net: dsa: sja1105: Add P/Q/R/S support for dynamic L2 lookup operations

These are needed in order to implement the switchdev FDB callbacks.

Compared to the E/T generation, not only the ABI (bit offsets) is
different, but also the introduction of the HOSTCMD field which permits
O(1) TCAM search for an FDB entry.  Make use of the newly introduce
OP_SEARCH to permit that.  It will be used while adding and deleting an
FDB entry (to see whether it exists or not).
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_dynamic_config.c

@@ -44,17 +44,63 @@ struct sja1105_dyn_cmd {
 	u64 index;
 };
 
+enum sja1105_hostcmd {
+	SJA1105_HOSTCMD_SEARCH = 1,
+	SJA1105_HOSTCMD_READ = 2,
+	SJA1105_HOSTCMD_WRITE = 3,
+	SJA1105_HOSTCMD_INVALIDATE = 4,
+};
+
 static void
 sja1105pqrs_l2_lookup_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd,
 				  enum packing_op op)
 {
 	u8 *p = buf + SJA1105PQRS_SIZE_L2_LOOKUP_ENTRY;
 	const int size = SJA1105_SIZE_DYN_CMD;
+	u64 lockeds = 0;
+	u64 hostcmd;
 
 	sja1105_packing(p, &cmd->valid,    31, 31, size, op);
 	sja1105_packing(p, &cmd->rdwrset,  30, 30, size, op);
 	sja1105_packing(p, &cmd->errors,   29, 29, size, op);
+	sja1105_packing(p, &lockeds,       28, 28, size, op);
 	sja1105_packing(p, &cmd->valident, 27, 27, size, op);
+
+	/* VALIDENT is supposed to indicate "keep or not", but in SJA1105 E/T,
+	 * using it to delete a management route was unsupported. UM10944
+	 * said about it:
+	 *
+	 *   In case of a write access with the MGMTROUTE flag set,
+	 *   the flag will be ignored. It will always be found cleared
+	 *   for read accesses with the MGMTROUTE flag set.
+	 *
+	 * SJA1105 P/Q/R/S keeps the same behavior w.r.t. VALIDENT, but there
+	 * is now another flag called HOSTCMD which does more stuff (quoting
+	 * from UM11040):
+	 *
+	 *   A write request is accepted only when HOSTCMD is set to write host
+	 *   or invalid. A read request is accepted only when HOSTCMD is set to
+	 *   search host or read host.
+	 *
+	 * So it is possible to translate a RDWRSET/VALIDENT combination into
+	 * HOSTCMD so that we keep the dynamic command API in place, and
+	 * at the same time achieve compatibility with the management route
+	 * command structure.
+	 */
+	if (cmd->rdwrset == SPI_READ) {
+		if (cmd->search)
+			hostcmd = SJA1105_HOSTCMD_SEARCH;
+		else
+			hostcmd = SJA1105_HOSTCMD_READ;
+	} else {
+		/* SPI_WRITE */
+		if (cmd->valident)
+			hostcmd = SJA1105_HOSTCMD_WRITE;
+		else
+			hostcmd = SJA1105_HOSTCMD_INVALIDATE;
+	}
+	sja1105_packing(p, &hostcmd, 25, 23, size, op);
+
 	/* Hack - The hardware takes the 'index' field within
 	 * struct sja1105_l2_lookup_entry as the index on which this command
 	 * will operate. However it will ignore everything else, so 'index'
@@ -65,7 +111,6 @@ sja1105pqrs_l2_lookup_cmd_packing(void *buf, struct sja1105_dyn_cmd *cmd,
 	 */
 	sja1105_packing(buf, &cmd->index, 15, 6,
 			SJA1105PQRS_SIZE_L2_LOOKUP_ENTRY, op);
-	/* TODO hostcmd */
 }
 
 static void
@@ -319,9 +364,9 @@ struct sja1105_dynamic_table_ops sja1105pqrs_dyn_ops[BLK_IDX_MAX_DYN] = {
 	[BLK_IDX_L2_LOOKUP] = {
 		.entry_packing = sja1105pqrs_l2_lookup_entry_packing,
 		.cmd_packing = sja1105pqrs_l2_lookup_cmd_packing,
-		.access = (OP_READ | OP_WRITE | OP_DEL),
+		.access = (OP_READ | OP_WRITE | OP_DEL | OP_SEARCH),
 		.max_entry_count = SJA1105_MAX_L2_LOOKUP_COUNT,
-		.packed_size = SJA1105ET_SIZE_L2_LOOKUP_DYN_CMD,
+		.packed_size = SJA1105PQRS_SIZE_L2_LOOKUP_DYN_CMD,
 		.addr = 0x24,
 	},
 	[BLK_IDX_L2_POLICING] = {0},
@@ -403,7 +448,7 @@ int sja1105_dynamic_config_read(struct sja1105_private *priv,
 
 	ops = &priv->info->dyn_ops[blk_idx];
 
-	if (index >= ops->max_entry_count)
+	if (index >= 0 && index >= ops->max_entry_count)
 		return -ERANGE;
 	if (index < 0 && !(ops->access & OP_SEARCH))
 		return -EOPNOTSUPP;
@@ -426,6 +471,7 @@ int sja1105_dynamic_config_read(struct sja1105_private *priv,
 		cmd.index = index;
 		cmd.search = false;
 	}
+	cmd.valident = true;
 	ops->cmd_packing(packed_buf, &cmd, PACK);
 
 	if (cmd.search)