mlxsw: item: Add support for local_port field in a split form

Currently, local_port field uses 8 bits, which means that maximum 256
ports can be used.

As preparation for the next ASIC, which will support more than 256
ports, local_port field should be extended to 10 bits.

It is not possible to use 10 consecutive bits in all registers, and
therefore, the field is split into 2 fields:
1. local_port - the existing 8 bits, represent LSB of the extended
   field.
2. lp_msb - extra 2 bits, represent MSB of the extended field.

To avoid complex programming when reading/writing local_port, add a
dedicated macro which creates get and set functions which handle both parts
of local_port.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/item.h b/drivers/net/ethernet/mellanox/mlxsw/item.h
index ab70a873a01a859fde37a0a8b1cf34f8289f8281..cfafbeb425863037ca25ca356d44a191085ded7e 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/item.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/item.h
@@ -367,6 +367,42 @@ mlxsw_##_type##_##_cname##_##_iname##_set(char *buf, u32 val)                      \
        __mlxsw_item_set32(buf, &__ITEM_NAME(_type, _cname, _iname), 0, val);   \
 }
 
+#define LOCAL_PORT_LSB_SIZE 8
+#define LOCAL_PORT_MSB_SIZE 2
+
+#define MLXSW_ITEM32_LP(_type, _cname, _offset1, _shift1, _offset2, _shift2)   \
+static struct mlxsw_item __ITEM_NAME(_type, _cname, local_port) = {            \
+       .offset = _offset1,                                                     \
+       .shift = _shift1,                                                       \
+       .size = {.bits = LOCAL_PORT_LSB_SIZE,},                                 \
+       .name = #_type "_" #_cname "_local_port",                               \
+};                                                                             \
+static struct mlxsw_item __ITEM_NAME(_type, _cname, lp_msb) = {                        \
+       .offset = _offset2,                                                     \
+       .shift = _shift2,                                                       \
+       .size = {.bits = LOCAL_PORT_MSB_SIZE,},                                 \
+       .name = #_type "_" #_cname "_lp_msb",                                   \
+};                                                                             \
+static inline u32 __maybe_unused                                               \
+mlxsw_##_type##_##_cname##_local_port_get(const char *buf)                     \
+{                                                                              \
+       u32 local_port, lp_msb;                                                 \
+                                                                               \
+       local_port = __mlxsw_item_get32(buf, &__ITEM_NAME(_type, _cname,        \
+                                       local_port), 0);                        \
+       lp_msb = __mlxsw_item_get32(buf, &__ITEM_NAME(_type, _cname, lp_msb),   \
+                                  0);                                          \
+       return (lp_msb << LOCAL_PORT_LSB_SIZE) + local_port;                    \
+}                                                                              \
+static inline void __maybe_unused                                              \
+mlxsw_##_type##_##_cname##_local_port_set(char *buf, u32 val)                  \
+{                                                                              \
+       __mlxsw_item_set32(buf, &__ITEM_NAME(_type, _cname, local_port), 0,     \
+                          val & ((1 << LOCAL_PORT_LSB_SIZE) - 1));             \
+       __mlxsw_item_set32(buf, &__ITEM_NAME(_type, _cname, lp_msb), 0,         \
+                          val >> LOCAL_PORT_LSB_SIZE);                         \
+}
+
 #define MLXSW_ITEM32_INDEXED(_type, _cname, _iname, _offset, _shift, _sizebits,        \
                             _step, _instepoffset, _norealshift)                \
 static struct mlxsw_item __ITEM_NAME(_type, _cname, _iname) = {                        \