:		User supplied parameters
@@ -825,16 +781,11 @@ int resctrl_val(const struct resctrl_test *test,
 	if (ret)
 		goto out;
 
-	if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||
-	    !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {
-		ret = initialize_mem_bw_imc();
+	if (param->init) {
+		ret = param->init(param, domain_id);
 		if (ret)
 			goto out;
-
-		initialize_mem_bw_resctrl(param->ctrlgrp, domain_id);
-	} else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
-		initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp,
-					    domain_id, resctrl_val);
+	}
 
 	/* Parent waits for child to be ready. */
 	close(pipefd[1]);