[PATCH 7/9] common/mlx5: use common sysfs routines

[Stephen Hemminger]

mlx5_sys_roce_disable() read the roce_enable attribute and then
reopened the same file to write it. Use the EAL read and write
routines instead.

The dev_port lookup is left alone: it selects the scanf format at
runtime and distinguishes ENOENT from other errors to fall back to
dev_id on older kernels.

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 drivers/common/mlx5/linux/mlx5_common_os.c | 39 ++++++++--------------
 1 file changed, 14 insertions(+), 25 deletions(-)

diff --git a/drivers/common/mlx5/linux/mlx5_common_os.c 
b/drivers/common/mlx5/linux/mlx5_common_os.c
index 3e9cd86062..cf496b0b58 100644
--- a/drivers/common/mlx5/linux/mlx5_common_os.c
+++ b/drivers/common/mlx5/linux/mlx5_common_os.c
@@ -16,6 +16,7 @@
 #include <eal_export.h>
 #include <rte_errno.h>
 #include <rte_string_fns.h>
+#include <rte_sysfs.h>
 #include <bus_pci_driver.h>
 #include <bus_auxiliary_driver.h>
 
@@ -658,45 +659,33 @@ mlx5_nl_roce_disable(const char *addr)
        return ret;
 }
 
+#define MLX5_ROCE_ENABLE_PATH "/sys/bus/pci/devices/%s/roce_enable"
+
 /* Try to disable ROCE by sysfs. */
 static int
 mlx5_sys_roce_disable(const char *addr)
 {
-       FILE *file_o;
-       int enable;
+       unsigned long enable;
        int ret;
 
-       MKSTR(file_p, "/sys/bus/pci/devices/%s/roce_enable", addr);
-       file_o = fopen(file_p, "rb");
-       if (!file_o) {
+       if (rte_sysfs_parse_uint(&enable, MLX5_ROCE_ENABLE_PATH, addr) != 0) {
                rte_errno = ENOTSUP;
                return -ENOTSUP;
        }
-       ret = fscanf(file_o, "%d", &enable);
-       if (ret != 1) {
-               rte_errno = EINVAL;
-               ret = EINVAL;
-               goto close;
-       } else if (!enable) {
-               ret = 0;
+       if (enable == 0) {
                DRV_LOG(INFO, "ROCE has already disabled(sysfs).");
-               goto close;
+               return 0;
        }
-       fclose(file_o);
-       file_o = fopen(file_p, "wb");
-       if (!file_o) {
+
+       ret = rte_sysfs_write_string("0\n", MLX5_ROCE_ENABLE_PATH, addr);
+       if (ret != 0) {
                rte_errno = ENOTSUP;
+               DRV_LOG(DEBUG, "Failed to disable ROCE by sysfs.");
                return -ENOTSUP;
        }
-       fprintf(file_o, "0\n");
-       ret = 0;
-close:
-       if (ret)
-               DRV_LOG(DEBUG, "Failed to disable ROCE by sysfs: %d.", ret);
-       else
-               DRV_LOG(INFO, "ROCE is disabled by sysfs successfully.");
-       fclose(file_o);
-       return ret;
+
+       DRV_LOG(INFO, "ROCE is disabled by sysfs successfully.");
+       return 0;
 }
 
 static int
-- 
2.53.0