bnxt_re/lib: Support debug logging

Introduce a new logging function and new enviornment variables
to control it. This will be used in subsequent patches for
debug logging.

Below environment variables are supported.

BNXT_DEBUG_FILE:
User can provide absolute file location that will
be used for logging the prints from library code.
Default path is – “/var/log/messages”

BNXT_DEBUG_MASK:
Set this value to log direct verbs related information.
        BNXT_DUMP_DV = 1

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Reviewed-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>

Author: kadesai16

providers/bnxt_re/main.c

@@ -91,6 +91,8 @@ static const struct verbs_match_ent cna_table[] = {
 	{}
 };
 
+uint32_t bnxt_debug_mask;
+
 static const struct verbs_context_ops bnxt_re_cntx_ops = {
 	.query_device_ex = bnxt_re_query_device,
 	.query_port    = bnxt_re_query_port,
@@ -181,6 +183,39 @@ static int bnxt_re_alloc_map_dbr_bar_page(struct ibv_context *ibvctx)
 	return 0;
 }
 
+static void bnxt_open_debug_file(FILE **dbg_fp)
+{
+	FILE *default_dbg_fp = NULL;
+	const char *env;
+
+	env = getenv("BNXT_DEBUG_FILE");
+
+	if (!env)
+		env = "/var/log/messages";
+
+	*dbg_fp = fopen(env, "aw+");
+	if (!*dbg_fp) {
+		*dbg_fp = default_dbg_fp;
+		bnxt_err(NULL, "Failed opening debug file %s\n", env);
+		return;
+	}
+}
+
+static void bnxt_close_debug_file(FILE *dbg_fp)
+{
+	if (dbg_fp && dbg_fp != stderr)
+		fclose(dbg_fp);
+}
+
+static void bnxt_set_debug_mask(void)
+{
+	char *env;
+
+	env = getenv("BNXT_DEBUG_MASK");
+	if (env)
+		bnxt_debug_mask = strtol(env, NULL, 0);
+}
+
 /* Context Init functions */
 static struct verbs_context *bnxt_re_alloc_context(struct ibv_device *vdev,
 						   int cmd_fd,
@@ -261,6 +296,9 @@ static struct verbs_context *bnxt_re_alloc_context(struct ibv_device *vdev,
 	if (ret)
 		goto failed;
 
+	bnxt_open_debug_file(&cntx->dbg_fp);
+	bnxt_set_debug_mask();
+
 	return &cntx->ibvctx;
 
 failed:
@@ -274,6 +312,8 @@ static void bnxt_re_free_context(struct ibv_context *ibvctx)
 	struct bnxt_re_context *cntx = to_bnxt_re_context(ibvctx);
 	struct bnxt_re_dev *rdev = to_bnxt_re_dev(ibvctx->device);
 
+	bnxt_close_debug_file(cntx->dbg_fp);
+
 	/* Unmap if anything device specific was mapped in init_context. */
 	pthread_mutex_destroy(&cntx->shlock);
 	if (cntx->shpg)

providers/bnxt_re/main.h

@@ -45,6 +45,8 @@
 #include <endian.h>
 #include <pthread.h>
 #include <sys/param.h>
+#include <stdio.h>
+#include <stdarg.h>
 
 #include <util/mmio.h>
 #include <util/util.h>
@@ -270,6 +272,7 @@ struct bnxt_re_context {
 	uint32_t wc_handle;
 	void *dbr_page;
 	void *bar_map;
+	FILE	*dbg_fp;
 };
 
 struct bnxt_re_pacing_data {
@@ -321,6 +324,45 @@ int bnxt_re_get_toggle_mem(struct ibv_context *ibvctx,
 			   struct bnxt_re_mmap_info *minfo,
 			   uint32_t *page_handle);
 
+extern uint32_t bnxt_debug_mask;
+enum {
+	BNXT_DUMP_DV			= 1 << 0,
+};
+
+#define LEN_50		50
+#define bnxt_trace_dv(cntx, fmt, ...)		\
+{							\
+	if (bnxt_debug_mask & BNXT_DUMP_DV)		\
+		bnxt_err(cntx, fmt, ##__VA_ARGS__);	\
+}
+
+static inline void bnxt_err(struct bnxt_re_context *cntx, const char *fmt, ...)
+	__attribute__((format(printf, 2, 3)));
+
+static inline void bnxt_err(struct bnxt_re_context *cntx, const char *fmt, ...)
+{
+	FILE *fp = cntx ? cntx->dbg_fp : stderr;
+	char prefix[LEN_50] = {};
+	char timestamp[LEN_50];
+	struct tm *timeinfo;
+	time_t rawtime;
+	va_list args;
+
+	time(&rawtime);
+	timeinfo = localtime(&rawtime);
+
+	strftime(timestamp, LEN_50, "%b %d %X", timeinfo);
+	sprintf(prefix, " %s: ", "libbnxt_re");
+
+	if (!fp)
+		return;
+	va_start(args, fmt);
+	fprintf(fp, "%s", timestamp);
+	fprintf(fp, "%s", prefix);
+	vfprintf(fp, fmt, args);
+	va_end(args);
+}
+
 /* pointer conversion functions*/
 static inline struct bnxt_re_dev *to_bnxt_re_dev(struct ibv_device *ibvdev)
 {