Merge branch 'ethtool-eeprom'

Moshe Shemesh says:

====================
ethtool: Extend module EEPROM dump API

Ethtool supports module EEPROM dumps via the `ethtool -m <dev>` command.
But in current state its functionality is limited - offset and length
parameters, which are used to specify a linear desired region of EEPROM
data to dump, is not enough, considering emergence of complex module
EEPROM layouts such as CMIS 4.0.
Moreover, CMIS 4.0 extends the amount of pages that may be accessible by
introducing another parameter for page addressing - banks.

Besides, currently module EEPROM is represented as a chunk of
concatenated pages, where lower 128 bytes of all pages, except page 00h,
are omitted. Offset and length are used to address parts of this fake
linear memory. But in practice drivers, which implement
get_module_info() and get_module_eeprom() ethtool ops still calculate
page number and set I2C address on their own.

This series tackles these issues by adding ethtool op, which allows to
pass page number, bank number and I2C address in addition to offset and
length parameters to the driver, adds corresponding netlink
infrastructure and implements the new interface in mlx5 driver.

This allows to extend userspace 'ethtool -m' CLI by adding new
parameters - page, bank and i2c. New command line format:
 ethtool -m <dev> [hex on|off] [raw on|off] [offset N] [length N] [page N] [bank N] [i2c N]

The consequence of this series is a possibility to dump arbitrary EEPROM
page at a time, in contrast to dumps of concatenated pages. Therefore,
offset and length change their semantics and may be used only to specify
a part of data within half page boundary, which size is currently limited
to 128 bytes.

As for drivers that support legacy get_module_info() and
get_module_eeprom() pair, the series addresses it by implementing a
fallback mechanism. As mentioned earlier, such drivers derive a page
number from 'global' offset, so this can be done vice versa without
their involvement thanks to standardization. If kernel netlink handler
of 'ethtool -m' command detects that new ethtool op is not supported by
the driver, it calculates offset from given page number and page offset
and calls old ndos, if they are available.
====================

\Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 174 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 b185a0452629..c8057a44d5ab 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -1770,6 +1770,49 @@ 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)
+{
+	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 i = 0;
+
+	if (!page_data->length)
+		return -EINVAL;
+
+	memset(data, 0, page_data->length);
+
+	query.offset = page_data->offset;
+	query.i2c_address = page_data->i2c_address;
+	query.bank = page_data->bank;
+	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);
+
+		/* Done reading, return how many bytes was read */
+		if (!size_read)
+			return i;
+
+		if (size_read == -EINVAL)
+			return -EINVAL;
+		if (size_read < 0) {
+			netdev_err(priv->netdev, "%s: mlx5_query_module_eeprom_by_page failed:0x%x\n",
+				   __func__, size_read);
+			return i;
+		}
+
+		i += size_read;
+		query.offset += size_read;
+	}
+
+	return i;
+}
+
 int mlx5e_ethtool_flash_device(struct mlx5e_priv *priv,
 			       struct ethtool_flash *flash)
 {
@@ -2159,6 +2202,7 @@ const struct ethtool_ops mlx5e_ethtool_ops = {
 	.set_wol	   = mlx5e_set_wol,
 	.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,
 	.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/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
index 4bb219565c58..1ef2b6a848c1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
@@ -353,69 +353,123 @@ static void mlx5_sfp_eeprom_params_set(u16 *i2c_addr, int *page_num, u16 *offset
 	*offset -= MLX5_EEPROM_PAGE_LENGTH;
 }
 
-int mlx5_query_module_eeprom(struct mlx5_core_dev *dev,
-			     u16 offset, u16 size, u8 *data)
+static int mlx5_query_mcia(struct mlx5_core_dev *dev,
+			   struct mlx5_module_eeprom_query_params *params, u8 *data)
 {
-	int module_num, status, err, page_num = 0;
 	u32 in[MLX5_ST_SZ_DW(mcia_reg)] = {};
 	u32 out[MLX5_ST_SZ_DW(mcia_reg)];
-	u16 i2c_addr = 0;
-	u8 module_id;
+	int status, err;
 	void *ptr;
+	u16 size;
 
-	err = mlx5_query_module_num(dev, &module_num);
+	size = min_t(int, params->size, MLX5_EEPROM_MAX_BYTES);
+
+	MLX5_SET(mcia_reg, in, l, 0);
+	MLX5_SET(mcia_reg, in, size, size);
+	MLX5_SET(mcia_reg, in, module, params->module_number);
+	MLX5_SET(mcia_reg, in, device_address, params->offset);
+	MLX5_SET(mcia_reg, in, page_number, params->page);
+	MLX5_SET(mcia_reg, in, i2c_device_address, params->i2c_address);
+
+	err = mlx5_core_access_reg(dev, in, sizeof(in), out,
+				   sizeof(out), MLX5_REG_MCIA, 0, 0);
 	if (err)
 		return err;
 
-	err = mlx5_query_module_id(dev, module_num, &module_id);
+	status = MLX5_GET(mcia_reg, out, status);
+	if (status) {
+		mlx5_core_err(dev, "query_mcia_reg failed: status: 0x%x\n",
+			      status);
+		return -EIO;
+	}
+
+	ptr = MLX5_ADDR_OF(mcia_reg, out, dword_0);
+	memcpy(data, ptr, size);
+
+	return size;
+}
+
+int mlx5_query_module_eeprom(struct mlx5_core_dev *dev,
+			     u16 offset, u16 size, u8 *data)
+{
+	struct mlx5_module_eeprom_query_params query = {0};
+	u8 module_id;
+	int err;
+
+	err = mlx5_query_module_num(dev, &query.module_number);
+	if (err)
+		return err;
+
+	err = mlx5_query_module_id(dev, query.module_number, &module_id);
 	if (err)
 		return err;
 
 	switch (module_id) {
 	case MLX5_MODULE_ID_SFP:
-		mlx5_sfp_eeprom_params_set(&i2c_addr, &page_num, &offset);
+		mlx5_sfp_eeprom_params_set(&query.i2c_address, &query.page, &query.offset);
 		break;
 	case MLX5_MODULE_ID_QSFP:
 	case MLX5_MODULE_ID_QSFP_PLUS:
 	case MLX5_MODULE_ID_QSFP28:
-		mlx5_qsfp_eeprom_params_set(&i2c_addr, &page_num, &offset);
+		mlx5_qsfp_eeprom_params_set(&query.i2c_address, &query.page, &query.offset);
 		break;
 	default:
 		mlx5_core_err(dev, "Module ID not recognized: 0x%x\n", module_id);
 		return -EINVAL;
 	}
 
-	if (offset + size > MLX5_EEPROM_PAGE_LENGTH)
+	if (query.offset + size > MLX5_EEPROM_PAGE_LENGTH)
 		/* Cross pages read, read until offset 256 in low page */
 		size -= offset + size - MLX5_EEPROM_PAGE_LENGTH;
 
-	size = min_t(int, size, MLX5_EEPROM_MAX_BYTES);
+	query.size = size;
 
-	MLX5_SET(mcia_reg, in, l, 0);
-	MLX5_SET(mcia_reg, in, module, module_num);
-	MLX5_SET(mcia_reg, in, i2c_device_address, i2c_addr);
-	MLX5_SET(mcia_reg, in, page_number, page_num);
-	MLX5_SET(mcia_reg, in, device_address, offset);
-	MLX5_SET(mcia_reg, in, size, size);
+	return mlx5_query_mcia(dev, &query, data);
+}
+EXPORT_SYMBOL_GPL(mlx5_query_module_eeprom);
 
-	err = mlx5_core_access_reg(dev, in, sizeof(in), out,
-				   sizeof(out), MLX5_REG_MCIA, 0, 0);
+int mlx5_query_module_eeprom_by_page(struct mlx5_core_dev *dev,
+				     struct mlx5_module_eeprom_query_params *params,
+				     u8 *data)
+{
+	u8 module_id;
+	int err;
+
+	err = mlx5_query_module_num(dev, &params->module_number);
 	if (err)
 		return err;
 
-	status = MLX5_GET(mcia_reg, out, status);
-	if (status) {
-		mlx5_core_err(dev, "query_mcia_reg failed: status: 0x%x\n",
-			      status);
-		return -EIO;
+	err = mlx5_query_module_id(dev, params->module_number, &module_id);
+	if (err)
+		return err;
+
+	switch (module_id) {
+	case MLX5_MODULE_ID_SFP:
+		if (params->page > 0)
+			return -EINVAL;
+		break;
+	case MLX5_MODULE_ID_QSFP:
+	case MLX5_MODULE_ID_QSFP28:
+	case MLX5_MODULE_ID_QSFP_PLUS:
+		if (params->page > 3)
+			return -EINVAL;
+		break;
+	case MLX5_MODULE_ID_DSFP:
+		break;
+	default:
+		mlx5_core_err(dev, "Module ID not recognized: 0x%x\n", module_id);
+		return -EINVAL;
 	}
 
-	ptr = MLX5_ADDR_OF(mcia_reg, out, dword_0);
-	memcpy(data, ptr, size);
+	if (params->i2c_address != MLX5_I2C_ADDR_HIGH &&
+	    params->i2c_address != MLX5_I2C_ADDR_LOW) {
+		mlx5_core_err(dev, "I2C address not recognized: 0x%x\n", params->i2c_address);
+		return -EINVAL;
+	}
 
-	return size;
+	return mlx5_query_mcia(dev, params, data);
 }
-EXPORT_SYMBOL_GPL(mlx5_query_module_eeprom);
+EXPORT_SYMBOL_GPL(mlx5_query_module_eeprom_by_page);
 
 static int mlx5_query_port_pvlc(struct mlx5_core_dev *dev, u32 *pvlc,
 				int pvlc_size,  u8 local_port)
diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 2e11176c6b94..e61de66e973b 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -556,6 +556,26 @@ int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
 
 /**
+ * sfp_get_module_eeprom_by_page() - Read a page from the SFP module EEPROM
+ * @bus: a pointer to the &struct sfp_bus structure for the sfp module
+ * @page: a &struct ethtool_module_eeprom
+ * @extack: extack for reporting problems
+ *
+ * Read an EEPROM page as specified by the supplied @page. See the
+ * documentation for &struct ethtool_module_eeprom for the page to be read.
+ *
+ * Returns 0 on success or a negative errno number. More error
+ * information might be provided via extack
+ */
+int sfp_get_module_eeprom_by_page(struct sfp_bus *bus,
+				  const struct ethtool_module_eeprom *page,
+				  struct netlink_ext_ack *extack)
+{
+	return bus->socket_ops->module_eeprom_by_page(bus->sfp, page, extack);
+}
+EXPORT_SYMBOL_GPL(sfp_get_module_eeprom_by_page);
+
+/**
  * sfp_upstream_start() - Inform the SFP that the network device is up
  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
  *
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 7998acc689b7..37f722c763d7 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -2330,6 +2330,30 @@ static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
 	return 0;
 }
 
+static int sfp_module_eeprom_by_page(struct sfp *sfp,
+				     const struct ethtool_module_eeprom *page,
+				     struct netlink_ext_ack *extack)
+{
+	if (page->bank) {
+		NL_SET_ERR_MSG(extack, "Banks not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (page->page) {
+		NL_SET_ERR_MSG(extack, "Only page 0 supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (page->i2c_address != 0x50 &&
+	    page->i2c_address != 0x51) {
+		NL_SET_ERR_MSG(extack, "Only address 0x50 and 0x51 supported");
+		return -EOPNOTSUPP;
+	}
+
+	return sfp_read(sfp, page->i2c_address == 0x51, page->offset,
+			page->data, page->length);
+};
+
 static const struct sfp_socket_ops sfp_module_ops = {
 	.attach = sfp_attach,
 	.detach = sfp_detach,
@@ -2337,6 +2361,7 @@ static const struct sfp_socket_ops sfp_module_ops = {
 	.stop = sfp_stop,
 	.module_info = sfp_module_info,
 	.module_eeprom = sfp_module_eeprom,
+	.module_eeprom_by_page = sfp_module_eeprom_by_page,
 };
 
 static void sfp_timeout(struct work_struct *work)
diff --git a/drivers/net/phy/sfp.h b/drivers/net/phy/sfp.h
index b83f70526270..27226535c72b 100644
--- a/drivers/net/phy/sfp.h
+++ b/drivers/net/phy/sfp.h
@@ -14,6 +14,9 @@ struct sfp_socket_ops {
 	int (*module_info)(struct sfp *sfp, struct ethtool_modinfo *modinfo);
 	int (*module_eeprom)(struct sfp *sfp, struct ethtool_eeprom *ee,
 			     u8 *data);
+	int (*module_eeprom_by_page)(struct sfp *sfp,
+				     const struct ethtool_module_eeprom *page,
+				     struct netlink_ext_ack *extack);
 };
 
 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev);