[dpdk-dev] [PATCH v4 1/2] common/mlx5: support pcie device guid query

[Rongwei Liu <rongweil@nvidia.com>]

sysfs entry "phys_switch_id" holds each PCIe device'
guid.

The devices which reside in the same physical NIC should
have the same guid.

Signed-off-by: Rongwei Liu <rongweil@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/common/mlx5/linux/mlx5_common_os.c | 41 ++++++++++++++++++++++
 drivers/common/mlx5/linux/mlx5_common_os.h | 19 ++++++++++
 2 files changed, 60 insertions(+)

diff --git a/drivers/common/mlx5/linux/mlx5_common_os.c b/drivers/common/mlx5/linux/mlx5_common_os.c
index 9e0c823c97..8b3ee2baea 100644
--- a/drivers/common/mlx5/linux/mlx5_common_os.c
+++ b/drivers/common/mlx5/linux/mlx5_common_os.c
@@ -2,6 +2,7 @@
  * Copyright 2020 Mellanox Technologies, Ltd
  */
 
+#include <sys/types.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdio.h>
@@ -428,3 +429,43 @@ mlx5_os_get_ibv_device(const struct rte_pci_addr *addr)
 	mlx5_glue->free_device_list(ibv_list);
 	return ibv_match;
 }
+
+int
+mlx5_get_device_guid(const struct rte_pci_addr *dev, uint8_t *guid, size_t len)
+{
+	char tmp[512];
+	char cur_ifname[IF_NAMESIZE + 1];
+	FILE *id_file;
+	DIR *dir;
+	struct dirent *ptr;
+	int ret;
+
+	if (guid == NULL || len < sizeof(u_int64_t) + 1)
+		return -1;
+	memset(guid, 0, len);
+	snprintf(tmp, sizeof(tmp), "/sys/bus/pci/devices/%04x:%02x:%02x.%x/net",
+			dev->domain, dev->bus, dev->devid, dev->function);
+	dir = opendir(tmp);
+	if (dir == NULL)
+		return -1;
+	/* Traverse to identify PF interface */
+	do {
+		ptr = readdir(dir);
+		if (ptr == NULL || ptr->d_type != DT_DIR) {
+			closedir(dir);
+			return -1;
+		}
+	} while (strchr(ptr->d_name, '.') || strchr(ptr->d_name, '_') ||
+		 strchr(ptr->d_name, 'v'));
+	snprintf(cur_ifname, sizeof(cur_ifname), "%s", ptr->d_name);
+	closedir(dir);
+	snprintf(tmp + strlen(tmp), sizeof(tmp) - strlen(tmp),
+			"/%s/phys_switch_id", cur_ifname);
+	/* Older OFED like 5.3 doesn't support read */
+	id_file = fopen(tmp, "r");
+	if (!id_file)
+		return 0;
+	ret = fscanf(id_file, "%16s", guid);
+	fclose(id_file);
+	return ret;
+}
diff --git a/drivers/common/mlx5/linux/mlx5_common_os.h b/drivers/common/mlx5/linux/mlx5_common_os.h
index c3202b6786..3cdea75373 100644
--- a/drivers/common/mlx5/linux/mlx5_common_os.h
+++ b/drivers/common/mlx5/linux/mlx5_common_os.h
@@ -296,4 +296,23 @@ __rte_internal
 struct ibv_device *
 mlx5_os_get_ibv_dev(const struct rte_device *dev);
 
+/**
+ * This is used to query system_image_guid as describing in PRM.
+ *
+ * @param dev[in]
+ *  Pointer to a device instance as PCIe id.
+ * @param guid[out]
+ *  Pointer to the buffer to hold device guid.
+ *  Guid is uint64_t and corresponding to 17 bytes string.
+ * @param len[in]
+ *  Guid buffer length, 17 bytes at least.
+ *
+ * @return
+ *  -1 if internal failure.
+ *  0 if OFED doesn't support.
+ *  >0 if success.
+ */
+int
+mlx5_get_device_guid(const struct rte_pci_addr *dev, uint8_t *guid, size_t len);
+
 #endif /* RTE_PMD_MLX5_COMMON_OS_H_ */
-- 
2.27.0