mlxsw: core_env: Avoid unnecessary memcpy()s

Simply get a pointer to the data in the register payload instead of
copying it to a temporary buffer.
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core_env.c

@@ -26,8 +26,8 @@ struct mlxsw_env {
 static int mlxsw_env_validate_cable_ident(struct mlxsw_core *core, int id,
 					  bool *qsfp, bool *cmis)
 {
-	char eeprom_tmp[MLXSW_REG_MCIA_EEPROM_SIZE];
 	char mcia_pl[MLXSW_REG_MCIA_LEN];
+	char *eeprom_tmp;
 	u8 ident;
 	int err;
 
@@ -36,7 +36,7 @@ static int mlxsw_env_validate_cable_ident(struct mlxsw_core *core, int id,
 	err = mlxsw_reg_query(core, MLXSW_REG(mcia), mcia_pl);
 	if (err)
 		return err;
-	mlxsw_reg_mcia_eeprom_memcpy_from(mcia_pl, eeprom_tmp);
+	eeprom_tmp = mlxsw_reg_mcia_eeprom_data(mcia_pl);
 	ident = eeprom_tmp[0];
 	*cmis = false;
 	switch (ident) {
@@ -64,8 +64,8 @@ mlxsw_env_query_module_eeprom(struct mlxsw_core *mlxsw_core, int module,
 			      u16 offset, u16 size, void *data,
 			      bool qsfp, unsigned int *p_read_size)
 {
-	char eeprom_tmp[MLXSW_REG_MCIA_EEPROM_SIZE];
 	char mcia_pl[MLXSW_REG_MCIA_LEN];
+	char *eeprom_tmp;
 	u16 i2c_addr;
 	u8 page = 0;
 	int status;
@@ -116,7 +116,7 @@ mlxsw_env_query_module_eeprom(struct mlxsw_core *mlxsw_core, int module,
 	if (status)
 		return -EIO;
 
-	mlxsw_reg_mcia_eeprom_memcpy_from(mcia_pl, eeprom_tmp);
+	eeprom_tmp = mlxsw_reg_mcia_eeprom_data(mcia_pl);
 	memcpy(data, eeprom_tmp, size);
 	*p_read_size = size;
 
@@ -127,13 +127,13 @@ int mlxsw_env_module_temp_thresholds_get(struct mlxsw_core *core, int module,
 					 int off, int *temp)
 {
 	unsigned int module_temp, module_crit, module_emerg;
-	char eeprom_tmp[MLXSW_REG_MCIA_EEPROM_SIZE];
 	union {
 		u8 buf[MLXSW_REG_MCIA_TH_ITEM_SIZE];
 		u16 temp;
 	} temp_thresh;
 	char mcia_pl[MLXSW_REG_MCIA_LEN] = {0};
 	char mtmp_pl[MLXSW_REG_MTMP_LEN];
+	char *eeprom_tmp;
 	bool qsfp, cmis;
 	int page;
 	int err;
@@ -195,7 +195,7 @@ int mlxsw_env_module_temp_thresholds_get(struct mlxsw_core *core, int module,
 	if (err)
 		return err;
 
-	mlxsw_reg_mcia_eeprom_memcpy_from(mcia_pl, eeprom_tmp);
+	eeprom_tmp = mlxsw_reg_mcia_eeprom_data(mcia_pl);
 	memcpy(temp_thresh.buf, eeprom_tmp, MLXSW_REG_MCIA_TH_ITEM_SIZE);
 	*temp = temp_thresh.temp * 1000;
 
@@ -357,8 +357,8 @@ mlxsw_env_get_module_eeprom_by_page(struct mlxsw_core *mlxsw_core, u8 module,
 	device_addr = page->offset;
 
 	while (bytes_read < page->length) {
-		char eeprom_tmp[MLXSW_REG_MCIA_EEPROM_SIZE];
 		char mcia_pl[MLXSW_REG_MCIA_LEN];
+		char *eeprom_tmp;
 		u8 size;
 		int err;
 
@@ -380,7 +380,7 @@ mlxsw_env_get_module_eeprom_by_page(struct mlxsw_core *mlxsw_core, u8 module,
 		if (err)
 			return err;
 
-		mlxsw_reg_mcia_eeprom_memcpy_from(mcia_pl, eeprom_tmp);
+		eeprom_tmp = mlxsw_reg_mcia_eeprom_data(mcia_pl);
 		memcpy(page->data + bytes_read, eeprom_tmp, size);
 		bytes_read += size;
 	}