net/mlx5: add log file procedure for debug data

Add a global function in the PMD which dumps debug information to
specific file.

The data can be printed in hexadecimal format or as regular string.

The number of debug files per PMD entity should be limited by a new PMD
probe parameter called max_dump_files_num.

The files will be created in the /var/log directory or in the current
directory.

Cc: stable@dpdk.org

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>

doc/guides/nics/mlx5.rst

@@ -500,6 +500,13 @@ Run-time configuration
 
     representor=[0-2]
 
+- ``max_dump_files_num`` parameter [int]
+
+  The maximum number of files per PMD entity that may be created for debug information.
+  The files will be created in /var/log directory or in current directory.
+
+  set to 128 by default.
+
 Firmware configuration
 ~~~~~~~~~~~~~~~~~~~~~~
 

drivers/net/mlx5/mlx5.c

@@ -116,6 +116,9 @@
 /* Select port representors to instantiate. */
 #define MLX5_REPRESENTOR "representor"
 
+/* Device parameter to configure the maximum number of dump files per queue. */
+#define MLX5_MAX_DUMP_FILES_NUM "max_dump_files_num"
+
 #ifndef HAVE_IBV_MLX5_MOD_MPW
 #define MLX5DV_CONTEXT_FLAGS_MPW_ALLOWED (1 << 2)
 #define MLX5DV_CONTEXT_FLAGS_ENHANCED_MPW (1 << 3)
@@ -927,6 +930,8 @@ mlx5_args_check(const char *key, const char *val, void *opaque)
 		config->dv_flow_en = !!tmp;
 	} else if (strcmp(MLX5_MR_EXT_MEMSEG_EN, key) == 0) {
 		config->mr_ext_memseg_en = !!tmp;
+	} else if (strcmp(MLX5_MAX_DUMP_FILES_NUM, key) == 0) {
+		config->max_dump_files_num = tmp;
 	} else {
 		DRV_LOG(WARNING, "%s: unknown parameter", key);
 		rte_errno = EINVAL;
@@ -971,6 +976,7 @@ mlx5_args(struct mlx5_dev_config *config, struct rte_devargs *devargs)
 		MLX5_DV_FLOW_EN,
 		MLX5_MR_EXT_MEMSEG_EN,
 		MLX5_REPRESENTOR,
+		MLX5_MAX_DUMP_FILES_NUM,
 		NULL,
 	};
 	struct rte_kvargs *kvlist;
@@ -1440,6 +1446,8 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 		DRV_LOG(WARNING, "Multi-Packet RQ isn't supported");
 		config.mprq.enabled = 0;
 	}
+	if (config.max_dump_files_num == 0)
+		config.max_dump_files_num = 128;
 	eth_dev = rte_eth_dev_allocate(name);
 	if (eth_dev == NULL) {
 		DRV_LOG(ERR, "can not allocate rte ethdev");

drivers/net/mlx5/mlx5.h

@@ -204,6 +204,7 @@ struct mlx5_dev_config {
 	unsigned int flow_prio; /* Number of flow priorities. */
 	unsigned int tso_max_payload_sz; /* Maximum TCP payload for TSO. */
 	unsigned int ind_table_max_size; /* Maximum indirection table size. */
+	unsigned int max_dump_files_num; /* Maximum dump files per queue. */
 	int txq_inline; /* Maximum packet size for inlining. */
 	int txqs_inline; /* Queue number threshold for inlining. */
 	int txqs_vec; /* Queue number threshold for vectorized Tx. */

drivers/net/mlx5/mlx5_rxtx.c

@@ -524,6 +524,50 @@ mlx5_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	return rx_queue_count(rxq);
 }
 
+#define MLX5_SYSTEM_LOG_DIR "/var/log"
+/**
+ * Dump debug information to log file.
+ *
+ * @param fname
+ *   The file name.
+ * @param hex_title
+ *   If not NULL this string is printed as a header to the output
+ *   and the output will be in hexadecimal view.
+ * @param buf
+ *   This is the buffer address to print out.
+ * @param len
+ *   The number of bytes to dump out.
+ */
+void
+mlx5_dump_debug_information(const char *fname, const char *hex_title,
+			    const void *buf, unsigned int hex_len)
+{
+	FILE *fd;
+
+	MKSTR(path, "%s/%s", MLX5_SYSTEM_LOG_DIR, fname);
+	fd = fopen(path, "a+");
+	if (!fd) {
+		DRV_LOG(WARNING, "cannot open %s for debug dump\n",
+			path);
+		MKSTR(path2, "./%s", fname);
+		fd = fopen(path2, "a+");
+		if (!fd) {
+			DRV_LOG(ERR, "cannot open %s for debug dump\n",
+				path2);
+			return;
+		}
+		DRV_LOG(INFO, "New debug dump in file %s\n", path2);
+	} else {
+		DRV_LOG(INFO, "New debug dump in file %s\n", path);
+	}
+	if (hex_title)
+		rte_hexdump(fd, hex_title, buf, hex_len);
+	else
+		fprintf(fd, "%s", (const char *)buf);
+	fprintf(fd, "\n\n\n");
+	fclose(fd);
+}
+
 /**
  * DPDK callback for TX.
  *

drivers/net/mlx5/mlx5_rxtx.h

@@ -337,6 +337,8 @@ uint16_t removed_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts,
 int mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int mlx5_tx_descriptor_status(void *tx_queue, uint16_t offset);
 uint32_t mlx5_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id);
+void mlx5_dump_debug_information(const char *path, const char *title,
+				 const void *buf, unsigned int len);
 
 /* Vectorized version of mlx5_rxtx.c */
 int mlx5_check_raw_vec_tx_support(struct rte_eth_dev *dev);