[RFC net-next 4/4] net/mlx5e: Implement set_module_eeprom_by_page ethtool callback
From: Björn Töpel
Date: Thu Feb 19 2026 - 08:02:23 EST
Add EEPROM write support by implementing the set_module_eeprom_by_page
ethtool_ops callback, mirroring the existing get_module_eeprom_by_page
read path. This enables the kernel's module loopback SET path which
requires both get and set callbacks.
The write path reuses the MCIA register (MLX5_REG_MCIA) via
mlx5_core_access_reg() with write=1 instead of write=0.
This seems to work, but I'd like some proper feedback from the mlx5
folks! ;-)
Signed-off-by: Björn Töpel <bjorn@xxxxxxxxxx>
---
.../ethernet/mellanox/mlx5/core/en_ethtool.c | 52 +++++++++++++------
.../ethernet/mellanox/mlx5/core/mlx5_core.h | 6 +--
.../net/ethernet/mellanox/mlx5/core/port.c | 34 ++++++++----
3 files changed, 64 insertions(+), 28 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index 4a8dc85d5924..1dce67485651 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -2103,22 +2103,24 @@ static int mlx5e_get_module_eeprom(struct net_device *netdev,
return 0;
}
-static int mlx5e_get_module_eeprom_by_page(struct net_device *netdev,
- const struct ethtool_module_eeprom *page_data,
- struct netlink_ext_ack *extack)
+static int __mlx5e_access_module_eeprom_by_page(struct net_device *netdev,
+ const struct ethtool_module_eeprom *page_data,
+ struct netlink_ext_ack *extack,
+ bool write)
{
struct mlx5e_priv *priv = netdev_priv(netdev);
struct mlx5_module_eeprom_query_params query;
struct mlx5_core_dev *mdev = priv->mdev;
u8 *data = page_data->data;
- int size_read;
+ int size_xfered;
u8 status = 0;
int i = 0;
if (!page_data->length)
return -EINVAL;
- memset(data, 0, page_data->length);
+ if (!write)
+ memset(data, 0, page_data->length);
query.offset = page_data->offset;
query.i2c_address = page_data->i2c_address;
@@ -2126,28 +2128,47 @@ static int mlx5e_get_module_eeprom_by_page(struct net_device *netdev,
query.page = page_data->page;
while (i < page_data->length) {
query.size = page_data->length - i;
- size_read = mlx5_query_module_eeprom_by_page(mdev, &query,
- data + i, &status);
+ size_xfered = mlx5_access_module_eeprom_by_page(mdev, &query,
+ data + i, &status,
+ write);
- /* Done reading, return how many bytes was read */
- if (!size_read)
+ if (!size_xfered)
return i;
- if (size_read < 0) {
+ if (size_xfered < 0) {
NL_SET_ERR_MSG_FMT_MOD(
extack,
- "Query module eeprom by page failed, read %u bytes, err %d, status %u",
- i, size_read, status);
- return size_read;
+ "%s module eeprom by page failed, %s %u bytes, err %d, status %u",
+ write ? "Set" : "Query",
+ write ? "wrote" : "read",
+ i, size_xfered, status);
+ return size_xfered;
}
- i += size_read;
- query.offset += size_read;
+ i += size_xfered;
+ query.offset += size_xfered;
}
return i;
}
+static int mlx5e_get_module_eeprom_by_page(struct net_device *netdev,
+ const struct ethtool_module_eeprom *page_data,
+ struct netlink_ext_ack *extack)
+{
+ return __mlx5e_access_module_eeprom_by_page(netdev, page_data, extack, false);
+}
+
+static int mlx5e_set_module_eeprom_by_page(struct net_device *netdev,
+ const struct ethtool_module_eeprom *page_data,
+ struct netlink_ext_ack *extack)
+{
+ int err;
+
+ err = __mlx5e_access_module_eeprom_by_page(netdev, page_data, extack, true);
+ return err < 0 ? err : 0;
+}
+
int mlx5e_ethtool_flash_device(struct mlx5e_priv *priv,
struct ethtool_flash *flash)
{
@@ -2776,6 +2797,7 @@ const struct ethtool_ops mlx5e_ethtool_ops = {
.get_module_info = mlx5e_get_module_info,
.get_module_eeprom = mlx5e_get_module_eeprom,
.get_module_eeprom_by_page = mlx5e_get_module_eeprom_by_page,
+ .set_module_eeprom_by_page = mlx5e_set_module_eeprom_by_page,
.flash_device = mlx5e_flash_device,
.get_priv_flags = mlx5e_get_priv_flags,
.set_priv_flags = mlx5e_set_priv_flags,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index b635b423d972..b69730727764 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -361,9 +361,9 @@ void mlx5_query_port_fcs(struct mlx5_core_dev *mdev, bool *supported,
int mlx5_query_module_eeprom(struct mlx5_core_dev *dev,
u16 offset, u16 size, u8 *data, u8 *status);
int
-mlx5_query_module_eeprom_by_page(struct mlx5_core_dev *dev,
- struct mlx5_module_eeprom_query_params *params,
- u8 *data, u8 *status);
+mlx5_access_module_eeprom_by_page(struct mlx5_core_dev *dev,
+ struct mlx5_module_eeprom_query_params *params,
+ u8 *data, u8 *status, bool write);
int mlx5_query_port_dcbx_param(struct mlx5_core_dev *mdev, u32 *out);
int mlx5_set_port_dcbx_param(struct mlx5_core_dev *mdev, u32 *in);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
index ee8b9765c5ba..d68f9f9d7a80 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
@@ -369,9 +369,9 @@ static int mlx5_mcia_max_bytes(struct mlx5_core_dev *dev)
return (MLX5_CAP_MCAM_FEATURE(dev, mcia_32dwords) ? 32 : 12) * sizeof(u32);
}
-static int mlx5_query_mcia(struct mlx5_core_dev *dev,
- struct mlx5_module_eeprom_query_params *params,
- u8 *data, u8 *status)
+static int __mlx5_access_mcia(struct mlx5_core_dev *dev,
+ struct mlx5_module_eeprom_query_params *params,
+ u8 *data, u8 *status, bool write)
{
u32 in[MLX5_ST_SZ_DW(mcia_reg)] = {};
u32 out[MLX5_ST_SZ_DW(mcia_reg)];
@@ -388,8 +388,13 @@ static int mlx5_query_mcia(struct mlx5_core_dev *dev,
MLX5_SET(mcia_reg, in, page_number, params->page);
MLX5_SET(mcia_reg, in, i2c_device_address, params->i2c_address);
+ if (write) {
+ ptr = MLX5_ADDR_OF(mcia_reg, in, dword_0);
+ memcpy(ptr, data, size);
+ }
+
err = mlx5_core_access_reg(dev, in, sizeof(in), out,
- sizeof(out), MLX5_REG_MCIA, 0, 0);
+ sizeof(out), MLX5_REG_MCIA, 0, write);
if (err)
return err;
@@ -399,12 +404,21 @@ static int mlx5_query_mcia(struct mlx5_core_dev *dev,
return -EIO;
}
- ptr = MLX5_ADDR_OF(mcia_reg, out, dword_0);
- memcpy(data, ptr, size);
+ if (!write) {
+ ptr = MLX5_ADDR_OF(mcia_reg, out, dword_0);
+ memcpy(data, ptr, size);
+ }
return size;
}
+static int mlx5_query_mcia(struct mlx5_core_dev *dev,
+ struct mlx5_module_eeprom_query_params *params,
+ u8 *data, u8 *status)
+{
+ return __mlx5_access_mcia(dev, params, data, status, false);
+}
+
int mlx5_query_module_eeprom(struct mlx5_core_dev *dev,
u16 offset, u16 size, u8 *data, u8 *status)
{
@@ -446,9 +460,9 @@ int mlx5_query_module_eeprom(struct mlx5_core_dev *dev,
return mlx5_query_mcia(dev, &query, data, status);
}
-int mlx5_query_module_eeprom_by_page(struct mlx5_core_dev *dev,
- struct mlx5_module_eeprom_query_params *params,
- u8 *data, u8 *status)
+int mlx5_access_module_eeprom_by_page(struct mlx5_core_dev *dev,
+ struct mlx5_module_eeprom_query_params *params,
+ u8 *data, u8 *status, bool write)
{
int err;
@@ -462,7 +476,7 @@ int mlx5_query_module_eeprom_by_page(struct mlx5_core_dev *dev,
return -EINVAL;
}
- return mlx5_query_mcia(dev, params, data, status);
+ return __mlx5_access_mcia(dev, params, data, status, write);
}
static int mlx5_query_port_pvlc(struct mlx5_core_dev *dev, u32 *pvlc,
--
2.53.0